CN110095184A - Light sensing circuit - Google Patents

Abstract

The present invention discloses a kind of light sensing circuit, including compensating unit, photosensitive unit and switching transistor.Photosensitive unit includes two light sensing transistors and capacitor being mutually coupled, and compensating unit includes multiple groups compensation transistor group, and light sensing transistor coupling compensation transistor group, switching transistor and capacitor couple.For the present invention by way of improving two light sensing transistor layouts and each light sensing transistor concatenates multiple groups light compensation transistor group, the accuracy for increasing optical path judgement expands the detection range of light sensing circuit simultaneously.The present invention increases the accuracy of optical path judgement by way of changing original light sensing transistor layout, expands the detection range of light sensing circuit, does not increase the density of light sensing transistor, will not reduce the aperture opening ratio of display panel.

Description

light sensing circuit

technical field

The present invention relates to a light sensing circuit, in particular to a light sensing circuit which can avoid the influence of ambient light.

Background technique

With the advancement of science and technology, it has become an inevitable trend for many electronic products that support different inputs to be used in daily life. These electronic products often use the input panel as a communication interface between the user and the electronic product, allowing the user to directly control the operation of the electronic product through the input panel without the need for a keyboard or a mouse. Generally speaking, the input mode of the input panel is roughly divided into a light sensing input mode and a touch input mode. However, in the touch input mode, since the panel needs to perform touch input, the surface of the panel may be damaged due to frequent touches, resulting in a reduced life span. Therefore, the panel in the light sensing input mode has a longer life than the panel in the touch input mode.

In the panel supporting the light sensing input mode, there are multiple light sensing units inside the panel, and the circuit of each light sensing unit has multiple transistors. When the negative bias voltage of each transistor is fixed, the stronger the intensity of incident light, the greater the photocurrent generated by the transistor. Using transistors to generate photocurrent, the light sensing unit can identify whether there is a light input signal. Such panels that support the light sensing input mode are also often sensed for specific light sources. For example, the input panel is used to sense the red light source emitted by the red light pen and so on. When used to sense a specific light source, the transistor in the light sensing unit will cover the corresponding filter, and the effect of the filter can be regarded as a band-pass filter, and its function is Extracts photons in specific frequency bands in the spectrum of light and filters out photons in other frequency bands. For example, the transistor is covered with a red filter, and the transistor can only generate photocurrent for red light, so the light sensing unit can only respond to the red light source emitted by the red light pen.

However, under white ambient light, since the spectrum of ambient light includes all color bands, in the above example, if the ambient light is too strong, even if the red light source emitted by the red light pen is not used in the light sensing unit, when If the red light component of ambient light received by the transistor covered with the red filter in the light sensing unit is too large, the light sensing unit will judge that the red light source emitted by the red light pen has been received, resulting in an incorrect input judgment. In other words, when the light sensing unit receives ambient light, the signal (voltage) used in the light sensing unit to determine whether there is a specific light input changes with the intensity of the ambient light. This change will be accompanied by a severe shadow effect (Shadow Effect), and the overall judgment mechanism for specific light will reduce its Signal-to-Noise Ratio (SNR), so it will increase the probability of misjudgment. Moreover, the detection range of the photosensitive transistor in the photosensitive circuit of the prior art is relatively small.

SUMMARY OF THE INVENTION

In view of the problems in the prior art, the present invention provides a light sensing circuit to solve the problems of the interference of ambient light on light sensing and the small detection range of the light sensing circuit.

The technical problem to be solved by the present invention is to provide a light sensing circuit, which comprises:

Compensation unit, including:

A first compensation transistor group, the first compensation transistor group includes a first transistor, a second transistor and a third transistor, a control end of the first transistor, a first end of the first transistor, and a first end of the second transistor and the first end of the third transistor is electrically coupled, the second end of the first transistor is used for receiving the first driving signal, the control end of the second transistor, the second end of the second transistor, the third end The control terminal of the transistor and the second terminal of the third transistor are coupled to a low voltage terminal; and

a second compensation transistor group, the circuit structure of the second transistor group is the same as that of the first transistor group;

Photosensitive unit, including:

a first photosensitive transistor, the first end of the first photosensitive transistor is coupled to the first end of the first transistor of the first compensation transistor group;

a second photosensitive transistor, the first end of the second photosensitive transistor is coupled to the first end of the first transistor of the second compensation transistor group; and

a capacitor, the first end of the capacitor is coupled to the second end of the first photosensitive transistor, the control end of the first photosensitive transistor, the second end of the second photosensitive transistor and the control end of the second photosensitive transistor, the the second end of the capacitor is coupled to a low potential end; and

a switch transistor, the first end of the switch transistor is coupled to the first end of the capacitor, the second end of the switch transistor is coupled to the sensing line, and the control end of the switch transistor is used for receiving the second driving signal;

Wherein, the first transistor, the second transistor and the third transistor of the first compensation transistor group correspond to three sub-pixels of a pixel unit, and the first transistor, the second transistor and the The third transistor corresponds to three sub-pixels of one pixel unit.

