阅读说明：本技术 投影设备及其投影幕片的升降控制方法 (Projection equipment and lifting control method of projection screen thereof ) 是由 陈许 肖纪臣 于 2020-06-11 设计创作，主要内容包括：本申请公开了一种投影设备及其投影幕片的升降控制方法,属于投影显示领域。该投影设备中的信号检测器可以在检测到容纳槽的开口处存在异物时,向控制组件发送第一检测信号。控制组件可以在接收到第一检测信号时,则停止向幕片驱动组件提供上升驱动信号。由于本申请能够在检测到容纳槽的开口处存在异物时,停止向幕片驱动组件提供上升驱动信号。从而避免在容纳槽的开口处存在异物时,出现投影幕片上升时被异物阻挡无法上升的情况,提高了投影幕片上升控制的可靠性。(The application discloses projection equipment and a lifting control method of a projection screen thereof, and belongs to the field of projection display. The signal detector in the projection equipment can send a first detection signal to the control component when detecting that foreign matters exist at the opening of the accommodating groove. The control component can stop providing the rising driving signal to the curtain driving component when receiving the first detection signal. Because this application can stop providing the drive signal that rises to curtain piece drive assembly when detecting the opening part of holding tank and having the foreign matter. Thereby when avoiding having the foreign matter at the opening part of holding tank, appear that the projection screen piece rises and is blockked the unable circumstances that rises by the foreign matter, improved the reliability of projection screen piece rising control.)

1. A projection device, characterized in that the projection device comprises: the projection screen comprises a shell, a signal detector, a projection screen, a screen driving assembly and a control assembly positioned in the shell;

one side of the shell is provided with an accommodating groove for accommodating the projection screen;

the signal detector is connected with the control assembly and used for responding to a starting-up instruction and detecting whether foreign matters exist at the opening of the accommodating groove, when the foreign matters exist at the opening of the accommodating groove, a first detection signal is sent to the control assembly, and when the foreign matters do not exist at the opening of the accommodating groove, a second detection signal is sent to the control assembly;

the control assembly is also connected with the curtain driving assembly and is used for stopping providing the rising driving signal for the curtain driving assembly when receiving the first detection signal and providing the rising driving signal for the curtain driving assembly when receiving the second detection signal;

the screen driving group is connected with the projection screen and used for controlling the projection screen to be lifted out of the accommodating groove under the control of the lifting driving signal.

2. The projection device of claim 1, wherein the signal detector comprises a signal emitter and a signal receiver;

the signal emitter and the signal receiver are oppositely arranged on two sides of the accommodating groove;

or the signal emitter and the signal receiver are both arranged on one side of the accommodating groove;

or, the signal emitter and the signal receiver are both arranged in the accommodating groove;

or, the curtain driving assembly comprises a cross rod assembly, and the signal transmitter and the signal receiver are both arranged on the cross rod assembly;

or, the curtain piece driving assembly comprises a cross rod assembly, one of the signal emitter and the signal receiver is arranged in the accommodating groove, and the other is arranged on the cross rod assembly.

3. The projection device of claim 1, wherein the screen driving assembly comprises a screen driving circuit, a motor, a lift rod driving assembly, and a cross rod assembly;

the curtain driving circuit is respectively connected with the control component and the motor and is used for responding to the rising driving signal and providing a first driving current for the motor;

the lifting rod driving assembly is respectively connected with the motor and the lifting rod, and the motor is used for driving the lifting rod driving assembly to push the lifting rod to ascend under the driving of the first driving current;

the lifting rod is connected with the cross rod component, and the cross rod component is connected with the projection screen.

4. The projection device of any of claims 1 to 3, wherein the control component is further configured to:

turning off the signal detector when the second detection signal is received.

5. The projection device of any of claims 1 to 3, wherein the control component is further configured to:

in the process of controlling the projection screen to lift out of the accommodating groove, acquiring the moving distance of the projection screen in the detection period every other detection period;

if the moving distance is larger than a first distance threshold, reducing the frequency of the rising driving signal provided for the curtain driving assembly;

if the moving distance is smaller than a second distance threshold, increasing the frequency of the rising driving signal provided for the curtain driving assembly;

wherein the first distance threshold is greater than the second distance threshold, and the moving speed of the projection screen is positively correlated with the frequency.

6. A projection device, characterized in that the projection device comprises: the projection screen comprises a shell, a signal detector, a projection screen, a screen driving assembly and a control assembly positioned in the shell;

one side of the shell is provided with an accommodating groove for accommodating the projection screen;

the signal detector is connected with the control assembly and used for responding to a shutdown instruction or detecting whether foreign matters exist at the opening of the accommodating groove when the descending distance of the projection screen is greater than a third distance threshold value, sending a fifth detection signal to the control assembly when detecting that the foreign matters exist at the opening of the accommodating groove, and sending a sixth detection signal to the control assembly when detecting that the foreign matters do not exist at the opening of the accommodating groove;

the control assembly is also connected with the curtain driving assembly and is used for stopping providing a descending driving signal for the curtain driving assembly when the fifth detection signal is received, and providing the descending driving signal for the curtain driving assembly when the sixth detection signal is received;

the screen driving set is connected with the projection screen and used for controlling the projection screen to withdraw the accommodating groove under the control of the descending driving signal.

7. The projection device of claim 6, wherein the signal detector comprises a signal emitter and a signal receiver;

the signal emitter and the signal receiver are oppositely arranged on two sides of the accommodating groove;

or the signal emitter and the signal receiver are both arranged on one side of the accommodating groove;

or, the signal emitter and the signal receiver are both arranged in the accommodating groove;

or, the curtain driving assembly comprises a cross rod assembly, and the signal transmitter and the signal receiver are both arranged on the cross rod assembly;

or, the curtain piece driving assembly comprises a cross rod assembly, one of the signal emitter and the signal receiver is arranged in the accommodating groove, and the other is arranged on the cross rod assembly.

8. The projection device of claim 6, wherein the screen drive assembly comprises a screen drive circuit, a motor, a lift rod drive assembly, and a cross rod assembly;

the curtain driving circuit is respectively connected with the control component and the motor and is used for responding to the descending driving signal and providing a second driving current for the motor;

the lifting rod driving assembly is respectively connected with the motor and the lifting rod, and the motor is used for driving the lifting rod driving assembly to pull the lifting rod to descend under the driving of the second driving current;

the lifting rod is connected with the cross rod component, and the cross rod component is connected with the projection screen.

9. The projection device of any of claims 6 to 8, wherein the control component is further configured to:

when the falling distance of the projection screen is greater than a fourth distance threshold, turning off the signal detector and increasing the frequency of the falling driving signal provided to the screen driving component;

wherein the fourth distance threshold is greater than the third distance threshold.

10. The projection device of any of claims 6 to 8, wherein the control component is further configured to:

in the process of controlling the projection screen to retract into the accommodating groove, acquiring the moving distance of the projection screen in the detection period every other detection period;

if the moving distance is larger than a first distance threshold, reducing the frequency of the descending driving signal provided for the curtain driving assembly;

if the moving distance is smaller than a second distance threshold, increasing the frequency of the descending driving signal provided for the curtain driving assembly;

wherein the first distance threshold is greater than the second distance threshold, and the moving speed of the projection screen is positively correlated with the frequency.

11. The projection device of claim 10, further comprising a distance detector disposed on at least one side of the receiving groove; the screen driving assembly comprises a cross rod assembly, and the cross rod assembly is connected with the projection screen;

the distance detector is connected with the control component and is used for emitting light signals and receiving the light signals reflected by the transverse rod component;

the control component is also used for determining the moving distance of the projection screen within the detection period according to the transmitting time of the optical signal transmitted by the distance detector and the receiving time of the optical signal reflected by the transverse rod component.

12. A projection device, characterized in that the projection device comprises: the projection screen comprises a shell, a signal detector, a projection screen, a screen driving assembly and a control assembly positioned in the shell;

one side of the shell is provided with an accommodating groove for accommodating the projection screen;

the signal detector is connected with the control assembly and used for responding to a shutdown instruction or detecting whether foreign matters exist at the opening of the accommodating groove when the descending distance of the projection screen is greater than a third distance threshold value, sending a fifth detection signal to the control assembly when detecting that the foreign matters exist at the opening of the accommodating groove, and sending a sixth detection signal to the control assembly when detecting that the foreign matters do not exist at the opening of the accommodating groove;

the control assembly is also connected with the curtain driving assembly and is used for stopping providing a descending driving signal for the curtain driving assembly when the fifth detection signal is received and providing the descending driving signal for the curtain driving assembly when the sixth detection signal is received;

the screen driving group is connected with the projection screen and is used for controlling the projection screen to retract into the accommodating groove under the control of the descending driving signal;

the control component is further used for increasing the frequency of the descending driving signal provided to the screen driving component when the descending distance of the projection screen is larger than a fourth distance threshold;

wherein the fourth distance threshold is greater than the third distance threshold, and the moving speed of the projection screen is positively correlated to the frequency.

13. A lifting control method of a projection screen is characterized in that the lifting control method is applied to a control assembly positioned in a shell of a projection device, and the projection device further comprises the following steps: the screen driving device comprises a signal detector, a projection screen and a screen driving assembly, wherein one side of the shell is provided with an accommodating groove for accommodating the projection screen; the control assembly is respectively connected with the signal detector and the screen driving assembly, and the screen driving assembly is connected with the projection screen; the method comprises the following steps:

when a first detection signal sent by the signal detector is received, stopping providing a rising driving signal for the curtain driving assembly;

when the second detection signal sent by the signal detector is received, providing a rising driving signal to the screen driving assembly, wherein the rising driving signal is used for controlling the screen driving assembly to control the projection screen to rise out of the accommodating groove;

the first detection signal is that the signal detector responds to a starting-up instruction to detect whether foreign matters exist at the opening of the accommodating groove and sends the foreign matters to the control assembly when detecting that the foreign matters exist at the opening of the accommodating groove, and the second detection signal is that the signal detector responds to the starting-up instruction to detect whether the foreign matters exist at the opening of the accommodating groove and sends the foreign matters to the control assembly when detecting that the foreign matters do not exist at the opening of the accommodating groove.

