A display panel, ambient light detection circuit and ambient light detection method

Abstract

Embodiments of the present application disclose a display panel, an ambient light detection circuit and an ambient light detection method. The display panel comprises a substrate and pixel circuits and light sensing circuits on the substrate; the light sensing circuits are used for detecting ambient light illumination of a space where the display panel is located; the light sensing circuits and the pixel circuits each comprise a transistor, and an active layer of the transistor in the light sensing circuit is made of the same material as an active layer of the transistor in the pixel circuit. Embodiments of the present application can save at least part of a preparation process of an integrated ambient light sensor, avoid the problem of increasing manufacturing cost and time cost caused by additional preparation process of the ambient light sensor, and meanwhile, can make the integrated ambient light sensor have a smaller size and volume, and need not be separately packaged, thereby achieving common saving of preparation cost from two aspects of process and packaging.

Description

Technical Field

[0001] This invention relates to the field of display technology, and more particularly to a display panel, an ambient light detection circuit, and an ambient light detection method. Background Technology

[0002] Currently, the display effect of display devices is greatly affected by the ambient light. For example, the display screen in a car may become unreadable due to ambient light.

[0003] For this type of display device, an ambient light sensor is typically integrated to measure ambient light levels and then adjust the screen brightness accordingly to ensure optimal display quality and a superior viewing experience. However, existing ambient light measurement technologies still suffer from issues such as large integrated structure size and high integration costs. Summary of the Invention

[0004] This invention provides a display panel, an ambient light detection circuit, and an ambient light detection method, which integrates the light-sensing circuit inside the display panel and simultaneously fabricates the light-sensing circuit during the display panel manufacturing process, thereby reducing the size of the light-sensing circuit, saving integration processes, and lowering costs.

[0005] In a first aspect, embodiments of the present invention provide a display panel, including a substrate and pixel circuits and a photosensitive circuit located on the substrate; both the photosensitive circuit and the pixel circuit include transistors, and... When the number of transistors in the pixel circuit is one, the active layer of the transistor in the photosensitive circuit is made of the same material as the active layer of the transistor in the pixel circuit; when the number of transistors in the pixel circuit is at least two, the active layer of the transistor in the photosensitive circuit is made of the same material as the active layer of at least some of the transistors in the pixel circuit.

[0006] Secondly, embodiments of the present invention also provide an ambient light detection circuit, the ambient light detection circuit including a photosensing circuit; the photosensing circuit includes a first transistor, a second transistor and a first capacitor; the first transistor and the second transistor are connected in series between a first voltage terminal and a second voltage terminal, and the first capacitor is connected in parallel across the two ends of the second transistor; the photosensing circuit has a light-receiving side, the first transistor is provided with a light-shielding structure on the light-receiving side, and the second transistor is provided with a passage structure on the light-receiving side; the first transistor and the second transistor are connected to a first node.

[0007] Thirdly, embodiments of the present invention also provide an ambient light detection circuit, executed by the ambient light detection circuit provided in the embodiments of the present invention; the ambient light detection circuit includes a photosensing period and a calculation period; the photosensing period includes a reset phase and an integration phase, the integration phase being located after the reset phase; the calculation period being located after the photosensing period; The ambient light detection method includes: During the reset phase, the first transistor is turned on and the second transistor is turned off. During the integration phase, both the first transistor and the second transistor are turned off. During the calculation cycle, the ambient illuminance of the space where the photosensitive circuit is located is determined based on the voltage change amplitude of the first node during the integration phase.

[0008] This invention provides a display panel, an ambient light detection circuit, and an ambient light detection method. The display panel includes a substrate and pixel circuits and a photosensing circuit located on the substrate. The photosensing circuit detects the ambient light illuminance of the space where the display panel is located. Both the photosensing circuit and the pixel circuit include transistors, and the active layer of the transistors in the photosensing circuit is made of the same material as the active layer of at least a portion of the transistors in the pixel circuit. This invention can save at least part of the fabrication process for the integrated ambient light sensor, avoiding the increased manufacturing and time costs caused by additional ambient light sensor fabrication processes. Simultaneously, it allows the integrated ambient light sensor to have a smaller size and volume, eliminating the need for separate packaging, thus achieving cost savings from both process and packaging perspectives. Attached Figure Description

[0009] Figure 1 and Figure 2 These are schematic diagrams of two integrated ambient light sensor schemes for display devices in related technologies; Figure 3 This is a top view structural diagram of a display panel provided in an embodiment of the present invention; Figure 4 yes Figure 3 A cross-sectional view of the display panel shown. Figure 5 This is a schematic diagram of a pixel circuit provided in an embodiment of the present invention; Figure 6 This is a cross-sectional schematic diagram of another display panel provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the structure of a photosensitive circuit provided in an embodiment of the present invention; Figure 8 yes Figure 7 The diagram shows a signal timing diagram of a photosensitive circuit. Figure 9This is a flowchart of an ambient light detection method provided in an embodiment of the present invention; Figure 10 This is a schematic diagram of another optical sensing circuit provided in an embodiment of the present invention; Figure 11 This is a schematic diagram of a reference circuit provided in an embodiment of the present invention; Figure 12 yes Figure 11 The signal timing diagram of the reference circuit shown is as follows; Figure 13 and Figure 14 These are top view structural diagrams of two other display panels provided in embodiments of the present invention; Figure 15 This is a top view structural diagram of another display panel provided in an embodiment of the present invention; Figure 16 This is a schematic diagram of the layout structure of a photosensitive circuit provided in an embodiment of the present invention; Figure 17 This is a schematic diagram of the layout structure of another photosensitive circuit provided in an embodiment of the present invention; Figure 18 This is a partial layout structure diagram of a display panel provided in an embodiment of the present invention; Figure 19 yes Figure 18 The image shown is a magnified view of point A on the display panel. Figure 20 yes Figure 18 The image shown is a magnified view of point B on the display panel. Figure 21 This is a schematic diagram of the structure of an electrostatic protection circuit provided in an embodiment of the present invention; Figure 22 This is a cross-sectional structural diagram of another display panel provided in an embodiment of the present invention; Figure 23 This is a partial top-view enlarged schematic diagram of another display panel provided in an embodiment of the present invention. Figure 24 This is an enlarged partial cross-sectional view of another display panel provided in an embodiment of the present invention; Figure 25 This is a response curve diagram of the ambient light detection function of a display panel provided in an embodiment of the present invention; Figure 26 This is a partial top view enlarged schematic diagram of another display panel provided in an embodiment of the present invention; Figure 27 This is an enlarged partial cross-sectional view of another display panel provided in an embodiment of the present invention; Figure 28This is a response curve diagram of the ambient light detection function of a display panel provided in another embodiment of the present invention; Figure 29 This is a top view structural diagram of another display panel provided in an embodiment of the present invention; Figure 30 This is a top view structural diagram of another display panel provided in an embodiment of the present invention; Figure 31 and Figure 32 These are top view structural diagrams of two more display panels provided in embodiments of the present invention; Figure 33 This is a top view structural diagram of another display panel provided in an embodiment of the present invention; Figure 34 This is a partial top view enlarged schematic diagram of another display panel provided in an embodiment of the present invention; Figure 35 yes Figure 7 Another signal timing diagram of the photosensitive circuit shown; Figure 36 This is a flowchart of another ambient light detection method provided in an embodiment of the present invention; Figure 37 This is a flowchart of another ambient light detection method provided in an embodiment of the present invention; Figure 38 yes Figure 7 Another signal timing diagram of the photosensitive circuit shown; Figure 39 This is a flowchart of another ambient light detection method provided in an embodiment of the present invention; Figure 40 yes Figure 7 The diagram shows another signal timing diagram for the optical sensing circuit. Detailed Implementation

[0010] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0011] The terminology used in the embodiments of this invention is for the purpose of describing specific embodiments only and is not intended to limit the invention. It should be noted that directional terms such as "upper," "lower," "left," and "right" described in the embodiments of this invention are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of this invention. Furthermore, in the context, it should be understood that when referring to an element being formed "on" or "below" another element, it can be formed not only directly on or below the other element, but also indirectly on or below it through intermediate elements. The terms "first," "second," etc., are used for descriptive purposes only and do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0012] The term "comprising" and its variations as used in this invention are open-ended, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment".

[0013] It should be noted that the concepts of "first" and "second" mentioned in this invention are only used to distinguish the corresponding contents and are not used to limit the order or interdependence.

[0014] It should be noted that the terms "a" and "a plurality of" used in this invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0015] As described in the background section, existing display devices integrate an ambient light sensor to measure the ambient light intensity. Based on the ambient light intensity, the display brightness of the display device is adjusted adaptively. For example, when the ambient light intensity is high, the display brightness of the display device is increased, thereby solving the problem that external objects will have obvious reflections on the display device when the ambient light is strong, which affects the display effect. Figure 1 and Figure 2 These are schematic diagrams of two ambient light sensor integration schemes for display devices in related technologies. (Reference) Figure 1 and Figure 2 Display devices typically include a display panel 1 and a cover glass 2.

[0016] like Figure 1As shown, in one scenario, the ambient light sensor 3 is positioned outside the display panel 1 and encapsulated together with the display panel 1 under the cover glass 2. In other words, the ambient light sensor 3 is an external component relative to the display panel 1. However, in this case, the ambient light sensor 3 needs to be separately packaged, forming a separate component, before being assembled with the display panel 1. This results in a relatively large size, occupying more space in the display device, and the cost of this independent component is also relatively high. Figure 2 As shown, in another scenario, an additional fabrication process for the ambient light sensor 3 is included during the fabrication of the display panel 1, integrating the ambient light sensor 3 into the display panel 1. However, while the ambient light sensor in this case does not require separate packaging, it necessitates multiple additional processes, thus increasing manufacturing costs.

[0017] To address the aforementioned technical problems, embodiments of the present invention provide a display panel. The display panel includes a substrate and pixel circuits and a photosensitive circuit located on the substrate. Both the photosensitive circuit and the pixel circuit include transistors. When the pixel circuit has one transistor, the active layer of the transistor in the photosensitive circuit is made of the same material as the active layer of the transistor in the pixel circuit. When the pixel circuit has at least two transistors, the active layer of the transistor in the photosensitive circuit is made of the same material as the active layer of at least a portion of the transistors in the pixel circuit.

[0018] As a display component, a display panel typically requires multiple light-emitting units. These units work together to display the image. This coordinated light emission is primarily achieved through pixel circuitry. Each unit emits light according to a specific target pattern, driven by its own pixel circuitry, thus forming the desired display image. The pixel circuitry mainly consists of multiple transistors. Corresponding driving signals are provided to the transistors, and the switching of the transistors is controlled based on the timing and level of these signals, thereby controlling the light emission of the light-emitting units. During fabrication, transistors are fabricated on a substrate according to a pre-defined process to form the pixel circuitry.

[0019] In this embodiment of the invention, based on the aforementioned structure and manufacturing process of the display panel, a light-sensing circuit is provided in the display panel. The purpose is to integrate the light-sensing circuit as an ambient light sensor within the display panel. Specifically, the light-sensing circuit includes transistors, and these transistors use the same active layer material as some transistors in the pixel circuit. This allows for the simultaneous fabrication of some transistors in the pixel circuit and the transistors in the light-sensing circuit, at least in the active layer process. This saves on the manufacturing steps of the display panel, making the integration scheme of the ambient light sensor in the display panel relatively economical, thus saving manufacturing costs and time. Furthermore, since the light-sensing circuit integrates with some transistors in the pixel circuit using the same active layer material and manufacturing process, it ensures that the light-sensing circuit has the same structure and size, allowing the ambient light sensor to have a smaller volume and reducing its impact on the structural layout of the display panel.

[0020] The above technical solution, by setting the display panel to include a substrate and pixel circuits and light-sensing circuits located on the substrate, and by using the same active layer material for the transistors in the light-sensing circuit and the pixel circuit, can save at least part of the fabrication process of the integrated ambient light sensor, avoiding the problem of increased manufacturing costs and time costs caused by the additional ambient light sensor fabrication process. At the same time, it can make the integrated ambient light sensor smaller in size and volume, without the need for separate packaging, thus achieving cost savings from both the process and packaging perspectives.

[0021] The above is the core idea of ​​this invention. The technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0022] Figure 3 This is a top view schematic diagram of a display panel according to an embodiment of the present invention. Figure 4 yes Figure 3 The cross-sectional view of the display panel shown is for reference. Figure 3 and Figure 4 The display panel includes a substrate 10 and a pixel circuit 200 and a photosensitive circuit 300 located on the substrate 10. Both the photosensitive circuit 300 and the pixel circuit 200 include transistors T, and the number of transistors in the pixel circuit 200 is at least two. The active layer 21 of the transistor T in the photosensitive circuit 300 is made of the same material as the active layer 21 of at least a portion of the transistor T in the pixel circuit 200.

