Pixel circuit and display device

Abstract

The invention discloses a pixel circuit and a display device. The pixel circuit includes a light emitting element, a first light sensor, and a variable resistor. The first light sensor receives the first operation voltage and provides a first control voltage according to the intensity of the first to-be-sensed light. The variable resistor adjusts the provided resistance value according to the first control voltage so as to adjust the current value of the driving current flowing through the light-emitting element.

Description

Technical Field

[0001] The present invention relates to a pixel circuit, and in particular to a pixel circuit which can be dynamically adjusted according to the state of ambient light and a display device using the pixel circuit. Background Art

[0002] In the current technical field, LED display devices, such as direct-view LED display devices, can be applied to various fields, including indoors and outdoors. However, under such application conditions, the display device is easily affected by the ambient light around the indoor and outdoor environment, and the display quality of the displayed image is affected by the ambient light (light, reflection or sunlight). Summary of the invention

[0003] The present invention provides a pixel circuit and a display device, which can reduce the interference of display effect caused by different ambient light states and maintain the display quality.

[0004] The pixel circuit of the present invention comprises:

[0005] Light emitting element;

[0006] A first light sensor receives a first operating voltage and provides a first control voltage according to the intensity of a first light to be sensed; and

[0007] The variable resistor is coupled in series with the light emitting element between the second operating voltage and the reference voltage. The resistance value provided by the variable resistor is adjusted according to the first control voltage to adjust the current value of the driving current flowing through the light emitting element.

[0008] Preferably, when the intensity of the first light to be sensed is greater than a first threshold, the first light sensor is turned on and the first control voltage is increased to a first voltage value.

[0009] Further preferably, the variable resistor reduces the resistance value to a first resistance value according to the first control voltage, so as to increase the current value of the driving current flowing through the light-emitting element; wherein the voltage value of the first control voltage is the first voltage value.

[0010] Further preferably, when the intensity of the first light to be sensed is less than a second threshold, the first light sensor is turned off and the first control voltage is decreased to a second voltage value.

[0011] Further preferably, the variable resistor increases the resistance value to a second resistance value according to the first control voltage, so as to reduce the current value of the driving current flowing through the light-emitting element; wherein the voltage value of the first control voltage is the second voltage value.

[0012] Further preferably, the first light sensor comprises a first photosensitive diode, a cathode of the first photosensitive diode receives the first operating voltage, and an anode of the first photosensitive diode provides the first control voltage.

[0013] Further preferably, the variable resistor comprises:

[0014] a first transistor and a first resistor, wherein the first transistor and the first resistor are coupled in series between the light emitting element and the second operating voltage, or the first transistor and the first resistor are coupled in series between the light emitting element and the reference voltage, and a control terminal of the first transistor receives the first control voltage; and

[0015] The second resistor is coupled in parallel with a circuit string formed by the first transistor and the first resistor.

[0016] More preferably, it also includes:

[0017] The second light sensor receives the first operating voltage and provides a second control voltage according to the intensity of the first light to be sensed, wherein the variable resistor further adjusts the resistance value provided by the variable resistor according to the second control voltage.

[0018] Further preferably, the second light sensor comprises a second photosensitive diode, a cathode of the second photosensitive diode receives the first operating voltage, and an anode of the second photosensitive diode provides the second control voltage.

[0019] Further preferably, the variable resistor comprises:

[0020] A second transistor and a third resistor, the second transistor and the third resistor are coupled in series between the light emitting element and the second operating voltage, or the second transistor and the third resistor are coupled in series between the light emitting element and the reference voltage, and the control end of the second transistor receives the second control voltage.

[0021] More preferably, it also includes:

[0022] The fourth resistor is coupled between the cathode of the first photodiode and the reference voltage.

[0023] More preferably, it also includes:

[0024] The fifth resistor is coupled between the cathode of the second photosensitive diode and the reference voltage.

[0025] Further preferably, when the intensity of the first light to be sensed is greater than a third threshold, the second light sensor is turned on and the second control voltage is increased to the first voltage value, wherein the third threshold is greater than the first threshold.

[0026] Further preferably, the variable resistor also reduces the resistance value to a second resistance value according to the second control voltage to increase the current value of the driving current flowing through the light-emitting element, wherein the second resistance value is smaller than the first resistance value; wherein the voltage value of the second control voltage is the first voltage value.