14. A lifting control method of a projection screen is characterized in that the lifting control method is applied to a control assembly positioned in a shell of a projection device, and the projection device further comprises the following steps: the screen driving device comprises a signal detector, a projection screen and a screen driving assembly, wherein one side of the shell is provided with an accommodating groove for accommodating the projection screen; the control assembly is respectively connected with the signal detector and the screen driving assembly, and the screen driving assembly is connected with the projection screen; the method comprises the following steps:

when a fifth detection signal sent by the signal detector is received, stopping providing a descending driving signal for the curtain driving assembly;

when a sixth detection signal sent by the signal detector is received, a descending driving signal is provided for the screen driving assembly, and the descending driving signal is used for controlling the screen driving assembly to control the projection screen to retract into the accommodating groove;

the fifth detection signal is that the signal detector responds to a shutdown instruction, or detects whether foreign matters exist at the opening of the accommodating groove when the descending distance of the projection screen is greater than a third distance threshold, and sends the foreign matters to the control component when detecting that the foreign matters exist at the opening of the accommodating groove, and the sixth detection signal is that the signal detector responds to the shutdown instruction, or detects whether foreign matters exist at the opening of the accommodating groove when the descending distance of the projection screen is greater than the third distance threshold, and sends the foreign matters to the control component when detecting that the foreign matters do not exist at the opening of the accommodating groove.

15. A lifting control method of a projection screen is characterized in that the lifting control method is applied to a control assembly positioned in a shell of a projection device, and the projection device further comprises the following steps: the screen driving device comprises a signal detector, a projection screen and a screen driving assembly, wherein one side of the shell is provided with an accommodating groove for accommodating the projection screen; the control assembly is respectively connected with the signal detector and the screen driving assembly, and the screen driving assembly is connected with the projection screen; the method comprises the following steps:

when a fifth detection signal sent by the signal detector is received, stopping providing a descending driving signal for the curtain driving assembly;

when a sixth detection signal sent by the signal detector is received, a descending driving signal is provided for the screen driving assembly, and the descending driving signal is used for controlling the screen driving assembly to control the projection screen to retract into the accommodating groove;

increasing the frequency of the falling drive signal provided to the screen drive assembly when the falling distance of the projection screen is greater than a fourth distance threshold;

wherein, the fifth detection signal is that the signal detector detects whether there is a foreign object at the opening of the receiving tank when the descending distance of the projection screen is greater than the third distance threshold, and when detecting that there is a foreign object at the opening of the receiving tank, sends to the control component, the sixth detection signal is that the signal detector responds to the shutdown instruction, or when the descending distance of the projection screen is greater than the third distance threshold, detects whether there is a foreign object at the opening of the receiving tank, and when detecting that there is no foreign object at the opening of the receiving tank, sends to the control component, the fourth distance threshold is greater than the third distance threshold, the moving speed of the projection screen is positively correlated with the frequency.

Technical Field

The disclosure relates to the field of projection display, and in particular relates to a projection device and a lifting control method of a projection screen thereof.

Background

At present, a projection screen and a host in a projection device may be an integrated structure. The host computer of this projection equipment is provided with the holding tank, is provided with the curtain drive assembly in this holding tank, and this curtain drive assembly is connected with the projection curtain for the drive projection curtain rises or descends.

However, if there is a foreign object at the opening of the accommodating groove, the foreign object blocks the projection screen sheet and cannot lift the projection screen sheet, or the foreign object blocks the projection screen sheet and cannot be retracted into the accommodating groove when the projection screen sheet descends, which results in low reliability of controlling the lifting of the projection screen sheet.

Disclosure of Invention

The embodiment of the disclosure provides a projection device and a lifting control method of a projection screen thereof, which can solve the problem of low reliability of lifting control of the projection screen in the related art. The technical scheme is as follows:

in one aspect, a projection apparatus is provided, the projection apparatus comprising: the projection screen comprises a shell, a signal detector, a projection screen, a screen driving assembly and a control assembly positioned in the shell;

one side of the shell is provided with an accommodating groove for accommodating the projection screen;

the signal detector is connected with the control assembly and used for responding to a starting-up instruction and detecting whether foreign matters exist at the opening of the accommodating groove, when the foreign matters exist at the opening of the accommodating groove, a first detection signal is sent to the control assembly, and when the foreign matters do not exist at the opening of the accommodating groove, a second detection signal is sent to the control assembly;

the control assembly is also connected with the curtain driving assembly and is used for stopping providing the rising driving signal for the curtain driving assembly when receiving the first detection signal and providing the rising driving signal for the curtain driving assembly when receiving the second detection signal;

the screen driving group is connected with the projection screen and used for controlling the projection screen to be lifted out of the accommodating groove under the control of the lifting driving signal.

In another aspect, a projection apparatus is provided, the projection apparatus comprising: the projection screen comprises a shell, a signal detector, a projection screen, a screen driving assembly and a control assembly positioned in the shell;

one side of the shell is provided with an accommodating groove for accommodating the projection screen;

the signal detector is connected with the control assembly and used for responding to a shutdown instruction or detecting whether foreign matters exist at the opening of the accommodating groove when the descending distance of the projection screen is greater than a third distance threshold value, and when detecting that foreign matters exist at the opening of the accommodating groove, the signal detector sends a fifth detection signal to the control assembly and when detecting that foreign matters do not exist at the opening of the accommodating groove, a sixth detection signal to the control assembly;

the control assembly is also connected with the curtain driving assembly and is used for stopping providing a descending driving signal for the curtain driving assembly when the fifth detection signal is received and providing the descending driving signal for the curtain driving assembly when the sixth detection signal is received;

the screen driving set is connected with the projection screen and used for controlling the projection screen to withdraw the accommodating groove under the control of the descending driving signal.

In yet another aspect, a projection apparatus is provided, the projection apparatus comprising: the projection screen comprises a shell, a signal detector, a projection screen, a screen driving assembly and a control assembly positioned in the shell;

one side of the shell is provided with an accommodating groove for accommodating the projection screen;

the signal detector is connected with the control assembly and used for responding to a shutdown instruction or detecting whether foreign matters exist at the opening of the accommodating groove when the descending distance of the projection screen is greater than a third distance threshold value, and when detecting that foreign matters exist at the opening of the accommodating groove, the signal detector sends a fifth detection signal to the control assembly and when detecting that foreign matters do not exist at the opening of the accommodating groove, a sixth detection signal to the control assembly;

the control assembly is also connected with the curtain driving assembly and is used for stopping providing a descending driving signal for the curtain driving assembly when the fifth detection signal is received and providing the descending driving signal for the curtain driving assembly when the sixth detection signal is received;

the screen driving group is connected with the projection screen and is used for controlling the projection screen to retract into the accommodating groove under the control of the descending driving signal;

the control assembly is further configured to increase a frequency of the falling driving signal provided to the screen driving assembly when a falling distance of the projection screen is greater than a fourth distance threshold in a process of controlling the projection screen to retract into the accommodating groove;

wherein the fourth distance threshold is greater than the third distance threshold, and the moving speed of the projection screen is positively correlated to the frequency.

In another aspect, a method for controlling the lifting of a projection screen is provided, which is applied to a control assembly located in a housing of a projection apparatus, and the projection apparatus further includes: the screen driving device comprises a signal detector, a projection screen and a screen driving assembly, wherein one side of the shell is provided with an accommodating groove for accommodating the projection screen; the control assembly is respectively connected with the signal detector and the screen driving assembly, and the screen driving assembly is connected with the projection screen; the method comprises the following steps:

when a first detection signal sent by the signal detector is received, stopping providing a rising driving signal for the curtain driving assembly;

when the second detection signal sent by the signal detector is received, providing a rising driving signal to the screen driving assembly, wherein the rising driving signal is used for controlling the screen driving assembly to control the projection screen to rise out of the accommodating groove;

the first detection signal is that the signal detector responds to a starting-up instruction to detect whether foreign matters exist at the opening of the accommodating groove and sends the foreign matters to the control assembly when detecting that the foreign matters exist at the opening of the accommodating groove, and the second detection signal is that the signal detector responds to the starting-up instruction to detect whether the foreign matters exist at the opening of the accommodating groove and sends the foreign matters to the control assembly when detecting that the foreign matters do not exist at the opening of the accommodating groove.

In another aspect, a method for controlling the lifting of a projection screen is provided, which is applied to a control assembly located in a housing of a projection apparatus, where the projection apparatus further includes: the screen driving device comprises a signal detector, a projection screen and a screen driving assembly, wherein one side of the shell is provided with an accommodating groove for accommodating the projection screen; the control assembly is respectively connected with the signal detector and the screen driving assembly, and the screen driving assembly is connected with the projection screen; the method comprises the following steps:

when a fifth detection signal sent by the signal detector is received, stopping providing a descending driving signal for the curtain driving assembly;

when a sixth detection signal sent by the signal detector is received, a descending driving signal is provided for the screen driving assembly, and the descending driving signal is used for controlling the screen driving assembly to control the projection screen to retract into the accommodating groove;

the fifth detection signal is that the signal detector responds to a shutdown instruction, or detects whether foreign matters exist at the opening of the accommodating groove when the descending distance of the projection screen is greater than a third distance threshold, and sends the foreign matters to the control component when detecting that the foreign matters exist at the opening of the accommodating groove, and the sixth detection signal is that the signal detector responds to the shutdown instruction, or detects whether foreign matters exist at the opening of the accommodating groove when the descending distance of the projection screen is greater than the third distance threshold, and sends the foreign matters to the control component when detecting that the foreign matters do not exist at the opening of the accommodating groove.

In another aspect, a projection apparatus is provided, which is applied to a control assembly located in a housing of the projection apparatus, and the projection apparatus further includes: the screen driving device comprises a signal detector, a projection screen and a screen driving assembly, wherein one side of the shell is provided with an accommodating groove for accommodating the projection screen; the control assembly is respectively connected with the signal detector and the screen driving assembly, and the screen driving assembly is connected with the projection screen; the method comprises the following steps:

when a fifth detection signal sent by the signal detector is received, stopping providing a descending driving signal for the curtain driving assembly;

when a sixth detection signal sent by the signal detector is received, a descending driving signal is provided for the screen driving assembly, and the descending driving signal is used for controlling the screen driving assembly to control the projection screen to retract into the accommodating groove;

in the process of controlling the projection screen to retract into the accommodating groove, when the descending distance of the projection screen is greater than a fourth distance threshold, increasing the frequency of the descending driving signal provided for the screen driving component;

wherein, the fifth detection signal is that the signal detector detects whether there is a foreign object at the opening of the receiving tank when the descending distance of the projection screen is greater than the third distance threshold, and when detecting that there is a foreign object at the opening of the receiving tank, sends to the control component, the sixth detection signal is that the signal detector responds to the shutdown instruction, or when the descending distance of the projection screen is greater than the third distance threshold, detects whether there is a foreign object at the opening of the receiving tank, and when detecting that there is no foreign object at the opening of the receiving tank, sends to the control component, the fourth distance threshold is greater than the third distance threshold, the moving speed of the projection screen is positively correlated with the frequency.

The beneficial effects brought by the technical scheme provided by the embodiment of the disclosure at least comprise:

the embodiment of the disclosure provides a projection device and a lifting control method of a projection screen thereof, wherein a signal detector in the projection device can respond to a starting instruction, detect whether foreign matters exist at an opening of an accommodating groove, and send a first detection signal to a control assembly when detecting that the foreign matters exist at the opening of the accommodating groove. The control assembly can stop providing the rising driving signal to the curtain driving assembly after receiving the first detection signal. Therefore, the situation that the projection screen cannot rise due to the fact that the foreign matter blocks the projection screen when the projection screen rises when the foreign matter exists at the opening of the accommodating groove is avoided, and therefore the reliability of rising control of the projection screen is improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present disclosure, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a projection apparatus provided in an embodiment of the present disclosure;

FIG. 2 is a schematic structural diagram of another projection apparatus provided in the embodiments of the present disclosure;

FIG. 3 is a schematic structural diagram of another projection apparatus provided in the embodiments of the present disclosure;

fig. 4 is a schematic structural diagram of a signal detector provided in an embodiment of the present disclosure;

FIG. 5 is a schematic structural diagram of another projection apparatus provided in an embodiment of the present disclosure;

FIG. 6 is a schematic structural diagram of another projection apparatus provided in the embodiments of the present disclosure;

fig. 7 is a schematic structural diagram of another projection apparatus provided in an embodiment of the present disclosure;

fig. 8 is a schematic structural diagram of another projection apparatus provided in an embodiment of the present disclosure;

fig. 9 is a schematic structural diagram of another projection apparatus provided in the embodiments of the present disclosure;

fig. 10 is a schematic structural diagram of another projection apparatus provided in the embodiment of the present disclosure;

fig. 11 is a schematic structural diagram of another projection apparatus provided in an embodiment of the present disclosure;

FIG. 12 is a schematic view of a shielding rod according to an embodiment of the present disclosure;

fig. 13 is a schematic structural diagram of another projection apparatus provided in the embodiment of the present disclosure;

FIG. 14 is a schematic diagram of a pulse signal sequence provided by an embodiment of the present disclosure;

FIG. 15 is a schematic diagram of another pulse signal sequence provided by embodiments of the present disclosure;

fig. 16 is a flowchart of a method for controlling the lifting of a projection screen according to an embodiment of the disclosure;

fig. 17 is a flowchart of another method for controlling the lifting of a projection screen according to an embodiment of the disclosure;

fig. 18 is a flowchart of a method for controlling the lifting of a projection screen according to another embodiment of the disclosure.

Detailed Description

To make the objects, technical solutions and advantages of the present disclosure more apparent, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of a projection apparatus provided in an embodiment of the present disclosure. Fig. 2 is a schematic structural diagram of another projection apparatus provided in the embodiment of the present disclosure. As shown in fig. 1 and 2, the projection device may include a housing 10, a signal detector 20, a projection screen 30, a screen drive assembly 40, and a control assembly 50 located within the housing 10. As shown in fig. 3, a receiving groove 00 for receiving the projection screen 30 is formed on one side of the housing 10, and one end of the projection screen 30 can be fixed in the receiving groove 00.

Referring to fig. 2, the signal detector 20 is connected to the control assembly 50, and the signal detector 20 is configured to detect whether a foreign object exists at the opening of the accommodating groove 00 in response to a power-on command, and send a first detection signal to the control assembly 50 when the foreign object exists at the opening of the accommodating groove 00. When it is detected that the foreign matter is not present at the opening of the accommodating groove 00, a second detection signal is transmitted to the control member 50.

In the embodiment of the disclosure, the control component 50 may start the signal detector 20 after receiving a power-on instruction for the projection device, and may send the power-on instruction to the signal detector 20. The signal detector 20 can detect whether a foreign object exists at the opening of the accommodating groove 00 in response to the power-on command. The foreign matter is an object that can block the opening of the housing groove 00. The foreign object may be, for example, a cup, a toy, or a user's hand.

Referring to fig. 2, the control assembly 50 is further connected to the curtain driving assembly 40, and the control assembly 50 is configured to stop providing the rising driving signal to the curtain driving assembly 40 when receiving the first detection signal. When the second detection signal is received, a rising driving signal is provided to the curtain driving assembly 40.

Referring to fig. 2, the screen driving assembly 40 is connected to the projection screen 30, and the screen driving assembly 40 is used for controlling the projection screen 30 to be lifted out of the accommodating slot 00 or retracted into the accommodating slot 00 under the control of the lifting driving signal.

For example, referring to fig. 2 and 3, when the projection apparatus is in the closed state, the projection screen 30 is located in the accommodating groove 00. The control component 50 may turn on the signal detector 20 after receiving a power-on command for the projection device, and may send the power-on command to the signal detector 20. The signal detector 20 can further detect whether a foreign object exists at the opening of the accommodating groove 00 in response to the power-on command, and send a first detection signal to the control component 50 when detecting that the foreign object exists at the opening of the accommodating groove 00. The control unit 50 may not provide the lifting driving signal to the screen driving unit 40 after receiving the first detection signal, so as to avoid the situation that the projection screen cannot lift due to being blocked by a foreign object during the lifting process.

When the signal detector 20 detects that there is no foreign object at the opening of the accommodating groove 00, a second detection signal may be transmitted to the control member 50. The control module 50 can provide the ascending driving signal to the screen driving module 40 after receiving the second detecting signal, and the screen driving module 40 can control the projection screen 30 to ascend from the accommodating slot 00 as shown in fig. 3 to the state as shown in fig. 1. And, the control component 50 may turn off the signal detector 20 after receiving the second detection signal.

To sum up, the embodiment of the present disclosure provides a projection apparatus, where a signal detector in the projection apparatus can respond to a power-on instruction and detect whether a foreign object exists at an opening of an accommodating groove. When detecting that there is the foreign matter in the opening part of holding tank, send first detected signal to control assembly. The control assembly can stop providing the rising driving signal to the curtain driving assembly after receiving the first detection signal. Therefore, the situation that the projection screen cannot rise due to the fact that the foreign matter blocks the projection screen when the projection screen rises when the foreign matter exists at the opening of the accommodating groove is avoided, and therefore the reliability of rising control of the projection screen is improved.

Referring to fig. 4, the signal detector 20 may include a signal transmitter 21 and a signal receiver 22. The signal transmitter 21 is used for transmitting a detection signal, and the signal receiver 22 is used for receiving the detection signal transmitted by the signal transmitter 21. If the signal receiver 22 does not receive the detection signal transmitted by the signal transmitter 21, the signal receiver 22 may determine that a foreign object exists at the opening of the accommodating groove 00, and may transmit a first detection signal to the control component 50. If the signal receiver 22 receives the detection signal transmitted by the signal transmitter 21, the signal receiver 22 can determine that no foreign object exists at the opening of the accommodating groove 00, and then send a second detection signal to the control component 50.

As an alternative implementation manner of the embodiment of the present disclosure, the signal emitter 21 and the signal receiver 22 are oppositely disposed at two sides of the accommodating groove 00, wherein the signal detector 20 may be a projected infrared sensor or a projected non-infrared sensor.

For example, referring to fig. 5, the opening of the receiving groove 00 may be a quadrangle, for example, may be a rectangle. The signal emitter 21 and the signal receiver 22 may be oppositely disposed at both sides of the long side of the opening of the accommodating groove 00, and the signal emitter 21 emits the detection signal along the extending direction of the long side of the opening of the accommodating groove 00. Alternatively, the signal emitter 21 and the signal receiver 22 may be oppositely disposed on both sides of the short side of the opening of the accommodating groove 00, and the signal emitter 21 emits the detection signal in the extending direction of the short side of the opening of the accommodating groove 00. If the signal receiver 22 receives the detection signal sent by the signal transmitter 21, the signal receiver 22 can determine that no foreign object exists at the opening of the accommodating groove 00. If the signal receiver 22 cannot receive the detection signal sent by the signal transmitter 21, the signal receiver 22 can determine that a foreign object exists at the opening of the accommodating groove 00.

As another optional implementation manner of the embodiment of the present disclosure, the signal transmitter 21 and the signal receiver 22 are both disposed on one side of the accommodating groove 00.

For example, referring to fig. 5, the signal emitter 21 and the signal receiver 22 may be both disposed at one side of the long side of the opening of the accommodating groove 00. Or the signal emitter 21 and the signal receiver 22 may be both disposed at one side of the short side of the opening of the receiving groove 00.

Assuming that the signal emitter 21 and the signal receiver 22 are both disposed on one side of the short side of the opening of the accommodating groove 00, if the signal receiver 22 receives the detection signal sent by the signal emitter 21, the signal receiver 22 can determine that there is a foreign object at the opening of the accommodating groove 00, that is, after the detection signal emitted by the signal emitter 21 is reflected by the foreign object, the signal receiver 22 receives the detection signal. If the signal receiver 22 does not receive the detection signal sent by the signal transmitter 21, the signal receiver 22 can determine that no foreign object exists at the opening of the accommodating groove 00.

As still another optional implementation manner of the embodiment of the present disclosure, the signal transmitter 21 and the signal receiver 22 are both disposed in the accommodating groove 00. Referring to fig. 1, 5, 6, and 7, the screen drive assembly 40 can include a cross bar assembly 41, the cross bar assembly 41 being coupled to the projection screen 30. The beam assembly 41 has a light transmissive area 01 therein, and the orthographic projection of the signal emitter 21 on the beam assembly 41 and the orthographic projection of the signal receiver 22 on the beam assembly 41 are both located on the light transmissive area 01 of the beam assembly 41. The detection signal that signal transmitter 21 launches can see through horizontal pole subassembly 41 from this to avoid appearing that the detection signal that signal transmitter 21 launches is sheltered from by horizontal pole subassembly 41, thereby lead to signal receiver 22 can't receive the detection signal and the condition that misjudgement appears, ensured the reliability to the foreign matter detection. The signal detector 20 may be an emissive infrared sensor or a reflective non-infrared sensor.

As yet another alternative implementation of the disclosed embodiment, the signal transmitter 21 and the signal receiver 22 may be both disposed on the cross bar assembly 41. Optionally, the rail assembly 41 has a light-transmissive region 01 therein, and the orthographic projection of the signal emitter 21 on the rail assembly 41 and the orthographic projection of the signal receiver 22 on the rail assembly 41 are both located on the light-transmissive region 01 of the rail assembly 41.

The detection signal emitted from the signal emitter 21 can be transmitted through the cross-bar assembly 41. If the signal receiver 22 receives the detection signal sent by the signal transmitter 21, the signal receiver 22 can determine that there is a foreign object at the opening of the accommodating groove 00, that is, the detection signal sent by the signal transmitter 21 is reflected by the foreign object after passing through the cross bar assembly 41, and the reflected detection signal passes through the cross bar assembly 41 again and is received by the signal receiver 22.

As still another alternative implementation manner of the disclosed embodiment, one of the signal transmitter 21 and the signal receiver 22 is disposed in the accommodating groove 00, and the other is disposed on the cross bar assembly 41. For example, the signal emitter 21 can be disposed in the receiving groove 00, the signal receiver 22 can be disposed on the rail assembly 41, the rail assembly 41 has the light-transmissive area 01 therein, and the orthographic projection of the signal emitter 21 on the rail assembly 41 and the orthographic projection of the signal receiver 22 on the rail assembly 41 are both located on the light-transmissive area 01 of the rail assembly 41.

Alternatively, the detection signal emitted from the signal emitter 21 may be transmitted through the cross-bar assembly 41. If the signal receiver 22 receives the detection signal sent by the signal transmitter 21, the signal receiver 22 can determine that there is a foreign object at the opening of the accommodating groove 00, that is, the detection signal sent by the signal transmitter 21 is reflected by the foreign object after passing through the cross bar assembly 41, and the reflected detection signal passes through the cross bar assembly 41 again and is received by the signal receiver 22.

The detection signal that signal transmitter 21 launched can see through horizontal pole subassembly 41 from this, and the detection signal that is reflected by the foreign matter also can see through horizontal pole subassembly 41 to avoid appearing the detection signal that signal transmitter 21 launched and being sheltered from by horizontal pole subassembly 41 by the detection signal that the foreign matter reflects, thereby lead to signal receiver 22 can't receive the detection signal and the condition that the erroneous judgement appears, ensured the reliability to the foreign matter detection.

Referring to fig. 7, the curtain driving assembly 40 may further include a curtain driving circuit 42, a motor 43, a lift lever 44, and a lift lever driving assembly 45. Alternatively, the electric motor 43 may also be referred to as a motor.

The curtain driving circuit 42 is connected to the control component 50 and the motor 43, and the curtain driving circuit 42 is configured to provide a first driving current to the motor 43 in response to the rising driving signal.

The lifting rod driving assembly 45 is respectively connected with the motor 43 and the lifting rod 44, and the motor 43 is used for driving the lifting rod driving assembly 45 to push the lifting rod 44 to ascend under the driving of the first driving current.

The lifting rod 44 is connected to the rail assembly 41, and the lifting rod 44 is used for pushing the rail assembly 41 to ascend under the pushing of the lifting rod driving assembly 45, so as to push the projection screen 30 to ascend.

Referring to fig. 8, the sheet driving assembly 40 may include a guide rail 02 disposed in the receiving groove 00, and two driving subassemblies oppositely disposed at both sides of the receiving groove 00, each driving subassembly including a sheet driving circuit 42 (not shown in fig. 8), a motor 43, a lift bar 44, and a lift bar driving assembly 45. Each lifter drive assembly 45 includes a slider drive subassembly (not shown in fig. 8), a slider 450, and a power bar 451. Each of the lift pins 44 may include a first pin 440, a second pin 441, and a resilient member 442 for connecting the two pins.

Wherein, in each driving subassembly, the motor 43 is connected with a corresponding one of the curtain driving circuits 42. One end of the first rod 440 is connected to one end of the cross bar assembly 41, the other end is connected to one end of the second rod 441 through an elastic assembly 442, and the other end of the second rod 441 is connected to the guide rail 02. One end of the power rod 451 is connected to the slider 450, and the other end of the power rod 451 is connected to the side wall of the second rod 441 near one end of the guide rail 02.

Each motor 43 is driven by the first driving current provided by the corresponding curtain driving circuit 42 to drive each slider driving sub-assembly to push the corresponding slider 450 to slide along the guide rail 02 toward the side close to the motor 43, so as to push the power rod 451 to move toward the side close to the motor 43. The power rod 451 can further push the first rod 440 to ascend through the second rod 441, and further push the lifting rod 44 to ascend.

Referring to fig. 9, the projection apparatus may further include a position detector 60, the position detector 60 may be disposed in the accommodating groove 00, and the position detector 60 is connected to the control assembly 50. The position detector 60 is used for detecting whether the projection screen 30 is at the top position in response to a power-on command. A third detection signal is sent to the control component 50 when the projection screen 30 is detected to be in the top position, and a fourth detection signal is sent to the control component 50 when the projection screen 30 is detected not to be in the top position.

The control module 50 is configured to determine that the projection screen 30 is currently at the top position when receiving the third detection signal, and further stop providing the ascending driving signal to the screen driving module 40 and provide the maintaining signal to the screen driving module 40. When the fourth detection signal is received, it can be determined that the projection screen 30 has not reached the top position, and an up driving signal can be provided to the screen driving assembly 40.

The screen driving assembly 40 is used for controlling the projection screen 30 to be at the top position under the control of the holding driving signal and controlling the projection screen 30 to ascend under the control of the ascending driving signal.

Referring to fig. 9, the projection device may further include a multimedia component 70, and the multimedia component 70 may include an audio-visual control circuit 71, and the audio-visual control circuit 71 is connected to the control component 50. A start button may be disposed on the casing 10 of the projection device, and the audio/video control circuit 71 may generate a power-on instruction when detecting a click operation of a user on the start button, and may send the power-on instruction to the control component 50. The control component 50 may activate the position detector 60 after receiving the power-on command, and send the power-on command to the position detector 60. The position detector 60 can then detect whether the projection screen 30 is in the top position in response to the power-on command.

Alternatively, the power-on instruction may be triggered by a user through a remote controller, and the audio/video control circuit 71 may send the power-on instruction to the control component 50 after receiving the power-on instruction sent by the remote controller. The control component 50 may activate the position detector 60 after receiving the power-on command, and may send the power-on command to the position detector 60. The position detector 60 can detect whether the projection screen 30 is in the top position in response to the power-on command.

Optionally, communication interfaces may be provided on the multimedia component 70 and the control component 50. The multimedia component 70 and the control component 50 can be connected through the communication interface, and transmit the power-on command according to a serial communication protocol. The communication interface may be a standard (RS) 232 communication interface.

In the embodiment of the present disclosure, the position detector 60 can detect whether the projection screen 30 is at the top position in real time during the process of controlling the projection screen 30 to ascend by the screen driving assembly 40. Upon detecting that the projection screen 30 is not yet in the top position, the fourth detection signal may be continuously sent to the control component 50. The control module 50 continues to send the ascending driving signal to the screen driving module 40, so as to control the ascending of the projection screen 30. This is repeated until the position detector 60 detects that the projection screen 30 is at the top position, and the position detector 60 can send a third detection signal to the control component 50. The control assembly 50 may stop sending the rising driving signal to the curtain driving assembly 40 and provide the maintaining signal to the curtain driving assembly 40 after receiving the third detection signal. The screen driving assembly 40 may control the projection screen 30 to be at a constant position in response to the hold signal.

Referring to fig. 10, 11, 12 and 13, the curtain driving assembly 40 may further include a blocking lever 47, and the motor 43 includes a rotating shaft 430, and the blocking lever 47 is disposed on the rotating shaft 430. The motor 43 is also used to drive the blocking lever 47 to rotate under the drive of the first drive current. The shielding lever 47 is disposed opposite to the position detector 60, and the position detector 60 is shielded by the shielding lever 47 during rotation.

The position detector 60 is also used to count the number m of rotations of the blocking lever 431 in response to a power-on command. And detecting whether the number M of the rotation turns is less than or equal to the threshold M of the number of turns, and if the number M of the rotation turns is equal to the threshold M of the number of turns, determining that the projection screen 30 is at the top position. If the number M of rotations is less than the threshold number M, it is determined that the projection screen 30 is not in the top position. Wherein the threshold value M is a fixed value pre-stored in the position detector 60.

Alternatively, the position detector 60 may include a transmitter for transmitting the optical signal and a receiver for receiving the transmitter for transmitting the optical signal. If the light path between the transmitter and the receiver is not blocked, the receiver can receive the optical signal transmitted by the transmitter, and the receiver cannot detect the pulse signal. If the light path between the transmitter and the receiver is blocked, the receiver cannot receive the optical signal transmitted by the transmitter, and the receiver can detect a pulse signal.

Referring to fig. 11, 12 and 13, the shielding lever 47 may include h shielding portions 470 and a connecting rod 471, one end of the connecting rod 471 is sleeved on the rotating shaft 430, and the other end of the connecting rod 471 is connected with the shielding portions 470. For example, fig. 12 shows that the blocking lever 47 includes three blocking portions, a first blocking portion 4701 and two second blocking portions 4702, respectively. The first shielding portion 4701 is located at one side of the connecting rod 471, and one end of the first shielding portion 4701 is connected to one end of each of the two second shielding portions 4702. The two second shielding portions 4702 are located at the other side of the connecting rod 471, and one ends of the two second shielding portions 4702 are also connected. Wherein h is a positive integer greater than 0.

During one rotation of the shaft 430, the position detector 60 can detect a pulse signal sequence of one period T. And in the one period T, the h shielding parts 470 sequentially shield the position detector 60, the position detector 60 can detect h pulse signals.

In the process of controlling the projection screen 30 to ascend, the screen driving circuit 42 provides a first driving current to the motor 43 under the control of the ascending driving signal provided by the control component 50, and the rotating shaft 430 of the motor 43 is driven by the first driving current to rotate along the first direction, so as to drive the connecting rod 471 to rotate along the first direction, and further drive the shielding portion 470 to rotate along the first direction. Wherein, the first direction may be a clockwise direction.

Referring to fig. 12 and 14, during one rotation of the rotation shaft 430 in the first direction, the position detector 60 may detect a pulse signal sequence of one period T. And in the one period T, if the two second shielding portions 4702 shield the position detector 60 in sequence, the position detector 60 can detect two pulse signals with a short time interval in the time period T1. If the first blocking portion 4701 blocks the position detector 60, the position detector 60 can detect a pulse signal at time t 2.

In the disclosed embodiment, it is assumed that the position detector 60 detects k pulse signals in total during the movement of the projection screen 30 from the initial position to the top position. The position detector 60 can detect a pulse signal sequence of one period T for every rotation of the rotary shaft 430 in the motor 43. And in the one period T, the position detector 60 can detect h pulse signals. Therefore, the position detector 60 can count the number of rotations of the blocking lever 47 as m, which satisfies:wherein k is a positive integer greater than 0.

Since the starting frequency of the motor 43 is too high or the load is too large during the starting process, the number M of rotations may be smaller than the threshold number M.

Assuming that the motor 43 is in a normal starting frequency and the load is normal, the motor 43 needs to rotate N steps of θ degrees during the movement of the projection screen 30 from the initial position to the top position. The motor 43 rotates 360 degrees, so that one rotation requires n steps, whichThe projection screen 30 moves from the initial position to the top position, the motor 43 needs to rotate y turns,wherein both N and θ are greater than 0.

The position detector 60 can detect a pulse signal sequence of one period T for every rotation of the rotary shaft 430 in the motor 43. And in the one period T, the position detector 60 can detect h pulse signals. Therefore, the rotating shaft 430 in the motor 43 rotates y times, and the position detector 60 can detect h × y pulse signals. Based on the detected pulses of the projection screen 30 moving from the initial position to the top positionThe number of impulse signals, and the number of impulse signals detected per period T, a threshold number of turns M can be determined, which threshold number of turns M

As an example, assuming that N is 480 and the step angle θ is 7.5 °, one rotation of the motor 43 requires a rotationAt each step angle, the projection screen 30 moves from the initial position to the top position, and the motor 43 needs to rotateThe number of turns threshold M-y-10.

Optionally, the control component 50 is further configured to acquire the moving distance of the projection screen 30 during the detection period every other detection period in the process of controlling the projection screen 30 to lift out of the accommodating slot 00. And respectively detecting whether the moving distance is greater than a first distance threshold. If the moving distance is greater than the first distance threshold, indicating that the moving speed of the projection screen 20 is faster, the frequency of the rising driving signal provided to the screen driving assembly 40 can be reduced, thereby reducing the moving speed of the projection screen 30. If the moving distance is less than or equal to the first distance threshold, it can be detected whether the moving distance is less than the second distance threshold, and if the moving distance is less than the second distance threshold, which indicates that the moving speed of the projection screen 30 is slow, the frequency of the ascending driving signal provided to the screen driving assembly 40 can be increased, thereby increasing the moving speed of the projection screen 30.

Wherein, the first distance threshold is greater than the second distance threshold, the moving speed of the projection screen 30 is positively correlated with the frequency, that is, the higher the frequency of the ascending driving signal is, the faster the moving speed of the projection screen 30 is; the smaller the frequency of the rising driving signal, the slower the moving speed of the projection screen 30.

In the embodiment of the present disclosure, in the process of controlling the projection screen 30 to lift out of the accommodating slot 00, the moving speed of the projection screen 30 can be dynamically adjusted according to the moving distance of the projection screen 30 in the detection period, so that the flexibility of controlling the lifting of the projection screen is improved.

Referring to fig. 9, the projection apparatus may further include a distance detector 80, and the distance detector 80 is disposed at least one side of the accommodating groove 00. Alternatively, a distance sensor 80 is provided on either side of the long side of the opening of the accommodation groove 00. Alternatively, referring to fig. 5, both sides of the long side of the opening of the accommodation groove 00 are provided with the distance detectors 80. Alternatively, the distance detector 80 may be an infrared sensor or a non-infrared sensor.

The distance detector 80 is connected to the control assembly 50, and the distance detector 80 is used for emitting light signals and receiving light signals reflected by the cross bar assembly 41.

The control assembly 50 is further configured to determine the moving distance d of the projection screen 30 during the detection period according to the emitting time t3 when the distance detector 80 emits the light signal and the receiving time t4 when the light signal reflected by the cross bar assembly 41 is received. Wherein t3 and t4 are both greater than 0.

Optionally, the transmission speed V of the optical signal is stored in the control unit 50 in advance. The control unit 50 may acquire, at every detection cycle, an emission time t3 at which the distance detector 80 emits a light signal, and a reception time t4 at which the distance detector 80 receives the light signal reflected by the rail assembly 41. And determines the transmission time length T1 of the optical signal in the detection period according to the transmitting time T3 of the optical signal and the receiving time T4 of the optical signal. The transmission time period T1 is T4-T3.

Then, the control component 50 can determine the moving distance d of the projection screen 30 in the detection period according to the transmission speed V and the transmission time length T1 of the optical signal stored in advance. The moving distance d satisfies:

in the embodiment of the present disclosure, referring to fig. 5, if the distance detector 80 is disposed on both sides of the long side of the opening of the accommodating groove 00. The control unit 50 may determine two movement distances from the two distance detectors 80. The control component 50 can use the average of the two moving distances as the moving distance of the projection screen 30 in the detection period.

Referring to fig. 5 and 8, both sides of the long side of the opening of the accommodating groove 00 are provided with distance detectors 80. The control unit 50 determines two moving distances according to the two distance detectors at every detection period in the process of controlling the projection screen 30 to ascend by the two motors 43. It may be detected whether the difference between the two movement distances is greater than a difference threshold. If the difference is greater than the difference threshold, it indicates that the difference between the moving distances of the two sides of the projection screen 30 is large, so the frequency of the rising driving signal provided to any one of the screen driving circuits 42 can be adjusted to ensure that the difference between the moving distances of the two sides of the projection screen 30 is within a constant range. If the difference is less than or equal to the difference threshold, indicating that the difference between the moving distances of the two sides of the projection screen 30 is small, the frequencies of the rising driving signals provided to the two screen driving circuits 42 do not need to be adjusted.

Alternatively, the control component 50 may decrease the frequency of the rising driving signal provided to one of the curtain driving circuits 42 in the process of adjusting the frequency of the rising driving signal provided to any one of the curtain driving circuits 42, thereby decreasing the moving speed of one side of the projection curtain 30. Or the control assembly 50 may increase the frequency of the up drive signal provided to the other curtain drive circuit 42, thereby increasing the speed of movement of the other side of the projection curtain 30.

