阅读说明：本技术 光轴模块及其控制方法 (Optical axis module and control method thereof ) 是由 林国恩 林致远 周士闳 蔡欣翰 谢逸婷 于 2020-06-10 设计创作，主要内容包括：一种光轴模块,包括一光产生电路、一光接收电路与一控制单元。光产生电路包括一光产生单元与一控制端,并依据来自控制端的控制信号以产生光线。光接收电路包括一光接收单元与一信号读取端,并用以接收光线据以在信号读取端产生一检测信号。控制单元是电性连接控制端与信号读取端,用以产生控制信号并接收检测信号。控制单元并可选择性地将信号读取端配置为输出模式或是输入模式。在控制单元将信号读取端配置为输入模式读取检测信号前,控制单元先将信号读取端配置为输出模式以拉高光接收单元的电位。本公开并提供此光轴模块的一控制方法。(An optical axis module includes a light generating circuit, a light receiving circuit and a control unit. The light generating circuit comprises a light generating unit and a control end, and generates light according to a control signal from the control end. The light receiving circuit comprises a light receiving unit and a signal reading end and is used for receiving light so as to generate a detection signal at the signal reading end. The control unit is electrically connected with the control end and the signal reading end and used for generating a control signal and receiving a detection signal. The control unit can selectively configure the signal reading end into an output mode or an input mode. Before the control unit configures the signal reading end as an input mode reading detection signal, the control unit configures the signal reading end as an output mode to pull up the electric potential of the light receiving unit. The present disclosure also provides a control method of the optical axis module.)

1. An optical axis module for an input device, the optical axis module comprising:

the light generating circuit comprises a light generating unit and a control end, wherein the light generating unit generates light rays according to a control signal from the control end; and

the optical receiving circuit comprises an optical receiving unit and a signal reading end, wherein the optical receiving unit is used for receiving the light from the optical generating unit so as to generate a detection signal at the signal reading end;

the control unit is electrically connected with the control end and the signal reading end and used for generating the control signal at the control end and receiving the detection signal by the signal reading end, and the control unit can selectively configure the signal reading end into an output mode or an input mode;

wherein before the control unit configures the signal reading terminal in the input mode to read the detection signal, the control unit configures the signal reading terminal in the output mode to pull up a potential of the light receiving unit.

2. The optical axis module of claim 1, wherein the output mode is a push-pull mode.

3. The optical axis module of claim 1, wherein the output mode is an open drain mode.

4. The optical axis module as claimed in claim 1, wherein the control unit activates the light generating unit to generate light by the control signal after the signal reading end is configured in the input mode.

5. The optical axis module of claim 1, wherein the light generating unit is an infrared light emitting diode.

6. The optical axis module of claim 1, wherein the light receiving unit is a phototransistor.

7. The optical axis module as claimed in claim 1, wherein the light generating circuit further comprises a switching element, the switching element comprises a first terminal, a second terminal and a third terminal, the first terminal is electrically connected to a power supply terminal, the second terminal is electrically connected to the control terminal, the third terminal is electrically connected to the light generating unit, and the switching element is controlled by the control signal to selectively transmit the power of the power supply terminal to the light generating unit.

8. The optical axis module of claim 7, wherein the light generating circuit further comprises a first resistor, and two ends of the first resistor are electrically connected to the third end and the high voltage end of the light generating unit, respectively.

9. The optical axis module as claimed in claim 1, wherein the light receiving circuit further comprises a second resistor, two ends of the second resistor are electrically connected to the light receiving unit and the power supply terminal, respectively, and the signal reading terminal is located on a circuit between the second resistor and the light receiving unit.

10. A control method of an optical axis module is suitable for the optical axis module, the optical axis module comprises a light generating circuit and a light receiving circuit, wherein the light generating circuit comprises a light generating unit and a control end and generates light according to a control signal from the control end, the light receiving circuit comprises a light receiving unit and a signal reading end and is used for receiving the light from the light generating unit so as to generate a detection signal at the signal reading end, and the control method is characterized by comprising the following steps:

configuring the signal reading terminal to an output mode to raise a potential of the light receiving unit;

configuring the signal reading terminal to be in an input mode ready to read the detection signal;

starting the light generating unit by using the control signal to generate light;

after the light receiving unit reaches a stable state, reading the detection signal through the signal reading end to judge the key state; and

turning off the light generating unit.

Technical Field

The present disclosure relates to input devices, and more particularly, to an optical axis module for an input device and a control method thereof.

Background

Optical switch is a micro-switch technology which is born on a traditional mechanical keyboard, a metal elastic sheet in a traditional mechanical switch structure is replaced by a light-emitting diode and an infrared optical sensing element, and an open circuit state and a closed circuit state are formed by utilizing a light sensing principle, so that a key signal is triggered. The optical axis keyboard has the advantages of strong anti-interference capability, stable work, long service life and the like.