As an optional technical solution, the first driving signal is the source driving signal output by the nth data line, the second driving signal is the gate driving signal output by the nth stage shift register, and n is a positive integer.

As an optional technical solution, the first photosensitive transistor and the first transistor of the first compensation transistor group cover two filters of the same color, and the second photosensitive transistor and the first transistor of the second compensation transistor group A transistor covers two filters of the same color, and the color of the filters of the same color is any one of red, blue and green.

As an optional technical solution, the second transistor and the third transistor respectively cover two different-color filters, and the colors of the two different-color filters are different from the same-color filters, and are Two colors of red, blue and green.

The present invention also provides another light-sensing circuit, the light-sensing circuit includes a plurality of light-sensing units, wherein each of the light-sensing units includes:

Compensation unit, including:

A first compensation transistor group, the first compensation transistor group includes a first transistor, a second transistor and a third transistor, the first end of the first transistor is coupled to the first end of the second transistor, the second transistor The control terminal, the first terminal of the third transistor and the control terminal of the third transistor, the second terminal of the first transistor and the control terminal are used to receive the first driving signal, the second terminal of the second transistor and the The second terminal of the three transistors is coupled to a high voltage terminal; and

a second compensation transistor group, the circuit structure of the second transistor group is the same as that of the first transistor group;

Photosensitive unit, including:

a first photosensitive transistor, the control end of the first photosensitive transistor and the first end of the first photosensitive transistor are coupled to the second end of the first transistor of the first compensation transistor group;

A second photosensitive transistor, the control end of the second photosensitive transistor and the first end of the second photosensitive transistor are coupled to the second end of the first transistor of the second compensation transistor group, and the first photosensitive transistor is The second end is coupled to the first end of the second photosensitive transistor; and

a capacitor, a first end of the capacitor is coupled to a second end of the second photosensitive transistor, and a second end of the capacitor is coupled to a high potential end; and

a switch transistor, the first end of the switch transistor is coupled to the first end of the capacitor, the second end of the switch transistor is coupled to the sensing line, and the control end of the switch transistor is used for receiving the second driving signal;

Wherein, the first transistor, the second transistor and the third transistor of the first compensation transistor group correspond to three sub-pixels of a pixel unit, and the first transistor, the second transistor and the The third transistor corresponds to three sub-pixels of one pixel unit.

As an optional technical solution, the first driving signal is the source driving signal output by the nth data line, the second driving signal is the gate driving signal output by the nth stage shift register, and n is a positive integer.

As an optional technical solution, the first photosensitive transistor and the first transistor of the first compensation transistor group cover two filters of the same color, and the second photosensitive transistor and the first transistor of the second compensation transistor group A transistor covers two filters of the same color, and the color of the filters of the same color is any one of red, blue and green.

As an optional technical solution, the second transistor and the third transistor respectively cover two different-color filters, and the colors of the two different-color filters are different from the same-color filters, and are Two colors of red, blue and green.

As an optional technical solution, the compensation unit further includes:

a third compensation transistor group, the third transistor group has the same structure as the first transistor group; and

A fourth compensation transistor group, the fourth transistor group has the same structure as the first transistor group.

The first end of the first photosensitive transistor is coupled to the first end of the first transistor of the third compensation transistor group; the first end of the second photosensitive transistor is coupled to the fourth compensation transistor group the first end of the first transistor.

As an optional technical solution, the first photosensitive transistor, the first transistor of the first compensation transistor group, and the first transistor of the third compensation transistor group cover three filters of the same color, and the The color of the filter is any one of red, blue and green; the second photosensitive transistor, the first transistor of the second compensation transistor group, and the first transistor of the fourth compensation transistor group cover three A filter of the same color, and the color of the filter of the same color is any one of red, blue and green.

Compared with the prior art, the present invention provides a light sensing circuit, which can make correct input judgment when a light source of a specific color is illuminated. When the ambient light source is illuminated, the light sensing circuit will not have misjudgment. The invention also improves the accuracy of optical path determination and expands the detection range of the optical sensing circuit by improving the layout of the two photosensitive transistors and using the photosensitive transistors in series with the optical compensation transistors. The present invention increases the accuracy of optical path judgment and expands the detection range of the light sensing circuit by changing the original layout of the photosensitive transistor, without increasing the density of the photosensitive transistor and reducing the aperture ratio of the display panel.