[0023] Specifically, the display panel can be a liquid crystal display panel, an organic light-emitting diode (OLED) display panel, or an inorganic light-emitting diode (LED) display panel, etc., and the pixel circuit 200 is responsible for driving the corresponding light-emitting units or light-emitting elements to emit light. In a liquid crystal display panel, the light-emitting unit is a liquid crystal cell, and the pixel circuit 200 is responsible for driving the deflection of liquid crystal molecules in the liquid crystal cell to control the transmittance of backlight through the liquid crystal cell. In an organic light-emitting diode (OLED) or inorganic light-emitting diode (LED) display panel, the organic light-emitting device or inorganic light-emitting device is the light-emitting element, and the pixel circuit 200 directly controls whether the organic light-emitting device or inorganic light-emitting device emits light and its brightness. For example, Figure 5 This is a schematic diagram of a pixel circuit provided in an embodiment of the present invention, for reference. Figure 5 The pixel circuit includes 7 thin-film transistors and 1 storage capacitor, i.e., the pixel circuit is a 7T1C pixel circuit. The pixel circuit controls the transistors M1 and M6 to conduct through the light emission control signal Emit, which can make the series path between the first power supply voltage terminal PVDD and the second power supply voltage terminal PVEE conduct, thereby providing a driving circuit to the organic light-emitting element OLED and driving the organic light-emitting element OLED to emit light.

[0024] The light-sensing circuit 300 is responsible for detecting the ambient light intensity of the space where the display panel is located, and it is equivalent to an ambient light sensor integrated into the display panel. The light-sensing circuit 300 may also include a transistor T, which, through corresponding signal control, can obtain an output signal related to the ambient light intensity, thereby realizing ambient light detection. In this embodiment of the invention, the light-sensing circuit 300 is designed similarly to the pixel circuit 200, also having a transistor T, and both transistors T have the same active layer 21 material. Essentially, this allows the active layer 21 of both transistors T to be fabricated simultaneously during the manufacturing process of the display panel, thereby avoiding the need for an additional process to fabricate the light-sensing circuit 300.

[0025] Continue to refer to Figure 4 Specifically, the active layer 21 of the transistor T in the pixel circuit 200 can be fabricated using low-temperature polycrystalline silicon. Some transistors T in the pixel circuit 200 can be configured as P-type channel transistors, such as... Figure 5 The transistors M1, M2, M3, M6, and M7 in the example are examples of N-channel transistors, such as... Figure 5 In the example transistors M4 and M5, the active layer 21 is fabricated using low-temperature polycrystalline silicon (LTPS). This ensures that the transistor T has low leakage current under illumination, thereby enabling precise and controllable switching of the switching transistors and ensuring accurate control of the light emission of the organic light-emitting element (OLED) by the pixel circuit 200. Based on the requirement of using the same fabrication process, the transistor T in the photosensitive circuit 300 can also use LTPS to fabricate the active layer 21, and can be configured as a P-type or N-type channel transistor, similar to some transistors T in the pixel circuit 200.

[0026] It should be noted that, as Figure 5 The transistors in the 7T1C pixel circuit shown are partly P-channel transistors and partly N-channel transistors, which is an example of the present invention. In normal circumstances, the transistors in the pixel circuit can be configured to have the same channel type.

[0027] Continue to refer to Figure 4 In addition to the active layer 21, the transistors in the photosensitive circuit 300 and the pixel circuit 200 also include gate, source, and drain structures. During fabrication, the transistors in the photosensitive circuit 300 and the pixel circuit 200 can be fabricated simultaneously using the same process. Therefore, it can be ensured that not only the active layer 21 of the transistors in the photosensitive circuit 300 can be fabricated simultaneously with the active layer 21 of the transistors in the pixel circuit 200, but the fabrication of the transistors in the photosensitive circuit 300 can be completed simultaneously during the fabrication of the transistors in the pixel circuit 200, without the need for additional fabrication processes for the photosensitive circuit 300, thus saving panel fabrication costs and time.

[0028] Specifically, refer to Figure 4 The display panel also includes a semiconductor layer 20 and a gate metal layer 30, with the gate metal layer 30 located on the side of the semiconductor layer 20 facing away from the substrate 10. The transistors T in the photosensitive circuit 300 and the pixel circuit 200 each include a gate G and an active layer 21, with the gate G located on the gate metal layer 30 and the active layer 21 located on the semiconductor layer 20.

[0029] The transistor T of the pixel circuit 200 includes a gate G and an active layer 21. During the fabrication of the display panel, a semiconductor layer 20 and a gate metal layer 30 are formed. The active layer 21 of the pixel circuit 200 transistor T is formed in the semiconductor layer 20, and the gate G of the pixel circuit 200 transistor T is formed in the gate metal layer 30. Based on the same fabrication process, in this embodiment of the invention, the photosensitive circuit 300 also includes a gate G and an active layer 21. Therefore, in the same fabrication process, the active layer 21 of the photosensitive circuit 300 transistor T can be formed in the semiconductor layer 20, and the gate G of the photosensitive circuit 300 transistor T can be formed in the gate metal layer 30. Exemplarily, the semiconductor layer 20 can be made of low-temperature polycrystalline silicon, and the gate metal layer 30 can be made of metals or alloys such as aluminum or silver.

[0030] It should also be added that, in this embodiment of the invention, the transistor T in the photosensitive circuit 300 can be optionally configured as an N-channel type, such as an NMOS transistor. After fabricating the active layer using low-temperature polycrystalline silicon material, the active layer can be P-type doped, and then N-type heavy doping can be performed on the source and drain regions of the P-doped active layer to form an NMOS transistor. It can be understood that since the entire active layer is P-type doped, the carrier concentration in the transistor channel can be increased, generating a certain amount of photogenerated carriers under illumination, thus forming the photosensitive function utilized in this embodiment of the invention.

[0031] Figure 6 This is a cross-sectional schematic diagram of another display panel provided in an embodiment of the present invention, for reference. Figure 6 In one embodiment, a light-shielding layer 40 may also be provided in the display panel. The light-shielding layer 40 is located between the substrate 10 and the semiconductor layer 20. The light-shielding layer 40 includes a plurality of light-shielding patterns 41. In the photosensitive circuit 300 and the pixel circuit 200, the active layer 21 of the transistor T is projected and overlapped with different light-shielding patterns 41 in the thickness direction.

[0032] refer to Figure 5 and Figure 6 It should be noted that in these two embodiments, the transistors T in the pixel circuit 200 and the photosensitive circuit 300 are essentially top-gate transistors, with their gates G located above the active layer 21. However, for the liquid crystal display panel, the substrate 10 is a transparent substrate, such as a glass substrate, and a backlight needs to be provided on the back side of the substrate 10. In this case, the backlight emitted upwards from the back side will illuminate the transistors T in the pixel circuit 200 and the photosensitive circuit 300, causing the transistors T to generate photo-induced leakage current, interfering with the switching state of the transistors T themselves and the potential of the circuit nodes, thus affecting the normal operation of the pixel circuit 200 and the photosensitive circuit 300. Based on this, as Figure 6 The display panel of the illustrated embodiment essentially has a light-shielding structure, i.e., a light-shielding pattern 41, provided below the transistors T of the pixel circuit 200 and the light-sensing circuit 300, thereby preventing the influence of the light below on the two circuits. The light-shielding layer 40 can be made of a light-shielding material such as a metal material that meets the light-shielding requirements, and there is no limitation here.

[0033] It should be further explained that the light-shielding pattern 41 in the light-shielding layer 40 can be an independently set light-shielding pattern 41 for each transistor T in the pixel circuit 200 and the photosensitive circuit 300, or some transistors T in the pixel circuit 200 can share a large area of ​​light-shielding pattern 41, and some transistors T in the photosensitive circuit 300 can share a large area of ​​light-shielding pattern 41. On the premise of not blocking too much backlight, the setting scheme of the light-shielding pattern 41 in the light-shielding layer 40 can be reasonably set, and there are no restrictions here.

[0034] Furthermore, in other embodiments of the present invention, the transistors T in both the pixel circuit 200 and the photosensing circuit 300 can be configured as bottom-gate transistors, i.e., the gate metal layer 30 is located between the semiconductor layer 20 and the substrate 10. In this case, the backlight can be blocked by the lower gate electrode, preventing the backlight from illuminating the active layer 21 of the transistor T, thus avoiding interference with the switching state of the transistor T itself and the potential of the circuit nodes, and affecting the normal operation of the pixel circuit 200 and the photosensing circuit 300. Of course, the transistors T in both the pixel circuit and the photosensing circuit can also be configured as dual-gate transistors, i.e., having both a bottom gate and a top gate. The above-mentioned gate configuration methods of transistors and their variations all fall within the protection scope of the present invention.

[0035] Figure 7 This is a schematic diagram of a photosensitive circuit provided in an embodiment of the present invention, for reference. Figure 7 The photosensitive circuit 300 includes a first transistor T1, a second transistor T2, and a first capacitor C1. The first transistor T1 and the second transistor T2 are connected in series between a first voltage terminal V1 and a second voltage terminal V2, and the first capacitor C1 is connected in parallel across the two ends of the second transistor T2. The display panel has a light-emitting side. The first transistor T1 has a light-shielding structure on the side near the light-emitting side, and the second transistor T2 has a light-transmitting structure on the side near the light-emitting side. The first transistor T1 and the second transistor T2 are connected to a first node N1.

[0036] In the photosensitive circuit 300, the voltage of the first node N1 changes with the leakage current generated by the second transistor T2 when illuminated. Therefore, the ambient light level of the space where the display panel is located can be determined by the voltage change of the first node N1, thus achieving ambient light detection. Specifically, the first transistor T1 and the second transistor T2 in the photosensitive circuit 300 have different functions. The first transistor T1 is responsible for resetting the voltage of the first node N1, while the second transistor T2 is responsible for generating a response signal in response to the ambient light level to achieve ambient light detection. Due to their different functions, these two transistors need to be provided with different auxiliary structures on the display panel. Specifically, the display panel, as a display device, has a light-emitting side in the display state. To avoid ambient light affecting the display effect, the object detected by the photosensitive circuit 300 is essentially the ambient light level on the light-emitting side of the display panel. Therefore, since the second transistor T2 is responsible for ambient light detection in the photosensitive circuit 300 and needs to acquire light, a light-transmitting structure needs to be provided on the side of the second transistor T2 closest to the light-emitting side of the display panel to ensure that it acquires light. As for the first transistor T1, it is only responsible for the voltage reset of the first node N1 in the photosensitive circuit 300 and does not need to obtain light. Therefore, a light-shielding structure needs to be set on the side of it near the light-emitting side of the display panel to block the ambient light on the light-emitting side and prevent the external ambient light from shining on the first transistor T1 and affecting the voltage of the first node N1, thus interfering with the normal operation of the photosensitive circuit 300.

[0037] Figure 8 yes Figure 7 The diagram shown is a signal timing diagram of a photosensitive circuit. Figure 9 This is a flowchart of an ambient light detection method provided in an embodiment of the present invention, see reference. Figures 7-9 This invention also provides an ambient light detection method, executed by the photosensing circuit 300. The photosensing circuit 300 includes a photosensing period t1 and a calculation period; the photosensing period t1 includes a reset phase t11 and an integration phase t12, with the integration phase t12 following the reset phase t11; the calculation period follows the photosensing period t1. The ambient light detection method includes: S111. During the reset phase, the first transistor is turned on and the second transistor is turned off.

[0038] Among them, reference Figure 7 and Figure 8The gate of the first transistor T1 receives a first control signal, which can be understood as a reset signal. The gate of the second transistor T2 receives a second control signal, which can be understood as a status control signal. Both the first transistor T1 and the second transistor T2 are N-channel transistors. During the reset phase t11, the first control signal (reset signal) is high, turning on the first transistor T1; the second control signal (status control signal) is low, turning off the second transistor T2. At this time, the first capacitor C1 is charged, and the first node N1 is written with a first voltage signal, thus resetting the first node N1.

[0039] S112. During the integration phase, both the first transistor and the second transistor are turned off.

[0040] During the integration phase t12, both the first and second control signals are at low levels, and both the first transistor T1 and the second transistor T2 are turned off. Since the second transistor T2 is under illumination, it generates photo-induced leakage current under ambient light, causing the first capacitor C1 to gradually discharge. During this process, the voltage at the first node N1 gradually decreases. Furthermore, the stronger the ambient light intensity, the greater the photo-induced leakage current of the second transistor T2, the more the first capacitor C1 discharges, and the greater the voltage change amplitude Δv1 at the first node N1. The voltage change amplitude Δv1 at the first node N1 is positively correlated with both the duration of the integration phase t12 and the ambient light intensity.

[0041] S113. During the calculation period, the ambient illuminance of the space where the photosensitive circuit is located is determined based on the voltage change amplitude of the first node during the integration phase.

[0042] The voltage drop at the first node N1 is due to the photogenerated leakage current of the second transistor T2. By acquiring the voltage of the first node N1 in real time during the integration phase t12, the voltage change amplitude Δv1 of the first node N1 during this integration phase t12 can be determined. The voltage change amplitude Δv1 of the first node N1 is the integration effect of the photogenerated leakage current generated by the second transistor T2 during this integration phase t12. Since the voltage change amplitude Δv1 of the first node N1 is positively correlated with the integration time and the ambient illuminance, the magnitude of the ambient illuminance can be calculated or reflected by the voltage change amplitude Δv1 of the first node N1, given the integration time.

[0043] It is important to emphasize that, in this embodiment of the invention, because the active layer of the transistor is fabricated using low-temperature polycrystalline silicon, its photo-generated leakage current under illumination is relatively small. That is, the transistor in the photosensing circuit is not sensitive to illumination. To address this issue, this embodiment of the invention includes an integration phase t12, which accumulates the amount of photo-generated leakage current, thereby accumulating the voltage change amplitude Δv1 generated by the first node N1. This improves the sensitivity of the photosensing circuit to ambient light detection. Furthermore, this embodiment of the invention also includes a first capacitor C1 in the photosensing circuit. Its function is twofold: firstly, to stabilize the voltage of the first node N1 during the reset phase t11; and secondly, to increase the voltage change amplitude of the first node N1 by using an appropriate capacitance value when the photo-generated leakage current of the second transistor T2 is small during the integration phase t12, further improving the sensitivity of the photosensing circuit to ambient light detection.

[0044] Furthermore, it would be added that the channel type of the first transistor T1 and the second transistor T2 in the embodiments of the present invention is not limited to N-type, but can also be set to P-type. Therefore, when a P-type channel transistor is also provided in the pixel circuit, the first transistor T1 and the second transistor T2 can be fabricated simultaneously using the same process as the P-type channel transistors in the pixel circuit, saving processes and costs. Correspondingly, the control signals of the gates of the two transistors have the same... Figure 9 Conversely, the high and low level states can be adaptively designed and changed by those skilled in the art according to their needs, and will not be elaborated here. Furthermore, the second transistor T2 is turned on when the display panel is powered on and off, at which time the second control signal is at a high level.

[0045] In one embodiment, optionally, the channel width-to-length ratio of the first transistor T1 is smaller than that of the second transistor T2. It can be understood that the function of the first transistor T1 is to reset the voltage of the first node N1; that is, the photosensing circuit does not require the first transistor T1 to generate photo-generated leakage current, and the dark-state leakage current of the first transistor T1 should be as small as possible. By setting the first transistor T1 to have a smaller channel width-to-length ratio, the interference of the dark-state leakage current generated by the first transistor T1 on the voltage of the first node N1 can be reduced, ensuring the accuracy of ambient light detection. Conversely, by setting the second transistor T2 to have a larger channel width-to-length ratio, the second transistor T2 can have a larger photo-generated leakage current under illumination, thereby helping to increase the voltage change amplitude of the first node N1 and improve detection sensitivity.

[0046] Figure 10 This is a schematic diagram of another optical sensing circuit provided in an embodiment of the present invention, for reference. Figure 10In an optional embodiment, the first transistor T1 includes a first sub-transistor T11 and a second sub-transistor T12; the first sub-transistor T11 and the second sub-transistor T12 are connected in series between the first voltage terminal V1 and the first node N1, and the gates of the first sub-transistor T11 and the second sub-transistor T12 receive the same control signal.

[0047] In this embodiment, the first transistor T1 includes two sub-transistors connected in series. Compared to a single transistor, the sub-transistors connected in series have a smaller dark-state leakage current under the same channel area. This can also reduce the interference of the dark-state leakage current generated by the first transistor T1 itself on the voltage of the first node N1, thus ensuring the accuracy of ambient light detection.

[0048] Figure 11 This is a schematic diagram of a reference circuit provided in an embodiment of the present invention. Figure 11 In one embodiment, the display panel may further include a reference circuit 400 located on the substrate 10. The reference circuit 400 includes a third transistor T3, a fourth transistor T4, and a second capacitor C2. The third transistor T3 and the fourth transistor T4 are connected in series between a first voltage terminal V1 and a second voltage terminal V2, and the second capacitor C2 is connected in parallel across the fourth transistor T4. The third transistor T3 and the first transistor T1 have the same electrical parameters, the fourth transistor T4 and the second transistor T2 have the same electrical parameters, and the second capacitor C2 and the first capacitor C1 have the same electrical parameters. Both the third transistor T3 and the fourth transistor T4 have a light-shielding structure on the side closest to the light-emitting side; the third transistor T3 and the fourth transistor T4 are connected to the second node N2.

[0049] In the reference circuit 400, the voltage of the second node N2 also changes with the leakage current generated by the fourth transistor T4 in the dark state, i.e., without light. Therefore, by detecting the difference in voltage changes of the first node N1 and the second node N2, the error caused by the leakage current in the dark state can be eliminated, and the ambient light intensity of the space where the display panel is located can be determined more accurately, thus realizing ambient light detection.

[0050] Specifically, Figure 12 yes Figure 11 The signal timing diagram of the reference circuit shown is for reference. Figure 11 and Figure 12In this embodiment of the invention, a reference circuit 400 is also integrated into the display panel. The reference circuit 400 and the photosensitive circuit 300 have the same component composition, namely, two transistors and one capacitor with the same electrical parameters. For the transistors, the identical electrical parameters of the transistors in the reference circuit 400 and the photosensitive circuit 300 can be understood as having the same aspect ratio, channel area, etc., and essentially the same electrical characteristic curves. For the capacitors, the identical electrical parameters of the capacitors in the reference circuit 400 and the photosensitive circuit 300 can be understood as having the same capacitance value, plate area, dielectric, etc. The difference between the reference circuit 400 and the photosensitive circuit 300 is that both transistors in the reference circuit 400 have a light-shielding structure on the side near the light-emitting side of the display panel. Both transistors only generate dark-state leakage current. Ignoring the dark-state leakage current of the third transistor T3, which serves as a reset function, both the third transistor T3 and the fourth transistor T4 generate their own dark-state leakage current. Since the electrical parameters are the same, the dark-state leakage current of the fourth transistor T4 can be considered to be the same as that generated by the third transistor T3. That is, by detecting the voltage change amplitude Δv2 of the second node N2 caused by the dark-state leakage current of the fourth transistor T4 during the integration phase t12, it can be equivalent to the voltage change amplitude of the first node N1 caused by the dark-state leakage current of the second transistor T2 during the integration phase t12. Thus, the interference caused by the dark-state leakage current of the second transistor T2 during the integration phase t12 can be eliminated, and the voltage change amplitude of the first node N1 caused solely by the photogenerated leakage current of the second transistor T2 during the integration phase t12 can be obtained, making the ambient light illuminance detection more accurate.

[0051] The reference circuit 400 in this embodiment needs to be consistent with the photosensing circuit 300, as shown below. Figure 10 The first transistor T1 shown, and the third transistor T3 in the reference circuit 400 can also be configured as two sub-transistors connected in series. In addition, the gate of the transistor in the reference circuit 400 can also be the same as that of the transistor in the photosensitive circuit 300, using a top gate, bottom gate or dual gate structure, and there are no restrictions here.

[0052] Accordingly, based on the reference circuit 400, the ambient light detection method provided in the above embodiments may further include the following steps: S121. During the reset phase, the third transistor is turned on and the fourth transistor is turned off.

[0053] S122. During the integration phase, both the third and fourth transistors are turned off.

[0054] In the above embodiment, S113, during the calculation cycle, the ambient illuminance of the space where the photosensitive circuit is located is determined based on the voltage change amplitude of the first node during the integration phase. Specifically, this may include: S123. During the calculation period, the ambient illuminance of the space where the photosensitive circuit is located is determined based on the difference in voltage change amplitude between the first node and the second node during the integration phase.

[0055] During the integration phase t12, the fourth transistor T4 in the reference circuit 400 will cause a voltage change in the second node N2 due to its own dark-state leakage current. For example, the voltage change of the second node N2 is Δv2. At the same time, the second transistor T2 in the photosensitive circuit 300 will not only generate a photo-generated leakage current due to illumination, causing a voltage change in the first node N1, but will also cause a voltage change in the first node N1 due to its own dark-state leakage current. For example, the voltage change of the first node N1 during this phase is Δv1. Based on this, the voltage change amplitude Δv2 of the second node N2 caused by the dark-state leakage current of the fourth transistor T4 during the integration phase t12 can be equated to the voltage change amplitude of the first node N1 caused by the dark-state leakage current of the second transistor T2 during the integration phase t12. By subtracting the two, the error caused by the dark-state leakage current of the second transistor T2 during the integration phase t12 can be eliminated, and the voltage change amplitude of the first node N1 caused solely by the photogenerated leakage current of the second transistor T2 during the integration phase t12 can be obtained. That is, the difference between Δv1 and Δv2 is the voltage change of the first node N1 caused by the photogenerated leakage current, and thus the ambient illuminance can be determined, which can ensure more accurate ambient illuminance detection.

[0056] Figure 13 and Figure 14 These are top view structural diagrams of two other display panels provided in embodiments of the present invention, for reference. Figure 13 and Figure 14 In one embodiment, optionally, the number of photosensitive circuits 300 and reference circuits 400 are the same, and they correspond one-to-one to form multiple detection channels. The photosensitive circuits 300 and reference circuits 400 in the same detection channel satisfy the following: the third transistor T3 and the first transistor T1 have the same electrical parameters; the fourth transistor T4 and the second transistor T2 have the same electrical parameters; and at least two detection channels satisfy the following: the electrical parameters of the two second transistors T2 are different, and / or the electrical parameters of the two first capacitors C1 are different.

[0057] As mentioned above, when the electrical parameters of the components in the reference circuit 400 and the photosensitive circuit 300 are consistent, the error caused by the dark-state leakage current of the second transistor T2 in the photosensitive circuit 300 can be eliminated through the reference circuit 400, thereby improving the detection accuracy of the photosensitive circuit 300. Based on this, in an optional embodiment of the present invention, multiple photosensitive circuits 300 can be set, and the electrical parameters of the second transistor T2 in at least two photosensitive circuits 300 are different. In this case, the two second transistors T2 with different electrical parameters can generate different photogenerated leakage currents under the same ambient light illuminance, causing the voltage change amplitude of the first node N1 in the two photosensitive circuits 300 to differ. Thus, two photosensitive circuits 300 with different ambient light detection sensitivities can be realized to meet different detection requirements. Similarly, by setting different electrical parameters for the first capacitor C1 in at least two photosensitive circuits 300, when the second transistor T2 in the two photosensitive circuits 300 generates the same photogenerated leakage current under the same ambient light illuminance, the voltage change amplitude of the first node N1 in the two photosensitive circuits 300 will be different. Thus, two photosensitive circuits 300 with different ambient light detection sensitivities can be realized to meet different detection requirements.

[0058] Continue to refer to Figure 7 , Figure 13 and Figure 14 In one embodiment, the photosensing circuit 300 includes a first photosensing circuit 310 and a second photosensing circuit 320; the channel width-to-length ratio of the second transistor T2 in the first photosensing circuit 310 is W / L_1, and the channel width-to-length ratio of the second transistor T2 in the second photosensing circuit 320 is W / L_2; wherein W / L_1 > W / L_2. Further, C1 can also be set to C2.

[0059] At this time, since the capacitance values ​​of the first capacitor C1 in the first photosensitive circuit 310 and the second photosensitive circuit 320 are equal, but the channel width-to-length ratios of their respective second transistors T2 are different, the second transistor T2 in the first photosensitive circuit 310 has a larger channel width-to-length ratio, which allows the second transistor T2 in the first photosensitive circuit 310 to generate a larger photogenerated leakage current under the same ambient light illuminance. The voltage change amplitude of the first node N1 in the first photosensitive circuit 310 will be larger, and higher ambient light detection sensitivity can be obtained.

[0060] Continue to refer to Figure 7 , Figure 13 and Figure 14 In another embodiment, the photosensitive circuit 300 includes a first photosensitive circuit 310 and a second photosensitive circuit 320; the capacitance value of the first capacitor C1 in the first photosensitive circuit 310 is C1, and the capacitance value of the first capacitor C1 in the second photosensitive circuit 320 is C2; wherein, C1 < C2.

[0061] At this time, the channel width-to-length ratio of the corresponding transistors in the first photosensitive circuit 310 and the second photosensitive circuit 320 can be set to be equal. Based on this, by setting the capacitance values ​​of the first capacitor C1 of the two photosensitive circuits to be different, the capacitance value of the first capacitor C1 in the first photosensitive circuit 310 is smaller. Under the same ambient light illuminance, when the second transistor T2 generates the same photogenerated leakage current, the voltage change amplitude of the first node N1 is larger. That is, a higher ambient light detection sensitivity can also be obtained.

[0062] Continue to refer to Figure 13 and Figure 14 In one embodiment, optionally, each photosensitive circuit 300 and each reference circuit 400 are arranged along a first direction X; wherein: the first direction X is a direction parallel to the substrate 10; the photosensitive circuits 300 are arranged adjacent to each other in sequence; some reference circuits 400 are located on one side of all the photosensitive circuits 300 in the first direction X, and some reference circuits 400 are located on the other side of all the photosensitive circuits 300 in the first direction X, such as... Figure 9 As shown; or, all reference circuits 400 are located on the same side of all photosensitive circuits 300 in the first direction X, such as... Figure 10 As shown.

[0063] Since ambient light detection requires determining the voltage variation amplitudes of the first node N1 in the photosensing circuit 300 and the second node N2 in the reference circuit 400, parasitic capacitances exist between circuits and signal lines, causing unnecessary capacitive coupling. The signal of the first node N1, with a large voltage variation amplitude, can easily interfere with the voltage signal of the second node N2 in the reference circuit 400, leading to inaccurate voltage measurement of the second node N2. Conversely, voltage variations in the second node N2 in the reference circuit 400 can also affect the voltage signal of the first node N1 in the photosensing circuit 300, resulting in inaccurate voltage measurement of the first node N1. In this embodiment of the invention, the photosensing circuits 300 and reference circuits 400 are arranged in the same direction, and the reference circuits 400 are positioned on one or both sides of all the photosensing circuits 300. The purpose is to maximize the distance between the reference circuits 400 and the photosensing circuits 300, avoiding mutual interference and ensuring signal accuracy to obtain more accurate ambient light detection results.

[0064] Continue to refer to Figure 14 The first light-sensing circuit 310 can be set to be located on the side of the second light-sensing circuit 320 away from the reference circuit 400.

[0065] In this embodiment, signal interference exists between the photosensitive circuit 300 and the reference circuit 400. Since the first photosensitive circuit 310 has higher sensitivity than the second photosensitive circuit 320, meaning there is more significant signal interference between them, this embodiment places the more sensitive first photosensitive circuit 310 further away from the reference circuit 400. This reduces signal interference between the first photosensitive circuit 310 and the reference circuit 400, ensuring the accuracy of ambient light detection by the first photosensitive circuit 310.

[0066] It should be noted that both the first photosensitive circuit 310 and the second photosensitive circuit 320 are provided with a corresponding reference circuit 400. The first photosensitive circuit 310 is positioned away from the reference circuit 400. This can be understood as the reference circuits 400 corresponding to the first photosensitive circuit 310 and the second photosensitive circuit 320 being placed on one side of the second photosensitive circuit 320, while the first photosensitive circuit 310 is placed on the other side of the second photosensitive circuit 320. The first photosensitive circuit 310 and the reference circuit 400, which belong to the same detection channel, are not adjacent to each other in terms of position.

[0067] Figure 15 This is a top view structural diagram of another display panel provided in an embodiment of the present invention, for reference. Figure 15 In this embodiment, the light sensing circuit 300 may include an illuminance detection circuit 301 and / or at least one color temperature detection circuit 302; the light-receiving side of the second transistor T2 in the illuminance detection circuit 301 is provided with a light-transmitting hole; the light-receiving side of the second transistor T2 in the color temperature detection circuit 302 is provided with a light-transmitting hole, and a color resist is provided in the light-transmitting hole.

[0068] Continue to refer to Figure 15 In one specific embodiment, at least one color temperature detection circuit 302 includes a first color temperature detection circuit 3021, a second color temperature detection circuit 3022, and a third color temperature detection circuit 3023; a red color resist is disposed in the light-transmitting hole corresponding to the second transistor T2 in the first color temperature detection circuit 3021; ​​a green color resist is disposed in the light-transmitting hole corresponding to the second transistor T2 in the second color temperature detection circuit 3022; and a blue color resist is disposed in the light-transmitting hole corresponding to the second transistor T2 in the third color temperature detection circuit 3023.

[0069] In the light-sensing circuit 300, the second transistor T2 generates photo-induced leakage current when affected by illumination. This light is not limited to white light but can also be light of different wavelengths. By detecting light of a specific wavelength, the illuminance of that wavelength in the current environment can be obtained, reflecting the color temperature of the current environment. It can be understood that the second transistor T2 in the light-sensing circuit 300 needs to receive illumination for ambient light detection. The light-receiving side of the second transistor T2 can be understood as the side of the second transistor T2 closest to the light-emitting side of the display panel, as mentioned above. A light-passing hole is provided on this side to ensure that ambient light enters the second transistor T2, generating photo-induced leakage current. By placing a color resistor 60 in the light-passing hole on the light-receiving side of the second transistor T2, light of a specific wavelength in the ambient light can be filtered out, allowing the second transistor T2 to detect only the illuminance of that specific wavelength, thus achieving color temperature detection. In practical applications, the red, green and blue color resistances can be set to 60 on the panel to meet the detection of the color temperature of the three colors. This allows for convenient and adaptive adjustment of the display panel's color temperature to suit the current ambient light color temperature and ensure the display effect.

[0070] It is also understandable that the color temperature detection circuit 302 can also be configured with a corresponding reference circuit 400. Each color temperature detection circuit 302 and a reference circuit 400 can also form a color temperature detection channel. The reference circuit 400 can eliminate the error caused by the dark state leakage current of the second transistor T2 in the color temperature detection circuit 302, thus ensuring the accuracy of color temperature detection.

[0071] Figure 16 This is a schematic diagram of the layout structure of a photosensitive circuit provided in an embodiment of the present invention, with reference to... Figure 7 and Figure 16 In the layout of this photosensitive circuit, the first transistor T1 and the second transistor T2 both include a gate G, a first electrode S, and a second electrode D; the first capacitor C1 includes a first plate C+ and a second plate C-; the first plate C+ of the first capacitor C1 is connected to the second electrode D of the first transistor T1 and the first electrode S of the second transistor T2 at the first node N1; the second plate C- of the first capacitor C1 is connected to the second electrode D of the second transistor T2; the first plate C+, the first electrode S and the second electrode D of the first transistor T1 and the first electrode S and the second electrode D of the second transistor T2 are located on the same metal layer; the second plate C- is located on the same metal layer as the gate G of the first transistor T1 and the gate G of the second transistor T2.

[0072] In this embodiment, the first electrode S can be understood as the source, and the second electrode D can be understood as the drain. Essentially, this embodiment involves setting the first electrode C+ of the first capacitor C1 in the metal layer containing the first electrode S and the second electrode D of the first transistor T1 and the first electrode S and the second electrode D of the second transistor T2, and setting the second electrode C- of the first capacitor C1 in the metal layer containing the gate G of the first transistor T1 and the gate G of the second transistor T2. This allows for the formation of two overlapping electrodes in the two metal layers, thus constituting the first capacitor C1. Furthermore, since the first electrode C+ and the second electrode C- can be relatively freely positioned in the two metal layers without interfering with the layout of other electrodes in the same metal layer, the areas of the first electrode C+ and the second electrode C-, as well as their overlapping area, can be reasonably set. This allows for the flexible determination of the capacitance value of the first capacitor C1, satisfying the capacitance requirements of the first capacitor C1 proposed by different photosensitive circuits based on sensitivity. Furthermore, by placing the two plates of the first capacitor C1 and the different electrodes of the transistor on the same metal layer, the first capacitor C1 can be fabricated simultaneously when the transistor electrodes are fabricated, without the need for an additional capacitor fabrication process. This allows the entire photosensitive circuit to be fabricated simultaneously with the pixel circuit fabrication process, significantly saving manufacturing and time costs.

[0073] Figure 17 This is a schematic diagram of another optical sensing circuit layout provided in an embodiment of the present invention, for reference. Figure 7 and Figure 17 In the layout of the photosensitive circuit, the first capacitor C1 includes a first plate C+ and a second plate C-; the first plate C+ of the first capacitor C1 is connected to the second terminal D of the first transistor T1 and the first terminal S of the second transistor T2 at the first node N1; the second plate C- of the first capacitor C1 is connected to the second terminal D of the second transistor T2; the display panel also includes an output signal line 501, a first voltage signal line 502 and a second voltage signal line 503; the output signal line 501 is connected to the first node N1, the first voltage signal line 502 is connected to the first voltage terminal V1, and the second voltage signal line 503 is connected to the second voltage terminal V2; the output signal line 501 and the second voltage signal line 503 extend in parallel at least partially.

[0074] In this embodiment, the first capacitor C1 is essentially formed by the parallel extensions of the output signal line 501 and the second voltage signal line 503. In these parallel extensions, the output signal line 501 is multiplexed as the first plate C+ of the first capacitor C1, and the second voltage signal line is multiplexed as the second plate C- of the first capacitor C1. It is understood that in the display panel, the pixel circuit 200 needs to be provided with corresponding driving signal lines, and the photosensitive circuit also needs to be provided with output signal line 501, first voltage signal line 502, and second voltage signal line 503. Therefore, when fabricating the driving signal lines of the pixel circuit 200, the aforementioned one or more signal lines of the photosensitive circuit can be fabricated simultaneously in one or more metal layers. This eliminates the need for an additional fabrication process for the photosensitive circuit's signal lines. Furthermore, since the first capacitor C1 is formed through the parallel extension between the output signal line 501 and the second voltage signal line 503, there is also no need for an additional fabrication process for the first capacitor C1. Similarly, the entire photosensitive circuit can be fabricated simultaneously with the pixel circuit 200 fabrication process, significantly saving manufacturing costs and time. The first capacitor C1, which is formed by the parallel extended output signal line 501 and the second voltage signal line 503, can also have its capacitance value freely designed by reasonably setting the line width and the line spacing of the two, so as to meet the capacitance value requirements of the first capacitor C1 proposed by different photosensitive circuits based on sensitivity.

[0075] It should be noted that the implementation of the first capacitor C1 in the photosensing circuit 300 in this embodiment of the invention is not limited to the following. Figure 16 The method shown is to achieve this by overlapping the two plates, or, as... Figure 17 The method shown is to extend the two signal lines in parallel. It can also be achieved by using both of the above methods at the same time. This is not a limitation.

[0076] Figure 18 This is a partial layout diagram of a display panel provided in an embodiment of the present invention. Figure 19 yes Figure 18 The image shown is a magnified view of a portion of the display panel at point A. Figure 20 yes Figure 18 The enlarged view of point B in the display panel shown is for reference. Figure 7 , Figures 18-20The display panel also includes a first voltage signal line 502, a second voltage signal line 503, a first control signal line 504, a second control signal line 505, and an electrostatic discharge protection circuit 600; the first voltage signal line 502 is connected to the first voltage terminal V1, the second voltage signal line 503 is connected to the second voltage terminal V2, the first control signal line 504 is connected to the gate G of the first transistor T1, and the second control signal line 505 is connected to the gate G of the second transistor T2; at least one of the first voltage signal line 502, the second voltage signal line 503, the first control signal line 504, and the second control signal line 505 is connected to the corresponding electrostatic discharge protection circuit 600.

[0077] Continue to refer to Figures 18-20 In one specific embodiment, the electrostatic discharge (ESD) protection circuit 600 includes a first ESD protection circuit 601, a second ESD protection circuit 602, a third ESD protection circuit 603, and a fourth ESD protection circuit 604. A first voltage signal line 502 is connected to the first ESD protection circuit 601, a second voltage signal line 503 is connected to the second ESD protection circuit 602, a first control signal line 504 is connected to the third ESD protection circuit 603, and a second control signal line 505 is connected to the fourth ESD protection circuit 604. The first voltage signal line 502, the second voltage signal line 503, the first control signal line 504, and the second control signal line 505 extend along a first direction X and are arranged along a second direction Y. The first ESD protection circuit 601, the second ESD protection circuit 602, the third ESD protection circuit 603, and the fourth ESD protection circuit 604 are arranged along the second direction Y.

[0078] The electrostatic discharge (ESD) protection circuit 600 is an auxiliary circuit used to discharge and suppress high-voltage electrostatic discharge, protecting electronic components. In this embodiment of the invention, the ESD protection circuit 600 is set up along the signal lines corresponding to the photosensitive circuit. This discharges static electricity generated on the panel, preventing it from being transmitted to the photosensitive circuit via the signal lines and damaging the components, thus causing the ambient light detection function to fail. In this embodiment of the invention, corresponding ESD protection circuits 600 are provided for the four signal lines that provide signals to the photosensitive circuit (excluding the output signal line): the first voltage signal line 502, the second voltage signal line 503, the first control signal line 504, and the second control signal line 505. This effectively blocks the electrostatic conduction path and reduces the risk of electrostatic damage to the photosensitive circuit.

[0079] Figure 21 This is a schematic diagram of an electrostatic discharge protection circuit provided in an embodiment of the present invention. (Refer to...) Figures 18-21First, the electrostatic discharge (ESD) protection circuit 600 is typically implemented by connecting the high-voltage signal line VGH and the low-voltage signal line VGL already present within the panel. One ESD protection circuit 600 can be connected to any one of the following signal lines: the first voltage signal line 502, the second voltage signal line 503, the first control signal line 504, and the second control signal line 505. When no high-voltage ESD is generated on the signal line, the ESD protection circuit 600 is nearly open, not affecting the transmission of normal signals on the signal line. When high-voltage ESD is generated on the signal line, the transistor in the ESD protection circuit 600 is automatically activated by the voltage difference, turning on the ESD protection circuit 600. This directs the high-voltage ESD to the low-level voltage line and further to ground, preventing the ESD from being conducted to the photosensitive circuit via the signal line.