[0027] Preferably, it also includes:

[0028] The second light sensor receives the first operating voltage and provides a second control voltage according to the intensity of the second light to be sensed, wherein the variable resistor further adjusts the resistance value provided according to the second control voltage.

[0029] The first light to be sensed has a first wavelength, the second light to be sensed has a second wavelength, and the first wavelength is different from the second wavelength.

[0030] Further preferably, the first light sensor includes a first photosensitive diode and a first color filter, the second light sensor includes a second photosensitive diode and a second color filter, the first color filter is arranged between the paths through which the first photosensitive diode receives the first light to be sensed, and the second color filter is arranged between the paths through which the second photosensitive diode receives the second light to be sensed.

[0031] The display device of the present invention comprises: any one of the pixel circuits described above, wherein the plurality of pixel circuits are arranged in an array to provide display images.

[0032] Compared with the prior art, the pixel circuit of the present invention generates a control voltage according to the state of the light to be sensed through a light sensor. Then, a variable resistor is used to adjust the resistance value provided according to the control voltage, and further adjust the current value of the driving current flowing through the light-emitting element. In this way, the light luminance of the light-emitting element can be dynamically adjusted according to the state of the light to be sensed. The interference of the light to be sensed can be reduced, and the display performance of the generated image can be maintained. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 FIG. 4 is a schematic diagram of a pixel circuit according to an embodiment of the present invention.

[0034] Figure 2 FIG. 4 is a schematic diagram of a pixel circuit according to another embodiment of the present invention.

[0035] Figure 3 FIG. 4 is a schematic diagram of a pixel circuit according to another embodiment of the present invention.

[0036] Figure 4A as well as Figure 4B They are schematic diagrams of different implementations of a pixel circuit according to another embodiment of the present invention.

[0037] Figure 5A as well as Figure 5B They are schematic diagrams of different implementations of a pixel circuit according to another embodiment of the present invention.

[0038] Figure 6 FIG. 4 is a cross-sectional view of the structure of a light sensor according to an embodiment of the present invention.

[0039] Figure 7 is a schematic diagram of a display device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to provide a further understanding of the purpose, structure, features and functions of the present invention, the following detailed description is given in conjunction with the embodiments.

[0041] Certain words are used in the specification and claims to refer to specific components. Those with ordinary knowledge in the field should understand that manufacturers may use different terms to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of the components as the criteria for distinction. The position descriptions such as up, down, top, and bottom mentioned in the specification are based on the directions marked in the drawings and the definition methods that people are accustomed to, to explain the positional relationship between the components, and do not limit the actual placement or use direction of the product. The "including" mentioned throughout the specification and claims is an open-ended term, so it should be interpreted as "including but not limited to".

[0042] Please refer to Figure 1 , Figure 1 Schematic diagram of a pixel circuit according to an embodiment of the present invention. The pixel circuit 100 includes a first light sensor 110, a variable resistor 120, and a light emitting element LD1. The first light sensor 110 receives a first operating voltage VDD and is coupled to the variable resistor 120. The variable resistor 120 and the light emitting element LD1 are coupled in series between a second operating voltage VCC and a reference voltage VSS. The first light sensor 110 generates a first control voltage Vctrl1 according to the intensity of the light to be sensed, and provides the first control voltage Vctrl1 to the variable resistor 120. The variable resistor 120 can adjust the resistance value provided according to the first control voltage Vctrl1. By adjusting the resistance value provided by the variable resistor 120, the current value of the driving current Idrv flowing through the light emitting element LD1 can be adjusted accordingly. In this way, the light emitting brightness of the light emitting element LD1 can also be adjusted accordingly.

[0043] In detail, when the intensity of the light to be sensed is greater than the preset first threshold value, the first light sensor 110 can adjust the voltage value of the first control voltage Vctrl1 according to the first operating voltage VDD, for example, so that the voltage value of the first control voltage Vctrl1 is increased to the first voltage value. Correspondingly, the variable resistor 120 can reduce the resistance value provided by the variable resistor 120 according to the increased first control voltage Vctrl1. In this way, the current value of the driving current Idrv flowing through the light-emitting element LD1 can be increased, and the light-emitting brightness of the light-emitting element LD1 is correspondingly increased. Conversely, when the intensity of the light to be sensed is less than the preset second threshold value, the first light sensor 110 can adjust the voltage value of the first control voltage Vctrl1 according to the first operating voltage VDD, for example, so that the voltage value of the first control voltage Vctrl1 is reduced to the second voltage value. Correspondingly, the variable resistor 120 can increase the provided resistance value corresponding to the reduced first control voltage Vctrl1. In this way, the current value of the driving current Idrv flowing through the light emitting element LD1 can be lowered, and the light emitting brightness of the light emitting element LD1 can be correspondingly reduced. The first threshold value can be greater than or equal to the second threshold value.

[0044] Incidentally, in this embodiment, the first operating voltage VDD received by the first light sensor 110 and the second operating voltage VCC received by the light emitting element LD1 may be equal or unequal, without any specific limitation. The reference voltage VSS in this embodiment may be a ground voltage. Figure 1 The coupling sequence between the light emitting element LD1 and the variable resistor 120 can also be interchanged. Figure 1 It is only an illustrative example and is not intended to limit the scope of implementation of the present invention.

[0045] The light emitting element LD1 in this embodiment can be any form of light emitting diode, such as a direct-view light emitting diode (dvLED), a micro light emitting diode (Micro LED) or an organic light emitting diode (Organic LED, OLED), etc., without any specific limitation.

[0046] Incidentally, the first light sensor 110 may be used to sense the brightness of the light to be sensed which is white light, or may also be used to sense the brightness of the light to be sensed which has a specific wavelength, such as red light, blue light or green light.

[0047] Please refer to the following Figure 2 , Figure 2Schematic diagram of a pixel circuit of another embodiment of the present invention. The pixel circuit 200 includes a first light sensor 210, a variable resistor 220, and a light emitting element LD1. In this embodiment, the first light sensor 210 may be a photodiode PD1. The anode of the photodiode PD1 may be coupled to the variable resistor 220 and used to provide a first control voltage Vctrl1, and the cathode of the photodiode PD1 may receive a second operating voltage VCC. In addition, the light emitting element LD1 may be a light emitting diode. The anode of the light emitting element LD1 may receive a second operating voltage VCC, and the cathode of the light emitting element LD1 may be coupled to the variable resistor 220.

[0048] On the other hand, the variable resistor 220 includes a transistor T1, a first resistor R1, and a second resistor R2. The second resistor R2 is connected in series between the cathode of the light emitting element LD1 and the reference voltage VSS. The transistor T1 and the first resistor R1 are connected in series between the cathode of the light emitting element LD1 and the reference voltage VSS, and are coupled in parallel with the second resistor R2. The control end of the transistor T1 is coupled to the cathode of the photodiode PD1 to receive the first control voltage Vctrl1.

[0049] In terms of action details, the photodiode PD1 can adjust the degree of conduction according to the intensity of the light to be sensed received. When the intensity of the light to be sensed is less than the second threshold, the photodiode PD1 can be completely turned off. At this time, the first control voltage Vctrl1 cannot turn on the transistor T1, and can make the transistor T1 in a cut-off state. At the same time, the resistance value provided by the variable resistor 220 is equal to the resistance value of the second resistor R2, and the driving current Idrv flowing through the light emitting element LD1 can be equal to the second operating voltage VCC divided by the resistance value of the second resistor R2.

[0050] When the intensity of the light to be sensed is increased and is higher than the preset first threshold, the photodiode PD1 can be fully turned on and the first control voltage Vctrl1 is substantially equal to the second operating voltage VCC (the photodiode PD1 still has a small on-resistance). At the same time, the transistor T1 can be fully turned on according to the first control voltage Vctrl1. In this way, the variable resistor 220 can provide a resistance value R1 / / R2 of the first resistor R1 and the second resistor R2 connected in parallel, wherein the resistance value R1 / / R2 is less than the resistance value of the second resistor R2. In this way, the driving current Idrv flowing through the light-emitting element LD1 can be increased to be equal to the second operating voltage VCC divided by the resistance value R1 / / R2, thereby increasing the light emitting brightness of the light-emitting element LD1.

[0051] From the above description, it can be known that the pixel circuit 200 of the embodiment of the present invention can dynamically adjust the light emitting brightness of the light emitting element LD1 according to the intensity of the light to be sensed, which can effectively reduce the interference of ambient light on the display brightness of the pixel circuit 200 and maintain the display quality.

[0052] In this embodiment, the light emitting element LD1 and the photodiode PD1 receive the same second operating voltage VCC. In other embodiments of the present invention, the light emitting element LD1 and the photodiode PD1 may also receive different operating voltages. In the variable resistor 220, the transistor T1 may be a bipolar transistor or any other type of transistor without fixed restrictions. Figure 2 The positions of the transistor T1 and the first resistor R1 in the embodiment may also be interchanged without any specific limitation.

[0053] Please refer to Figure 3 , Figure 3 Schematic diagram of a pixel circuit of another embodiment of the present invention. The pixel circuit 300 includes a first light sensor 310, a second light sensor 330, a variable resistor 320, and a light emitting element LD1. Different from the above-mentioned embodiment, in this embodiment, the pixel circuit 300 has a plurality of light sensors: a first light sensor 310 and a second light sensor 330. The first light sensor 310 and the second light sensor 330 respectively include a first photosensitive diode PD1 and a second photosensitive diode PD2, and receive a first operating voltage VDD. The light emitting element LD1 receives a second operating voltage VCC. In addition, the variable resistor 320 includes a second resistor R2, and includes a first transistor T1 corresponding to the first light sensor 310, a first resistor R1, and a second transistor T2 and a third resistor R3 corresponding to the second light sensor 330. Among them, the first transistor T1 and the first resistor R1 are coupled in series between the cathode of the light-emitting element LD1 and the reference voltage VSS; the second transistor T2 and the third resistor R3 are coupled in series between the cathode of the light-emitting element LD1 and the reference voltage VSS; and the second resistor R2 is also coupled between the cathode of the light-emitting element LD1 and the reference voltage VSS.

[0054] The first light sensor 310 and the second light sensor 330 provide a first control voltage Vctrl1 and a second control voltage Vctrl2 respectively according to the intensity of the light to be sensed. The first transistor T1 and the second transistor T2 are turned on or off respectively according to the first control voltage Vctrl1 and the second control voltage Vctrl2. When the first transistor T1 and the second transistor T2 are both turned off, the variable resistor 320 can provide the maximum resistance value (equal to the resistance value of the second resistor R2). When one of the first transistor T1 and the second transistor T2 is turned off and the other is turned on, the variable resistor 320 can provide a secondary large resistance value (equal to the resistance value of the second resistor R2 in parallel with one of the first resistor R1 and the third resistor R3). When the first transistor T1 and the second transistor T2 are both turned on, the variable resistor 320 can provide the minimum resistance value (equal to the resistance value of the second resistor R2, the first resistor R1, and the third resistor R3 in parallel).

[0055] Correspondingly, when the variable resistor 320 provides the maximum resistance value, the driving current Idrv passing through the light-emitting element LD1 has the lowest current value, and the light-emitting element LD1 emits the lowest brightness; when the variable resistor 320 provides a secondary large resistance value, the driving current Idrv passing through the light-emitting element LD1 has a secondary low current value, and the light-emitting element LD1 emits a secondary low brightness; when the variable resistor 320 provides the minimum resistance value, the driving current Idrv passing through the light-emitting element LD1 has the maximum current value, and the light-emitting element LD1 emits the highest brightness.

[0056] In the first implementation of the present embodiment, the first light sensor 310 and the second light sensor 330 can sense the same light to be sensed. The first light sensor 310 can be turned on when the intensity of the light to be sensed is greater than a preset first threshold, and the second light sensor 330 can be turned on only when the intensity of the light to be sensed is greater than a preset third threshold, wherein the third threshold is greater than the first threshold. That is, in the first implementation of the present embodiment, when the intensity of the light to be sensed is lower than the first threshold, the first light sensor 310 and the second light sensor 330 are not turned on, the first transistor T1 and the second transistor T2 are turned off, and the light emitting element LD1 provides the lowest brightness. When the intensity of the light to be sensed is higher than the first threshold but lower than the third threshold, the first light sensor 310 can be turned on, while the second light sensor 330 is not turned on, the first transistor T1 is turned on and the second transistor T2 is turned off, and the light emitting element LD1 provides a secondary low brightness. When the intensity of the light to be sensed is higher than the third threshold, the first light sensor 310 and the second light sensor 330 can be turned on, the first transistor T1 and the second transistor T2 can be turned on, and the light emitting element LD1 provides the highest brightness.

[0057] From the above description, it can be known that the present embodiment improves the brightness level of the light to be sensed by setting the first light sensor 310 and the second light sensor 330. And through the first transistor T1, the second transistor T2 and the corresponding first resistor R1 and the third resistor R3, the brightness provided by the light emitting element LD1 can be adjusted in multiple stages according to the intensity of the light to be sensed, so as to improve the working efficiency of the pixel circuit 300.

[0058] On the other hand, in the second implementation of the present embodiment, the first light sensor 310 and the second light sensor 330 can sense different light to be sensed having different wavelengths. The first light sensor 310 can be used to sense the first light to be sensed having a first wavelength, and the second light sensor 330 can be used to sense the second light to be sensed having a second wavelength, wherein the first wavelength is different from the second wavelength.

[0059] In the second embodiment, the first light sensor 310 further includes a first color filter CF1, and the first color filter CF1 is disposed between the paths of the first photosensitive diode PD1 receiving the ambient light. The second light sensor 330 further includes a second color filter CF2, and the second color filter CF2 is disposed between the paths of the second photosensitive diode PD2 receiving the ambient light. The first color filter CF1 is used to generate the first light to be sensed by passing the first wavelength portion of the ambient light, and the first light sensor 310 can generate the first control voltage Vctrl1 according to the intensity of the first light to be sensed. The second color filter CF2 is used to generate the second light to be sensed by passing the second wavelength portion of the ambient light, and the second light sensor 330 can generate the second control voltage Vctrl2 according to the intensity of the second light to be sensed.

[0060] The configuration of the color filter and the corresponding light sensor will be described in detail in the following embodiments.

[0061] In the second embodiment, when the intensity of the first light to be sensed of the first wavelength is greater than the first threshold value, the first light sensor 310 can generate a first control voltage Vctrl1 substantially equal to the first operating voltage VDD, so that the first transistor T1 is turned on. By turning on the first transistor T1, the resistance value provided by the variable resistor 320 can be reduced, thereby increasing the brightness generated by the light-emitting element LD1. In addition, when the intensity of the second light to be sensed of the second wavelength is greater than the third threshold value, the second light sensor 320 can generate a second control voltage Vctrl2 substantially equal to the first operating voltage VDD, so that the second transistor T2 is turned on. By turning on the second transistor T2, the resistance value provided by the variable resistor 320 can also be reduced, thereby increasing the brightness generated by the light-emitting element LD1. It is worth mentioning that in this embodiment, the above-mentioned first threshold value can be greater than, equal to, or less than the third threshold value.

[0062] For example, the light to be sensed of the first wavelength may be blue light, the light to be sensed of the second wavelength may be green light, and the light emitting element LD1 may emit red light. When the intensity of at least one of the blue light and the green light is too strong, the pixel circuit 300 may increase the brightness of the light emitting element LD1 to achieve a color balance effect.

[0063] It is worth mentioning that in other embodiments of the present invention, a larger number of light sensors may be disposed in the pixel circuit to detect more segments of ambient light or to detect more light of different wavelengths to be sensed.

[0064] Please refer to Figure 4A as well as Figure 4B , Figure 4A as well as Figure 4B They are schematic diagrams of different implementations of a pixel circuit according to another embodiment of the present invention. Figure 4A , the pixel circuit 401 includes a first light sensor 410, a variable resistor 420, a light emitting element LD1, and a fourth resistor RD1. The variable resistor 420 includes a first transistor T1, a first resistor R1, and a second resistor R2. The pixel circuit 401 is similar to the pixel circuit 200, and the same parts can be referred to. Figure 2 The description of the embodiment is not repeated here. The difference is that the pixel circuit 401 further includes a fourth resistor RD1 coupled between the anode of the photodiode PD1 and the reference voltage VSS. The fourth resistor RD1 is used to adjust the resistance value. When the photodiode PD1 is turned off, the voltage on the control terminal of the transistor T1 is lowered to the reference voltage VSS, and the first transistor T1 is ensured to be turned off.

