Ambient light detection circuit, display panel, and display panel testing method

Abstract

The present application belongs to the field of display driver technology, and specifically relates to an ambient light detection circuit, a display panel and a display panel testing method. The ambient light detection circuit includes a first driving module for generating a first driving voltage; a photosensitive module for generating a first photosensitive current corresponding to the current environment under the action of the first driving voltage; a shading module for generating a first reference current corresponding to the black state environment under the action of the first driving voltage; and a second driving module for generating a corresponding first photosensitive voltage and a first reference voltage according to the first photosensitive current and the first reference current respectively. The present application uses the current generated by the shading module as a reference basis for the photosensitive module. When the photosensitive characteristics shift due to aging of components or high temperature and high humidity environment, the offset generated by the photosensitive module can offset the offset of the shading module, thereby improving the accuracy of ambient light detection.

Description

Technical Field

[0001] The present disclosure belongs to the field of display drive technology, and particularly relates to an ambient light detection circuit, a display panel, and a display panel testing method. Background Art

[0002] In ambient light detection technology, photosensitive elements (such as photoresistors, photodiodes, or photosensors) are usually used to detect the ambient light intensity and convert the light signal into an electrical signal output for subsequent circuits to adjust brightness or control energy saving.

[0003] However, when the photosensitive element is affected by device aging or high temperature and high humidity environment, its photosensitivity characteristics may shift. This shift phenomenon will cause the accuracy of ambient light detection to gradually decrease, making it impossible to correctly perceive the actual lighting conditions, thereby affecting the reliability of brightness adjustment.

[0004] Therefore, how to improve the accuracy of ambient light detection in device aging or high temperature and high humidity environments is an urgent problem to be solved. Summary of the Invention

[0005] The present application provides an ambient light detection circuit, a display panel, and a display panel testing method, which solve the problem of low ambient light detection accuracy in device aging or high temperature and high humidity environments.

[0006] In the first aspect, the present application provides an ambient light detection circuit, which includes: a first driving module for generating a first driving voltage; a photosensitive module, wherein the first end of the photosensitive module is connected to the first connection end of the first driving module, and is used to generate a first photosensitive current corresponding to the current environment under the action of the first driving voltage; a shading module, wherein the first end of the shading module is connected to the second connection end of the first driving module, and is used to generate a first reference current corresponding to the black state environment under the action of the first driving voltage; a second driving module, wherein the first connection end of the second driving module is connected to the second end of the photosensitive module, and the second connection end of the second driving module is connected to the second end of the shading module, and is used to generate a corresponding first photosensitive voltage and a first reference voltage according to the first photosensitive current and the first reference current, respectively, so that the subsequent load obtains the light intensity corresponding to the current environment according to the difference between the first photosensitive voltage and the first reference voltage.

[0007] Optionally, the second driving module is also used to generate a second driving voltage, so that the photosensitive module is also used to generate a second photosensitive current corresponding to the current environment under the action of the second driving voltage, and the shading module is also used to generate a second reference current corresponding to the black state environment under the action of the second driving voltage; the first driving module is also used to generate a corresponding second photosensitive voltage and a second reference voltage according to the second photosensitive current and the second reference current, respectively, so that the subsequent load obtains the light intensity corresponding to the current environment according to the difference between the second photosensitive voltage and the second reference voltage.

[0008] Optionally, the control end of the photosensitive module is connected to the external enable end, and is used to generate a corresponding photosensitive current in the current environment according to the first driving voltage or the second driving voltage under the control of the enable signal output by the external enable end; the control end of the light-shielding module is connected to the external enable end, and is used to generate a corresponding reference current in the black state environment according to the first driving voltage or the second driving voltage under the control of the enable signal output by the external enable end.

[0009] Optionally, the photosensitive module includes: a first photosensitive transistor, wherein the control end of the first photosensitive transistor is connected to the external enable end, the first end of the first photosensitive transistor is connected to the first connection end of the first driving module, and the second end of the first photosensitive transistor is connected to the first connection end of the second driving module;

[0010] The shading module includes: a second photosensitive transistor, the control end of the second photosensitive transistor is connected to the external enable end, the first end of the second photosensitive transistor is connected to the second connection end of the first driving module, and the second end of the second photosensitive transistor is connected to the second connection end of the second driving module.

[0011] Optionally, the first driving module includes: a first transistor, wherein the control end of the first transistor is connected to the first power supply end, and the first end of the first transistor is connected to the control end of the first transistor; a first resistor, wherein the first end of the first resistor is connected to the first end of the first transistor, and the second end of the first resistor is connected to the second end of the first transistor; a second transistor, wherein the control end of the second transistor is connected to the first power supply end, and the first end of the second transistor is connected to the control end of the second transistor; and a second resistor, wherein the first end of the second resistor is connected to the first end of the second transistor, and the second end of the second resistor is connected to the second end of the second transistor; wherein the second end of the first transistor serves as the first connection end of the first driving module, and the second end of the second transistor serves as the second connection end of the first driving module.

[0012] Optionally, the second driving module includes: a third transistor, wherein the control end of the third transistor is connected to the second power supply end, and the first end of the third transistor is connected to the control end of the third transistor; a third resistor, wherein the first end of the third resistor is connected to the first end of the third transistor, and the second end of the third resistor is connected to the second end of the third transistor; a fourth transistor, wherein the control end of the fourth transistor is connected to the second power supply end, and the first end of the fourth transistor is connected to the control end of the fourth transistor; and a fourth resistor, wherein the first end of the fourth resistor is connected to the first end of the fourth transistor, and the second end of the fourth resistor is connected to the second end of the fourth transistor; wherein the first end of the third transistor serves as the first connection end of the second driving module, and the first end of the fourth transistor serves as the second connection end of the second driving module.