The one screen driving circuit 42 is a screen driving circuit that drives one side of the projection screen 30 to move a larger distance in the detection period among the two screen driving circuits 42. The other one of the two curtain driving circuits 42 is the curtain driving circuit that drives the other side of the projection curtain 30 to move a smaller distance during the detection period.

In summary, the embodiment of the present disclosure provides a projection apparatus, where a signal detector in the projection apparatus is capable of sending a first detection signal to a control component when a foreign object is detected at an opening of a receiving groove. The control assembly can stop providing the rising driving signal to the curtain driving assembly after receiving the first detection signal. Therefore, the situation that the projection screen cannot rise due to the fact that the foreign matter blocks the projection screen when the projection screen rises when the foreign matter exists at the opening of the accommodating groove is avoided, and therefore the reliability of rising control of the projection screen is improved.

In the embodiment of the present disclosure, referring to fig. 2, the signal detector 20 is further configured to detect whether a foreign object exists at the opening of the accommodating groove 00 in response to a shutdown instruction, or when the descending distance of the projection screen 30 is greater than a third distance threshold, and send a fifth detection signal to the control component 50 when the foreign object is detected at the opening of the accommodating groove 00. When it is detected that the foreign matter is not present at the opening of the accommodating groove 00, a sixth detection signal is transmitted to the control member 50.

In the disclosed embodiment, the control component 50 may activate the signal detector 20 after receiving a shutdown instruction for the projection device, and may send the shutdown instruction to the signal detector 20. The signal detector 20 may detect whether foreign substances exist at the opening of the accommodating groove 00 in response to the shutdown instruction.

Alternatively, the control component 50 may obtain the descending distance of the projection screen 30 in real time during the process of controlling the projection screen 30 to retract into the accommodating groove 00, and detect whether the descending distance is greater than the third distance threshold. If the drop distance is greater than the third distance threshold, it can be determined that the projection screen 30 has dropped within the detection range of the signal detector 20. The control assembly 50 may activate the signal detector 20, and the signal detector 20 may detect whether foreign materials exist at the opening of the receiving groove 00. The third distance threshold is a fixed value pre-stored in the control unit 50.

Referring to fig. 2, the control assembly 50 is further configured to stop providing the falling driving signal to the curtain driving assembly 40 when receiving the fifth detection signal. When the sixth detection signal is received, a falling driving signal is provided to the curtain driving assembly 40.

Referring to fig. 2, the screen driving assembly 40 is connected to the projection screen 30, and the screen driving assembly 40 is used for controlling the projection screen 30 to retract into the accommodating cavity 00 under the control of the descending driving signal.

Referring to fig. 1 and 2, the projection screen 30 is in an open state when the projection device is in the open state. After receiving the shutdown instruction for the projection apparatus, the control component 50 may turn on the signal detector 20 again, and the signal detector 20 may further detect whether there is a foreign object at the opening of the accommodating groove 00, and send a fifth detection signal to the control component 50 when detecting that there is a foreign object at the opening of the accommodating groove 00. After receiving the fifth detection signal, the control assembly 50 stops providing the descending driving signal to the screen driving assembly 40, so as to avoid the situation that the projection screen is blocked by a foreign object during the descending process and cannot be retracted into the accommodating groove 00.

The signal detector 20 may send a sixth detection signal to the control assembly 50 when detecting that no foreign object exists in the accommodating groove 00, and the control assembly 50 provides a descending driving signal to the curtain driving assembly 40 after receiving the sixth detection signal, so as to control the projection curtain 30 to retract into the accommodating groove 00 from the state shown in fig. 1.

To sum up, the embodiment of the present disclosure provides a projection apparatus, where a signal detector in the projection apparatus can respond to a shutdown instruction, or detect whether a foreign object exists at an opening of an accommodating groove when a descending distance of a projection screen is greater than a third distance threshold. When detecting that there is the foreign matter in the opening part of holding tank, send the fifth detected signal to control assembly. The control assembly may stop providing the falling driving signal to the curtain driving assembly after receiving the fifth detection signal. Therefore, the situation that the projection screen cannot descend due to the fact that the foreign matter blocks the projection screen when the projection screen descends is avoided when the foreign matter exists at the opening of the accommodating groove, and the reliability of descending control of the projection screen is improved.

Referring to fig. 4, the signal detector 20 may include a signal transmitter 21 and a signal receiver 22. The signal transmitter 21 and the signal receiver 22 are oppositely disposed at both sides of the accommodating groove 00. Alternatively, the signal transmitter 21 and the signal receiver 22 are both disposed at one side of the accommodating groove 00. Alternatively, the signal transmitter 21 and the signal receiver 22 are both disposed in the accommodating groove 00.

Alternatively, the signal transmitter 21 and the signal receiver 22 may both be disposed on the crossbar assembly 41.

Alternatively, one of the signal transmitter 21 and the signal receiver 22 is disposed in the receiving groove 00, and the other is disposed on the crossbar assembly 41. Alternatively, the detection signal emitted by the signal emitter 21 may pass through the cross bar assembly 41, and if the signal receiver 22 receives the detection signal emitted by the signal emitter 21, the signal receiver 22 may determine that no foreign object exists at the opening of the accommodating groove 00. If the signal receiver 22 cannot receive the detection signal sent by the signal transmitter 21, the signal receiver 22 can determine that a foreign object exists at the opening of the accommodating groove 00.

Referring to fig. 7, the curtain driving circuit 42 is also configured to supply a second driving current to the motor 43 in response to the falling driving signal. The motor 43 is used to drive the lifting rod driving assembly 45 to pull the lifting rod 44 to descend under the driving of the second driving current. The lifting rod 44 is also used to pull the cross rod assembly 41 down, thereby pulling the projection screen 30 down, under the pulling of the lifting rod driving assembly 45.

Referring to fig. 8, each motor 43 is driven by the second driving current provided by the corresponding curtain driving circuit 42 to drive each slider driving sub-assembly to push the corresponding slider 450 to slide along the guide rail 02 toward the side away from the motor 43, so as to push the power rod 451 to move toward the side away from the motor 43. The power rod 451 can further pull the first rod 440 to descend through the second rod 441, and further pull the lifting rod 44 to descend.

Referring to fig. 9, the position detector 60 is further configured to detect whether the projection screen 30 is at the initial position in response to a shutdown instruction, send a seventh detection signal to the control component 50 when the projection screen 30 is detected to be at the initial position, and send an eighth detection signal to the control component 50 when the projection screen 30 is detected not to be at the initial position.

The control assembly 50 is configured to stop providing the falling driving signal to the curtain driving assembly 40 when the seventh detection signal is received and it is determined that the projection curtain 30 is currently at the initial position. When the eighth detection signal is received, it can be determined that the projection screen 30 is not currently in the initial position, and a falling driving signal is sent to the screen driving assembly 40.

The screen driving assembly 40 is further configured to control the projection screen 30 to descend under the control of the descending driving signal.

Optionally, a power-off button may be further disposed on the housing 10 of the projection device. Referring to fig. 9, the audio/video control circuit 71 may generate a shutdown instruction when detecting a click operation of the shutdown button by the user, and may transmit the shutdown instruction to the control component 50. The control component 50 may activate the position detector 60 after receiving the shutdown command, and send the shutdown command to the position detector 60, and the position detector 60 detects whether the projection screen 30 is at the initial position in response to the shutdown command.

Alternatively, the shutdown instruction may be triggered by a user through a remote controller, and the audio/video control circuit 71 may send the shutdown instruction to the control component 50 after receiving the shutdown instruction sent by the remote controller. The control component 50 may activate the position detector 60 after receiving the shutdown command, and may send the shutdown command to the position detector 60, and the position detector 60 may detect whether the projection screen 30 is at the initial position in response to the shutdown command.

In the embodiment of the present disclosure, the position detector 60 can detect whether the projection screen 30 is at the initial position in real time during the process of controlling the projection screen 30 to descend by the screen driving assembly 40. If it is detected that the projection screen 30 is not yet at the initial position, the eighth detection signal may be continuously sent to the control component 50, and after the control component 50 receives the eighth detection signal, it may be determined that the projection screen 30 is not yet at the initial position, the descending driving signal may be continuously sent to the screen driving component 40 to control the projection screen 30 to descend. This is repeated until the position detector 60 sends a fifth detection signal to the control assembly 50 after detecting that the projection screen 30 is at the initial position, and the control assembly 50 stops providing the falling driving signal to the screen driving assembly 40 after receiving the seventh detection signal.

In the embodiment of the present disclosure, the position detector 60 is further configured to count the number m of rotations of the shielding rod 431 during a fixed period in response to a shutdown command. And detecting whether the number M of the rotation turns is less than or equal to the threshold M of the turn number, and if the number M of the rotation turns is equal to the threshold M of the turn number, determining that the projection screen 30 is at the initial position. If the number of rotations M is less than the threshold number of rotations M, it is determined that the projection screen 30 is not in the initial position.

In the process of controlling the projection screen 30 to descend, the screen driving circuit 42 provides a second driving current to the motor 43 under the control of the descending driving signal provided by the control component 50, and the rotating shaft 430 of the motor 43 rotates along the second direction under the driving of the second driving current, so as to drive the connecting rod 471 to rotate along the second direction, and further drive the shielding portion 470 to rotate along the second direction. Wherein the second direction may be a counterclockwise direction.

Referring to fig. 12 and 15, during one rotation of the shaft 430 in the second direction, the position detector 60 may detect a pulse signal sequence of one period T. And in the one period T, if the first shielding portion 4701 shields the position detector 60, the position detector 60 can detect a pulse signal at a time period T5. If the two second blocking portions 4702 sequentially block the position detector 60, the position detector 60 can sequentially detect two pulse signals with a short time interval in the time period t 6.