The present invention is described in detail below with reference to the accompanying drawings and specific embodiments, but is not intended to limit the present invention.

Description of drawings

FIG. 1 is a schematic circuit diagram of a light sensing circuit according to a first embodiment of the present invention.

FIG. 2 is a schematic circuit diagram of a light sensing circuit according to a second embodiment of the present invention.

FIG. 3 is a schematic circuit diagram of a light sensing circuit according to a third embodiment of the present invention.

FIG. 4 is a schematic circuit diagram of a light sensing circuit according to a fourth embodiment of the present invention.

Detailed ways

Below in conjunction with accompanying drawing, structure principle and working principle of the present invention are described in detail:

Please refer to FIG. 1 , which is a schematic circuit diagram of a light sensing circuit according to a first embodiment of the present invention. The light sensing circuit 100 includes a compensation unit 110 , a photosensitive unit 120 and a switch transistor Tsw. The compensation unit 110 includes a first compensation transistor group 111 and a second compensation transistor group 112 . The first compensation transistor group 110 includes a first transistor T1, a second transistor T2 and a third transistor T3. In the present invention, the control end of the first transistor T1, the first end of the first transistor T1, and the first end of the second transistor T2 The terminal and the first terminal of the third transistor are electrically coupled. The second end of the first transistor T1 is used for receiving the first driving signal S(n), the control end of the second transistor T2, the first end of the second transistor T2, the control end of the third transistor T3 and the control end of the third transistor T3. The first terminal is coupled to a low voltage terminal Vsl. The circuit structure of the second transistor group 112 is the same as the circuit structure and circuit connection of the first transistor group 111 , that is, the first compensation transistor group 110 and the second compensation transistor group 110 are arranged in parallel in the circuit structure.

Continuing to refer to FIG. 1 , the photosensitive unit 120 includes a first photosensitive transistor Tp1 , a second photosensitive transistor Tp2 and a capacitor C. The first end of the first photosensitive transistor Tp1 is coupled to the first end of the first transistor T1 of the first compensation transistor group 111 . terminal; the first terminal of the second photosensitive transistor Tp2 is coupled to the first terminal of the first transistor T1 of the second compensation transistor group 112 . Through this connection, the first light-sensing transistor Tp1 is connected in series with the first transistor T1 of the first compensation transistor group 111 , and the second light-sensing transistor Tp2 is connected in series with the first transistor T1 of the second compensation transistor group 112 . The second end of the first photosensitive transistor Tp1, the control end of the first photosensitive transistor Tp1, the second end of the second photosensitive transistor Tp2, and the control end of the second photosensitive transistor Tp2 are coupled to the first end of the capacitor C. The second terminal is coupled to a low voltage terminal Vsl. The first end of the switching transistor Tsw is coupled to the first end of the capacitor C, the second end of the switching transistor Tsw is coupled to the sensing line L, and the control end of the switching transistor is used for receiving the second driving signal G(n), when When the second driving signal G(n) is at a high level, the switching transistor Tsw is turned on and the detection result of the light sensing circuit 100 is output through the sensing line L.

In the light sensing circuit 100 of this embodiment, the first driving signal S(n) is the source driving signal output by the readout line of the n-th level light sensing circuit 100, and the second driving signal G(n) is the n-th level The gate driving signal output by the shift register is used to control different working states of the light sensing circuit 100 .

In this embodiment, the first transistor T1 , the second transistor T2 and the third transistor T3 of the first compensation transistor group 111 cover three sub-pixels of one pixel unit, and the first transistor T1 , the second transistor T1 of the second compensation transistor group 112 , the second transistor T3 The transistor T2 and the third transistor T3 cover three sub-pixels of an adjacent pixel unit.

In this embodiment, the first transistor T1 of the first compensation circuit group 111 is covered with a first filter F1, the second transistor T2 is covered with a second filter F2, and the third transistor T3 is covered with a third filter F2. The filter F3, the photosensitive transistor Tp1 is covered with the fourth filter F4. The first filter F1 and the fourth filter F4 are two filters of the same color, and the colors of the first filter F1 and the second filter F2 are any one of red, blue and green. . The second filter F2 and the third filter F3 are two different-color filters, and the colors of the second filter F2 and the third filter F3 are the same as those of the first filter F1 and the fourth filter. The colors of the sheets F4 are different, and the colors of the second filter F2 and the third filter F3 are two colors of red, blue and green. The relationship between the second compensation transistor group 112 and the second photosensitive transistor Tp2 and the optical filter is the same as the relationship between the first compensation transistor group 112 and the second photosensitive transistor Tp2 and the optical filter, which is not repeated here. The operation of the light sensing circuit 100 of this embodiment will be described in detail below.

In this embodiment of the present invention, an example is used to describe the specific implementation of the light sensing circuit 100 . Assuming that the red light pen is used in this embodiment, the color of the first filter F1 and the fourth filter F4 in the light sensing circuit 100 is red, the color of the second filter F2 is blue, and the color of the third filter F2 is blue. The color of slice F3 is green.

In the first embodiment of the present invention, the second end of the capacitor C is connected to the low voltage end, so the first end of the capacitor (ie point A in FIG. 1 ) is the low potential Vsl in the circuit operating state. When the light sensing circuit 100 does not receive the red light source emitted by the red light pen but receives ambient light with strong light, taking the first photosensitive transistor Tp1 and the first compensation transistor group 111 as an example, the first photosensitive transistor Tp1 and the series The connected first transistor T1 receives the red light filtered by the filter and generates a photocurrent I1. The direction of the photocurrent I1 is from the first photosensitive transistor Tp1 to the first end of the capacitor (ie point A in Figure 1). The second transistor T2 receives the blue light filtered by the filter to generate a photocurrent I2, and the third transistor T3 receives the green light filtered by the filter to generate a photocurrent I3. The directions of the photocurrent I2 and the photocurrent I3 are from the second transistor T2 and the third transistor T3. The transistor T3 flows to the second end of the capacitor C, and the photocurrent I2 and the photocurrent I3 form a compensation effect at the capacitor C, so that the point A of the capacitor C is not affected by the charging of I1, so that the potential of the point A remains low and does not change. The second photosensitive transistor Tp2 and the second compensation transistor group 112 also generate the photocurrent I2 and the photocurrent I3 for compensating the photocurrent I1, so as to prevent misjudgment when the light sensing circuit 100 is irradiated by strong ambient light. In practical applications, the areas of two adjacent pixel units covered by the first compensation transistor group 111 and the second compensation transistor group 112 can both achieve the compensation effect for light sensing.

In the embodiment of the present invention, when the red light source is emitted from the red light pen, the first transistor T1 connected in series with the first photosensitive transistor Tp1 receives the red light filtered by the filter to generate a photocurrent I1, the second transistor T2 and the third transistor T3 will still receive ambient light to generate photocurrent I2 and photocurrent I3. At this time, photocurrent I1 is much larger than photocurrent I2 and photocurrent I3. Therefore, capacitor C will be charged by photocurrent I1. The two transistors T1 receive the red light filtered by the filter and generate a photocurrent I1 that also charges the capacitor C, so that the potential at point A increases. When the switching transistor Tsw is turned on, the potential change at point A is detected, thereby outputting a photo-sensing result.

The first embodiment of the light-sensing circuit of the present invention is a charging mode circuit, that is, whether the light-sensing circuit is charged to the capacitor C by the signal output by the sensing line L determines whether the light emitted by the light pen is sensed. In the light sensing circuit 100 of the present invention, through two coupled photosensitive transistors, the first photosensitive transistor Tp1 and the second photosensitive transistor Tp2, and the two parallel compensation transistor groups, the first compensation transistor group 111 and the second compensation transistor group 112, The range of light sensing is increased without increasing the density of light sensing transistors, so as to avoid reducing the aperture ratio of the display and avoid the influence of ambient light on the light sensing result.

Please continue to refer to FIG. 2 . FIG. 1 is a schematic circuit diagram of a light sensing circuit according to a first embodiment of the present invention. In the light sensing circuit 200 of the second embodiment of the present invention, the light sensing circuit 200 of the second embodiment is a discharge mode circuit. The optical sensing circuit 200 of the second embodiment uses the same components as the optical sensing circuit 100 of the first embodiment, and there are only differences in circuit connections. Therefore, some components of the optical sensing circuit 200 of the second embodiment The device numbers follow the numbers of the light sensing circuit 100 of the first embodiment.

Continuing to refer to FIG. 2 , in the second embodiment of the present invention, the light sensing circuit 200 includes a compensation unit 210 , a photosensitive unit 220 and a switch transistor Tsw. The compensation unit 210 includes a first compensation transistor group 211 and a second compensation transistor group 212 . The first compensation transistor group 210 includes a first transistor T1, a second transistor T2 and a third transistor T3. In the present invention, the first end of the first transistor T1, the control end of the second transistor T2, and the first end of the second transistor T2 The terminal, the control terminal of the third transistor T3 and the first terminal of the third transistor T3 are electrically coupled. The control terminal of the first transistor T1 and the second terminal of the first transistor T1 are used to receive the first driving signal S(n). The second terminal of the second transistor T2 and the second terminal of the third transistor T3 are coupled to one High voltage terminal Vsh. The circuit structure of the second transistor group 212 is the same as the circuit structure and circuit connection of the first transistor group 211 , that is, the first compensation transistor group 210 and the second compensation transistor group 210 are arranged in parallel in the circuit structure.

Continuing to refer to FIG. 2 , the photosensitive unit 220 includes a first photosensitive transistor Tp1 , a second photosensitive transistor Tp2 and a capacitor C. The control terminal of the first photosensitive transistor Tp1 and the first terminal of the first photosensitive transistor Tp1 are coupled to the first compensation transistor group The first end of the first transistor T1 of 211 ; the control end of the second photosensitive transistor Tp2 and the first end of the second photosensitive transistor Tp2 are coupled to the first end of the first transistor T1 of the second compensation transistor group 212 . Through this connection, the first light-sensing transistor Tp1 is connected in series with the first transistor T1 of the first compensation transistor group 211 , and the second light-sensing transistor Tp2 is connected in series with the first transistor T1 of the second compensation transistor group 212 . The second end of the first photosensitive transistor Tp1 is coupled to the first end of the second photosensitive transistor Tp2, the second end of the second photosensitive transistor Tp2 is coupled to the first end of the capacitor C, and the second end of the capacitor C is coupled to the A high voltage terminal Vsh. The first end of the switching transistor Tsw is coupled to the first end of the capacitor C, the second end of the switching transistor Tsw is coupled to the sensing line L, and the control end of the switching transistor is used for receiving the second driving signal G(n), when When the second driving signal G(n) is at a high level, the switching transistor Tsw is turned on and the detection result of the light sensing circuit 200 is output through the sensing line L.

In the light sensing circuit 200 of this embodiment, the first drive signal S(n) is the source drive signal output by the readout line of the nth level light sensing circuit 200, and the second drive signal G(n) is the nth level The gate driving signal output by the shift register is used to control different working states of the light sensing circuit 200 .

In this embodiment, the first transistor T1 , the second transistor T2 and the third transistor T3 of the first compensation transistor group 211 cover three sub-pixels of one pixel unit, and the first transistor T1 , the second transistor T1 and the second transistor of the second compensation transistor group 212 The transistor T2 and the third transistor T3 cover three sub-pixels of an adjacent pixel unit.

In this embodiment, the first transistor T1 of the first compensation circuit group 211 is covered with a first filter F1, the second transistor T2 is covered with a second filter F2, and the third transistor T3 is covered with a third filter F2. The filter F3, the photosensitive transistor Tp1 is covered with the fourth filter F4. The first filter F1 and the fourth filter F4 are two filters of the same color, and the colors of the first filter F1 and the second filter F2 are any one of red, blue and green . The second filter F2 and the third filter F3 are two different-color filters, and the colors of the second filter F2 and the third filter F3 are the same as those of the first filter F1 and the fourth filter. The colors of the sheets F4 are different, and the colors of the second filter F2 and the third filter F3 are two colors of red, blue and green. The relationship between the second compensation transistor group 212 and the second photosensitive transistor Tp2 and the optical filter is the same as the relationship between the first compensation transistor group 212 and the second photosensitive transistor Tp2 and the optical filter, which is not repeated here. The operation of the light sensing circuit 200 of this embodiment will be described in detail below.

In this embodiment of the present invention, an example is used to describe the specific implementation of the light sensing circuit 200 . Assuming that the red light pen is used in this embodiment, the color of the first filter F1 and the fourth filter F4 in the light sensing circuit 200 is red, the color of the second filter F2 is blue, and the color of the third filter F2 is blue. The color of slice F3 is green.

In the second embodiment of the present invention, the second end of the capacitor C is connected to the high voltage end, so the first end of the capacitor (ie, point A in FIG. 1 ) is a high potential Vsh in the working state of the circuit. When the light sensing circuit 200 does not receive the red light source emitted by the red light pen but receives ambient light with strong light, taking the first photosensitive transistor Tp1 and the first compensation transistor group 211 as an example, the first photosensitive transistor Tp1 and the series The connected first transistor T1 receives the red light filtered by the filter to generate a photocurrent I1, and the direction of the photocurrent I1 is from the first end of the capacitor C (ie point A in Figure 2) to the first photosensitive transistor Tp1, that is, from The capacitor C discharges to the first photosensitive transistor Tp1. The second transistor T2 receives the blue light filtered by the filter to generate a photocurrent I2, and the third transistor T3 receives the green light filtered by the filter to generate a photocurrent I3. The direction of the photocurrent I2 and the photocurrent I3 is the first The two terminals flow to the second transistor T2 and the third transistor T3, that is, the photocurrent I2 and the photocurrent I3 are discharged to the first photosensitive transistor Tp1, so the photocurrent I2 and the photocurrent I3 form a compensation effect on the first photosensitive transistor Tp1, which can prevent the capacitance C discharges to the first photosensitive transistor Tp1, so that the potential at point A of the capacitor C can be maintained at a high potential without changing. The second photosensitive transistor Tp2 and the second compensation transistor group 212 also generate a photocurrent I2 and a photocurrent I3 to prevent the capacitor C from discharging to the second photosensitive transistor Tp2. In this way, the effect of preventing misjudgment when ambient light with strong light irradiates the light sensing circuit 200 is achieved. In practical applications, the regions of two adjacent pixel units covered by the first compensation transistor group 111 and the second compensation transistor group 212 can achieve the compensation effect for light sensing and prevent detection errors caused by ambient light.

In the embodiment of the present invention, when the red light source is emitted from the red light pen, the first photosensitive transistor Tp1 and the first transistor T1 connected in series receive the red light filtered by the filter to generate a photocurrent I1, the second transistor T2 and the third transistor T2 Transistor T3 will still receive ambient light to generate photocurrent I2 and photocurrent I3. At this time, photocurrent I1 is much larger than photocurrent I2 and photocurrent I3. Therefore, capacitor C discharges to the first photosensitive transistor Tp1, and capacitor C also discharges to the second photosensitive transistor. Tp2 discharges, so the potential at point A decreases. When the switching transistor Tsw is turned on, the potential change at point A is detected, thereby outputting a photo-sensing result.

The second embodiment of the light sensing circuit of the present invention is a discharge mode circuit, that is, it is judged whether the light emitted by the light pen is sensed by judging whether the capacitor C discharges to the light sensing circuit through the signal output by the sensing line L. In the light sensing circuit 200 of the present invention, through two coupled photosensitive transistors, the first photosensitive transistor Tp1 and the second photosensitive transistor Tp2, and the two parallel compensation transistor groups, the first compensation transistor group 211 and the second compensation transistor group 212, The range of light sensing is increased without increasing the density of light sensing transistors, so as to avoid reducing the aperture ratio of the display and avoid the influence of ambient light on the light sensing result.

Please refer to FIG. 3 , which is a schematic circuit diagram of a light sensing circuit according to a third embodiment of the present invention. In the third embodiment of the present invention, the light sensing circuit 100 of the first embodiment further includes a third compensation transistor group 113 and a fourth compensation transistor group 114, the third compensation transistor group 113 and the fourth compensation transistor group 114 and the third compensation transistor group 113 and the fourth compensation transistor group 114. The circuit connections of a transistor group 111 are the same, and are not repeated here.

In this embodiment, the first end of the first photosensitive transistor Tp1 is coupled to the first end of the first transistor T1 of the third compensation transistor group 113 ; the first end of the second photosensitive transistor Tp2 is coupled to the fourth compensation transistor The first terminal of the first transistor T1 of the group 114 . That is, the first photosensitive transistor Tp1, the first transistor T1 of the first compensation transistor group 111 and the first transistor T1 of the third compensation transistor group 113 are connected in series in the circuit; The transistor T1 and the first transistor T1 of the fourth compensation transistor group 114 are connected in series in the circuit.

In this embodiment, the third compensation transistor group 113 covers three sub-pixels of one pixel unit, and the fourth compensation transistor group 114 covers three sub-pixels of an adjacent pixel unit. For the relationship between the transistors in the third compensation transistor group 113 and the fourth compensation transistor group 114 and corresponding color filters, reference may be made to the corresponding relationship in the first compensation transistor group 111 in the first embodiment. The filters covered by the first photosensitive transistor Tp1, the first transistor T1 of the first compensation transistor group 111 and the first transistor T1 of the third compensation transistor group 113 are three filters of the same color; the second photosensitive transistor The filters covered by Tp2 , the first transistor T1 of the second compensation transistor group 112 and the first transistor T1 of the fourth compensation transistor group 114 are three filters of the same color.

In this embodiment, the photocurrents generated by the third compensation transistor group 113 and the fourth compensation transistor group 114 in the light sensing circuit 100 play a compensation role in the detection of the circuit, and the light compensation unit 110 can increase the power of the light compensation unit 110 to the photosensitive circuit 100 The overall compensation effect makes the light sensing result better and more accurate. In this embodiment, the light sensing circuit 100 can also increase the number of capacitors C according to actual requirements, and a plurality of capacitors C are arranged in parallel in the circuit. In practical applications, the number of compensation transistor groups of the light compensation unit 210 can also be increased according to actual requirements, which is not limited to the embodiment, but the number of compensation transistor groups needs to be greater than or equal to the number of photosensitive transistors to make the compensation effect better.