[0013] Optionally, the ambient light detection circuit further includes: an output module, which is respectively connected to the first driving module, the second driving module and the subsequent load, and is used to output the first photosensitive voltage and / or the second photosensitive voltage to the subsequent load, and is also used to output the first reference voltage and / or the second reference voltage to the subsequent load.

[0014] Optionally, the output module includes: a fifth transistor, wherein the control end of the fifth transistor is connected to the second power supply end, and the first end of the fifth transistor is connected to the second end of the first transistor; a sixth transistor, wherein the control end of the sixth transistor is connected to the control end of the fifth transistor, and the first end of the sixth transistor is connected to the second end of the second transistor; a seventh transistor, wherein the control end of the seventh transistor is connected to the first power supply end, the first end of the seventh transistor is connected to the second end of the third transistor, and the second end of the seventh transistor is connected to the second end of the fifth transistor; an eighth transistor, wherein the control end of the eighth transistor is connected to the control end of the seventh transistor, the first end of the eighth transistor is connected to the second end of the fourth transistor, and the second end of the eighth transistor is connected to the second end of the sixth transistor; wherein the second end of the seventh transistor is used as a photosensitive voltage output end for outputting the first photosensitive voltage or / and the second photosensitive voltage; and the second end of the eighth transistor is used as a reference voltage output end for outputting the first reference voltage or / and the second reference voltage.

[0015] In a second aspect, the present application provides a display panel comprising a display area and a non-display area, wherein the display area comprises a pixel array and at least one ambient light detection circuit; the non-display area comprises a microcontroller electrically connected to the ambient light detection circuit, for calculating the voltage difference between the photosensitive voltage output by the ambient light detection circuit and a reference voltage, and for obtaining the light intensity corresponding to the current environment based on the voltage difference.

[0016] In a third aspect, the present application provides a display panel testing method, which is applied to a display panel testing system, wherein the testing system includes a host computer and a display panel, the host computer includes a central processing unit and a graphics card, the display panel also includes a timing controller and a source driver, the microcontroller is electrically connected to the central processing unit, the central processing unit is also electrically connected to the graphics card, the graphics card is connected to the timing controller, the timing controller is connected to the source driver, and the source driver is electrically connected to the pixel array; the display panel testing method includes: when receiving a trigger signal sent by the microcontroller, the central processing unit sends a test instruction to the graphics card, so that the graphics card sends display data to the timing controller; the timing controller converts the display data into a signal, generates drive data and sends it to the source driver; the source driver drives the pixel array to display the picture according to the drive data; the ambient light detection circuit collects the photosensitive voltage and reference voltage corresponding to the current picture; the microcontroller obtains the light intensity according to the photosensitive voltage and the reference voltage, so that the central processing unit obtains the test result of the display panel according to the light intensity.

[0017] The technical solution provided by this application has at least the following beneficial effects:

[0018] The photosensitive module and the light-shielding module in the present application respectively generate a first photosensitive current corresponding to the current environment and a first reference current corresponding to the black state environment under the action of the first driving voltage output by the first driving module; then the first photosensitive current and the first reference current are converted into corresponding first photosensitive voltage and first reference voltage through the second driving module, so that the subsequent load calculates the light intensity corresponding to the current environment according to the difference between the first photosensitive voltage and the first reference voltage; therefore, the present application uses the current generated by the light-shielding module as the reference basis of the photosensitive module. When the photosensitivity characteristics shift due to aging of components or high temperature and high humidity environment, the offset generated by the photosensitive module can offset the offset of the light-shielding module, thereby improving the accuracy of ambient light detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification, are used to explain the principles of the present disclosure. Obviously, the drawings described below are only some embodiments of the present disclosure, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0020] Figure 1 Shown is a structural schematic diagram of an ambient light detection circuit provided in an embodiment of the present application.

[0021] Figure 2 Shown is a circuit diagram of a first ambient light detection circuit provided in an embodiment of the present application.

[0022] Figure 3 Shown is a schematic diagram of current flow provided in an embodiment of the present application.

[0023] Figure 4 Shown is another current flow schematic diagram provided in an embodiment of the present application.

[0024] Figure 5 The figure shows a driving timing diagram provided in an embodiment of the present application.

[0025] Figure 6 Shown is a structural schematic diagram of a second ambient light detection circuit provided in an embodiment of the present application.

[0026] Figure 7 Shown is a structural schematic diagram of a post-stage load provided in an embodiment of the present application.

[0027] Figure 8 Shown is a test connection schematic diagram in the related art.

[0028] Figure 9 Shown is a schematic diagram of the configuration of an ambient light detection circuit provided in an embodiment of the present application.

[0029] Figure 10 Shown is a structural schematic diagram of a display panel testing system provided in an embodiment of the present application.

[0030] Figure 11 Shown is a flow chart of a display panel testing method provided in an embodiment of the present application.

[0031] Description of reference numerals:

[0032] 100, ambient light detection circuit; 110, first driving module; 120, photosensitive module; 130, light shielding module; 140, second driving module; 150, output module;

[0033] M1, first photosensitive transistor; M2, second photosensitive transistor; T1, first transistor; T2, second transistor; T3, third transistor; T4, fourth transistor; T5, fifth transistor; T6, sixth transistor; T7, seventh transistor; T8, eighth transistor; R1, first resistor; R2, second resistor; R3, third resistor; R4, fourth resistor; V1, first power supply terminal; V2, second power supply terminal; TE, external enable terminal; Vp, photosensitive voltage output terminal; Vn, reference voltage output terminal; Vp1, first photosensitive voltage output terminal; Vn1, first reference voltage output terminal; Vp2, second photosensitive voltage output terminal; Vn2, second reference voltage output terminal. DETAILED DESCRIPTION

[0034] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art.

[0035] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner.In the following description, many specific details are provided so as to provide a full understanding of the embodiments of the present application. However, it will be appreciated by those skilled in the art that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps etc. can be adopted. In other cases, known methods, devices, implementations or operations are not shown or described in detail to avoid blurring the various aspects of the application.

[0036] The present application is further described below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the technical features involved in the various embodiments of the present application described below can be combined with each other as long as they do not conflict with each other. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be understood as limiting the present application.

[0037] In a first aspect, the present application provides an ambient light detection circuit, specifically including the following embodiments:

[0038] Figure 1 FIG. 1 is a schematic diagram of the structure of an ambient light detection circuit provided in an embodiment of the present application; Figure 1 As shown, the ambient light detection circuit 100 includes a first driving module 110 for generating a first driving voltage; wherein the first driving voltage can be a square wave timing, that is, the first driving voltage is a high level when ambient light intensity detection is required, and the first driving voltage is a low level when ambient light intensity detection is not required.

[0039] In this embodiment, the ambient light detection circuit 100 also includes a photosensitive module 120, and the first end of the photosensitive module 120 is connected to the first connection end of the first driving module 110, and is used to generate a first photosensitive current corresponding to the current environment under the action of the first driving voltage. Specifically, the photosensitive module 120 includes a photosensitive element, which utilizes the working principle of the photosensitive element: when photoelectrons are generated (when brightness changes), they are absorbed by the anode of the photosensitive element, thereby generating current. As the light intensity continues to increase, more photoelectrons will be generated, and the photocurrent will also increase accordingly, so that the light intensity can be calculated using the photosensitive current. In this embodiment, when the first driving voltage is at a high level, the photosensitive module 120 will generate a photosensitive current, and the corresponding photosensitive current will be different in different environments.

[0040] In this embodiment, the ambient light detection circuit 100 further includes a light shielding module 130, wherein a first end of the light shielding module 130 is connected to a second connection end of the first driving module 110, and is configured to generate a reference current corresponding to a black state environment under the action of the first driving voltage. Specifically, the light shielding module 130 and the photosensitive module 120 have the same operating principle, device model, and process, with the only difference being that the photosensitive module 120 is in a normal environment with illumination, while the light shielding module 130 is in a black state environment without illumination. The light shielding module 130 may be provided with a light shielding housing on the surface of the photosensitive module 120, so that the light shielding module 130 generates a first reference current corresponding to a black state environment when the first driving voltage is at a high level. From this, it can be seen that the shading module 130 and the photosensitive module 120 are identical in device process, device model, working principle, overall environment and aging degree. Even if there is a problem of photosensitivity characteristic offset in the photosensitive device, the shading module 130 and the photosensitive module 120 will both offset in the same direction, and then the offset of the shading module 130 can offset the offset of the photosensitive module 120.

[0041] In this embodiment, the ambient light detection circuit 100 also includes a second driving module 140, the first connection end of the second driving module 140 is connected to the second end of the photosensitive module 120, and the second connection end of the second driving module 140 is connected to the second end of the shading module 130, and is used to generate a corresponding first photosensitive voltage and a first reference voltage according to the first photosensitive current and the first reference current, so that the subsequent load obtains the light intensity corresponding to the current environment according to the difference between the first photosensitive voltage and the first reference voltage.

[0042] It should be noted that the second driving module 140 is also connected to the subsequent load. The second driving module 140 converts the received first photosensitive current and the first reference current into a first photosensitive voltage and a first reference voltage respectively, and then outputs them to the subsequent load, so that the subsequent load obtains the current light intensity corresponding to the current environment according to the difference voltage between the first photosensitive voltage and the first reference voltage; wherein the subsequent load can be a module with computing functions such as a control chip, a processing chip or a single-chip microcomputer.

[0043] In summary, the photosensitive module 120 and the light shielding module 130 in the present application generate a first photosensitive current corresponding to the current environment and a first reference current corresponding to the black state environment respectively under the action of the first driving voltage output by the first driving module 110; then the first photosensitive current and the first reference current are converted into corresponding first photosensitive voltage and first reference voltage through the second driving module 140, so that the subsequent load calculates the light intensity corresponding to the current environment according to the difference between the first photosensitive voltage and the first reference voltage; therefore, the present application uses the current generated by the light shielding module 130 as the reference basis of the photosensitive module 120. When the photosensitivity characteristics shift due to aging of components or high temperature and high humidity environment, the offset generated by the photosensitive module 120 can offset the offset of the light shielding module 130, thereby improving the accuracy of ambient light detection.

[0044] In another embodiment, the second driving module 140 is also used to generate a second driving voltage, so that the photosensitive module 120 is also used to generate a second photosensitive current corresponding to the current environment under the action of the second driving voltage, and the shading module 130 is also used to generate a second reference current corresponding to the black state environment under the action of the second driving voltage; the first driving module 110 is also used to generate a corresponding second photosensitive voltage and a second reference voltage according to the second photosensitive current and the second reference current, respectively, so that the subsequent load obtains the light intensity corresponding to the current environment according to the difference between the second photosensitive voltage and the second reference voltage.

[0045] It should be noted that the first driving voltage and the second driving voltage may be driving voltages with the same voltage value; in this embodiment, the first driving module 110 and the second driving module 140 do not generate the first driving voltage and the second driving voltage at the same time, that is, when the first driving module 110 generates the first driving voltage, the second driving module 140 does not generate the second driving voltage; when the second driving module 140 generates the second driving voltage, the first driving module 110 does not generate the first driving voltage.

[0046] Specifically, when the first driving module 110 generates a first driving voltage, the photosensitive module 120 generates a first photosensitive current corresponding to the current environment under the action of the first driving voltage, and the shading module 130 also generates a first reference current corresponding to the black state environment under the action of the first driving voltage; when the second driving module 140 generates a second driving voltage, the photosensitive module 120 generates a second photosensitive current corresponding to the current environment under the action of the second driving voltage, and the shading module 130 also generates a second reference current corresponding to the black state environment under the action of the second driving voltage; wherein, the current magnitudes of the first photosensitive current and the second photosensitive current may be the same, but the current directions must be opposite; the first photosensitive current flows from the first end of the photosensitive module 120 to the second end of the photosensitive module 120 At two ends, the second photosensitive current flows from the second end of the photosensitive module 120 to the first end of the photosensitive module 120; in addition, the current magnitudes of the first reference current and the second reference current may be the same, but the current directions must be opposite, the first reference current flows from the first end of the shading module 130 to the second end of the shading module 130, and the second reference current flows from the second end of the shading module 130 to the first end of the shading module 130; therefore, the direction of the current generated by the photosensitive module 120 and the shading module 130 can be controlled to switch forward and reverse through the first driving module 110 and the second driving module 140, so as to avoid the current generated by the photosensitive module 120 and the shading module 130 being in the same direction for a long time, and can effectively prevent the photosensitive module 120 and the shading device from aging, thereby extending the service life and improving the detection accuracy.

[0047] In another embodiment, Figure 1 As shown, the control end of the photosensitive module 120 is connected to the external enable end TE, and is used to generate a corresponding photosensitive current in the current environment according to the first driving voltage or the second driving voltage under the control of the enable signal output by the external enable end TE; the control end of the light shielding module 130 is connected to the external enable end TE, and is used to generate a corresponding reference current in the black state environment according to the first driving voltage or the second driving voltage under the control of the enable signal output by the external enable end TE.

[0048] It should be noted that when the enable signal output by the external enable terminal TE is at a high level, the photosensitive module 120 and the light shielding module 130 are controlled to operate simultaneously: that is, the photosensitive module 120 is controlled to generate the corresponding induced current in the current environment and the light shielding module 130 is controlled to generate the corresponding reference current in the black state environment; when the enable signal output by the external enable terminal TE is at a low level, the photosensitive module 120 and the light shielding module 130 are controlled to be turned off simultaneously: that is, neither the photosensitive module 120 nor the light shielding module 130 is controlled to generate current. Therefore, this embodiment can control the photosensitive module 120 and the light shielding module 130 to operate and be turned off simultaneously through the enable signal output by the external enable terminal TE, thereby preventing the photosensitive module 120 and the light shielding module 130 from being in an operating state all the time, reducing power consumption, and also increasing the service life of the photosensitive module 120 and the light shielding module 130.

[0049] Figure 2 FIG. 1 is a circuit diagram of a first ambient light detection circuit provided in an embodiment of the present application; FIG. Figure 2 As shown, the photosensitive module 120 includes: a first photosensitive transistor M1, the control end of the first photosensitive transistor M1 is connected to the external enable end TE, the first end of the first photosensitive transistor M1 is connected to the first connection end of the first driving module 110, and the second end of the first photosensitive transistor M1 is connected to the first connection end of the second driving module 140.

[0050] In this embodiment, the shading module 130 includes: a second photosensitive transistor M2, the control end of the second photosensitive transistor M2 is connected to the external enable end TE, the first end of the second photosensitive transistor M2 is connected to the second connection end of the first driving module 110, and the second end of the second photosensitive transistor M2 is connected to the second connection end of the second driving module 140.

[0051] It should be noted that, in order to reduce the errors caused by differences in transistor manufacturing processes, the first photosensitive transistor M1 and the second photosensitive transistor M2 in this embodiment have the same model, size and function. The difference between the two is that the first photosensitive transistor M1 is in a photosensitive area with ambient light, and the second photosensitive transistor M2 is in a light-shielding area without ambient light. The second photosensitive transistor M2 can be provided with a light-shielding housing on the basis of the first photosensitive transistor M1, so that the second photosensitive transistor M2 always generates a reference current corresponding to the black state environment. In addition, the function of the second photosensitive transistor M2 is to provide a reference current for the first photosensitive transistor M1 in a black state environment. Compared with the method of fixing the reference current in the related art, this embodiment can correct the offset of the photosensitivity characteristics of the photosensitive transistor under aging or high temperature and high humidity environments.

[0052] like Figure 2As shown, the first driving module 110 includes a first transistor T1, a first resistor R1, a second transistor T2, and a second resistor R2; specifically, the control end of the first transistor T1 is connected to the first power supply end V1, and the first end of the first transistor T1 is connected to the control end of the first transistor T1; the first end of the first resistor R1 is connected to the first end of the first transistor T1, and the second end of the first resistor R1 is connected to the second end of the first transistor T1; the control end of the second transistor T2 is connected to the first power supply end V1, and the first end of the second transistor T2 is connected to the control end of the second transistor T2; the first end of the second resistor R2 is connected to the first end of the second transistor T2, and the second end of the second resistor R2 is connected to the second end of the second transistor T2; wherein the second end of the first transistor T1 serves as the first connection end of the first driving module 110, and the second end of the second transistor T2 serves as the second connection end of the first driving module 110.

[0053] like Figure 2 As shown, the second driving module 140 includes a third transistor T3, a third resistor R3, a fourth transistor T4 and a fourth resistor R4; specifically, the control end of the third transistor T3 is connected to the second power supply end V2, and the first end of the third transistor T3 is connected to the control end of the third transistor T3; the first end of the third resistor R3 is connected to the first end of the third transistor T3, and the second end of the third resistor R3 is connected to the second end of the third transistor T3; the control end of the fourth transistor T4 is connected to the second power supply end V2, and the first end of the fourth transistor T4 is connected to the control end of the fourth transistor T4; the first end of the fourth resistor R4 is connected to the first end of the fourth transistor T4, and the second end of the fourth resistor R4 is connected to the second end of the fourth transistor T4; wherein the first end of the third transistor T3 serves as the first connection end of the second driving module 140, and the first end of the fourth transistor T4 serves as the second connection end of the second driving module 140.

[0054] Based on the specific circuit structure of the first driving module 110 and the second driving module 140, Figure 5 The timing diagram of FIG. 1 illustrates the working principle of the ambient light detection circuit 100 in detail:

[0055] (1) When the external enable terminal TE starts to output a regular pulse enable signal, the first photosensitive transistor M1 and the second photosensitive transistor M2 are turned on to start collecting light data.

[0056] (2) When the first power supply terminal V1 outputs a high level, the second power supply terminal V2 outputs a low level (which can be a ground signal), the first transistor T1 and the second transistor T2 are turned on, the third transistor T3 and the fourth transistor T4 are turned off, and the direction of the voltage is from high potential to low potential, that is, the direction of potential drop, as shown in the figure. Figure 3 As shown, the electrical signal passes through the upper first transistor T1 and the second transistor T2, then to the first photosensitive transistor M1 and the second photosensitive transistor M2, and finally flows out from both sides of the lower third resistor R3 and the fourth resistor R4. Therefore, the voltage at the first terminal of the third resistor R3 is the first photosensitive voltage, and the voltage at the first terminal of the fourth resistor R4 is the first reference voltage. The first terminal of the third resistor R3 serves as the first photosensitive voltage output terminal Vp1, and the first terminal of the fourth resistor R4 serves as the first reference voltage output terminal Vn1. The conversion of the optical signal to an electrical signal is achieved by the first photosensitive transistor M1, allowing the downstream load to obtain the corresponding light intensity of the current environment based on the difference between the first photosensitive voltage and the first reference voltage, through a table lookup or other method.

[0057] (3) When the second power supply terminal V2 outputs a high level, the first power supply terminal V1 outputs a low level (which can be a ground signal), the third transistor T3 and the fourth transistor T4 are turned on, and the first transistor T1 and the second transistor T2 are turned off. The direction of the voltage is from high potential to low potential, that is, the direction of potential drop, as shown in Figure 4 As shown, the electrical signal passes through the third transistor T3 and the fourth transistor T4 below, then to the first and second photosensitive transistors M1 and M2, and finally flows out from both sides of the first and second resistors R1 and R2 above. Therefore, the voltage at the second terminal of the first resistor R1 is the second photosensitive voltage, and the voltage at the second terminal of the second resistor R2 is the second reference voltage. The second terminal of the first resistor R1 serves as the second photosensitive voltage output terminal Vp2, and the second terminal of the second resistor R2 serves as the second reference voltage output terminal Vn2. The first photosensitive transistor M1 converts the optical signal into an electrical signal, allowing the downstream load to determine the corresponding light intensity of the current environment based on the difference between the second photosensitive voltage and the second reference voltage, using a table lookup or other method.

[0058] It can be seen here that the function of the first resistor R1 , the second resistor R2 , the third resistor R3 and the fourth resistor R4 in this embodiment is to convert the current signal into a voltage signal and output it to the subsequent load.

[0059] During the invention process, the inventors of the present application discovered that the ambient light detection circuit 100 of the above embodiment has a first photosensitive voltage output terminal Vp1, a second photosensitive voltage output terminal Vp2, a first reference voltage output terminal Vn1, and a second reference voltage output terminal Vn2, that is, it includes four voltage output terminals, which results in a problem of too many output terminals, affecting the connection with the subsequent load.

[0060] In order to solve the above-mentioned problem of having too many output terminals, the present application provides another ambient light detection circuit, which specifically includes the following embodiments:

[0061] Figure 6 FIG. 1 is a schematic diagram showing the structure of a second ambient light detection circuit provided in an embodiment of the present application; FIG. Figure 6 As shown, in Figure 2 On the basis of, the ambient light detection circuit 100 also includes: an output module 150, the output module 150 is respectively connected to the first driving module 110, the second driving module 140 and the subsequent load, and is used to output the first photosensitive voltage and / or the second photosensitive voltage to the subsequent load, and is also used to output the first reference voltage and / or the second reference voltage to the subsequent load.

[0062] like Figure 6 As shown, the output module 150 includes: a fifth transistor T5, a sixth transistor T6, a seventh transistor T7 and an eighth transistor T8; specifically, the control end of the fifth transistor T5 is connected to the second power supply end V2, and the first end of the fifth transistor T5 is connected to the second end of the first transistor T1; the control end of the sixth transistor T6 is connected to the control end of the fifth transistor T5, and the first end of the sixth transistor T6 is connected to the second end of the second transistor T2; the control end of the seventh transistor T7 is connected to the first power supply end V1, and the first end of the seventh transistor T7 is connected to the second end of the third transistor T3, A second end of the seventh transistor T7 is connected to the second end of the fifth transistor T5; a control end of the eighth transistor T8 is connected to the control end of the seventh transistor T7, a first end of the eighth transistor T8 is connected to the second end of the fourth transistor T4, and a second end of the eighth transistor T8 is connected to the second end of the sixth transistor T6; wherein the second end of the seventh transistor T7 is used as a photosensitive voltage output end Vp for outputting the first photosensitive voltage and / or the second photosensitive voltage; and the second end of the eighth transistor T8 is used as a reference voltage output end Vn for outputting the first reference voltage and / or the second reference voltage.