Alternatively, in the case of controlling the projection screen 30 to move from the top position to the initial position, the calculation manner of the threshold M of the number of turns and the number M of rotations can be referred to the calculation manner of the threshold M of the number of turns and the number M of rotations in the case of controlling the projection screen 30 to move from the initial position to the top position.

Optionally, the control assembly 50 is further configured to obtain a descending distance of the projection screen 30 during the process of controlling the projection screen 30 to retract into the accommodating groove 00. If the drop distance is greater than the fourth distance threshold, the signal detector 20 is turned off and the frequency of the drop drive signal provided to the curtain drive assembly 40 is increased.

Wherein, the descending distance refers to the distance between the side of the projection screen 30 connected to the rail assembly 41 and the housing 10. The fourth distance threshold is greater than the third distance threshold, and the fourth distance threshold is a fixed value pre-stored in the control component 50.

In the embodiment of the present disclosure, the control component 50 may obtain the descending distance of the projection screen 30 in real time during the process of controlling the projection screen 30 to retract into the accommodating groove 00, and when detecting whether the descending distance is greater than the fourth distance threshold, it may be determined that the distance between the projection screen 30 and the housing 10 is short, for example, the distance may be 30 millimeters (mm), and the control component 50 may turn off the signal detector 20, and simultaneously may increase the frequency of the descending driving signal provided to the screen driving component 40, so that the projection screen 30 retracts into the accommodating groove 00 quickly.

Optionally, the control assembly 50 is further configured to, in the process of controlling the projection screen 30 to retract into the accommodating groove 00, acquire a moving distance of the projection screen 30 in each detection period. And respectively detecting whether the moving distance is greater than a first distance threshold. If the moving distance is greater than the first distance threshold, indicating a faster moving speed of the projection screen 20, the frequency of the down driving signal provided to the screen driving assembly 40 can be reduced, thereby reducing the moving speed of the projection screen 30. If the moving distance is less than or equal to the first distance threshold, it can be detected whether the moving distance is less than the second distance threshold, and if the moving distance is less than the second distance threshold, which indicates that the moving speed of the projection screen 30 is slow, the frequency of the down driving signal provided to the screen driving assembly 40 can be increased, thereby increasing the moving speed of the projection screen 30.

Wherein, the first distance threshold is greater than the second distance threshold, the moving speed of the projection screen 30 is positively correlated with the frequency, that is, the higher the frequency of the falling driving signal is, the faster the moving speed of the projection screen 30 is; the smaller the frequency of the falling driving signal, the slower the moving speed of the projection screen 30.

In the embodiment of the present disclosure, in the process of controlling the projection screen 30 to retract into the accommodating groove 00, the moving speed of the projection screen 30 can be dynamically adjusted according to the moving distance of the projection screen 30 in the detection period, so that the flexibility of controlling the lifting of the projection screen is improved.

Referring to fig. 9, in controlling the projection screen 30 to retract from the accommodating groove 00, the control assembly 50 may determine the moving distance d of the projection screen 30 during the detection period according to the emitting time t3 when the distance detector 80 emits the light signal and the receiving time t4 when the light signal reflected by the rail assembly 41 is received.

Alternatively, referring to fig. 5, if the distance detector 80 is disposed on both sides of the long side of the opening of the accommodating groove 00. The control unit 50 can determine two moving distances according to the two distance detectors 80 during the process of controlling the projection screen 30 to retract from the accommodating groove 00. The control component 50 can use the average of the two moving distances as the moving distance of the projection screen 30 in the detection period.

Alternatively, the control assembly 50 can also determine the falling distance of the projection screen 30 according to the distance detector 80, wherein the emitting time of the light signal is the time when the control assembly 50 provides the falling driving signal to the screen driving assembly 40.

Meanwhile, if the distance detector 80 is disposed on both sides of the long side of the opening of the accommodating groove 00. The control assembly 50 may determine two drop distances based on the two distance detectors 80. The control component 50 can use the average of the two descending distances as the descending distance of the projection screen 30.

Referring to fig. 5 and 8, both sides of the long side of the opening of the accommodating groove 00 are provided with distance detectors 80. The control unit 50 determines two moving distances according to the two distance detectors at every detection period in the process of controlling the projection screen 30 to descend by the two motors 43. It may be detected whether the difference between the two movement distances is greater than a difference threshold. If the difference is greater than the difference threshold, it indicates that the difference between the moving distances of the two sides of the projection screen 30 is large, so that the frequency of the down driving signal provided to any one of the screen driving circuits 42 can be adjusted to ensure that the difference between the moving distances of the two sides of the projection screen 30 is within a constant range. If the difference is less than or equal to the difference threshold, indicating that the difference between the moving distances of the two sides of the projection screen 30 is small, the frequencies of the down driving signals provided to the two screen driving circuits 42 do not need to be adjusted.

Optionally, the control component 50 may decrease the frequency of the falling driving signal provided to one of the curtain driving circuits 42 in the process of adjusting the frequency of the falling driving signal provided to any one of the curtain driving circuits 42, thereby decreasing the moving speed of one side of the projection curtain 30. Or the control assembly 50 may increase the frequency of the falling drive signal provided to the other curtain drive circuit 42, thereby increasing the speed of movement of the other side of the projection curtain 30.

Referring to fig. 9, the multimedia component 70 may further include a power amplifier component 72 and a speaker 73, wherein the power amplifier component 72 is connected to the audio/video control circuit 71 and the speaker 74, respectively. The control component 50 may further send an alarm message to the audio/video control circuit 71 after receiving the first detection signal sent by the signal detector 20, the audio/video control circuit 71 may send the alarm message to the power amplifier component 72 after receiving the alarm message, and the power amplifier component 72 drives the speaker 74 to send an alarm sound, so as to prompt the user to remove the foreign object in time.

Referring to fig. 5 and 9, the projection device may further include an eye-shielding assembly 90 and a display control assembly 100, the eye-shielding assembly 90 being disposed at the front side of the housing 10. The eye-shielding assembly 90 may include an eye-shielding sensor 91, an amplification circuit 92, a comparison circuit 93, and a trigger 94. The display control assembly 100 may include a display driver circuit 1001 and a slave circuit 1002. The slave control circuit 1002 may be a Micro Controller Unit (MCU).

The amplifying circuit 92 is connected to the eye protection sensor 91 and the comparing circuit 93, and the flip-flop 94 is connected to the comparing circuit 93 and the slave control circuit 1002. The slave control circuit 1002 is connected to the audio/video control circuit 71. The eye protection sensor 90 may be an infrared sensor or a non-infrared sensor.

Before controlling the projection screen 30 to ascend or during controlling the projection screen 30 to descend, the human eye protection sensor 91 is configured to detect a distance between a human body and the projection apparatus and send the detected distance to the amplifying circuit 92 and the comparing circuit 93, the comparing circuit 93 is configured to compare the distance with a pre-stored distance threshold, and if the distance threshold is smaller than the distance threshold, provide a control signal to the trigger 94. The slave control circuit 1002 may determine that the human body is closer to the projection apparatus, that is, the human body may block the rising or falling possibility of the projection screen when detecting that the number of pulse signals output by the trigger 94 in a unit time is greater than the number threshold. The slave control circuit 1002 may send an alarm message to the audio/video control circuit 71, and the audio/video control circuit 71 may send the received alarm message to the power amplifier component 72, and the power amplifier component 72 drives the speaker 74 to generate an alarm sound to remind the user to get away from the projection screen 30.

Referring to fig. 9, the projection apparatus may further include a light source driving assembly 110 and a laser light source 120. The laser light source 120 is used to emit laser light. The laser light source 120 includes a red laser, a green laser assembly, a blue laser assembly, and a yellow laser assembly. The light-emitting side of each laser is provided with a glass lens with a light combination function.

The multimedia component 70 may also include a first memory 73. The first memory 73 is connected to the audio/video control circuit 71. The first memory 73 may be used to store the image to be projected for display. The audio/video control circuit 71 is further configured to obtain an image to be projected and displayed from the first memory 73, and send the image to be projected and displayed to the slave control circuit 1002 and further to the display driving circuit 1001. The display driving circuit 1001 may output a red PWM signal R _ PWM corresponding to a red laser component based on a red primary color component of an image to be displayed, output a green PWM signal G _ PWM corresponding to a green laser component based on a green primary color component of the image to be displayed, output a blue PWM signal B _ PWM corresponding to a blue laser component based on a blue primary color component of the image to be displayed, and output a yellow PWM signal Y _ PWM corresponding to a yellow laser component based on a yellow primary color component of the image to be displayed. The display driving circuit 1001 may output an enable signal R _ EN corresponding to the red laser element based on a lighting period of the red laser element in the driving period, output an enable signal G _ EN corresponding to the green laser element based on a lighting period of the green laser element in the driving period, and output an enable signal B _ EN corresponding to the blue laser element based on a lighting period of the blue laser element in the driving period. Based on the lighting time period of the yellow laser component in the driving period, the enable signal Y _ EN corresponding to the yellow laser component is output.

Referring to fig. 9, the display control assembly 100 may further include a second memory 1003 for storing primary color gradation values of pixels in the image to be projected, the second memory 1003 being used to store the primary color gradation values. The display driving circuit 1001 is further configured to obtain the stored primary color level values of the pixels in the image to be projected from the second memory, and control the light valve to turn over according to the primary color level values of the pixels in the image to be projected, so as to project and display the image to be projected on the projection screen.

In the embodiment of the present disclosure, the slave control circuit 1001 is also used for adjusting the ambient temperature inside the housing 10 and the temperature of the laser light source 120, and controlling the fan to adjust the ambient temperature inside the housing 10 and the temperature of the laser light source 120.

To sum up, the embodiment of the present disclosure provides a projection apparatus, where a signal detector in the projection apparatus responds to a shutdown instruction to detect whether a foreign object exists at an opening of an accommodating groove. When detecting that there is the foreign matter in the opening part of holding tank, send the fifth detected signal to control assembly. The control assembly may stop providing the falling driving signal to the curtain driving assembly after receiving the fifth detection signal. Therefore, the situation that the projection screen cannot descend due to the fact that the foreign matter blocks the projection screen when the projection screen descends is avoided when the foreign matter exists at the opening of the accommodating groove, and the reliability of descending control of the projection screen is improved. Meanwhile, the situation that the projection screen is clamped when the hands of a user are placed at the opening of the accommodating groove in the descending process can be avoided, and the safety of the user is ensured.

In the embodiment of the present disclosure, referring to fig. 2, the signal detector 20 is further configured to detect whether a foreign object exists at the opening of the accommodating groove 00 in response to a shutdown instruction, or when the descending distance of the projection screen 30 is greater than a third distance threshold, and send a fifth detection signal to the control component 50 when the foreign object is detected at the opening of the accommodating groove 00. When it is detected that the foreign matter is not present at the opening of the accommodating groove 00, a sixth detection signal is transmitted to the control member 50.

Referring to fig. 2, the control assembly 50 is further configured to stop providing the falling driving signal to the curtain driving assembly 40 when receiving the fifth detection signal. When the sixth detection signal is received, a falling driving signal is provided to the curtain driving assembly 40.

Referring to fig. 2, the screen driving assembly 40 is connected to the projection screen 30, and the screen driving assembly 40 is used for controlling the projection screen 30 to retract into the accommodating cavity 00 under the control of the descending driving signal.

Referring to fig. 2, the control assembly 50 is further configured to increase the frequency of the falling driving signal provided to the screen driving assembly 30 when the falling distance of the projection screen 00 is greater than the fourth distance threshold in the process of controlling the projection screen 30 to retract into the accommodating groove 00.

Wherein, the fourth distance threshold is larger than the third distance threshold, and the moving speed of the projection screen is positively correlated with the frequency.

To sum up, the embodiment of the present disclosure provides a projection apparatus, where a signal detector in the projection apparatus responds to a shutdown instruction to detect whether a foreign object exists at an opening of an accommodating groove. When detecting that there is the foreign matter in the opening part of holding tank, send the fifth detected signal to control assembly. The control assembly may stop providing the falling driving signal to the curtain driving assembly after receiving the fifth detection signal. Therefore, the situation that the projection screen cannot descend due to the fact that the foreign matter blocks the projection screen when the projection screen descends is avoided when the foreign matter exists at the opening of the accommodating groove, and the reliability of descending control of the projection screen is improved. Meanwhile, the situation that the projection screen is clamped when the hands of a user are placed at the opening of the accommodating groove in the descending process can be avoided, and the safety of the user is ensured. Meanwhile, when the descending distance of the projection screen is greater than the fourth distance threshold, the moving speed of the projection screen is increased, so that the projection screen can be accelerated to withdraw the accommodating groove.

Fig. 16 is a flowchart of a method for controlling the lifting of a projection screen according to an embodiment of the present disclosure. The lifting control method can be applied to the control assembly 50 located in the housing 10 of the projection apparatus shown in any one of fig. 1 to 13, the projection apparatus can further include the signal detector 20, the projection screen 30, and the screen driving assembly 40, and one side of the housing 10 is provided with an accommodating groove 00 for accommodating the projection screen 30. The control assembly 50 is connected to the signal detector 20 and the curtain driving assembly 40, respectively. As shown in fig. 16, the method may include:

step 1601, when receiving a first detection signal sent by the signal detector, stops providing the rising driving signal to the curtain driving component.

In step 1602, when a second detection signal sent by the signal detector is received, a rising driving signal is provided to the curtain driving component.

The ascending driving signal is used to control the screen driving assembly 40 to control the projection screen 30 to ascend from the accommodating slot 00. The first detection signal is sent to the control component 50 by the signal detector 20 responding to the power-on command, detecting whether a foreign object exists at the opening of the accommodating groove 00, and when detecting that a foreign object exists at the opening of the accommodating groove 00. The second detection signal is sent to the control component 50 by the signal detector 20 responding to the power-on command, detecting whether there is a foreign object at the opening of the accommodating groove 00, and when detecting that there is no foreign object at the opening of the accommodating groove 00.

To sum up, the embodiment of the present disclosure provides a lifting control method for a projection screen, where a signal detector in the lifting control method can respond to a start-up instruction, detect whether a foreign object exists at an opening of an accommodating groove, and send a first detection signal to a control component when detecting that the foreign object exists at the opening of the accommodating groove. The control component can stop providing the driving signal to the curtain driving component after receiving the first detection signal. Therefore, the situation that the projection screen cannot rise due to the fact that the foreign matter blocks the projection screen when the projection screen rises when the foreign matter exists at the opening of the accommodating groove is avoided, and therefore the reliability of rising control of the projection screen is improved.

Fig. 17 is a flowchart of another method for controlling the lifting of a projection screen according to an embodiment of the disclosure, and as shown in fig. 17, the method may include:

in step 1701, when the fifth detection signal sent by the signal detector is received, the supply of the falling driving signal to the curtain driving module is stopped.

Step 1702, when receiving the sixth detection signal sent by the signal detector, provide a falling driving signal to the film driving component.

The descending driving signal is used to control the screen driving assembly 40 to control the projection screen 30 to retract into the accommodating cavity 00. The fifth detection signal is sent to the control component 50 by the signal detector 20 in response to the shutdown instruction, or when the descending distance of the projection screen 30 is greater than the third distance threshold, detecting whether a foreign object exists at the opening of the accommodating groove 00, and when detecting that a foreign object exists at the opening of the accommodating groove 00. The sixth detection signal is sent to the control component 50 when the signal detector detects whether there is a foreign object at the opening of the accommodating groove 00 in response to the shutdown instruction or when the descending distance of the projection screen 30 is greater than the third distance threshold, and when it detects that there is no foreign object at the opening of the accommodating groove 00.

To sum up, the embodiment of the present disclosure provides a lifting control method for a projection screen, where the lifting control method may respond to a shutdown instruction, or detect whether a foreign object exists at an opening of an accommodating groove when a descending distance of the projection screen is greater than a third distance threshold. When detecting that there is the foreign matter in the opening part of holding tank, send the fifth detected signal to control assembly. The control assembly may stop providing the falling driving signal to the curtain driving assembly after receiving the fifth detection signal. Therefore, the situation that the projection screen cannot descend due to the fact that the foreign matter blocks the projection screen when the projection screen descends is avoided when the foreign matter exists at the opening of the accommodating groove, and the reliability of descending control of the projection screen is improved. Meanwhile, the situation that the projection screen is clamped when the hands of a user are placed at the opening of the accommodating groove in the descending process can be avoided, and the safety of the user is ensured.

Fig. 18 is a flowchart of a method for controlling the lifting of a projection screen according to another embodiment of the disclosure, and as shown in fig. 18, the method may include:

step 1801, when the fifth detection signal sent by the signal detector is received, the supply of the falling driving signal to the curtain driving assembly is stopped.

When receiving the sixth detection signal sent by the signal detector, step 1802 provides a falling driving signal to the curtain driving assembly.

Step 1803, when the falling distance of the projection screen is greater than the fourth distance threshold, increasing the frequency of the falling driving signal provided to the screen driving component.

The descending driving signal is used to control the screen driving assembly 40 to control the projection screen 30 to retract into the accommodating cavity 00. The fifth detection signal is sent to the control component 50 by the signal detector 20 in response to the shutdown instruction, or when the descending distance of the projection screen 30 is greater than the third distance threshold, detecting whether a foreign object exists at the opening of the accommodating groove 00, and when detecting that a foreign object exists at the opening of the accommodating groove 00. The sixth detection signal is a signal detector 20 that detects whether a foreign object exists at the opening of the accommodating groove 00 in response to a shutdown instruction, or when the descending distance of the projection screen 30 is greater than the third distance threshold, and sends the signal to the control component 50 when detecting that the foreign object does not exist at the opening of the accommodating groove 00, where the fourth distance threshold is greater than the third distance threshold, and the moving speed of the projection screen 30 is positively correlated with the frequency.

To sum up, the embodiment of the present disclosure provides a lifting control method for a projection screen, where the lifting control method responds to a shutdown instruction, or detects whether a foreign object exists at an opening of an accommodating groove when a descending distance of the projection screen is greater than a third distance threshold, and sends a fifth detection signal to a control component when detecting that the foreign object exists at the opening of the accommodating groove. The control assembly may stop providing the falling driving signal to the curtain driving assembly after receiving the fifth detection signal. Therefore, the situation that the projection screen cannot descend due to the fact that the foreign matter blocks the projection screen when the projection screen descends is avoided when the foreign matter exists at the opening of the accommodating groove, and the reliability of descending control of the projection screen is improved. Meanwhile, the situation that the projection screen is clamped when the hands of a user are placed at the opening of the accommodating groove in the descending process can be avoided, and the safety of the user is ensured. And because when the descending distance of the projection screen is greater than the fourth distance threshold, the moving speed of the projection screen is increased, thereby being capable of accelerating the projection screen to withdraw the accommodating groove.

The above description is intended to be exemplary only and not to limit the present disclosure, and any modification, equivalent replacement, or improvement made without departing from the spirit and scope of the present disclosure is to be considered as the same as the present disclosure.