[0080] Figure 22 This is a cross-sectional structural diagram of another display panel provided in an embodiment of the present invention, for reference. Figure 22 The display panel also includes a black matrix layer 71 and an ink layer 72. In the thickness direction, the black matrix layer 71 is located on the side of the pixel circuit 200 and the photosensitive circuit 300 away from the substrate 10, and the ink layer 72 is located on the side of the black matrix layer 71 away from the pixel circuit 200 and the photosensitive circuit 300. The black matrix layer 71 is provided with a first light-transmitting hole 51, and the ink layer 72 is provided with a second light-transmitting hole 52. The second transistor T2, the first light-transmitting hole 51, and the second light-transmitting hole 52 overlap at least partially in the thickness direction.

[0081] Taking a liquid crystal display panel as an example, those skilled in the art will know that a liquid crystal display panel contains a black matrix layer 71 and an ink layer 72. The black matrix layer 71 has a color resist 60 for each liquid crystal cell. The color resist 60 controls the color of light emitted from each liquid crystal cell, and different color resists are used to achieve color matching between sub-pixels, resulting in a color-adjustable pixel unit. The ink layer 72 is responsible for absorbing ambient light, reducing reflection, and ensuring viewing quality. Based on this, in this embodiment of the invention, a first light-transmitting hole 51 is provided in the black matrix layer 71, and a second light-transmitting hole 52 is provided in the ink layer 72. The two light-transmitting holes at least partially overlap with the second transistor T2 in the thickness direction, ensuring that ambient light can sequentially pass through the two light-transmitting holes and illuminate the second transistor T2, thus placing the second transistor T2 in an illuminated state for ambient light detection. It is understood that since the black matrix layer 71 and the ink layer 72 are both inherent structures of the display panel, and both require light-transmitting holes, this embodiment of the invention utilizes the fabrication process of the black matrix layer 71 and the ink layer 72 to perform illumination design for the photosensitive circuit without adding an extra fabrication process. This allows the entire photosensitive circuit to be fabricated synchronously with the fabrication process of the display panel, significantly saving manufacturing costs and time.

[0082] It should be added that the second transistor T2 here can be understood as an integral structure composed of the gate, source / drain, and active layer. The fact that the first light-passing hole 51, the second light-passing hole 52, and the second transistor T2 overlap at least partially in the thickness direction means that at least part of the ambient light can be directly projected onto the second transistor T2 and can be projected into the channel of the second transistor T2 to generate photo-generated leakage current. In other words, the positions of the two light-passing holes need to ensure that the second transistor T2 can be photosensitive. In addition, since the first transistor T1 needs to be in a light-shielding state, no light-passing holes are set on the black matrix layer 71 and the ink layer 72 corresponding to the first transistor T1, i.e., the position where it overlaps with the first transistor T1. The black matrix layer 71 and the ink layer 72 are used to make the first transistor T1 have a light-shielding structure on the side near the light-emitting side of the display panel.

[0083] Continue to refer to Figure 22 Optionally, the number of light-sensing circuits 300 and first light-transmitting holes 51 are both multiple, and the second transistor T2 and the first light-transmitting hole 51 are one-to-one overlapping in the thickness direction; the number of second light-transmitting holes 52 is at least one, and multiple first light-transmitting holes 51 and the same second light-transmitting hole 52 overlap in the thickness direction.

[0084] In this design, the first light-passing holes 51 in the black matrix layer 71 are configured one-to-one with the photosensitive circuits 300, allowing precise control of ambient light entering the corresponding second transistor T2 through the first light-passing holes 51 without affecting other transistors. The second light-passing holes 52 in the ink layer 72 overlap with the multiple first light-passing holes 51 in the thickness direction, essentially making the second light-passing holes 52 have a relatively larger area, with multiple first light-passing holes 51 sharing a single, larger area second light-passing hole 52. Therefore, while ensuring the illumination requirements of the photosensitive circuits 300, this design solves the problems of low patterning precision in the ink layer 72 and the inability to precisely set light-passing holes for each second transistor T2, adapting to existing ink layer 72 fabrication processes and reducing fabrication difficulty.

[0085] For example, the light-sensing circuit 300 may specifically include two illuminance detection circuits 301 and three color temperature detection circuits 302, namely a first illuminance detection circuit 3011, a second illuminance detection circuit 3012, a first color temperature detection circuit 3021, a second color temperature detection circuit 3022, and a third color temperature detection circuit 3023. The two illuminance detection circuits and the three color temperature detection circuits 302 are respectively provided with a first light-transmitting aperture 51, and different colored color resists 60 are provided in the first light-transmitting aperture 51 corresponding to the three color temperature detection circuits 302. Specifically, a red color resist 61 is provided in the first light-transmitting aperture 51 corresponding to the second transistor T2 in the first color temperature detection circuit 3021; ​​a green color resist 62 is provided in the first light-transmitting aperture 51 corresponding to the second transistor T2 in the second color temperature detection circuit 3022; and a blue color resist 63 is provided in the first light-transmitting aperture 51 corresponding to the second transistor T2 in the third color temperature detection circuit 3023.

[0086] It is understandable that when the light-sensing circuit 300 is the color temperature detection circuit 302, the process of setting the color resist through the opening of the black matrix layer 71 is used. At the same time, the color resist is set in the first light-passing hole 51 corresponding to the second transistor T2 of the color temperature detection circuit 302. This can achieve the color temperature detection function while ensuring that no additional process is required for the color temperature detection circuit 302, thus saving costs and improving production efficiency.

[0087] Continue to refer to Figure 22 Alternatively, the display panel may also include a polarizer 73, which is located between the black matrix layer 71 and the ink layer 72 in the thickness direction; the polarizer 73 overlaps with the first light-transmitting hole 51 and the second light-transmitting hole 52 in the thickness direction.

[0088] The polarizer 73 overlaps with the two light-transmitting holes, indicating that the polarizer 73 does not need to have a light-transmitting hole for the second transistor T2 in the photosensitive circuit 300. Furthermore, since ambient light passes through the polarizer 73 as it enters the second transistor T2 through the second light-transmitting hole 52 and the first light-transmitting hole 51, the polarizer 73 can block light rays that are not perpendicular to the transmission axis of the polarizer 73. This weakens the incident light and prevents the problem that excessive light intensity will cause the voltage change of the first node N1 in the photosensitive circuit 300 to exceed the preset change range, thus failing to accurately detect ambient light.

[0089] It will be understood by those skilled in the art that, as Figure 22The display panel shown is a liquid crystal display panel. The substrate 10 and the pixel circuit 200 disposed thereon essentially constitute an array substrate, while the other side of the liquid crystal layer 80 is essentially a color filter substrate. In addition to the black matrix layer 71 and color resist 60, the color filter substrate also includes a glass substrate 70. In fabricating the liquid crystal display panel, the array substrate and the color filter substrate must first be fabricated separately. Then, multiple liquid crystal cells are formed by aligning the two substrates and filling the space between them with a liquid crystal layer. Afterward, a polarizer 73 and an ink layer 72 are formed on the side of the glass substrate 70 facing away from the black matrix layer 71. It can be understood that during the fabrication of the color filter substrate, the glass substrate 70 is responsible for providing support; in other words, the glass substrate 70 acts as a carrier, and the black matrix layer 71, color resist 60, and other functional layers are fabricated on its surface. It should be noted that the black matrix layer 71 and color resist 60 in this embodiment are not limited to the following. Figure 22 As shown, the image is fabricated on a color filter substrate. In some optional embodiments, the black matrix layer 71 and the color resist 60 can also be disposed on the array substrate. Specifically, they can be fabricated on the side of the pixel circuit 200 and the photosensitive circuit 300 away from the substrate 10. Those skilled in the art can make corresponding designs according to actual needs, which is not a limitation.

[0090] Figure 23 This is a partial top view enlarged schematic diagram of another display panel provided in an embodiment of the present invention. Figure 24 This is an enlarged partial cross-sectional view of another display panel provided in an embodiment of the present invention, for reference. Figure 23 and Figure 24 Optionally, the first light-transmitting aperture 51 satisfies: ;in, The width of the first light-transmitting aperture 51 in the third direction Z. α is the width of the second transistor T2 in the third direction Z, α is the maximum viewing angle when the display panel is at its maximum responsivity in the third direction Z, and h is the distance between the second transistor T2 and the black matrix layer 71 in the thickness direction of the display panel; the third direction Z is any direction parallel to the substrate 10.

[0091] To meet the needs of different application scenarios, the ambient light detection function of the display panel needs to have a specific response curve at different viewing angles, that is, the light sensing circuit has a specific response at different viewing angles. Figure 25 This is a response curve diagram of the ambient light detection function of a display panel provided in an embodiment of the present invention, for reference. Figure 25 It is known that, in a certain direction, the ambient light detection function of the display panel needs to have a 100% responsiveness within the incident angle range of -α to α. Based on this, the size of the first light-transmitting hole 51 in this embodiment of the invention satisfies... This ensures that all external light rays can be incident on the second transistor T2 within the incident angle range of -α to α without being blocked, thereby achieving 100% responsivity and meeting the detection requirements of the corresponding scenario.

[0092] Figure 26 This is a partial top view enlarged schematic diagram of another display panel provided in an embodiment of the present invention. Figure 27 This is an enlarged partial cross-sectional view of another display panel provided in an embodiment of the present invention, for reference. Figure 26 and Figure 27 The black matrix layer 71 includes a first portion 711 and a second portion 712; the first portion 711 and the first light-transmitting hole 51 do not overlap in the thickness direction of the display panel, while the second portion 712 overlaps with the first light-transmitting hole 51 in the thickness direction of the display panel.

[0093] Figure 28 This is a response curve diagram of the ambient light detection function of a display panel provided in another embodiment of the present invention, for reference. Figure 26 It is known that in specific application scenarios of in-vehicle central control screens, the ambient light detection function of the display panel requires an M-shaped response curve, as shown in the figure. When the incident angle is 0°, i.e., perpendicular incidence, the required response is not 100%. That is, the ambient light detection requirement for perpendicularly incident light is not high in this application scenario. Based on this, in this embodiment, the black matrix layer 71 is set as a first part 711 and a second part 712. The first part 711 does not overlap with the first light-transmitting hole 51; in essence, the first part 711 is responsible for surrounding the first light-transmitting hole 51. The second part 712 overlaps with the first light-transmitting hole 51, indicating that the second part 712 is set in the first light-transmitting hole 51 and is responsible for blocking the corresponding position of the first light-transmitting hole 51 to meet the specific response requirements in the above-mentioned special scenario.

[0094] Continue to refer to Figure 26 and Figure 27 Specifically, the second part and the second transistor T2 satisfy: ;in, The width of the second part in the third direction Z. F is the width of the photosensitive part of the second transistor T2 in the third direction Z, and F is the target responsivity of the display panel at a 0° viewing angle in the third direction Z; the third direction Z is any direction parallel to the substrate 10.

[0095] In this embodiment, the dimensions of the second portion and the second transistor T2 satisfy... This ensures that the second section blocks light rays incident perpendicularly at a 0° viewing angle, meeting the application requirements of in-vehicle central control screens where the responsiveness to perpendicularly incident light is not high. It is understood that the aforementioned second section can be configured to overlap with the geometric center of the second transistor T2 in the thickness direction, thereby ensuring the second section's blocking effect on light rays incident perpendicularly to the second transistor T2, achieving the effect corresponding to... Figure 28 The M-type response curve is shown.

[0096] Furthermore, it should be noted that the aforementioned responsivity curve refers to the response requirements for light at different incident angles within a specific plane of the vertical display panel. It can be understood that since there are an infinite number of planes for a vertical display panel—for example, taking a vehicle infotainment screen—the aforementioned responsivity curve could be a horizontal curve extending to the left and right along the plane of the vertical display panel, or a vertical curve extending to the plane of the vertical display panel. Therefore, based on the requirements for the responsivity curves of different planes of the vertical display panel, and the aforementioned formula… The dimensions of the second portion in a specific direction can be calculated, thus obtaining the specific shape and size of the second portion. In this embodiment of the invention, the second portion can be rectangular, strip-shaped, or cross-shaped to meet the responsiveness requirements in different directions under different application scenarios. Ambient light is detected based on the responsiveness requirements, and feedback is used to control the display effect, improving the viewing effect in different directions and enhancing the user experience.

[0097] Figure 29 This is a top view structural diagram of another display panel provided in an embodiment of the present invention, for reference. Figure 29 The display panel also includes a light strip 90; there are multiple light-sensing circuits 300 arranged sequentially, and the arrangement direction of the multiple light-sensing circuits 300 and the extension direction of the light strip 90 are both parallel to the same side of the substrate 10.

[0098] Corresponding to the liquid crystal display panel, a backlight module is required. The backlight module needs to include LED strips 90, which generate heat. When close to the LED strips 90, the photosensitive circuits 300 integrated in the display panel are affected by temperature, causing changes in the electrical characteristics of the transistors within them. In this embodiment of the invention, the LED strips 90 are located on one side of the panel, and their extension direction is parallel to one side edge of the substrate 10, indicating that the backlight module is essentially a side-lit backlight module. Arranging the photosensitive circuits 300 parallel to the same side edge of the substrate 10, i.e., arranging them sequentially along the same side edge of the substrate 10, ensures that each photosensitive circuit 300 is at the same distance from the LED strips 90 and experiences the same temperature influence. This avoids uneven heating of different photosensitive circuits 300, which could lead to different changes in the electrical characteristics of the transistors. Ambient light detection can be performed under the same environmental conditions, ensuring the accuracy of ambient light detection and avoiding unnecessary errors. It is understandable that when multiple reference circuits 400 are set in the display panel for each photosensitive circuit 300, the multiple reference circuits 400 and the multiple photosensitive circuits 300 can be arranged sequentially along the same side of the substrate 10. This ensures that the transistors in the reference circuits 400 and the transistors in the photosensitive circuits 300 are heated in the same way, ensuring the accuracy of the reference function and improving the light detection accuracy of the photosensitive circuits 300.

[0099] Figure 30 This is a top view structural diagram of another display panel provided in an embodiment of the present invention, for reference. Figure 30 In one embodiment, the display panel further includes a display area AA and a non-display area NA, with pixel circuitry 200 located in display area AA and photosensitive circuitry 300 located in non-display area NA. Non-display area NA is provided with a first bonding area NA11, a second bonding area NA12, a first fan-out area NA21, and a second fan-out area NA22. The first fan-out area NA21 is located between the first bonding area NA11 and display area AA, and the second fan-out area NA22 is located between the second bonding area NA12 and display area AA. Photosensitive circuitry 300 is located between the first fan-out area NA21 and the second fan-out area NA22.

[0100] In this embodiment, the non-display area NA of the display panel is provided with two bonding areas, left and right. The signal lines located on the left and right sides of the display area AA can be connected to the two bonding areas respectively through the left and right fan-out areas. Placing the light-sensing circuit 300 responsible for ambient light detection between the first fan-out area NA21 and the second fan-out area NA22 of the non-display area NA not only avoids affecting the layout of the pixel circuit 200 in the display area AA and the arrangement and direction of the fan-out traces in the two fan-out areas, minimizing interference with the display panel's own layout, but also reduces the layout design difficulty of the panel and the light-sensing circuit, reduces integration difficulty, and saves costs. It should also be noted that the non-display area NA of the display panel in this embodiment is not limited to two bonding areas; correspondingly, it can have more than two fan-out areas. When multiple bonding areas and multiple fan-out areas are set, the light-sensing circuit 300 can be placed between any two fan-out areas according to the above principle, avoiding the fan-out traces of the fan-out areas, preventing the integration of the light-sensing circuit 300 from interfering with the layout of the fan-out traces, and simplifying the wiring design of the bezel area.

[0101] Figure 31 and Figure 32 These are top view structural diagrams of two more display panels provided in embodiments of the present invention, for reference. Figure 30 and Figure 32 The display panel includes a display area AA and a non-display area NA. Pixel circuitry 200 is located in the display area AA; light-sensing circuitry 300 is located in the non-display area NA, and a bonding area NA1 is provided in the non-display area NA. In other embodiments, the light-sensing circuitry 300 may also be located between the bonding area NA1 and the display area AA, such as... Figure 31 As shown, or, the light-sensing circuit 300 is located on the side of the display area AA away from the bonding area NA1, as shown. Figure 32 As shown.

[0102] In this embodiment of the invention, the light-sensing circuit 300 needs to be located in the non-display area NA near the display area AA, so as to more accurately detect the illuminance of the area displayed by the display panel. Therefore, as... Figure 31 and Figure 32 In the display panel shown, the light-sensing circuit 300 can be located on the lower or upper side of the display area AA. For example... Figure 31As shown, when the light-sensing circuit 300 is positioned below the display area AA, and a bonding area NA1 is provided in the non-display area NA below the display area AA, the light-sensing circuit 300 can be positioned directly above the bonding area NA1. In this case, when the signal lines of the display area AA are connected to the bonding area NA1 through the fan-out traces of the non-display area NA, because there are relatively few signal lines in the middle area of ​​the display area, correspondingly, there are relatively few or no fan-out traces directly above the bonding area NA1. Positioning the light-sensing circuit 300 directly above the bonding area NA1 not only ensures a close distance between the light-sensing circuit 300 and the display area AA, but also avoids excessive interference with the arrangement of the fan-out traces in the lower non-display area NA, facilitating the wiring design of the lower bezel. Furthermore, since the light-sensing circuit 300 is positioned directly above the bonding area NA1, the length of its output signal line connecting to the bonding area NA1 can also be shorter, which can to some extent prevent the output signal of the light-sensing circuit 300 from being interfered with during transmission, ensuring the accuracy of illuminance detection.

[0103] Figure 33 This is a top view structural diagram of another display panel provided in an embodiment of the present invention, for reference. Figure 31 and Figure 33 The display panel also includes a bonding area NA1. The bonding area NA1 is located in the non-display area NA, and a bonding pad is provided in the bonding area NA1. The photosensitive circuit 300 is electrically connected to the bonding pad; the bonding pad is used to bond the driver chip IC or the flexible circuit board FPC.

[0104] Figure 34 This is a partial top view enlarged schematic diagram of another display panel provided in an embodiment of the present invention, for reference. Figure 34 The display panel includes a display area AA and a non-display area NA. The pixel circuit 200 is located in the display area AA. The light sensing circuit 300 is located in the non-display area NA. The display panel also includes multiple output signal lines 501 and multiple shielded signal lines 506. Both the output signal lines 501 and the shielded signal lines 506 are located in the non-display area NA. The output signal lines 501 are connected to each light sensing circuit 300 in a one-to-one correspondence. At least one shielded signal line 506 is provided between two adjacent output signal lines 501. The shielded signal line 506 is provided with a fixed signal.

[0105] The output signal line 501 is responsible for outputting the voltage signal of the first node N1 of the photosensitive circuit 300 to an external processing module such as a processing chip for processing. During transmission, it is susceptible to interference from other output signal lines 501 of the photosensitive circuit 300 and other signal lines. Therefore, in this embodiment, a shielding signal line 506 is provided between two adjacent output signal lines 501, through which a fixed signal is passed. This can be used to stabilize the output signal on the output signal line 501, improve the transmission quality of the output signal, and enhance the accuracy of ambient light detection. Specifically, the fixed signal on the shielding signal line 506 can be the bias voltage signal Vbias, the common voltage signal COM, the ground signal GND, and the low voltage signal VGL provided to the AA pixel circuit 200 of the display area. It should be added that when a corresponding reference circuit 400 is provided for each photosensitive circuit 300 in the display panel, at least one shielding signal line 506 can also be provided between the output signal lines 501 of the reference circuit 400 to avoid interference between output signals, which can also improve the accuracy of ambient light detection.

[0106] Continue to refer to Figures 18-20 and Figure 34 For example, in this embodiment of the invention, the shielding signal line 506 can be supplied with a bias voltage signal Vbias. Furthermore, a shielding signal line 506 can be provided between the output signal lines 501 of different photosensitive circuits 300. Each shielding signal line 506 can be connected via a crossover line located on another metal layer to form a comb-shaped shielding signal line 506. It can be understood that by setting the shielding signal line 506 in a comb-like shape, i.e., connecting multiple shielding signal lines 506 to each other, it can be ensured that each shielding signal line 506 supplies the same fixed signal, ensuring that each output signal line 501 has the same shielding environment, and avoiding unnecessary errors in the output of each photosensitive circuit 300. At the same time, the comb-shaped shielding signal line 506 does not need to provide a fixed signal separately; it only needs to be connected to the bonding pad of a bonding area NA1, saving the area of ​​the bonding area NA1 and simplifying the design of the corresponding driver chip. It should also be noted that, as... Figure 34 The example only shows the comb-shaped shielded signal line 506. It is understood that the second voltage signal line 503, connected to the second voltage terminal V2 of the photosensitive circuit 300, also needs to be supplied with a bias voltage signal Vbias. In the fan-out region, the second voltage signal line 503 and the shielded signal line 506 can be... Figure 29 and Figure 20 As shown, it extends in parallel into the bonding area NA1 and is connected to the two bonding pads set in the bonding area NA1 respectively. The driver chip IC can provide the same bias voltage signal Vbias to the two bonding pads.

[0107] Based on the same inventive concept, embodiments of the present invention also provide an ambient light detection circuit, see reference. Figure 7 The ambient light detection circuit includes a light-sensing circuit 300; the light-sensing circuit 300 includes a first transistor T1, a second transistor T2, and a first capacitor C1; the first transistor T1 and the second transistor T2 are connected in series between a first voltage terminal V1 and a second voltage terminal V2, and the first capacitor C1 is connected in parallel across the two ends of the second transistor T2; the light-sensing circuit 300 has a light-receiving side, the first transistor T1 has a light-shielding structure on the light-receiving side, and the second transistor T2 has a light-passing structure on the light-receiving side; the first transistor T1 and the second transistor T2 are connected to a first node N1.

[0108] This ambient light detection circuit can be used in display devices and can be integrated into the display panel. The ambient light detection circuit has a light-receiving side. Similarly, since the first transistor T1 and the second transistor T2 have different functions, the first transistor T1 is responsible for resetting the voltage of the first node N1. The first transistor T1 should be in a light-shielding state, that is, a corresponding light-shielding structure should be set on the light-receiving side. The second transistor T2 is responsible for generating photo-induced leakage current under illumination, therefore it needs to be illuminated, and a corresponding light-transmitting structure should be set on its light-receiving side.

[0109] In one embodiment, the channel width-to-length ratio of the first transistor T1 is smaller than that of the second transistor T2.

[0110] In one embodiment, the first transistor T1 and the second transistor T2 are both N-channel transistors or both P-type transistors.

[0111] refer to Figure 11 The ambient light detection circuit also includes a reference circuit 400; the reference circuit 400 includes a third transistor T3, a fourth transistor T4, and a second capacitor C2. The third transistor T3 and the fourth transistor T4 are connected in series between the first voltage terminal V1 and the second voltage terminal V2, and the second capacitor C2 is connected in parallel across the fourth transistor T4. The third transistor T3 and the first transistor T1 have the same electrical parameters, the fourth transistor T4 and the second transistor T2 have the same electrical parameters, and the second capacitor C2 and the first capacitor C1 have the same electrical parameters. Both the third transistor T3 and the fourth transistor T4 are in a light-shielding state. The third transistor T3 and the fourth transistor T4 are connected to the second node N2.

[0112] In the reference circuit 400, the voltage of the second node N2 also changes with the leakage current generated by the fourth transistor T4 in the dark state, i.e., without light. Therefore, by detecting the difference in voltage changes of the first node N1 and the second node N2, the error caused by the leakage current in the dark state can be eliminated, and the ambient light intensity of the space where the display panel is located can be determined more accurately, thus realizing ambient light detection.

[0113] refer to Figure 13 and Figure 14In one embodiment, the number of photosensitive circuits 300 and reference circuits 400 in the ambient light detection circuit are the same, and they correspond one-to-one to form multiple detection channels; the photosensitive circuits 300 and reference circuits 400 in the same detection channel satisfy the following: the third transistor T3 and the first transistor T1 have the same electrical parameters, and the fourth transistor T4 and the second transistor T2 have the same electrical parameters; at least two detection channels satisfy the following: the electrical parameters of the two second transistors T2 are different, and / or the electrical parameters of the two first capacitors C1 are different.

[0114] By setting up multiple photosensitive circuits 300, and having different electrical parameters for the second transistor T2 in at least two photosensitive circuits 300, or different electrical parameters for the first capacitor C1 in at least two photosensitive circuits 300, the voltage change amplitude of the first node N1 in the two photosensitive circuits 300 can be made different. Thus, two photosensitive circuits with different ambient light detection sensitivities can be realized to meet different detection requirements.

[0115] refer to Figure 13 and Figure 14 In one embodiment, the ambient light detection circuit 300 includes a first light sensing circuit 310 and a second light sensing circuit 320; the channel width-to-length ratio of the second transistor T2 in the first light sensing circuit 310 is W / L_1, and the channel width-to-length ratio of the second transistor T2 in the second light sensing circuit 320 is W / L_2; wherein, W / L_1 > W / L_2.

[0116] By setting different channel width-to-length ratios for the second transistors T2 in the two photosensitive circuits, the second transistor T2 in the first photosensitive circuit 310 has a larger channel width-to-length ratio. This allows the second transistor T2 in the first photosensitive circuit 310 to generate a larger photogenerated leakage current under the same ambient light illuminance. Consequently, the voltage change amplitude at the first node N1 in the first photosensitive circuit 310 will be larger, resulting in higher ambient light detection sensitivity. Therefore, two photosensitive circuits with different ambient light detection sensitivities can be realized to meet different detection requirements.