[0063] It should be noted that the specific working principle of the output module 150 in this embodiment is:

[0064] (1) When the first power supply terminal V1 outputs a high level and the second power supply terminal V2 outputs a low level, the fifth transistor T5 and the sixth transistor T6 are turned off, and the seventh transistor T7 and the eighth transistor T8 are turned on. At this time, the voltage output by the photosensitive voltage output terminal Vp is the first photosensitive voltage, and the voltage output by the reference voltage output terminal Vn is the first reference voltage.

[0065] (2) When the second power supply terminal V2 outputs a high level and the first power supply terminal V1 outputs a low level, the fifth transistor T5 and the sixth transistor T6 are turned on, and the seventh transistor T7 and the eighth transistor T8 are turned off. At this time, the voltage output by the photosensitive voltage output terminal Vp is the second photosensitive voltage, and the voltage output by the reference voltage output terminal Vn is the second reference voltage.

[0066] It can be seen that this embodiment reduces the number of output terminals of the ambient light detection circuit from four to two through the output module, thereby reducing the demand for the number of subsequent load receiving terminals and improving the application scenarios of the ambient light detection circuit.

[0067] Figure 7 FIG. 1 is a schematic diagram of the structure of a post-stage load provided in an embodiment of the present application; Figure 7 As shown, the post-stage load provided in this embodiment includes but is not limited to a subtractor, a microcontroller (MCU) and a central processing unit (CPU). The ambient light detection circuit sends the detected photosensitive voltage and the reference voltage to the subtractor. After the subtractor performs a subtraction operation on the photosensitive voltage and the reference voltage, the obtained difference voltage is sent to the microcontroller (MCU) for further data analysis and processing, and finally the obtained light intensity is output to the central processing unit (CPU).

[0068] In the microcontroller (MCU), the voltage corresponding to the maximum white brightness (Lum white) is set as data_white, the voltage corresponding to the reference black brightness (Lum black) is set as data_n, and the voltage corresponding to the current brightness is data_p. Therefore, the brightness of the current display is equal to [(data_p - data_n) × Lum white] / (data_white - data_n). For example, if the maximum white brightness written in the EDID (Extended Display Identification Data) is 300 nits, the corresponding voltage is 5.2V. If the black brightness is 0.3 nits, the corresponding voltage is 0.2V. If the current voltage is 3.2V, the corresponding brightness is [(3.2V - 3V) × 300 nits] / (5.2V - 0.2V) = 180 nits.

[0069] In another embodiment, the microcontroller includes a difference operation function of a subtractor, so that the microcontroller can directly process the photosensitivity voltage and the reference voltage output by the ambient light detection circuit to obtain the corresponding light intensity.

[0070] In a second aspect, the present application provides a display panel, specifically including the following embodiments:

[0071] The current LCD (Liquid Crystal Display) display technology has been solidified in daily display and basic functions, such as the familiar industrial control, maintenance market or cost reduction products. Many customers will choose to use more feature-rich display screens when selecting applications, especially for the notebook market. In order to gain a more advantageous position in the market competition, more technologies have been applied to the functional side of notebooks, such as: AMD Freesync (gaming intelligent display technology), OD Function (OverDrive Function), DDS (Dynamic Dimming System, dynamic backlight adjustment technology), etc. In the related technologies listed, each technology will use a photon sensor or ambient light detection circuit as a test tool during testing; such as Figure 8 As shown, the host computer is connected to the photon sensor through the USB interface, and the photon sensor collects the light intensity of the environment in which the display panel is located; then the host computer generates a corresponding test signal based on the acquired light intensity, and sends it to the adapter board through the Type-C or HDMI interface, so that the adapter board lights up the display panel according to the test signal.

[0072] However, different host computers have CPU chips from different manufacturers, and each CPU chip manufacturer has its own corresponding photon sensor. Therefore, there are the following problems in testing the relevant optical data of the display panel: (1) Fragmentation of test tools: Different chip suppliers need to use their proprietary photon sensor equipment, resulting in frequent hardware switching during the test process; (2) Low operational efficiency: The steps for connecting external photon sensors are cumbersome, which increases the test time and complexity; (3) Insufficient system integration: The deep integration of the test module and the display panel has not been achieved, making it difficult to achieve standardized and integrated optical testing.

[0073] Therefore, in order to solve the above problems, the present application provides a display panel, including a display area and a non-display area, wherein the display area includes a pixel array and at least one ambient light detection circuit as described in the above embodiments; the non-display area includes a microcontroller, which is electrically connected to the ambient light detection circuit, and is used to calculate the voltage difference between the photosensitive voltage output by the ambient light detection circuit and the reference voltage, and is also used to obtain the light intensity corresponding to the current environment based on the voltage difference.

[0074] In this embodiment, by integrating the ambient light detection circuit into the interior of the display panel, relevant optical data can be tested by directly connecting to the host computer, avoiding the use of different photon sensors during testing, which leads to longer operation time and cumbersome operation steps.

[0075] It should also be noted that the first, second, third, and fourth resistors in the ambient light detection circuit can be replaced by wires of equivalent resistance. Regarding voltage input, the output signals on the first and second power supply terminals can be replaced by the VGH (Gate High Voltage) and VGL (Gate Low Voltage) commonly used on display panels. The enable signal output by the external enable terminal can also be replaced by a regular pulse signal, STV (Start the Vertical Sync).

[0076] The ambient light detection circuit in this embodiment not only measures the current brightness of the display panel, but also can test the color coordinates of the pixel by placing the ambient light detection circuit in the sub-pixel; Figure 9 As shown, an ambient light detection circuit is placed under each R / G / B subpixel. This is because the photosensitive voltage and brightness displayed by each subpixel are different for different colors. For example, if the display is white, R / G / B will light up simultaneously. The R / G / B data must be processed separately and then integrated by the microcontroller (MCU) to obtain the color coordinates of the white screen. If the display is red, the G / B data is 0, and only the R data needs to be processed.

[0077] exist Figure 9 Three sets of R / G / B ambient light detection circuits are placed in the display. This control group allows the three sets of data to be averaged, making the resulting color coordinates more accurate and avoiding measurement errors. The microcontroller (MCU) processes the voltage data of each sub-pixel to obtain the color coordinates corresponding to the current color.

[0078] In a third aspect, the present application provides a display panel testing method, which specifically includes the following embodiments:

[0079] Figure 10 FIG. 1 is a schematic diagram of the structure of a display panel testing system provided in an embodiment of the present application; FIG. Figure 10 As shown, the display panel testing system includes a host computer and the display panel described in the above embodiment; wherein, the host computer includes a central processing unit and a graphics card, the display panel also includes a timing controller and a source driver, the microcontroller is electrically connected to the central processing unit, the central processing unit is also electrically connected to the graphics card, the graphics card is connected to the timing controller, the timing controller is connected to the source driver, and the source driver is electrically connected to the pixel array.

[0080] Figure 11 FIG. 1 is a flow chart of a display panel testing method provided by an embodiment of the present application; FIG. Figure 11As shown, the display panel testing method specifically includes the following steps:

[0081] Step S100: When receiving a trigger signal sent by the microcontroller, the central processing unit sends a test instruction to the graphics card, causing the graphics card to send display data to the timing controller.

[0082] Specifically, when the test starts, the microcontroller MCU sends a trigger signal RX_0 to notify the central processing unit (CPU) that it has started working. The central processing unit (CPU) then sends a test instruction to the graphics card, notifying the graphics card that it can send display data to the display panel; then, the graphics card sends the display data to the timing controller (TCON) in the display panel through eDP (Embedded DisplayPort, a high-speed digital video interface).

[0083] Step S200: The timing controller converts the display data into signals, generates driving data, and sends the generated driving data to the source driver.

[0084] Specifically, the timing controller TCON converts the display data from an eDP signal into a P2P (Point-to-Point) signal.

[0085] Step S300: The source driver drives the pixel array to display a picture according to the driving data.

[0086] Specifically, the TCON sends a P2P signal to the source driver (Source IC), which converts the digital signal into an analog signal and outputs it to the pixel array in the display panel to display the corresponding image.

[0087] Step S400: The ambient light detection circuit collects the light-sensitive voltage and reference voltage corresponding to the current image.

[0088] Specifically, the ambient light detection circuit collects the photosensitivity voltage and reference voltage corresponding to the current screen. The enable signal TE is set to be consistent with the white screen and black screen cycle given by the system. The ambient light detection circuit sends the collected voltage data to the microcontroller (MCU) for processing.

[0089] In step S500 , the microcontroller obtains light intensity according to the light-sensitive voltage and the reference voltage, and enables the central processing unit to obtain a test result of the display panel according to the light intensity.

[0090] Specifically, the microcontroller (MCU) sends the acquired light intensity TX_1 to the central processing unit (CPU); the central processing unit (CPU) calculates optical parameters (such as response time, brightness uniformity, and color coordinates) based on the TX_1 data and outputs the final test results.

[0091] The test method of this embodiment can be used for conventional notebooks, mobile phone screens, and home TVs, and can also be used in some potential fields, such as: on medical equipment, self-detection detection is performed for the requirement of light intensity greater than 1000nit; on e-sports screens, self-test testing is performed for the response time of high frame rate games less than 5ms. This application integrates the ambient light detection device on the display panel, which greatly saves the verification cycle of the screen factory, such as Gamma, color coordinates, delay time, OD response time, etc. Moreover, since different test equipment will be connected to the computer (such as 410 or Photosensor) during normal optical testing, this can also save the data cable interface connected to the host computer system, and the optical data conversion can be achieved only by connecting the display interface (such as Type-C or HDMI), which is convenient, fast and efficient.

[0092] Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature specified as "first," "second," or "third" may explicitly or implicitly include one or more of the features. In the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0093] In the description of this specification, the reference terms "some embodiments", "exemplarily", etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0094] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application. Therefore, any changes or modifications made in accordance with the claims and description of the present application should fall within the scope of the patent application.

Claims

1. An ambient light detection circuit, characterized in that: The ambient light detection circuit comprises: A first driving module, configured to generate a first driving voltage; a photosensitive module, wherein a first end of the photosensitive module is connected to the first connection end of the first driving module, and is configured to generate a first photosensitive current corresponding to a current environment under the action of the first driving voltage; a light shielding module, a first end of which is connected to the second connection end of the first driving module, and configured to generate a first reference current corresponding to a black state environment under the action of the first driving voltage; a second driving module, wherein a first connection end of the second driving module is connected to the second end of the photosensitive module, and a second connection end of the second driving module is connected to the second end of the light shielding module, and is configured to generate a corresponding first photosensitive voltage and a first reference voltage according to the first photosensitive current and the first reference current, respectively, so that a subsequent load obtains a light intensity corresponding to the current environment according to a difference between the first photosensitive voltage and the first reference voltage; The second driving module is further configured to generate a second driving voltage, so that the photosensitive module is further configured to generate a second photosensitive current corresponding to the current environment under the action of the second driving voltage, and the light shielding module is further configured to generate a second reference current corresponding to the black state environment under the action of the second driving voltage; The first driving module is also used to generate corresponding second photosensitive voltage and second reference voltage according to the second photosensitive current and the second reference current, so that the subsequent load obtains the light intensity corresponding to the current environment according to the difference between the second photosensitive voltage and the second reference voltage.

2. The ambient light detection circuit according to claim 1, wherein: The control end of the photosensitive module is connected to the external enable end, and is used to generate a corresponding photosensitive current under the current environment according to the first driving voltage or the second driving voltage under the control of the enable signal output by the external enable end; The control end of the shading module is connected to the external enable end, and is used to generate a corresponding reference current in a black state environment according to the first driving voltage or the second driving voltage under the control of the enable signal output by the external enable end.

