阅读说明：本技术 纸张搬送机构以及图像形成装置 (Sheet conveying mechanism and image forming apparatus ) 是由 王顺祥 于 2019-09-05 设计创作，主要内容包括：本发明提供一种纸张搬送机构以及包括所述纸张搬送机构的图像形成装置。所述纸张搬送机构包括：给纸盒,用于收纳由多张纸张组成的纸叠；多个风扇,用于向所述给纸盒中的纸叠送风以使若干张纸张浮起；搬送皮带,位于所述纸叠的上方；搬送辊,沿纸张搬送方向位于所述搬送皮带的下游侧。其中,所述纸张搬送机构还包括控制部,所述控制部被配置成：当由所述搬送辊搬送所述纸张后,所述纸张沿纸张搬送方向的先端到达预定位置时,减小先端风扇和/或吸着风扇的风量,以使所述纸张与所述搬送皮带相分离,且不与其它的纸张相接触。所述图像形成装置包括：所述纸张搬送机构,用于搬送纸张；以及图像形成机构,用于在纸张上形成图像。(The invention provides a paper conveying mechanism and an image forming apparatus including the same. The paper sheet conveying mechanism includes: a paper feed cassette for receiving a stack of a plurality of sheets; the fans are used for supplying air to the paper stack in the paper feeding box so as to enable a plurality of pieces of paper to float; a conveying belt located above the paper stack; and a conveying roller located on a downstream side of the conveying belt in a sheet conveying direction. Wherein the sheet carrying mechanism further includes a control section configured to: when the leading end of the paper in the paper conveying direction reaches a predetermined position after the paper is conveyed by the conveying roller, the air volume of a leading end fan and/or a suction fan is reduced so that the paper is separated from the conveying belt and does not contact with other paper. The image forming apparatus includes: the paper conveying mechanism is used for conveying paper; and an image forming mechanism for forming an image on the sheet.)

1. A paper sheet conveying mechanism, comprising:

a paper feed cassette for receiving a stack of a plurality of sheets;

a plurality of fans for blowing air to the stack of sheets in the sheet feeding cassette to float the sheets;

a conveying belt located above the paper stack; and

a conveying roller located on a downstream side of the conveying belt in a sheet conveying direction;

wherein the plurality of fans include:

a tip fan located on a front side of the sheet bundle in the sheet conveying direction;

at least two side fans respectively positioned at two sides of the paper stack;

a suction fan positioned above the stack of sheets;

the front end fan is provided with a floating position and a separating position, when the front end fan is located at the floating position, the front end fan and the side face fan are matched with each other to supply air to the paper stack so as to float a plurality of pieces of paper, and the suction fan adsorbs the floated paper to the conveying belt;

when the tip fan is at the separation position, the tip fan supplies air to the lower side of the uppermost sheet of paper to separate the uppermost sheet of paper from the other sheets of paper;

the conveying belt is used for conveying the paper adsorbed on the conveying belt to the conveying roller, and the conveying belt stops conveying after the paper is conveyed by the conveying roller;

characterized in that the sheet carrying mechanism further comprises a control section configured to:

when the leading end of the paper sheet in the paper sheet conveying direction reaches a predetermined position after the paper sheet is conveyed by the conveying roller, the air volume of the leading end fan and/or the suction fan is reduced so that the paper sheet is separated from the conveying belt and does not contact with other paper sheets.

2. The sheet carrying mechanism as set forth in claim 1,

the conveyance belt stops conveyance until the trailing end of the paper sheet is separated from the rear end position of the conveyance belt.

3. The sheet carrying mechanism as set forth in claim 1,

the suction fan sucks and absorbs the paper in a suction area, and the conveying belt stops conveying the paper before the paper is conveyed to the suction area and exposed to the next paper.

4. The sheet conveying mechanism according to any one of claims 1 to 3, further comprising a distance sensor for detecting a distance L between the sheet being conveyed and the conveying belt.

5. The sheet conveying mechanism according to claim 4, wherein a distance L between the sheet being conveyed and the conveying belt is maintained within a predetermined distance range by reducing an air volume of the tip fan and/or the suction fan so that the sheet being conveyed is separated from the conveying belt and does not contact other sheets.

6. The sheet conveying mechanism according to claim 4 or 5, wherein the control section is configured to:

reducing the air volume of the tip fan and/or the suction fan at a set time interval, and detecting the distance L by the distance sensor;

when the distance sensor detects that the distance L falls into a preset distance range, keeping the current air volume of the tip fan and/or the sorption fan, and continuing to detect the distance L at the time interval;

if the distance L falls into the preset distance range in a plurality of continuous time intervals, keeping the current air volume of the front end fan and/or the suction fan; and if the distance L exceeds the preset distance range, strengthening the air volume of the front end fan and/or the suction fan.

7. The sheet carrying mechanism as claimed in claim 6, wherein the predetermined distance range is 0< L <10 mm.

8. The sheet conveying mechanism according to any one of claims 1 to 7, wherein the conveying roller rotates at the same rotational speed as the conveying belt before a leading end of the sheet being conveyed in the sheet conveying direction reaches a predetermined position.

9. An image forming apparatus, comprising:

the sheet carrying mechanism as claimed in any one of claims 1 to 8, for carrying a sheet; and

an image forming mechanism for forming an image on the sheet.

Technical Field

The present invention relates to the field of printing technologies, and in particular, to a paper conveyance mechanism and an image forming apparatus including the paper conveyance mechanism.

Background

When long sheets are conveyed, the sheets are first blown up by a fan, and then the sheets are attracted onto a conveying belt by an upper end fan and conveyed by the conveying belt. When the leading end of the sheet passes through the exit of the tray, the sheet is conveyed by the exit conveying roller, and the conveying belt stops. The reason why the conveyance belt stops conveyance is mainly because if the sheet is conveyed all the time, the trailing end or the middle portion of the sheet that is not conveyed is easily attracted to the conveyance belt and conveyed by the conveyance belt, which may cause a jam. However, since the paper sheet is still attached to the transport belt and transported by the transport roller while the transport belt stops transporting, friction is generated between the paper sheet and the transport belt, and paper powder (coating) is attached to the transport belt due to the friction, so that durability and transport force of the transport belt are deteriorated earlier than ideal.

In the prior art, in order to reduce friction between paper and a conveying belt in the paper conveying process, a separation mechanism is used for separating the paper from the conveying belt. However, this technique can improve the separability of plain paper, and is disadvantageous in the use of long paper.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a paper conveying mechanism, which reduces the friction between paper and a conveying belt by adjusting the air volume of a fan, thereby prolonging the durability and conveying force of the conveying belt. The invention also provides an image forming apparatus including the sheet conveying mechanism.

According to an aspect of the present invention, there is provided a sheet conveying mechanism including: a paper feed cassette for receiving a stack of a plurality of sheets; a plurality of fans for blowing air to the stack of sheets in the sheet feeding cassette to float the sheets; a conveying belt located above the paper stack; and a conveying roller located on a downstream side of the conveying belt in a sheet conveying direction.

Wherein the plurality of fans include: a tip fan located on a front side of the sheet bundle in the sheet conveying direction; at least two side fans respectively positioned at two sides of the paper stack; a suction fan positioned above the stack of sheets; the front end fan is provided with a floating position and a separating position, when the front end fan is located at the floating position, the front end fan and the side face fan are matched with each other to supply air to the paper stack so as to float a plurality of pieces of paper, and the suction fan adsorbs the floated paper to the conveying belt; when the tip fan is at the separation position, the tip fan supplies air to the lower side of the uppermost sheet of paper to separate the uppermost sheet of paper from the other sheets of paper; the transport belt transports the paper sheet adsorbed on the transport belt to the transport roller, and stops transport after the paper sheet is transported by the transport roller.

Wherein the sheet carrying mechanism further includes a control section configured to: when the leading end of the paper sheet in the paper sheet conveying direction reaches a predetermined position after the paper sheet is conveyed by the conveying roller, the air volume of the leading end fan and/or the suction fan is reduced so that the paper sheet is separated from the conveying belt and does not contact with other paper sheets.

Alternatively, the conveyance belt stops conveyance until the trailing end of the sheet leaves the rear end position of the conveyance belt.

Alternatively, the suction fan sucks the paper in a suction area, and the conveying belt stops conveying before the paper is conveyed to the suction area and exposed to the next paper.

Optionally, the sheet conveying mechanism further includes a distance sensor for detecting a distance L between the sheet being conveyed and the conveying belt.

Alternatively, the distance L between the sheet being conveyed and the conveyance belt is maintained within a predetermined distance range by reducing the air volume of the tip fan and/or the suction fan so that the sheet being conveyed is separated from the conveyance belt and does not contact other sheets.

Optionally, the control section is configured to:

reducing the air volume of the tip fan and/or the suction fan at a set time interval, and detecting the distance L by the distance sensor;

when the distance sensor detects that the distance L falls into a preset distance range, keeping the current air volume of the tip fan and/or the sorption fan, and continuing to detect the distance L at the time interval;

if the distance L falls into the preset distance range in a plurality of continuous time intervals, keeping the current air volume of the front end fan and/or the suction fan; and if the distance L exceeds the preset distance range, strengthening the air volume of the front end fan and/or the suction fan.

Optionally, the predetermined distance range is 0< L <10 mm.

Alternatively, the conveying roller rotates at the same rotational speed as the conveying belt before the leading end of the sheet being conveyed in the sheet conveying direction reaches a predetermined position.

According to another aspect of the present invention, there is also provided an image forming apparatus including the sheet carrying mechanism according to the present invention and an image forming mechanism, the sheet carrying mechanism being for carrying a sheet; the image forming mechanism is used for forming an image on a sheet.

Compared with the prior art, the technical scheme of the embodiment of the invention has the following beneficial effects:

when the front end of the paper in the paper conveying direction reaches a preset position after the paper is conveyed by the conveying roller, the air volume of the front end fan and/or the suction fan is reduced, so that the paper is separated from the conveying belt and is not contacted with other paper, and the friction between the paper and the conveying belt and other paper is avoided.

The air quantity is adjusted according to the suction pressure of the paper and the conveying belt, feedback is implemented in real time, the conveying effect is improved while the productivity is guaranteed, the motor load is reduced, and the service life of the conveying belt is prolonged.

Drawings

Other features and advantages of the present invention will be better understood by the following detailed description of alternative embodiments, taken in conjunction with the accompanying drawings, in which like characters represent the same or similar parts, and in which:

fig. 1 shows a schematic configuration diagram of a sheet carrying mechanism according to an embodiment of the present invention.

Fig. 2 shows a schematic diagram of a sheet carrying mechanism blowing up a sheet according to an embodiment of the present invention.

Fig. 3 shows a schematic view of a sheet conveyance mechanism adsorbing a sheet according to one embodiment of the present invention.

Fig. 4 shows a schematic view of the sheet conveyance mechanism separating sheets according to one embodiment of the present invention.

Fig. 5 shows a schematic diagram of starting to convey a sheet in the sheet conveying mechanism according to one embodiment of the present invention.

Fig. 6 shows a schematic diagram of arrival of a sheet at a conveyance roller in the sheet conveyance mechanism according to one embodiment of the present invention.

Fig. 7 shows a schematic view of a sheet being conveyed by the conveying roller in the sheet conveying mechanism according to an embodiment of the present invention.

Fig. 8 is a schematic diagram showing the adjustment of the air volume by the sheet carrying mechanism according to one embodiment of the present invention.

Fig. 9 is a schematic diagram showing the start of floating of the next sheet in the sheet carrying mechanism according to one embodiment of the present invention.

Fig. 10 shows a schematic diagram in which the next sheet has floated in the sheet carrying mechanism according to one embodiment of the present invention.

Fig. 11 shows a schematic diagram of the completion of conveyance of the preceding sheet in the sheet conveyance mechanism according to one embodiment of the present invention.

Fig. 12 shows a flowchart of the operation of the sheet carrying mechanism according to one embodiment of the present invention.

Fig. 13 shows a schematic diagram of an image forming apparatus according to an embodiment of the present invention.

Detailed Description

The practice and use of the embodiments are discussed in detail below. It should be understood, however, that the specific embodiments discussed are merely illustrative of specific ways to make and use the invention, and do not limit the scope of the invention. The description herein of the structural positions of the respective components, such as the directions of upper, lower, top, bottom, etc., is not absolute, but relative. When the respective components are arranged as shown in the drawings, these direction expressions are appropriate, but when the positions of the respective components in the drawings are changed, these direction expressions are changed accordingly.

As described in the background art, conventionally, in order to reduce friction between the sheet and the conveyance belt during the sheet conveyance, a separation mechanism is used to separate the sheet from the conveyance belt. This technique can improve the separability of plain paper, and is disadvantageous in the use of long paper. Long sheets generally refer to sheets having a length greater than or equal to 487.7mm, but less than 900 mm.

Problem 1: since the long paper is long, if the prior art spacing mechanism is used, the rear end of the paper drops onto the paper below the paper cassette, and rubbing with the paper below occurs, resulting in poor conveyance.

Problem 2: because the length of the long paper is very long, in the state that the suction device works, the mechanism can only ensure that the paper is separated from the belt in the area nearby, and the paper at the rear end is probably adsorbed on the belt again to continue friction conveying, so that the service life of the rear end of the belt is shortened, and the paper feeding is unstable.

To this end, the present invention provides a paper conveying mechanism comprising: a paper feed cassette for receiving a stack of a plurality of sheets; a plurality of fans for blowing air to the stack of sheets in the sheet feeding cassette to float the sheets; a conveying belt for adsorbing and conveying the floated paper; a conveying roller for conveying the paper from the conveying belt; the sheet carrying mechanism further includes a control section configured to: when the leading end of the paper sheet in the paper sheet conveying direction reaches a predetermined position after the paper sheet is conveyed by the conveying roller, the air volume of a leading end fan and/or a suction fan among the plurality of fans is reduced so that the paper sheet is separated from the conveying belt and does not contact other paper sheets.

Wherein the control part adjusts the air volume of the fan, so that the paper conveyed by the conveying belt is separated from the conveying belt and is not contacted with other paper. At this time, the leading end of the sheet is nipped by the conveying roller, and the sheet is in a floating state, and it is not in contact with the conveying belt above the sheet, nor with other sheets below the sheet, thereby avoiding friction between the sheet and the upper conveying mechanism and friction between the sheet and other sheets below.

Fig. 1 shows a schematic configuration diagram of a sheet carrying mechanism 100 according to an embodiment of the present invention. Specifically, the sheet conveying mechanism 100 includes a sheet feeding cassette 10, a plurality of fans 20, a conveying belt 30, and conveying rollers 40. The sheet feeding cassette 10 is configured to store a sheet bundle 50 including a plurality of sheets 51, the plurality of fans 20 are configured to blow air to the sheet bundle 50 in the sheet feeding cassette 10 to float a plurality of sheets 51, the conveying belt 30 is driven to rotate by a motor, for example, and is configured to convey an uppermost sheet 51 of the plurality of sheets that are sucked, and the conveying roller 40 is located at an exit of the sheet feeding cassette 10 and is configured to continue conveying the sheets 51 from the conveying belt 30 to a downstream image forming mechanism.

Wherein the plurality of fans 20 include a tip fan 21, a suction fan 22, and at least two side fans 23. The tip fan 21 is located at the front side of the sheet bundle 50 in the sheet conveying direction, and the suction fan 22 is located above the sheet bundle 50, and may be provided above the conveying belt 30, for example, to suck the uppermost sheet 51 of the plurality of sheets onto the belt through holes in the belt. The front end fan 21 has a floating position and a separating position, when the front end fan 21 is at the floating position, the front end fan 21 and the side fan 23 cooperate to supply air to the paper stack 50, so as to blow a plurality of sheets of paper on the upper part of the paper stack 50 in the paper feeding box 10; the suction fan sucks the floated paper to the conveyance belt 30. When the tip fan 21 is at the separation position, the tip fan 21 blows air to the lower side of the uppermost one of the plurality of sheets of paper that are floated to separate the uppermost one of the sheets of paper 51 from the other sheets of paper, and then the conveyance belt 30 conveys the uppermost one of the sheets of paper to the conveyance roller 40. The tip fan 21 may be switched between the blowing position and the separating position.

The sheet conveying mechanism 100 further includes a control unit (not shown) configured to reduce the air volume of the leading end fan 21 and/or the suction fan 22 so that the uppermost sheet 51 is separated from the conveying belt 30 and does not contact with other sheets 51 when the leading end in the sheet conveying direction reaches a predetermined position after the uppermost sheet 51 is conveyed by the conveying roller 40.

According to some embodiments of the present invention, after the sheet is conveyed by the conveying roller, the conveying belt 30 stops conveying before the uppermost sheet 51 is conveyed to the rear end position where the trailing end thereof is away from the conveying belt 30, so as to prevent the next sheet from being conveyed. Here, both the "trailing end" and the "trailing end" are along the sheet conveying direction, as shown in the right end in fig. 1.

According to some embodiments of the present invention, the suction fan 22 sucks the uppermost sheet 51 in a suction area, and the conveying belt 30 stops conveying before the uppermost sheet 51 is conveyed to the suction area and exposed to the next sheet, so as to prevent the next sheet from being conveyed.

According to some embodiments of the present invention, the sheet conveying mechanism 100 further includes a distance sensor 60, and the distance sensor 60 is disposed near the conveying belt 30 and is configured to detect a distance L between the uppermost sheet 51 and the conveying belt 30. The distance sensor 60 may be, for example, an ultrasonic distance sensor.

According to some embodiments of the present invention, the sheet conveying mechanism 100 further includes a suction sensor 70, and the suction sensor 70 is disposed near the conveying belt 30. When the state of the suction sensor 70 is on, it indicates that the paper sheet is in contact with the conveying belt 30; when the suction sensor 70 is off, it indicates that the sheet is separated from the conveyance belt 30.

According to some embodiments of the present invention, the distance L between the uppermost sheet 51 and the conveyor belt 30 is maintained within a predetermined distance range of 0< L <10 mm. Preferably, the predetermined distance range is 0< L <5 mm.

According to some embodiments of the invention, the control section is configured to: reducing the air volume of the tip fan 21 and/or the suction fan 22 at a set time interval and detecting the distance L by the distance sensor 60; when the distance sensor 60 detects that the distance L satisfies 0< L <10mm, the current air volume of the tip fan 21 and/or the suction fan 22 is maintained, and the distance L continues to be detected at the time interval; and in the consecutive n time intervals, if the distance L satisfies 0< L <10mm, keeping the current air volume of the tip fan 21 and/or the suction fan 22, and if the distance L is equal to 0 or the distance L is greater than or equal to 10mm, continuously adjusting the air volume of the tip fan 21 and/or the suction fan 22.

According to some embodiments of the invention, the time interval is 5ms to 20ms, and the n time intervals are 5 to 10 time intervals.

According to some embodiments of the present invention, when the uppermost sheet 51 starts to be conveyed by the conveying roller 40, the conveying belt 30 rotates at the same rotational speed as the conveying roller 40. With this arrangement, it is possible to reduce friction between the sheet and the conveyance belt 30 when an error occurs to cause the sheet to come into contact with the conveyance belt 30.

According to some embodiments of the present invention, after the uppermost sheet 51 is conveyed by the conveying roller 40, the rotation of the conveying belt 30 is stopped.

According to the embodiment of the present invention, in order to more accurately adjust the floating state of the uppermost one of the sheets 51, a distance sensor 60, for example, an ultrasonic distance sensor, is provided to accurately detect the distance L between the uppermost one of the sheets 51 and the conveying belt 30 while adjusting the air volume of the leading end fan 21 and/or the suction fan 22, so that the distance L between the uppermost one of the sheets 51 and the conveying belt 30 is maintained within a predetermined distance range of 0< L <10 mm.

Specifically, at the same time interval (for example, within a range of 5ms to 20ms), the air volumes of the tip fan 21 and the suction fan 22 are adjusted at the same rate (for example, within a range of 2% to 5% of the first air volume) each time, so that the uppermost sheet 51 is not in contact with the transport belt 30, and the distance L between the uppermost sheet 51 and the transport belt 30 is controlled to 0< L <10mm, and if the distance L between the uppermost sheet 51 and the transport belt 30 can be controlled to 0< L <10mm within the subsequent continuous 5 to 10 time intervals, the paper transport is performed by the transport roller 40 at the outlet of the paper cassette while keeping the currently set air volumes of the tip fan 21 and the suction fan 22 during the printing operation. If the distance L between the uppermost sheet 51 and the conveyor belt 30 is equal to 0 or greater than or equal to 10mm in the 8 th time interval within 5 to 10 consecutive time intervals, for example, 10 time intervals are set, the ratio of the adjusted air volume (for example, half of the original ratio) is changed and the adjustment is performed in the case of the current air volume.

In some embodiments according to the invention, one or more distance sensors 60, such as ultrasonic distance sensors, are provided along the sheet transport direction. In consideration of the fact that the long sheet is longer in size, providing a plurality of distance sensors 60 along the sheet conveying direction can more accurately detect the distance between the sheet and the conveying belt 30.

In the embodiment shown in fig. 1, a suction sensor 70 is provided upstream and a distance sensor 60 is provided downstream in the sheet conveying direction. The suction sensor 70 detects whether or not the uppermost sheet 51 at the position is in contact with the conveyor belt 30, and the distance sensor 60 detects the distance between the uppermost sheet 51 at the position and the conveyor belt 30.

According to some embodiments of the present invention, the ratio of the air volume per adjustment of the tip fan 21 and the suction fan 22 is 2% to 5% of the initial air volume of the tip fan 21 and the suction fan 22. For example, the initial air volume of the tip fan 21 and the suction fan 22 is 100%, the air volume is reduced by 5% to 95% at the time of adjustment, and is reduced by 5% to 90% at the time of the next adjustment.

For example, the air volume of the tip fan is reduced by 5% in 20ms, the air volume of the suction fan is reduced by 5% in 20ms, the state of the suction sensor is on, and the ultrasonic distance sensor detects that the distance L is 0 mm;

……

after the air volume is adjusted to the appropriate air volume, the air volumes of the tip fan and the suction fan are adjusted to the appropriate air volume every time the tip of the paper reaches the set position in the printing operation. In addition, the paper information and the appropriate air volume information can be stored in the storage unit, and the appropriate air volume can be automatically adjusted when the paper with the existing information is used.

Example 1

The air volume of the front end fan is reduced by 5% in 20ms, the air volume of the suction fan is reduced by 5% in 20ms, the state of the suction sensor is off at the moment, the ultrasonic distance sensor detects that the distance L is larger than 0 and smaller than 5mm, the current air volume is maintained, the distance L detected within 10 continuous time intervals (20ms) is larger than 0 and smaller than 5mm, the current air volume of the front end fan and the suction fan meets the requirement, and the current air volume is maintained for conveying the paper in the printing work.

Example 2

The air volume of the front-end fan is reduced by 5% in 20ms, the air volume of the suction fan is reduced by 5% in 20ms, the state of the suction sensor is on, and the ultrasonic distance sensor detects that the distance L is larger than 0 and smaller than 5 mm;

keeping the air volume of the front end fan unchanged, reducing the air volume of the suction fan by 5% within 20ms, wherein the state of the suction sensor is off, the ultrasonic distance sensor detects that the distance L is more than 0 and less than 5mm, keeping the current air volume, and detecting that the distance L is more than 0 and less than 5mm within 10 continuous time intervals (20ms), which indicates that the current air volume of the front end fan and the suction fan meets the requirement, keeping the current air volume to convey paper in the printing work.

Example 3

The air volume of the front end fan is reduced by 5% in 20ms, the air volume of the suction fan is reduced by 5% in 20ms, the state of the suction sensor is off, and the distance L detected by the ultrasonic distance sensor is 0 mm;

the air volume of the front end fan is reduced by 5% within 20ms, the air volume of the suction fan is kept unchanged, the state of the suction sensor is off at the moment, the ultrasonic distance sensor detects that the distance L is larger than 0 and smaller than 5mm, the current air volume is kept, the distance L detected within 10 continuous time intervals (20ms) is larger than 0 and smaller than 5mm, the current air volume of the front end fan and the suction fan meets the requirement, and the current air volume is kept for conveying the paper in the printing work.

Example 4

If the distance L is detected to be more than 5mm in a time interval of less than 10, for example, the air quantity of the front end fan is reduced by 5% in 20ms, the air quantity of the suction fan is reduced by 5% in 20ms, the state of the suction sensor is off, and the ultrasonic distance sensor detects that the distance L is more than 5 mm;

then, the air volume of the tip fan is increased by 2.5 ms, the air volume of the suction fan is kept unchanged, the state of the suction sensor is off, the ultrasonic distance sensor detects that the distance L is greater than 0 and less than 5mm, the current air volume is kept, the distance L detected within 10 continuous time intervals (20ms) is greater than 0 and less than 5mm, and the current air volume of the tip fan and the suction fan meets the requirement, and the paper is conveyed with the current air volume in the printing work.

According to some embodiments of the present invention, a storage portion is provided in the control portion, and the storage portion stores air volumes of tip fans and/or suction fans corresponding to the paper sheets of different weights, for keeping the paper sheets of different weights from contacting neither the upper conveying belt nor other paper sheets below when being conveyed by the conveying roller.

According to some embodiments of the present invention, the sheet carrying mechanism further includes a weight sensor for detecting a weight of the carried sheet, and the control section controls an air volume of the tip fan and/or the suction fan according to the weight of the sheet.

According to the embodiment of the invention, the side fans and the front end fan (blowing and floating position) float the paper sheets at the upper end in the paper feeding box, the air outlet of the suction fan at the upper end is opened, and the paper sheets are adsorbed on the conveying belt by the suction fan at the upper end. The air outlet position is adjusted to a separation position through a front end fan, the uppermost paper and the lower paper are separated, meanwhile, a conveying belt is driven, and the paper is conveyed to a conveying roller at the outlet of a paper feeding box. When the leading end of the paper reaches the conveying roller, the leading end of the paper is nipped by the conveying roller and is continuously conveyed by the conveying roller. At the same time, the conveyor belt will continue to run in order to reduce the dynamic friction between the paper and the conveyor belt.

At this time, the air volumes of the suction fan and the tip fan (separation position) are adjusted so that the sheet is continuously conveyed by the conveying roller without contacting the conveying belt or the sheet below. After the paper sheet is brought into the above state, the transport belt may be rotated at the same speed as the transport roller or may be stopped. When the back end of the paper leaves the conveying belt, the air outlet of the suction fan is closed. Thus, the service life of the conveying belt is ensured, and the friction between the paper and the conveying belt is reduced.

Fig. 2 shows a schematic view of the sheet carrying mechanism 100 blowing the sheet according to the embodiment of the present invention. The conveyance belt 30 and the conveyance roller 40 are stopped, the tip fan 21 is in the floating position, and the tip fan 21 and the side fan 23 cooperate to blow air to the sheet above the stack 50 in the sheet cassette 10.

Fig. 3 shows a schematic view of the sheet carrying mechanism 100 according to the embodiment of the present invention sucking the sheet. The conveyance belt 30 and the conveyance roller 40 are stopped, the air blown by the tip fan 21 and the side fan 23 floats a plurality of sheets above the sheet bundle 50, the suction fan 22 sucks the floated sheets to the conveyance belt 30, and then the tip fan 21 shifts from the floating position to the separation position.

Fig. 4 shows a schematic diagram of the sheet conveyance mechanism 100 separating sheets according to the embodiment of the present invention. The conveyance belt 30 and the conveyance roller 40 are stopped, the tip fan 21 is at the separation position, and air is blown to the lower side of the uppermost sheet 51 to separate the uppermost sheet 51 from the other sheets.

Fig. 5 shows a schematic diagram of the sheet conveying mechanism 100 according to the embodiment of the present invention starting to convey a sheet. The conveying roller 40 is in a stopped state, and the conveying belt 30 starts to rotate by the drive of the drive device, and conveys the uppermost sheet 51 attracted to the belt.

Fig. 6 shows a schematic diagram of the arrival of the sheet at the conveying roller 40 in the sheet conveying mechanism 100 according to the embodiment of the present invention. The conveying roller 40 is stopped, and the conveying belt 30 conveys the uppermost sheet 51 to the conveying roller 40 until the tip of the uppermost sheet 51 comes into contact with the conveying roller 40 to arch the sheet tip.

Fig. 7 shows a schematic view of the sheet conveyance mechanism 100 in which conveyance of the sheet by the conveyance roller 40 is started, according to the embodiment of the present invention. After the leading end of the uppermost sheet 51 is aligned with the conveying roller 40, the conveying roller 40 starts to rotate and convey the uppermost sheet 51.

Fig. 8 shows a schematic view of the sheet carrying mechanism 100 according to the embodiment of the present invention adjusting the air volume. After the conveyance roller 40 starts conveying the uppermost sheet 51, the air volumes of the tip fan 21 and the suction fan 22 are reduced so that the uppermost sheet 51 is separated from the conveyance belt 30 and is in a floating state, and the uppermost sheet 51 does not come into contact with the upper conveyance belt 30 nor fall into contact with other lower sheets. At this time, the distance sensor 60 detects that the distance L between the conveyance belt 30 and the uppermost sheet 51 satisfies 0< L <10 mm. The current fan air volume is maintained, the distance L between the conveyor belt 30 and the uppermost sheet 51 is continuously detected by the distance sensor 60, and if the continuous 10 time intervals satisfy 0< L <10mm, the air volumes of the leading fan 21 and the suction fan 22 do not need to be adjusted.

Fig. 9 shows a schematic diagram of the next sheet starting to float in the sheet carrying mechanism 100 according to the embodiment of the present invention. In order to ensure a processing waiting time after the sheet is floated, the next sheet starts to float before the preceding sheet leaves the conveyance belt 30, for example, when the trailing end of the preceding sheet is conveyed to the middle position of the conveyance belt 30. At this time, the tip fan 21 is in the floating position, and the tip fan 21 and the side fan 23 cooperate to blow air to the stack 50 of sheets in the sheet feeding cassette 10, thereby floating a plurality of sheets.

Fig. 10 shows a schematic diagram in which the next sheet has floated in the sheet carrying mechanism 100 according to the embodiment of the present invention. When the preceding sheet is about to leave the front end position of the conveyance belt 30, the next sheet has floated, and the front end fan 21 is switched to the separation position to separate the next sheet from the other sheets.

Fig. 11 shows a schematic diagram of the completion of conveyance of the preceding sheet in the sheet conveyance mechanism 100 according to the embodiment of the present invention. When the trailing end of the preceding sheet is separated from the conveying roller 40, the conveying roller 40 stops rotating, and the conveying roller 40 starts rotating again until the next uppermost sheet reaches the conveying roller 40.

Fig. 12 shows a flowchart of the operation of the sheet carrying mechanism 100 according to the embodiment of the present invention.

The method of operating the sheet carrying mechanism 100 includes the steps of:

s11, start;

s13, the front end of the paper is temporarily stopped when being conveyed to the tray opening of the paper feeding box by the conveying belt;

s15, the paper is conveyed continuously by the conveying roller, and the conveying roller and the conveying belt are conveyed simultaneously to reduce the load of the conveying roller and the friction between the conveying belt and the paper;

s17, after the paper is conveyed to a preset position, the air volume is adjusted; for example, the air volume may be adjusted when the paper sheet is conveyed by the conveying roller, or the air volume may be adjusted after the paper sheet is conveyed by the conveying roller for a certain distance. In practice, the position of the paper can be detected by a sensor near the conveying roller, and the air volume of the fan is adjusted when the paper reaches a predetermined position.

S19, adjusting the air volume of the front end fan to adjust the separation degree of the current paper and the paper below; adjusting the air quantity of the suction fan to adjust the adsorption state between the current paper and the conveying belt;

s21, adjusting the paper to an ideal state by adjusting the air volume, so that the paper is separated from the conveying belt;

s23, stopping the conveying belt and continuously conveying the paper by the conveying roller;

at S25, after the sheet leaves the conveying roller, the outlet of the suction fan is closed to prepare for the start of conveyance of the next sheet.

Fig. 13 shows a schematic diagram of an image forming apparatus 200 according to an embodiment of the present invention. The image forming apparatus 200 may be a multifunction peripheral including a plurality of sheet conveying mechanisms 100, an image reading unit 210, an operation display unit 220, an image forming mechanism 230, a conveying unit 240, and the like. The conveyance unit 240 conveys a sheet from the sheet conveyance mechanism 100 to the image forming mechanism 230, and forms an image on the document read by the image reading unit 210 on the sheet.

According to the above-described embodiment of the present invention, when the leading end of the sheet in the sheet conveying direction reaches the predetermined position after the sheet is conveyed by the conveying roller, the air volume of the leading end fan and/or the suction fan is reduced so that the sheet is separated from the conveying belt and does not contact other sheets, and friction between the sheet and the conveying belt and other sheets is avoided.

The air quantity is adjusted according to the suction pressure of the paper and the conveying belt, feedback is implemented in real time, the conveying effect is improved while the productivity is guaranteed, the motor load is reduced, and the service life of the conveying belt is prolonged.

While the technical content and the technical features of the invention have been disclosed, it is understood that various changes and modifications of the disclosed concept can be made by those skilled in the art within the spirit of the invention, and the invention is not limited thereto. The above description of embodiments is intended to be illustrative, and not restrictive, and the scope of the invention is defined by the appended claims.