[0117] refer to Figure 13 and Figure 14 In another embodiment, the ambient light detection circuit 300 includes a first light sensing circuit 310 and a second light sensing circuit 320; the capacitance of the first capacitor C1 in the first light sensing circuit 310 is C1, and the capacitance of the first capacitor C1 in the second light sensing circuit 320 is C2; wherein, C1 < C2.

[0118] By setting different values ​​for the first capacitor C1 in the two photosensitive circuits, with a smaller value for the first capacitor C1 in the first photosensitive circuit 310, the voltage change amplitude of the first node N1 can be greater under the same ambient light illuminance, while ensuring the same photogenerated leakage current is generated by the second transistor T2. This results in a higher ambient light detection sensitivity. Thus, two photosensitive circuits with different ambient light detection sensitivities can be implemented to meet different detection requirements.

[0119] refer to Figure 15 In one embodiment, the ambient light detection circuit 300 includes an illuminance detection circuit 301 and / or at least one color temperature detection circuit 302; a color resist is provided on the light-receiving side of the second transistor T2 in the color temperature detection circuit 302.

[0120] By setting a color resist on the light-receiving side of the second transistor T2, light of a specific wavelength in the ambient light can be filtered out, allowing the second transistor T2 to detect only the illuminance of that specific wavelength, thus achieving color temperature detection. In practical applications, red, green, and blue color resists can be set on the light-receiving side of the second transistor T2 in different photosensitive circuits to meet the detection requirements of the color temperatures of red, green, and blue colors.

[0121] It is understandable that each of the above-mentioned different types of photosensitive circuits can be equipped with a reference circuit 400 with the same components and electrical parameters. Through the corresponding reference circuit 400, the error caused by dark-state leakage current can be eliminated, and the ambient light intensity of the space where each photosensitive circuit is located can be determined more accurately, thereby realizing ambient light detection.

[0122] In addition to the aforementioned ambient light detection circuit, this embodiment of the invention also provides an ambient light detection method, which is executed by any of the aforementioned ambient light detection circuits. The ambient light detection circuit includes a photosensitivity period t1 and a calculation period. The photosensitivity period t1 includes a reset phase t11 and an integration phase t12, with the integration phase t12 following the reset phase t11. The calculation period follows the photosensitivity period t1. (Reference) Figures 7-9 Ambient light detection methods include: S111. During the reset phase, the first transistor is turned on and the second transistor is turned off.

[0123] S112. During the integration phase, both the first transistor and the second transistor are turned off.

[0124] S113. During the calculation period, the ambient illuminance of the space where the photosensitive circuit is located is determined based on the voltage change amplitude of the first node during the integration phase.

[0125] The working process of the light sensing circuit in this ambient light detection circuit can be referred to above, and will not be repeated here.

[0126] Figure 35 yes Figure 7 Another signal timing diagram of the photosensitive circuit is shown. Figure 36 This is a flowchart of another ambient light detection method provided in an embodiment of the present invention, see reference. Figure 7 , Figure 35 and Figure 36 First, the first voltage terminal V1 receives the first voltage signal, and the second voltage terminal V2 receives the second voltage signal.

[0127] This ambient light detection method also includes: S210. During the photosensitive period, the first voltage signal is configured as the first voltage v1, and the second voltage signal is configured as the second voltage v2; wherein, v1 > v2.

[0128] Further, optionally, the ambient light detection circuit also includes an anti-biasing phase t2, which is located after the photosensitivity period t1. (Continue to the previous section) Figure 35 and Figure 36 Ambient light detection methods also include: S220. During the anti-biasing stage, both the first transistor and the second transistor are turned on, and the first voltage signal is configured as the third voltage v3, and the second voltage signal is configured as the fourth voltage v4; wherein, v3≤v4.

[0129] For example, the first voltage v1 can be the power supply voltage signal VDD, the third voltage v3 can be the ground signal GND, and the second voltage v2 and the fourth voltage v4 can both be bias voltage signals Vbias. Where VDD > Vbias > GND. During the photosensitive period t1, the voltage signal at the first voltage terminal V1 of the photosensitive circuit is greater than the voltage signal at the second voltage terminal V2, i.e., v1 = VDD > v2 = Vbias. This allows the voltage of the first node N1 to be pulled high during the reset phase t11, while the leakage current generated by the second transistor T2 causes the voltage of the first node N1 to drop during the integration phase t12. The ambient light intensity can be determined by detecting the magnitude of the voltage drop. It is understood that during the photosensitive period t1, a forward voltage bias is formed between the source and drain of the first transistor T1 and the second transistor T2. Prolonged forward voltage bias can cause the electrical characteristic curve of the transistors to drift, affecting the switching state of the transistors and the leakage current effect. During the anti-biasing stage t2, the voltage signal at the first voltage terminal V1 of the photosensing circuit will be less than the voltage signal at the second voltage terminal V2. v3=GND<v4=Vbias, which will cause a reverse voltage bias between the source and drain of the first transistor T1 and the second transistor T2. The reverse voltage bias can cancel or compensate for the drift of the electrical characteristic curve caused by the forward voltage bias, thereby weakening or even eliminating the influence of bias on the transistor. Thus, by adding the anti-biasing stage t2 and the corresponding voltage signal control, the bias of the transistor can be adjusted, the electrical characteristics of the transistor can be stabilized, and the normal operation of the ambient light detection circuit can be guaranteed.

[0130] It should be noted that during the photosensitive period, the voltage signal of the first voltage terminal V1 can also be set to be less than the voltage signal of the second voltage terminal V2. In this case, during the integration phase t12, the voltage change of the first node N1 will be in an upward state. Correspondingly, by detecting the voltage rise of the first node N1, the ambient light intensity can also be determined. Here, there are no restrictions on the magnitude of the voltage signals of the first voltage terminal V1 and the second voltage terminal V2.

[0131] Figure 37 This is a flowchart of another ambient light detection method provided in an embodiment of the present invention. Figure 38 yes Figure 7 Another signal timing diagram of the photosensitive circuit shown is referenced. Figure 7 , Figure 37 and Figure 38 The photosensitive period t1 includes a reset phase t11 and an integration phase t12. Based on this, in the above embodiment, S113, during the calculation period, determining the ambient illuminance of the space where the photosensitive circuit is located based on the voltage change amplitude of the first node during the integration phase may include: S1131. During the calculation period, the ambient illuminance of the space where the photosensitive circuit is located is determined according to the voltage change amplitude of the first node at different times during the integration phase.

[0132] As shown in the figure, within an integration phase t12, by acquiring the voltage change amplitude at three different moments, three integration results can be obtained for integration time 1, integration time 2, and integration time 3. Using these three integration results, i.e., the voltage change amplitude, the ambient light intensity can be calculated, yielding three ambient light intensity data points. Furthermore, due to the difference in actual integration time, a longer integration time results in a larger voltage change amplitude. Therefore, different integration times can be used to obtain detection data with different sensitivities, ensuring more accurate detection results. It can be understood that since this embodiment acquires the voltage change amplitude of the first node N1 at different moments within the same integration phase t12, the time for acquiring the voltage signal can be compressed, detection efficiency improved, and real-time adjustment of display brightness in response to changes in ambient light can be facilitated.

[0133] Figure 39 This is a flowchart of another ambient light detection method provided in an embodiment of the present invention. Figure 40 yes Figure 7 Another signal timing diagram of the photosensitive circuit shown is referenced. Figure 7 , Figure 39 and Figure 40 The photosensitive period t1 includes multiple sub-periods, each sub-period including a reset phase t11 and an integration phase t12; the duration of the integration phase t12 varies in different sub-periods. Based on this, in the above embodiment, S113, during the calculation period, the ambient illuminance of the space where the photosensitive circuit is located is determined based on the voltage change amplitude of the first node during the integration phase, including: S1132. During the calculation period, the ambient illuminance of the space where the photosensitive circuit is located is determined according to the voltage change amplitude of the first node at the end of different integration stages.

[0134] This embodiment sets three integration stages t12 with different time lengths, thus obtaining three integration results. These three results, representing voltage change amplitudes, are used to calculate ambient light illuminance, yielding three ambient light illuminance data points. Furthermore, due to the difference in actual integration time, a longer integration time results in a larger voltage change amplitude. Therefore, different integration times can be used to obtain detection data with varying sensitivities, ensuring more accurate detection results. It is understood that because this embodiment acquires voltage signals at the end of each integration stage t12 rather than during the integration process, it avoids the voltage acquisition affecting the integration of the photosensing circuit, preventing errors introduced by the acquisition action, ensuring the accuracy of ambient light detection, and improving detection precision.

[0135] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, combinations, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A display panel, characterized in that, It includes a substrate and pixel circuitry and photosensitive circuitry located on the substrate; both the photosensitive circuitry and the pixel circuitry include transistors, and... When the number of transistors in the pixel circuit is one, the active layer of the transistor in the photosensitive circuit is made of the same material as the active layer of the transistor in the pixel circuit. When the number of transistors in the pixel circuit is at least two, the active layer of the transistors in the photosensitive circuit is made of the same material as the active layer of at least some of the transistors in the pixel circuit.

2. The display panel according to claim 1, characterized in that, The active layers of the transistors in the photosensitive circuit and the transistors in the pixel circuit are both made of low-temperature polycrystalline silicon.

3. The display panel according to claim 1, characterized in that, The transistors in the photosensitive circuit and the transistors in the pixel circuit are fabricated simultaneously using the same process.

4. The display panel according to claim 1, characterized in that, The display panel further includes a semiconductor layer and a gate metal layer, wherein the gate metal layer is located on the side of the semiconductor layer opposite to the substrate; The transistors in both the photosensitive circuit and the pixel circuit include a gate and an active layer, with the gate located in the gate metal layer and the active layer located in the semiconductor layer.

5. The display panel according to claim 4, characterized in that, The display panel further includes a light-shielding layer, which is located between the substrate and the semiconductor layer; The light-shielding layer includes multiple light-shielding patterns. In the photosensitive circuit and the pixel circuit, the active layer of the transistor is projected and overlapped with different light-shielding patterns in the thickness direction.

6. The display panel according to claim 1, characterized in that, The photosensitive circuit includes a first transistor, a second transistor, and a first capacitor; the first transistor and the second transistor are connected in series between a first voltage terminal and a second voltage terminal, and the first capacitor is connected in parallel across the two ends of the second transistor; The display panel has a light-emitting side, the first transistor has a light-shielding structure on the side near the light-emitting side, and the second transistor has a light-transmitting structure on the side near the light-emitting side; the first transistor and the second transistor are connected to a first node.

7. The display panel according to claim 6, characterized in that, The channel width-to-length ratio of the first transistor is smaller than that of the second transistor.

8. The display panel according to claim 6, characterized in that, The first transistor includes a first sub-transistor and a second sub-transistor; The first sub-transistor and the second sub-transistor are connected in series between the first voltage terminal and the first node, and the gates of the first sub-transistor and the second sub-transistor receive the same control signal.

9. The display panel according to claim 6, characterized in that, It also includes a reference circuit located on the substrate, the reference circuit including a third transistor, a fourth transistor and a second capacitor, the third transistor and the fourth transistor being connected in series between the first voltage terminal and the second voltage terminal, and the second capacitor being connected in parallel across the fourth transistor; The third transistor has the same electrical parameters as the first transistor, the fourth transistor has the same electrical parameters as the second transistor, and the second capacitor has the same electrical parameters as the first capacitor. Both the third transistor and the fourth transistor have a light-shielding structure on the side closest to the light-emitting side. The third transistor and the fourth transistor are connected to the second node.

10. The display panel according to claim 9, characterized in that, The number of the photosensitive circuits and the reference circuits are the same, and they correspond one-to-one to form multiple detection channels; The photosensitive circuit and the reference circuit in the same detection channel satisfy the following: the third transistor and the first transistor have the same electrical parameters, and the fourth transistor and the second transistor have the same electrical parameters; At least two of the detection channels satisfy the following conditions: the electrical parameters of the two second transistors are different, and / or the electrical parameters of the two first capacitors are different.

11. The display panel according to claim 10, characterized in that, Each of the said photosensitive circuits and each of the said reference circuits are arranged along a first direction; wherein: The first direction is parallel to the substrate; The aforementioned photosensitive circuits are arranged adjacent to each other in sequence; Some of the reference circuits are located on one side of all the photosensitive circuits in the first direction, and some of the reference circuits are located on the other side of all the photosensitive circuits in the first direction; or, all the reference circuits are located on the same side of all the photosensitive circuits in the first direction.

12. The display panel according to claim 6, characterized in that, The light-sensing circuit includes an illuminance detection circuit and / or at least one color temperature detection circuit; The second transistor in the illuminance detection circuit has a light-transmitting hole on its light-receiving side; The second transistor in the color temperature detection circuit has a light-receiving hole on its light-receiving side, and a color resist is disposed in the light-receiving hole.

13. The display panel according to claim 12, characterized in that, The at least one color temperature detection circuit includes a first color temperature detection circuit, a second color temperature detection circuit, and a third color temperature detection circuit; A red color resist is provided in the light-passing hole corresponding to the second transistor in the first color temperature detection circuit; A green color resist is provided in the light-passing hole corresponding to the second transistor in the second color temperature detection circuit; A blue color resist is provided in the light-passing hole corresponding to the second transistor in the third color temperature detection circuit.

14. The display panel according to claim 6, characterized in that, The photosensitive circuit includes a first photosensitive circuit and a second photosensitive circuit; The channel width-to-length ratio of the second transistor in the first photosensitive circuit is W / L_1, and the channel width-to-length ratio of the second transistor in the second photosensitive circuit is W / L_2; wherein, W / L_1 > W / L_2.

15. The display panel according to claim 14, characterized in that, C1=C2.

16. The display panel according to claim 6, characterized in that, The photosensitive circuit includes a first photosensitive circuit and a second photosensitive circuit; The capacitance of the first capacitor in the first photosensitive circuit is C1, and the capacitance of the first capacitor in the second photosensitive circuit is C2; wherein, C1 < C2.

17. The display panel according to claim 14 or 16, characterized in that, It also includes a reference circuit located on the substrate, the reference circuit including a third transistor, a fourth transistor and a second capacitor, the third transistor and the fourth transistor being connected in series between the first voltage terminal and the second voltage terminal, and the second capacitor being connected in parallel across the fourth transistor; Both the third transistor and the fourth transistor are in a light-shielding state; The first photosensitive circuit is located on the side of the second photosensitive circuit that is away from the reference circuit.

18. The display panel according to claim 6, characterized in that, Both the first transistor and the second transistor include a gate, a first electrode, and a second electrode; the first capacitor includes a first plate and a second plate. The first plate of the first capacitor is connected to the second terminal of the first transistor and the first terminal of the second transistor at the first node; the second plate of the first capacitor is connected to the second terminal of the second transistor. The first electrode plate is located on the same metal layer as the first and second electrodes of the first transistor and the first and second electrodes of the second transistor. The second electrode plate is located on the same metal layer as the gate of the first transistor and the gate of the second transistor.

19. The display panel according to claim 6, characterized in that, The first capacitor includes a first plate and a second plate; the first plate of the first capacitor is connected to the second terminal of the first transistor and the first terminal of the second transistor at the first node; the second plate of the first capacitor is connected to the second terminal of the second transistor. The display panel further includes an output signal line, a first voltage signal line, and a second voltage signal line; the output signal line is connected to the first node, the first voltage signal line is connected to the first voltage terminal, and the second voltage signal line is connected to the second voltage terminal; The output signal line extends at least partially in parallel with the second voltage signal line.

20. The display panel according to claim 6, characterized in that, It also includes a first voltage signal line, a second voltage signal line, a first control signal line, a second control signal line, and an electrostatic discharge protection circuit; The first voltage signal line is connected to the first voltage terminal, the second voltage signal line is connected to the second voltage terminal, the first control signal line is connected to the gate of the first transistor, and the second control signal line is connected to the gate of the second transistor. At least one of the first voltage signal line, the second voltage signal line, the first control signal line, and the second control signal line is connected to the corresponding electrostatic discharge protection circuit.

21. The display panel according to claim 20, characterized in that, The electrostatic discharge protection circuit includes a first electrostatic discharge protection circuit, a second electrostatic discharge protection circuit, a third electrostatic discharge protection circuit, and a fourth electrostatic discharge protection circuit. The first voltage signal line is connected to the first electrostatic discharge protection circuit, the second voltage signal line is connected to the second electrostatic discharge protection circuit, the first control signal line is connected to the third electrostatic discharge protection circuit, and the second control signal line is connected to the fourth electrostatic discharge protection circuit. The first voltage signal line, the second voltage signal line, the first control signal line, and the second control signal line extend along a first direction and are arranged along a second direction; The first electrostatic discharge (ESD) protection circuit, the second ESD protection circuit, the third ESD protection circuit, and the fourth ESD protection circuit are arranged along the second direction.

22. The display panel according to claim 6, characterized in that, It also includes a black matrix layer and an ink layer; in the thickness direction, the black matrix layer is located on the side of the pixel circuit and the photosensitive circuit facing away from the substrate, and the ink layer is located on the side of the black matrix layer facing away from the pixel circuit and the photosensitive circuit; The black matrix layer is provided with a first light-transmitting hole, and the ink layer is provided with a second light-transmitting hole; the second transistor, the first light-transmitting hole, and the second light-transmitting hole overlap at least partially in the thickness direction.

23. The display panel according to claim 22, characterized in that, The number of the photosensitive circuit and the first light-transmitting hole are both multiple, and the second transistor and the first light-transmitting hole are overlapped in the thickness direction in a one-to-one correspondence; The number of the second light-transmitting holes is at least one, and multiple first light-transmitting holes overlap with the same second light-transmitting hole in the thickness direction.

24. The display panel according to claim 22, characterized in that, The display panel also includes a polarizer, which is located between the black matrix layer and the ink layer in the thickness direction; The polarizer overlaps with the first light-transmitting hole and the second light-transmitting hole in the thickness direction, respectively.

25. The display panel according to claim 22, characterized in that, The number of the light-sensing circuit and the number of the first light-transmitting holes are both multiple. The second transistor and the first light-transmitting hole are overlapped in the thickness direction in a one-to-one correspondence. At least some of the first light-transmitting holes are provided with color resist.

26. The display panel according to claim 22, characterized in that, The first light-transmitting aperture satisfies: ; in, Let be the width of the first light-transmitting hole in the third direction. α is the width of the second transistor in the third direction, α is the maximum viewing angle of the display panel when the third direction has the maximum responsivity, and h is the distance between the second transistor and the black matrix layer in the thickness direction of the display panel; the third direction is any direction parallel to the substrate.

27. The display panel according to claim 22, characterized in that, The black matrix layer includes a first portion and a second portion; the first portion and the first light-transmitting hole do not overlap in the thickness direction of the display panel, while the second portion and the first light-transmitting hole overlap in the thickness direction of the display panel.

28. The display panel according to claim 27, characterized in that, The second portion and the second transistor satisfy: ; in, The width of the second portion in the third direction. F is the width of the photosensitive portion of the second transistor in the third direction, and F is the target responsivity of the display panel at a 0° viewing angle in the third direction; the third direction is any direction parallel to the substrate.

29. The display panel according to claim 27, characterized in that, The second section is rectangular, strip-shaped, or cross-shaped.

30. The display panel according to claim 1, characterized in that, The display panel also includes light strips; The number of photosensitive circuits is multiple, and the multiple photosensitive circuits are arranged sequentially. The arrangement direction of the multiple photosensitive circuits and the extension direction of the lamp strip are both parallel to the same side of the substrate.

31. The display panel according to claim 1, characterized in that, The display panel includes a display area and a non-display area, with the pixel circuit located in the display area and the light-sensing circuit located in the non-display area. The non-display area is provided with a first binding area, a second binding area, a first fan-out area, and a second fan-out area. The first fan-out area is located between the first binding area and the display area, and the second fan-out area is located between the second binding area and the display area. The photosensitive circuit is located between the first fan-out area and the second fan-out area.

32. The display panel according to claim 1, characterized in that, The display panel includes a display area and a non-display area, with the pixel circuit located in the display area and the light-sensing circuit located in the non-display area. The non-display area is equipped with a binding area; The photosensitive circuit is located between the bonding area and the display area, or the photosensitive circuit is located on the side of the display area away from the bonding area.

33. The display panel according to claim 1, characterized in that, The display panel includes a display area and a non-display area, with the pixel circuit located in the display area and the light-sensing circuit located in the non-display area. The display panel also includes multiple output signal lines and multiple shielded signal lines, all of which are located in the non-display area; Each of the output signal lines is connected to each of the photosensitive circuits in a one-to-one correspondence. At least one shielding signal line is provided between two adjacent output signal lines, and the shielding signal line is provided with a fixed signal.

34. The display panel according to claim 1, characterized in that, The display panel includes a display area and a non-display area, with the pixel circuit located in the display area and the light-sensing circuit located in the non-display area. The display panel also includes a bonding area located in the non-display area. The bonding area is provided with bonding pads, and the photosensitive circuit is electrically connected to the bonding pads. The bonding pads are used to bond driver chips or flexible circuit boards.

35. An ambient light detection circuit, characterized in that, The ambient light detection circuit includes a light-sensing circuit; The photosensitive circuit includes a first transistor, a second transistor, and a first capacitor; the first transistor and the second transistor are connected in series between a first voltage terminal and a second voltage terminal, and the first capacitor is connected in parallel across the two ends of the second transistor; The photosensitive circuit has a light-receiving side, the first transistor has a light-shielding structure on the light-receiving side, and the second transistor has a passage structure on the light-receiving side; the first transistor and the second transistor are connected to a first node.

36. The ambient light detection circuit according to claim 35, characterized in that, The channel width-to-length ratio of the first transistor is smaller than that of the second transistor.

37. The ambient light detection circuit according to claim 35, characterized in that, Both the first transistor and the second transistor are either N-channel transistors or both are P-channel transistors.

38. The ambient light detection circuit according to claim 35, characterized in that, It also includes a reference circuit; The reference circuit includes a third transistor, a fourth transistor, and a second capacitor. The third transistor and the fourth transistor are connected in series between the first voltage terminal and the second voltage terminal, and the second capacitor is connected in parallel across the fourth transistor. The third transistor has the same electrical parameters as the first transistor, the fourth transistor has the same electrical parameters as the second transistor, and the second capacitor has the same electrical parameters as the first capacitor. Both the third transistor and the fourth transistor are in a light-shielding state; The third transistor and the fourth transistor are connected to the second node.

39. The ambient light detection circuit according to claim 38, characterized in that, The number of the photosensitive circuits and the reference circuits are the same, and they correspond one-to-one to form multiple detection channels; The photosensitive circuit and the reference circuit in the same detection channel satisfy the following: the third transistor and the first transistor have the same electrical parameters, and the fourth transistor and the second transistor have the same electrical parameters; At least two of the detection channels satisfy the following conditions: the electrical parameters of the two second transistors are different, and / or the electrical parameters of the two first capacitors are different.

40. The ambient light detection circuit according to claim 35, characterized in that, The light-sensing circuit includes an illuminance detection circuit and / or at least one color temperature detection circuit; A color resist is provided on the light-receiving side of the second transistor in the color temperature detection circuit.

41. The ambient light detection circuit according to claim 35, characterized in that, The photosensitive circuit includes a first photosensitive circuit and a second photosensitive circuit; The channel width-to-length ratio of the second transistor in the first photosensitive circuit is W / L_1, and the channel width-to-length ratio of the second transistor in the second photosensitive circuit is W / L_2; wherein, W / L_1 > W / L_2.

42. The ambient light detection circuit according to claim 35, characterized in that, The photosensitive circuit includes a first photosensitive circuit and a second photosensitive circuit; The capacitance of the first capacitor in the first photosensitive circuit is C1, and the capacitance of the first capacitor in the second photosensitive circuit is C2; wherein, C1 < C2.

43. An ambient light detection method, characterized in that, The ambient light detection circuit according to any one of claims 35-52 is executed; the ambient light detection circuit includes a photosensing period and a calculation period; the photosensing period includes a reset phase and an integration phase, the integration phase being located after the reset phase; The calculation period is located after the photosensitivity period; The ambient light detection method includes: During the reset phase, the first transistor is turned on and the second transistor is turned off. During the integration phase, both the first transistor and the second transistor are turned off. During the calculation cycle, the ambient illuminance of the space where the photosensitive circuit is located is determined based on the voltage change amplitude of the first node during the integration phase.

44. The ambient light detection method according to claim 43, characterized in that, The first voltage terminal receives a first voltage signal, and the second voltage terminal receives a second voltage signal; The ambient light detection method further includes: During the photosensitive period, the first voltage signal is configured as a first voltage v1, and the second voltage signal is configured as a second voltage v2; wherein, v1 > v2.

45. The ambient light detection method according to claim 44, characterized in that, The ambient light detection circuit further includes an anti-biasing stage, which is located after the photosensitivity period; The ambient light detection method further includes: During the anti-biasing phase, both the first transistor and the second transistor are turned on, and the first voltage signal is configured as the third voltage v3, and the second voltage signal is configured as the fourth voltage v4; wherein v3≤v4.

46. ​​The ambient light detection method according to claim 43, characterized in that, The photosensitivity period includes a reset phase and an integration phase; During the calculation cycle, the ambient illuminance of the space where the photosensing circuit is located is determined based on the voltage change amplitude of the first node during the integration phase, including: During the calculation cycle, the ambient illuminance of the space where the photosensitive circuit is located is determined based on the voltage change amplitude of the first node at different times during the integration phase.

47. The ambient light detection method according to claim 43, characterized in that, The photosensitive period includes multiple sub-periods, and each sub-period includes a reset phase and an integration phase; the duration of the integration phase in different sub-periods is different. During the calculation cycle, the ambient illuminance of the space where the photosensing circuit is located is determined based on the voltage change amplitude of the first node during the integration phase, including: During the calculation cycle, the ambient illuminance of the space where the photosensitive circuit is located is determined based on the voltage change amplitude of the first node at the end of different integration stages.

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