3. The ambient light detection circuit according to claim 1, wherein: The photosensitive module includes: a first photosensitive transistor, wherein the control terminal of the first photosensitive transistor is connected to the external enable terminal, the first terminal of the first photosensitive transistor is connected to the first connection terminal of the first driving module, and the second terminal of the first photosensitive transistor is connected to the first connection terminal of the second driving module; The shading module includes: a second photosensitive transistor, wherein the control end of the second photosensitive transistor is connected to the external enable end, the first end of the second photosensitive transistor is connected to the second connection end of the first driving module, and the second end of the second photosensitive transistor is connected to the second connection end of the second driving module.

4. The ambient light detection circuit according to claim 1, wherein: The first driving module includes: a first transistor, wherein the control terminal of the first transistor is connected to the first power supply terminal, and the first terminal of the first transistor is connected to the control terminal of the first transistor; a first resistor, wherein a first end of the first resistor is connected to the first end of the first transistor, and a second end of the first resistor is connected to the second end of the first transistor; a second transistor, wherein a control terminal of the second transistor is connected to the first power supply terminal, and a first terminal of the second transistor is connected to the control terminal of the second transistor; a second resistor, wherein a first end of the second resistor is connected to the first end of the second transistor, and a second end of the second resistor is connected to the second end of the second transistor; The second end of the first transistor is used as the first connection end of the first driving module, and the second end of the second transistor is used as the second connection end of the first driving module.

5. The ambient light detection circuit according to claim 4, wherein: The second driving module includes: a third transistor, wherein the control terminal of the third transistor is connected to the second power supply terminal, and the first terminal of the third transistor is connected to the control terminal of the third transistor; a third resistor, wherein a first end of the third resistor is connected to the first end of the third transistor, and a second end of the third resistor is connected to the second end of the third transistor; a fourth transistor, wherein a control terminal of the fourth transistor is connected to the second power supply terminal, and a first terminal of the fourth transistor is connected to the control terminal of the fourth transistor; a fourth resistor, wherein a first end of the fourth resistor is connected to the first end of the fourth transistor, and a second end of the fourth resistor is connected to the second end of the fourth transistor; The first end of the third transistor is used as the first connection end of the second driving module, and the first end of the fourth transistor is used as the second connection end of the second driving module.

6. The ambient light detection circuit according to claim 5, wherein: The ambient light detection circuit further includes: an output module, wherein the output module is respectively connected to the first driving module, the second driving module and the subsequent load, and is used to output the first photosensitive voltage and / or the second photosensitive voltage to the subsequent load, and is also used to output the first reference voltage and / or the second reference voltage to the subsequent load.

7. The ambient light detection circuit according to claim 6, wherein: The output module includes: a fifth transistor, wherein a control terminal of the fifth transistor is connected to the second power supply terminal, and a first terminal of the fifth transistor is connected to the second terminal of the first transistor; a sixth transistor, wherein a control terminal of the sixth transistor is connected to the control terminal of the fifth transistor, and a first terminal of the sixth transistor is connected to the second terminal of the second transistor; a seventh transistor, wherein a control terminal of the seventh transistor is connected to the first power supply terminal, a first terminal of the seventh transistor is connected to the second terminal of the third transistor, and a second terminal of the seventh transistor is connected to the second terminal of the fifth transistor; an eighth transistor, wherein a control terminal of the eighth transistor is connected to the control terminal of the seventh transistor, a first terminal of the eighth transistor is connected to the second terminal of the fourth transistor, and a second terminal of the eighth transistor is connected to the second terminal of the sixth transistor; Among them, the second end of the seventh transistor is used as a photosensitive voltage output end, used to output the first photosensitive voltage and / or the second photosensitive voltage; the second end of the eighth transistor is used as a reference voltage output end, used to output the first reference voltage and / or the second reference voltage.

8. A display panel comprising a display area and a non-display area, characterized in that: The display area includes a pixel array and at least one ambient light detection circuit according to any one of claims 1 to 7; The non-display area includes a microcontroller, which is electrically connected to the ambient light detection circuit, and is used to calculate a first voltage difference between a first photosensitive voltage output by the ambient light detection circuit and a first reference voltage, and is also used to calculate a second voltage difference between a second photosensitive voltage output by the ambient light detection circuit and a second reference voltage, and is also used to obtain the light intensity corresponding to the current environment based on the first voltage difference or the second voltage difference.

9. A display panel testing method, characterized in that: Applicable to a display panel test system, the test system comprising a host computer and the display panel according to claim 8, the host computer comprising a central processing unit and a graphics card, the display panel further comprising a timing controller and a source driver, the microcontroller being electrically connected to the central processing unit, the central processing unit being also electrically connected to the graphics card, the graphics card being connected to the timing controller, the timing controller being connected to the source driver, and the source driver being electrically connected to the pixel array; The display panel testing method includes: When receiving a trigger signal sent by the microcontroller, the central processing unit sends a test instruction to the graphics card, causing the graphics card to send display data to the timing controller; The timing controller converts the display data into signals, generates driving data and sends the generated driving data to the source driver; The source driver drives the pixel array to display a picture according to the driving data; The ambient light detection circuit collects a first light-sensitive voltage and a first reference voltage corresponding to the current picture, or a second light-sensitive voltage and a second reference voltage corresponding to the current picture; The microcontroller obtains the light intensity corresponding to the current environment based on the difference between the first photosensitive voltage and the first reference voltage, or obtains the light intensity corresponding to the current environment based on the difference between the second photosensitive voltage and the second reference voltage, so that the central processing unit obtains the test result of the display panel based on the light intensity.

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