Fig. 1A and 1B are graphs of the operating wave form of a conventional optical axis. Fig. 1A corresponds to a case where the key is not pressed, and fig. 1B corresponds to a case where the key is pressed. The upper waveform in the figure is the voltage level corresponding to the high voltage side of the led, and the lower waveform is the voltage level corresponding to the high voltage side of the ir photo sensing element. First, at time T1, the infrared sensor is waiting to return to the steady state, and at time T2, the led is turned on to emit light. After the infrared sensing element reaches the steady state, at the time point T3, the signal of the infrared sensing element is read first to determine the state of the key, and then the light emitting diode is turned off to complete the key reading process.

As shown in the figure, after the light emitting diode is turned off, the optical axis keyboard needs to wait for the infrared optical sensing element to reach a steady state before turning on the light emitting diode again. After the light emitting diode is turned on, the infrared optical sensing element needs to wait for the key action to be detected after reaching the steady state, and the light emitting diode is turned on for a long time and consumes more power. Therefore, the conventional optical axis keyboard has the problems of low detection speed and power consumption.

Disclosure of Invention

The present disclosure provides an optical axis module for an input device. The optical axis module comprises a light generating circuit, a light receiving circuit and a control unit. The light generating circuit comprises a light generating unit and a control end. The light generating unit generates light according to a control signal from the control end. The light receiving circuit comprises a light receiving unit and a signal reading end. The light receiving unit is used for receiving the light from the light generating unit so as to generate a detection signal at the signal reading end. The control unit is electrically connected with the control end and the signal reading end and used for generating a control signal at the control end and receiving a detection signal by the signal reading end. The control unit can selectively configure the signal reading end to be in an output mode or an input mode. Before the control unit configures the signal reading end into an input mode to read the detection signal, the control unit configures the signal reading end into an output mode to pull up the potential of the light receiving unit.

The present disclosure also provides a control method of an optical axis module, which is suitable for an optical axis module. The optical axis module comprises a light generating circuit and a light receiving circuit, wherein the light generating circuit comprises a light generating unit and a control end and generates light according to a control signal from the control end, and the light receiving circuit comprises a light receiving unit and a signal reading end and is used for receiving the light from the light generating unit so as to generate a detection signal at the signal reading end. The control method comprises the following steps: configuring the signal reading end into an output mode to raise the potential of the light receiving unit; configuring a signal reading terminal to an input mode in preparation for reading the detection signal; starting the light generating unit by using the control signal to generate light; after the light receiving unit reaches a stable state, reading a detection signal through a signal reading end to judge the state of a key; and turning off the light generating unit.

The optical axis module and the control method thereof can effectively shorten the preparation time of the light receiving unit, improve the overall detection speed of the input device, further shorten the starting time of the light generating unit and reduce the energy consumption of the input device.

Drawings

FIGS. 1A and 1B are graphs of the operating wave form of a conventional optical axis;

FIG. 2 is a block diagram of an embodiment of an optical axis module according to the present disclosure;

fig. 3A and 3B are graphs of operational waveforms of the optical axis module of fig. 2.

Detailed Description

Specific embodiments of the present disclosure will be described in more detail below with reference to the schematic drawings. Advantages and features of the present disclosure will become apparent from the following description and claims. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present disclosure.

Fig. 2 is a block diagram of an optical axis module according to an embodiment of the disclosure. The optical axis module 10 can be applied to input devices such as a keyboard, a mouse, etc.

As shown in the figure, the optical axis module 10 includes a light generating circuit 12, a light receiving circuit 14 and a control unit 16.

The light generating circuit 12 includes a light generating unit 122 and a control terminal SW. The light generating unit 122 generates light according to a control signal S1 from the control terminal SW. In one embodiment, the light generating unit 122 may be an Infrared light-emitting diode (Infrared-emitting diode). In one embodiment, the light generating unit 122 can be a visible light emitting diode.

In one embodiment, as shown in the figure, the light generating circuit 12 further includes a switching element Q1. The switching element Q1 includes a first terminal P1, a second terminal P2 and a third terminal P3. The first terminal P1 is electrically connected to a power supply terminal VCC, the second terminal P2 is electrically connected to the control terminal SW, and the third terminal P3 is electrically connected to a high voltage terminal HV1 of the light generating unit 122. A low voltage terminal LV1 of the light generating unit 122 is grounded.

The switching element Q1 is controlled by the control signal S1 to selectively transmit the power from the power supply terminal VCC to the light generating unit 122, so that the light generating unit 122 emits light. In one embodiment, the light generating circuit 12 further includes a first resistor R1. Two ends of the first resistor R1 are electrically connected to the third terminal P3 of the switch device Q1 and the high voltage terminal HV1 of the light generating unit 122, respectively, for limiting the current flowing through the light generating unit 122. In one embodiment, the value of the first resistor R1 is less than or equal to 100 ohms so as to improve the light emitting brightness and the start-up speed of the light generating unit 122.