[0065] Figure 4B The pixel circuit 402 is Figure 4A The variable resistor 420 and the light emitting element LD1 of the pixel circuit 402 are coupled to the second operating voltage VCC and the reference voltage VSS in sequence, and have an opposite coupling sequence to the variable resistor 420 and the light emitting element LD1 of the pixel circuit 401.

[0066] Please refer to Figure 5A as well as Figure 5B , Figure 5A as well as Figure 5B They are schematic diagrams of different implementations of a pixel circuit according to another embodiment of the present invention. Figure 5A, the pixel circuit 501 includes a first light sensor 510, a second light sensor 530, a variable resistor 520, a light emitting element LD1, and a fourth resistor RD1 and a fifth resistor RD2. The variable resistor 420 includes a first transistor T1, a second transistor T2, a first resistor R1, a second resistor R2, and a third resistor R3. The pixel circuit 501 is similar to the pixel circuit 300, and the same parts can be referred to. Figure 3 The description of the embodiment is not repeated here. The difference is that the pixel circuit 501 further includes a fourth resistor RD1 coupled between the anode of the first photosensitive diode PD1 and the reference voltage VSS, and a fifth resistor RD2 coupled between the anode of the second photosensitive diode PD2 and the reference voltage VSS. The fourth resistor RD1 and the fifth resistor RD2 are used to adjust the resistance value. When the first photosensitive diode PD1 and the second photosensitive diode PD2 are turned off, the fourth resistor RD1 and the fifth resistor RD2 are used to lower the voltage on the control terminal of the first transistor T1 and the second transistor T2 to the reference voltage VSS, and ensure that the first transistor T1 and the second transistor T2 can be turned off.

[0067] Figure 5B The pixel circuit 502 is Figure 5A The variable resistor 520 and the light emitting element LD1 of the pixel circuit 502 are coupled to the second operating voltage VCC and the reference voltage VSS in sequence, and have an opposite coupling sequence to the variable resistor 520 and the light emitting element LD1 in the pixel circuit 501.

[0068] Please refer to Figure 6 , Figure 6 FIG. 1 is a cross-sectional view of the structure of the first light sensor according to an embodiment of the present invention. Figure 6 In the first light sensor 600, the first photodiode PD1 can be arranged in the substrate 610. The first color filter CF1 can be covered on the substrate 610 and completely covers the first photodiode PD1. The first light sensor 600 also has an infrared filter IRCF. The infrared filter IRCF covers the outside of the first color filter CF1 to filter out infrared light in the environment, which can ensure the accuracy of light sensing of the photodiode PD1. Among them, the structures of the second and more light sensors that can be arranged are similar to those of the first light sensor 600, and will not be repeated here.

[0069] Please refer to Figure 7 , Figure 7Schematic diagram of a display device according to an embodiment of the present invention. Display device 700 includes a plurality of pixel circuits 711-7MN. Each of pixel circuits 711-7MN can be implemented by applying the pixel circuits of the aforementioned embodiments and implementations. Pixel circuits 711-7MN can be arranged in an array and used to provide display images.

[0070] In summary, a light sensor is provided in the pixel circuit of the present invention. The light sensor provides a control voltage according to the intensity of the sensed light, and adjusts the resistance value provided by the variable resistor by the control voltage. By adjusting the resistance value, the driving current of the light-emitting element is adjusted, and the brightness of the light-emitting element is adjusted. In this way, the influence of ambient light on the display image generated by the display device can be effectively reduced, and the display quality of the display image can be maintained.

[0071] The present invention has been described by the above-mentioned relevant embodiments, however, the above-mentioned embodiments are only examples for implementing the present invention. It must be pointed out that the disclosed embodiments do not limit the scope of the present invention. On the contrary, changes and modifications made without departing from the spirit and scope of the present invention are all within the scope of patent protection of the present invention.

Claims

1. A pixel circuit, characterized in that: include: Light emitting element; The first light sensor receives a first operating voltage and provides a first control voltage according to the intensity of the first light to be sensed; as well as The variable resistor is coupled in series with the light emitting element between the second operating voltage and the reference voltage. The resistance value provided by the variable resistor is adjusted according to the first control voltage to adjust the current value of the driving current flowing through the light emitting element.

2. The pixel circuit according to claim 1, wherein: When the intensity of the first light to be sensed is greater than a first threshold, the first light sensor is turned on and the first control voltage is increased to a first voltage value.

3. The pixel circuit according to claim 2, characterized in that: The variable resistor reduces the resistance value to a first resistance value according to the first control voltage, so as to increase the current value of the driving current flowing through the light-emitting element; wherein the voltage value of the first control voltage is the first voltage value.

4. The pixel circuit according to claim 2, characterized in that: When the intensity of the first light to be sensed is less than a second threshold, the first light sensor is turned off and the first control voltage is reduced to a second voltage value.

5. The pixel circuit according to claim 4, characterized in that: The variable resistor increases the resistance value to a second resistance value according to the first control voltage, so as to reduce the current value of the driving current flowing through the light-emitting element; wherein the voltage value of the first control voltage is the second voltage value.

6. The pixel circuit according to claim 2, characterized in that: The first light sensor includes a first photodiode, a cathode of the first photodiode receives the first operating voltage, and an anode of the first photodiode provides the first control voltage.

7. The pixel circuit according to claim 6, characterized in that: The variable resistor includes: a first transistor and a first resistor, wherein the first transistor and the first resistor are coupled in series between the light emitting element and the second operating voltage, or the first transistor and the first resistor are coupled in series between the light emitting element and the reference voltage, and a control terminal of the first transistor receives the first control voltage; and The second resistor is coupled in parallel with a circuit string formed by the first transistor and the first resistor.

8. The pixel circuit according to claim 6, characterized in that: Also includes: The second light sensor receives the first operating voltage and provides a second control voltage according to the intensity of the first light to be sensed, wherein the variable resistor further adjusts the resistance value provided by the variable resistor according to the second control voltage.

9. The pixel circuit according to claim 6, characterized in that: The second light sensor includes a second photosensitive diode, a cathode of the second photosensitive diode receives the first operating voltage, and an anode of the second photosensitive diode provides the second control voltage.

10. The pixel circuit according to claim 9, characterized in that: The variable resistor includes: A second transistor and a third resistor, the second transistor and the third resistor are coupled in series between the light emitting element and the second operating voltage, or the second transistor and the third resistor are coupled in series between the light emitting element and the reference voltage, and the control end of the second transistor receives the second control voltage.

11. The pixel circuit according to claim 10, characterized in that: Also includes: The fourth resistor is coupled between the cathode of the first photodiode and the reference voltage.

12. The pixel circuit according to claim 11, characterized in that: Also includes: The fifth resistor is coupled between the cathode of the second photosensitive diode and the reference voltage.

13. The pixel circuit according to claim 9, characterized in that: When the intensity of the first light to be sensed is greater than a third threshold, the second light sensor is turned on and the second control voltage is increased to the first voltage value, wherein the third threshold is greater than the first threshold.

14. The pixel circuit according to claim 13, characterized in that: The variable resistor also reduces the resistance value to a second resistance value according to the second control voltage, so as to increase the current value of the driving current flowing through the light-emitting element, wherein the second resistance value is smaller than the first resistance value; wherein the voltage value of the second control voltage is the first voltage value.

15. The pixel circuit according to claim 1, wherein: Also includes: The second light sensor receives the first operating voltage and provides a second control voltage according to the intensity of the second light to be sensed, wherein the variable resistor further adjusts the resistance value provided according to the second control voltage. The first light to be sensed has a first wavelength, the second light to be sensed has a second wavelength, and the first wavelength is different from the second wavelength.

16. The pixel circuit according to claim 15, characterized in that: The first light sensor includes a first photosensitive diode and a first color filter, the second light sensor includes a second photosensitive diode and a second color filter, the first color filter is arranged between the paths for the first photosensitive diode to receive the first light to be sensed, and the second color filter is arranged between the paths for the second photosensitive diode to receive the second light to be sensed.

17. A display device, characterized in that: include: A plurality of pixel circuits as claimed in any one of claims 1 to 16, wherein the plurality of pixel circuits are arranged in an array to provide display images.

Images