Please refer to FIG. 4 , which is a schematic circuit diagram of a light sensing circuit according to a fourth embodiment of the present invention. In the fourth embodiment of the present invention, the light sensing circuit 200 of the second embodiment further includes a third compensation transistor group 213 and a fourth compensation transistor group 214, the third compensation transistor group 213 and the fourth compensation transistor group 214 and the third compensation transistor group 213 and the fourth compensation transistor group 214. The circuit connection of a transistor group 211 is the same, and will not be repeated here.

In this embodiment, the first end of the first photosensitive transistor Tp1 is coupled to the first end of the first transistor T1 of the third compensation transistor group 213 ; the first end of the second photosensitive transistor Tp2 is coupled to the fourth compensation transistor The first terminal of the first transistor T1 of the group 114 . That is, the first photosensitive transistor Tp1, the first transistor T1 of the first compensation transistor group 211, and the first transistor T1 of the third compensation transistor group 213 are connected in series in the circuit; The transistor T1 and the first transistor T1 of the fourth compensation transistor group 214 are connected in series in the circuit.

In this embodiment, the third compensation transistor group 213 covers three sub-pixels of one pixel unit, and the fourth compensation transistor group 214 covers three sub-pixels of an adjacent pixel unit. For the relationship between the transistors in the third compensation transistor group 213 and the fourth compensation transistor group 214 and corresponding color filters, refer to the corresponding relationship in the first compensation transistor group 211 in the second embodiment. The filters covered by the first photosensitive transistor Tp1, the first transistor T1 of the first compensation transistor group 211 and the first transistor T1 of the third compensation transistor group 113 are three filters of the same color; the second photosensitive transistor The filters covered by Tp2 , the first transistor T1 of the second compensation transistor group 212 and the first transistor T1 of the fourth compensation transistor group 214 are three filters of the same color.

In this embodiment, the photocurrents generated by the third compensation transistor group 213 and the fourth compensation transistor group 114 in the light sensing circuit 200 play a compensation role in the detection of the circuit. The overall compensation effect makes the light sensing result better and more accurate. In this embodiment, the light sensing circuit 200 may also increase the number of capacitors C according to actual requirements, and a plurality of capacitors C are arranged in parallel in the circuit. In practical applications, the number of compensation transistor groups of the light compensation unit 210 can also be increased according to actual requirements, which is not limited to the embodiment, but the number of compensation transistor groups needs to be greater than or equal to the number of photosensitive transistors to make the compensation effect better.

In the actual circuit fabrication process, the transistors and capacitors and other components in the above embodiments are connected by means of the original metal layer and the ITO (indium tin oxide) layer inside the array substrate, and the connection lines are formed at the same time when the pixel circuit is formed. No additional crafting process is added.

To sum up, the present invention provides a light sensing circuit, which can make a correct input judgment when a light source of a specific color is illuminated. When the ambient light source is illuminated, the light sensing circuit will not have misjudgment. The invention also improves the accuracy of optical path determination and expands the detection range of the optical sensing circuit by improving the layout of the two photosensitive transistors and using the photosensitive transistors in series with the optical compensation transistors. The present invention increases the accuracy of optical path judgment and expands the detection range of the light sensing circuit by changing the original layout of the photosensitive transistor, without increasing the density of the photosensitive transistor and reducing the aperture ratio of the display panel.

Of course, the present invention can also have other various embodiments, without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding changes and deformation should belong to the protection scope of the appended claims of the present invention.

Claims (10)

1. a kind of light sensing circuit, which is characterized in that the light sensing circuit includes:

Compensating unit, comprising:

First compensation transistor group, which includes the first transistor, second transistor and third crystal Pipe, control terminal, the first end of the first transistor, the first end of the second transistor and third of the first transistor are brilliant The first end electric property coupling of body pipe, the second end of the first transistor to receive the first driving signal, the second transistor The second end coupling of control terminal, the second end of the second transistor, the control terminal of the third transistor and the third transistor In a low-voltage end；And

Second compensation transistor group, the second transistor group are identical as the circuit structure of the first transistor group；

Photosensitive unit, comprising:

First light sensing transistor, the first end of first light sensing transistor are coupled to first crystalline substance of the first compensation transistor group The first end of body pipe；

Second light sensing transistor, the first end of second light sensing transistor are coupled to first crystalline substance of the second compensation transistor group The first end of body pipe；And

Capacitor, the first end of the capacitor are coupled to the control of the second end, first light sensing transistor of first light sensing transistor The control terminal at end, the second end of second light sensing transistor and second light sensing transistor, the second end of the capacitor are coupled to One cold end；And

Switching transistor, the first end of the switching transistor are coupled to the first end of the capacitor, and the second of the switching transistor End is coupled to sense wire, and the control terminal of the switching transistor is to receive the second driving signal；

Wherein, the first transistor, the second transistor and third transistor of the first compensation transistor group correspond to Three sub-pixels of one pixel unit, the second compensation the first transistor of transistor group, the second transistor and should Third transistor corresponds to three sub-pixels of a pixel unit.

2. light sensing circuit as described in claim 1, which is characterized in that first driving signal is the output of nth data line Source drive signal, second driving signal be n-th grade of shift register output gate drive signal, n is positive integer.

3. light sensing circuit as described in claim 1, which is characterized in that first light sensing transistor and the first compensation crystal The first transistor of pipe group covers two homochromy optical filters, and second light sensing transistor and the second compensation transistor The first transistor of group covers two homochromy optical filters, and the color of the homochromy optical filter is red, blue and green Any one color in color.

4. light sensing circuit as described in claim 1, which is characterized in that the second transistor and the third transistor are covered respectively Two heterochromatic optical filters are covered, the color of two heterochromatic optical filters is different from the homochromy optical filter, and is red, blue Dichromatism in color and green.

5. a kind of light sensing circuit, which is characterized in that the light sensing circuit includes multiple light sensing units, wherein each light sensation Surveying unit includes:

Compensating unit, comprising:

First compensation transistor group, which includes the first transistor, second transistor and third crystal Pipe, the first end of the first transistor are coupled to the first end of the second transistor, the control terminal of the second transistor, the third The control terminal of the first end of transistor and the third transistor, the second end and control terminal of the first transistor are to receive The second end of first driving signal, the second end of the second transistor and the third transistor is coupled to a high voltage end； And

Second compensation transistor group, the second transistor group are identical as the circuit structure of the first transistor group；

Photosensitive unit, comprising:

The first end of first light sensing transistor, the control terminal of first light sensing transistor and first light sensing transistor is coupled to this The second end of the first transistor of the first compensation transistor group；

The first end of second light sensing transistor, the control terminal of second light sensing transistor and second light sensing transistor is coupled to this The second end of the first transistor of the second compensation transistor group, and the second end of first light sensing transistor be coupled to this The first end of two light sensing transistors；And

Capacitor, the first end of the capacitor are coupled to the second end of second light sensing transistor, and the second end of the capacitor is coupled to one A hot end；And

Switching transistor, the first end of the switching transistor are coupled to the first end of the capacitor, the second end of the switching transistor It is coupled to sense wire, the control terminal of the switching transistor is to receive the second driving signal；

Wherein, the first transistor, the second transistor and third transistor of the first compensation transistor group correspond to Three sub-pixels of one pixel unit, the second compensation the first transistor of transistor group, the second transistor and should Third transistor corresponds to three sub-pixels of a pixel unit.

6. light sensing circuit as claimed in claim 5, which is characterized in that first driving signal is the output of nth data line Power driving signal, second driving signal be n-th grade of shift register output gate drive signal, n is positive integer.

7. light sensing circuit as claimed in claim 5, which is characterized in that first light sensing transistor and the first compensation crystal The first transistor of pipe group covers two homochromy optical filters, and second light sensing transistor and the second compensation transistor The first transistor of group covers two homochromy optical filters, and the color of the homochromy optical filter is red, blue and green Any one color in color.

8. light sensing circuit as claimed in claim 5, which is characterized in that the second transistor and the third transistor are covered respectively Two heterochromatic optical filters are covered, the color of two heterochromatic optical filters is different from the homochromy optical filter, and is red, blue Dichromatism in color and green.

9. the light sensing circuit as described in claim 1 or claim 5, which is characterized in that the compensating unit further include:

Third compensates transistor group, and the third transistor group is identical as the structure of the first transistor group；And

4th compensation transistor group, the 4th transistor group are identical as the structure of the first transistor group.

Wherein, the first end of first light sensing transistor be coupled to the first transistor of third compensation transistor group this One end；The first end of second light sensing transistor be coupled to the 4th compensation transistor group the first transistor this first End.

10. light sensing circuit as claimed in claim 9, which is characterized in that first light sensing transistor, the first compensation crystal The first transistor of pipe group, the first transistor of third compensation transistor group cover three homochromy optical filters, and The color for the optical filter that this is homochromy is any one color in red, blue and green；Second light sensing transistor, second benefit The first transistor of the first transistor, the 4th compensation transistor group for repaying transistor group covers three homochromy optical filterings Piece, and the color of the homochromy optical filter is any one color in red, blue and green.