The light receiving circuit 14 includes a light receiving unit 142 and a signal reading terminal DE. The light receiving unit 142 is used for receiving the light from the light generating unit 122 to generate a detection signal S2 at the signal reading end DE. In one embodiment, the light receiving unit 142 may be a photo transistor (phototransistor). In one embodiment, the light receiving unit 142 can be an infrared sensor.

In one embodiment, as shown in the figure, the light receiving circuit 14 further includes a second resistor R2. Two ends of the second resistor R2 are electrically connected to a high voltage terminal HV2 and a power supply terminal VCC of the light receiving unit 142, respectively, to limit the current flowing through the light receiving unit 142. In one embodiment, the value of the second resistor R2 is less than or equal to 4.7K ohms to shorten the time for the light receiving unit 142 to reach the steady state. A low voltage terminal LV2 of the light receiving unit 142 is grounded. The signal reading terminal DE is located on the circuit between the second resistor R2 and the light receiving unit 142. That is, the potential of the signal reading terminal DE is a potential corresponding to the high voltage terminal HV2 of the light receiving unit 142.

The control unit 16 is electrically connected to the control terminal SW and the signal reading terminal DE, and is configured to generate a control signal S1 at the control terminal SW and receive the detection signal S2 from the signal reading terminal DE. The control unit 16 can selectively configure the signal reading terminal DE to be in an output mode or an input mode. Before the control unit 16 configures the signal reading terminal DE to be in the input mode to read the detection signal S2, the control unit 16 configures the signal reading terminal DE to be in the output mode to pull up the potential of the high voltage terminal HV2 of the light receiving unit 142, i.e., to pull up the potential of the signal reading terminal DE. In one embodiment, the control unit 16 may be a Micro Control Unit (MCU) having a general purpose input/output (GPIO) pin, and the operation mode of the GPIO pin can be controlled to be adjusted to an input mode or an output mode. In one embodiment, the output mode may be a push-pull (push-pull) mode. In one embodiment, the output mode may be an open-drain (open-drain) mode. The input mode is a mode in which the control unit 16 reads an external signal (e.g., the detection signal S2).

Fig. 3A and 3B are diagrams illustrating the operation wave pattern of the optical axis module 10 of fig. 2. Fig. 3A corresponds to a case where the key is not pressed, and fig. 3B corresponds to a case where the key is pressed. The upper waveform in the figure is the voltage level corresponding to the high voltage terminal HV1 of the light generating unit 122; the lower waveform corresponds to the voltage level at the high voltage terminal HV2 of the light receiving unit 142, i.e., the voltage level at the signal reading terminal DE. As shown in the figure, the control method of the optical axis module 10 is as follows:

first, at time t1, the control unit 16 configures the signal reading terminal DE to be in an output mode to pull up the potential of the high voltage terminal HV2 of the light receiving unit 142, shortening the time for the light receiving unit 142 to reach a steady state.

Subsequently, at time t2, the control unit 16 configures the signal read terminal DE in the input mode, preparing to read the detection signal S2. The magnitude of the time interval between the time t2 and the time t1 is influenced by the potential boosting capability of the control unit 16 for the signal reading terminal DE. In an embodiment, the control unit 16 may configure the signal reading terminal DE in a push-pull mode at an interval between the time point t2 and the time point t 1. In another embodiment, as shown in the figure, the control unit 16 sets the signal reading terminal DE to be in the input mode after the potential of the signal reading terminal DE is raised to be close to the steady-state potential, so as to ensure that the signal reading terminal DE can read the detection signal S2 smoothly.

Next, at time t3, the control unit 16 activates the light generating unit 122 to generate light via the control signal S1. After the light generating unit 122 generates light, the control unit 16 waits for the light receiving unit 142 to reach a steady state (real time t4), then reads the detection signal S2 to determine whether the user presses the key, and turns off the light generating unit 122 after reading is completed (real time t5) to reduce power consumption. In one embodiment, the control unit 16 can determine whether the light receiving unit 142 reaches the steady state according to the potential variation of the signal reading end DE, or read the detection signal S2 after waiting a predetermined time to ensure that the light receiving unit 142 reaches the steady state according to the characteristics of the light receiving unit 142.

In the foregoing embodiment, the step of the control unit 16 configuring the signal reading end DE to be in the input mode and the step of the control unit 16 activating the light generating unit 122 to generate the light through the control signal S1 are performed sequentially. But is not limited thereto. In an embodiment, the step of the control unit 16 configuring the signal reading end DE to be in the input mode and the step of the control unit 16 activating the light generating unit 122 to generate the light through the control signal S1 may also be performed simultaneously to increase the detection speed.

In summary, the optical axis module 10 and the control method thereof provided by the present disclosure can effectively shorten the preparation time of the light receiving unit 142, increase the overall detection speed of the input device, and further shorten the turn-on time of the light generating unit 122, and reduce the energy consumption of the input device.

Although the present invention has been described with reference to the above embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention.