Display panel and display device

Abstract

The invention discloses a display panel and a display device. The display panel comprises a substrate; a pixel circuit area and a photosensitive area; the pixel circuit area comprises a pixel driving circuit and a light-emitting element electrically connected with the pixel driving circuit; the light sensing area comprises a light sensing circuit; the first type of transistors and the second type of transistors are located on the substrate; the first type transistor comprises a first active layer, a first top gate structure and a first source drain electrode layer which are sequentially arranged far away from the substrate; a shading layer is arranged on one side, close to the substrate, of the first active layer; the shading layer and the first active layer are at least partially overlapped in the direction perpendicular to the plane where the substrate is located; the second type transistor comprises a second active layer, a second top gate structure and a second source drain electrode layer which are sequentially arranged far away from the substrate; wherein the pixel driving circuit at least comprises a first type of transistors; the light sensing circuit at least comprises a second type transistor. According to the technical scheme provided by the invention, ambient light detection is carried out while the light transmittance is not influenced.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a display panel and a display device. Background Art

[0002] With the advancement of display technology, transparent displays are becoming more and more popular among users. Transparent displays can be applied to many fields, such as billboards, vehicle windows, etc. In order to ensure that the display pixel circuit is not affected by external light, transparent displays use top gate and bottom gate structures to surround the channel, blocking external light. As a result, thin film transistors (TFTs) cannot be used for ambient light detection.

[0003] In order to complete the ambient light detection process, in the prior art, a brightness sensor may be configured at the bottom of the display, but the configuration of the brightness sensor may affect the transmittance of the transparent display, thereby affecting the appearance characteristics of the display. Summary of the invention

[0004] Embodiments of the present invention provide a display panel and a display device to implement an ambient light detection function of the display panel.

[0005] In a first aspect, an embodiment of the present invention provides a display panel, including: a substrate;

[0006] Pixel circuit area and photosensitive area;

[0007] The pixel circuit area includes a pixel driving circuit and a light-emitting element electrically connected to the pixel driving circuit; the photosensitive area includes a photosensitive circuit;

[0008] A first type of transistor and a second type of transistor located on the substrate; the first type of transistor comprises a first active layer, a first top gate structure and a first source-drain layer arranged in sequence away from the substrate; a light shielding layer is arranged on a side of the first active layer close to the substrate; in a direction perpendicular to the plane where the substrate is located, the light shielding layer at least partially overlaps with the first active layer; the second type of transistor comprises a second active layer, a second top gate structure and a second source-drain layer arranged in sequence away from the substrate;

[0009] Wherein, the pixel driving circuit includes at least the first type of transistors; and the photosensitive circuit includes at least the second type of transistors.

[0010] In a second aspect, an embodiment of the present invention further provides a display device, comprising the display panel provided by any embodiment of the present invention.

[0011] In the present invention, the display panel includes a pixel circuit area and a photosensitive area, the pixel circuit area is provided with a pixel circuit for driving a light-emitting element, the photosensitive area is provided with a photosensitive circuit, a first type of transistor and a second type of transistor are formed on the substrate of the display panel, the first type of transistor includes a first active layer, a first top gate structure and a first source-drain electrode layer which are sequentially away from the substrate; the second type of transistor includes a second active layer, a second top gate structure and a second source-drain electrode layer which are sequentially away from the substrate; wherein a light shielding layer is provided between the first active layer and the substrate of the first type of transistor, the light shielding layer at least partially overlaps with the first active layer, the pixel circuit includes at least the first type of transistor, then when ambient light passes through the substrate, the light shielding layer can ensure that the driving current of the pixel circuit is not affected by external light, thereby improving the picture display accuracy of the transparent display panel, and the photosensitive circuit includes at least the second type of transistor, then the photosensitive circuit can detect the ambient light passing through the substrate, and because the photosensitive circuit is provided in the display panel, rather than provided on the side of the substrate away from the pixel circuit, it is not necessary to provide a brightness sensor on some parts of the substrate away from the pixel circuit, thereby simplifying the panel process, reducing the thickness of the display panel, and improving the appearance characteristics of the display. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 A schematic diagram of a planar structure of a display panel provided by an embodiment of the present invention;

[0013] Figure 2 A schematic cross-sectional structure diagram of a display panel provided by an embodiment of the present invention;

[0014] Figure 3 It is a schematic diagram of the cross-sectional structure of a display panel in the prior art;

[0015] Figure 4 A schematic diagram of the structure of a light sensing circuit provided by an embodiment of the present invention;

[0016] Figure 5 for Figure 4 Schematic diagram of the timing of the light-sensing current;

[0017] Figure 6 A schematic structural diagram of a pixel driving circuit provided by an embodiment of the present invention;

[0018] Figure 7 A schematic diagram of a planar structure of another display panel provided by an embodiment of the present invention;

[0019] Figure 8 A schematic structural diagram of another pixel driving circuit provided by an embodiment of the present invention;

[0020] Fig. 9 A schematic diagram of a planar structure of another display panel provided by an embodiment of the present invention;

[0021] Fig.10 A schematic diagram of a planar structure of another display panel provided by an embodiment of the present invention;

[0022] Fig.11 A schematic diagram of a planar structure of another display panel provided by an embodiment of the present invention;

[0023] Fig.12 A schematic cross-sectional structure diagram of another display panel provided by an embodiment of the present invention;

[0024] Fig.13 A schematic cross-sectional structure diagram of another display panel provided by an embodiment of the present invention;

[0025] Fig.14 A schematic structural diagram of a display device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0026] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0027] An embodiment of the present invention provides a display panel, such as Figure 1 and Figure 2 As shown, Figure 1 A schematic diagram of a planar structure of a display panel provided by an embodiment of the present invention, Figure 2 A schematic cross-sectional structure diagram of a display panel provided in an embodiment of the present invention, the display panel comprises: a substrate 11;

[0028] Pixel circuit area A1 and photosensitive area A2;

[0029] The pixel circuit area A1 includes a pixel driving circuit 21 and a light emitting element D1 electrically connected to the pixel driving circuit 21; the photosensitive area A2 includes a photosensitive circuit 22;

[0030] A first type transistor T1 and a second type transistor T2 are located on a substrate 11; the first type transistor T1 includes a first active layer 121, a first top gate structure 123 and a first source-drain layer 125 which are sequentially arranged away from the substrate 11; a light shielding layer 127 is arranged on a side of the first active layer 121 close to the substrate 11; in a direction perpendicular to the plane where the substrate 11 is located, the light shielding layer 127 at least partially overlaps with the first active layer 121; the second type transistor T2 includes a second active layer 122, a second top gate structure 124 and a second source-drain layer 126 which are sequentially arranged away from the substrate 11;

[0031] The pixel driving circuit 21 at least includes a first type of transistor T1 ; the light sensing circuit 22 at least includes a second type of transistor T2 .

[0032] In the present invention, the display panel includes a pixel circuit area and a photosensitive area, the pixel circuit area is provided with a pixel circuit for driving a light-emitting element, the photosensitive area is provided with a photosensitive circuit, a first type of transistor and a second type of transistor are formed on the substrate of the display panel, the first type of transistor includes a first active layer, a first top gate structure and a first source-drain electrode layer which are sequentially away from the substrate; the second type of transistor includes a second active layer, a second top gate structure and a second source-drain electrode layer which are sequentially away from the substrate; wherein a light shielding layer is provided between the first active layer and the substrate of the first type of transistor, the light shielding layer at least partially overlaps with the first active layer, the pixel circuit includes at least the first type of transistor, then when ambient light passes through the substrate, the light shielding layer can ensure that the driving current of the pixel circuit is not affected by external light, thereby improving the picture display accuracy of the transparent display panel, and the photosensitive circuit includes at least the second type of transistor, then the photosensitive circuit can detect the ambient light passing through the substrate, and because the photosensitive circuit is provided in the display panel, rather than provided on the side of the substrate away from the pixel circuit, it is not necessary to provide a brightness sensor on some parts of the substrate away from the pixel circuit, thereby simplifying the panel process, reducing the thickness of the display panel, and improving the appearance characteristics of the display.

[0033] The above is the core idea of ​​the present invention. The technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] like Figure 1 As shown, a pixel circuit area A1 and a photosensitive area A2 arranged in an array may be provided on the substrate 11 of the display panel. The substrate 11 may be a transparent material such as glass. The pixel circuit area A1 is used to set a pixel driving circuit 21, so as to provide a driving current for the light-emitting element D1 corresponding to the pixel driving circuit 21; the photosensitive area A2 may be provided with a photosensitive circuit 22, and the photosensitive circuit 22 may detect the ambient light passing through the substrate 11, and perform ambient light detection, so as to facilitate the display panel to adjust the display parameters of the display panel according to the ambient light. The pixel driving circuit 21 includes at least one transistor for realizing the driving function; the photosensitive circuit 22 also includes at least one transistor for realizing the light detection function.

[0035] like Figure 2As shown, in a direction perpendicular to the substrate 11, a driving circuit layer 12 and a light emitting element D1 may be sequentially arranged on the substrate 11. The driving circuit layer 12 may be provided with two types of transistors: a first type of transistor T1 and a second type of transistor T2. The first type of transistor T1 includes a first active layer 121, a first top gate structure 123, and a first source-drain layer 125 sequentially away from the substrate 11, and the second type of transistor T2 includes a second active layer 122, a second top gate structure 124, and a second source-drain layer 126 sequentially arranged away from the substrate 11. For example, Figure 2 As described above, the first active layer 121 and the second active layer 122 can be arranged in the same layer, the first top gate structure 123 and the second top gate structure 124 can be arranged in the same layer, and the first source and drain electrode layer 125 and the second source and drain electrode layer 126 can be arranged in the same layer, so as to save energy in panel process and improve panel preparation efficiency. At the same time, the film layer arrangement of the display panel is reduced, and the light transmittance of the display panel is improved, thereby enhancing the transparent picture display effect. It should be noted that the difference between the first type of transistor T1 and the second type of transistor T2 is that a light shielding layer 127 is provided between the first active layer 121 and the substrate 11, and there is an overlap between the light shielding layer 127 and the first active layer 121. The light shielding layer 127 is a light-proof structure, which is used to block the ambient light passing through the substrate 11, to ensure that the pixel driving circuit of the display panel is not affected by external light, and thus no leakage current is generated due to light, thereby improving the accuracy of the driving current output by the pixel driving circuit, and improving the picture display accuracy of the display panel. Preferably, in a plane parallel to the substrate 11, the light shielding layer 127 can cover the first active layer 121, thereby further reducing the situation where the transistor in the driving circuit generates leakage current due to light. Optionally, the light shielding layer 127 can be a metal material or a non-metal material, and this embodiment does not specifically limit it. Optionally, the material of the light shielding layer 127 may be a metal material. Exemplarily, the light shielding layer 127 is an alloy of one or more metals selected from the group consisting of chromium, molybdenum, aluminum, titanium, niobium, and copper, to achieve a light-proof metal film layer.

[0036] If no light shielding layer 127 is provided between the second active layer 122 and the substrate 11, the second type transistor T2 serves as a light detecting device of the light sensing circuit 22, and can detect the ambient light, so that the display panel can obtain accurate ambient light parameters (for example, light brightness), so as to adjust the display parameters of the display panel (for example, brightness, grayscale, etc.) according to the ambient light parameters, so that the display panel can display pictures or images of different brightness under different ambient lights, so that the display panel can display more clearly and accurately under different ambient lights.

[0037] Based on the above embodiments, a transparent display panel can be formed to provide a transparent display screen with strong transmittance uniformity and more accurate ambient light detection without setting a brightness sensor, thereby further improving the appearance characteristics of the display. Figure 1 In order to realize the transparent display of the display panel, an array of light-transmitting areas A3 are also formed on the substrate 11. The light-transmitting areas A3 are not provided with the above-mentioned transistors, thereby avoiding the adverse effects of the transistors on the light transmittance of the transparent areas A3, enhancing the transparent display effect of the display panel and improving the user experience. It should be noted that in order to further enhance the light transmittance of the light-transmitting areas A3, each insulating layer in this embodiment can increase transparency as much as possible through the design of material type and film thickness, thereby further enhancing the transparent display effect of the display panel.

[0038] Figure 3 The cross-sectional structure diagram of the display panel in the prior art. Compared with the solution of this embodiment, only the light-transmitting area A3' and the driving circuit area A1' for driving the light-emitting element D1' are set on the substrate 11' of the display panel in the prior art. In order to avoid the transistor T1' of the driving circuit area A1' from generating leakage current, a light shielding layer 127' is set, but no photosensitive area is set. Instead, a light brightness sensor 12' is formed on the side of the substrate 11' away from the light-emitting element D1'. In the prior art solution, the light brightness sensor 12' overlaps with the light-transmitting area A3', thereby affecting the uniformity of the transmittance of the entire transparent display panel, and further affecting the appearance characteristics of the transparent display. In the solution of this embodiment, a photosensitive area A2 is set in the display panel, and the photosensitive area A2 does not overlap with the light-transmitting area A3, thereby improving the light transmittance performance of the display panel and improving the user experience.

[0039] Continue to refer Figure 2 Optionally, the light shielding layer 127 can be reused as the first bottom gate structure 128 of the first type transistor T1. When the light shielding layer 127 is a metal material, it can be reused as the first bottom gate structure 128 of the first type transistor T1, and the first type transistor T1 can form a double-gate structure, and the gate voltage is input to the first bottom gate structure 128 and the first top gate structure 123 at the same time, thereby enhancing the switching performance of the first type transistor T1. Alternatively, only one of the first bottom gate structure 128 and the first top gate structure 123 is input with a gate voltage, and the other is input with a constant voltage, so as to control the threshold voltage of the first type transistor T1. In this embodiment, the light shielding layer 127 can be reused as the first bottom gate structure 128 of the first type transistor T1, further improving the performance of the pixel driving circuit 21 and improving the display effect of the corresponding light-emitting element D1.

[0040] Figure 4 A schematic structural diagram of a light sensing circuit provided by an embodiment of the present invention. Figure 5 for Figure 4The timing diagram of the light-sensing current in the figure. Optionally, the light-sensing circuit 22 may include: a first transistor M11 and a second transistor M12; the control end and the first end of the first transistor M11 are connected to the first power signal VDD; the second end of the first transistor M11 is electrically connected to the first end of the second transistor M12; the control end of the second transistor M12 is connected to the first scan signal SCAN1; the second end of the second transistor M12 is used to connect to the second power signal VEE or output the detection current sensor. The light-sensing circuit 22 in this embodiment may include a first transistor M11 and a second transistor M12, the first transistor M11 is used as a light detection device, the control end and the first end of the first transistor M11 are connected to the first power signal VDD, and the second end of the first transistor M12 is connected to the first end of the second transistor M12. Because the voltage difference (gate-source voltage difference) between the control terminal and the first terminal of the first transistor M11 is zero, the first transistor M11 is usually in the off state, but because the first transistor M11 is a light detection device, it can generate leakage current according to the ambient light passing through the substrate 11. For example, when the ambient light is stronger, the leakage current is larger, and the leakage current will form a high potential at the second terminal of the first transistor M11. When the control terminal of the second transistor M12 is connected to the valid pulse P1 of the first scan signal SCAN1, the high potential will be output to the second terminal of the second transistor M12 to form a detection current sensor and transmit it to the controller of the display device, so that the controller can obtain the ambient light parameters. After the output of the detection current is completed, the first scan signal SCAN1 is also a non-enable level. At this time, the second power supply signal VEE connected to the second terminal of the second transistor M12 can provide a reset signal for the second terminal of the second transistor M12 to wait for the next light detection process. Optionally, the first transistor M11 can be a second-type transistor T2; the second transistor M12 can be a first-type transistor T1. The first transistor M11 as a light detection device will not be blocked by the ambient light, and the light detection accuracy of the first transistor M11 is improved. According to the corresponding environmental pipeline, an accurate detection current sensor is output, so that the controller can determine the corresponding ambient light parameters according to the detection current sensor. The second transistor M12 needs to transmit the accurate leakage current to the second end of the second transistor M12, and it does not need the environmental ring irradiation. The second transistor M12 can be the first type transistor T1, and the second transistor M12 will not generate leakage current, but directly output the leakage current generated by the first transistor M11, so as to improve the accuracy of the leakage current signal transmission of the second transistor M12, and further improve the detection accuracy of the entire light sensing circuit.

[0041] Continue to refer Figure 3Optionally, the light sensing circuit 22 may further include: a first storage capacitor C1; a first end of the first storage capacitor C1 is electrically connected to a second end of the first transistor M11; and a second end of the first storage capacitor C1 is connected to a first power signal VDD. Because the first scan signal SCAN1 has an enable level and a disable level, the detection current sensor can be transmitted through the second transistor M12 only when the first scan signal SCAN1 is at an enable level. However, when the first scan signal SCAN1 is at a disable level, the first transistor M11 can also form a leakage current and transmit it to the second end of the first transistor M11. If the interval between the time when the current leakage current is generated and the time when the effective pulse P1 of the first scan signal SCAN1 is generated is long, the leakage current is easily consumed at the second end of the first transistor M11, that is, the high potential formed by the leakage current at the second end of the first transistor M11 cannot be maintained. In this embodiment, the light sensing circuit 22 further provides a first storage capacitor C1, and the first end of the first storage capacitor C1 is electrically connected to the second end of the first transistor M11, and the second end of the first storage capacitor C1 is connected to the first power supply signal VDD. Then, after the first transistor M11 outputs the leakage current, the first storage capacitor C1 can maintain the high potential formed by the leakage current, so that after the first scan signal SCAN1 outputs the effective pulse, the second transistor M12 can output the above leakage current, so that the detection current sensor is detected.

[0042] Figure 6 A structural schematic diagram of a pixel driving circuit provided in an embodiment of the present invention, optionally, the pixel driving circuit 21 may at least include: a first light-emitting control transistor M1, a driving transistor M3 and a second light-emitting control transistor M6; the first end of the first light-emitting control transistor M1 is connected to the third power supply signal PVDD; the second end of the first light-emitting control transistor M1 is electrically connected to the first end of the driving transistor M3; the second end of the driving transistor M3 is electrically connected to the first end of the second light-emitting control transistor M6; the second end of the second light-emitting control transistor M6 is electrically connected to the first end of the light-emitting element D1; the second end of the light-emitting element D1 is connected to the fourth power supply signal PVEE; the first power supply signal VDD of the photosensitive circuit 22 is the same signal as the third power supply signal PVDD of the pixel driving circuit 21; the second power supply signal VEE of the photosensitive circuit 22 is the same signal as the fourth power supply signal PVEE of the pixel driving circuit 21.

[0043] In this embodiment, the pixel driving circuit 21 includes a first light-emitting control transistor M1, a driving transistor M3, and a second light-emitting control transistor M6. Then, the third power signal PVDD, the first light-emitting control transistor M1, the driving transistor M3, the second light-emitting control transistor M6, the light-emitting element D1, and the fourth power signal PVEE are electrically connected in sequence to form a conduction path. The driving transistor M3 is used to form a driving current for driving the light-emitting element D1. The first light-emitting control transistor M1 and the second light-emitting control transistor M6 are used to control the conduction and disconnection of the conduction path. In this embodiment, the first power signal VDD of the photosensitive circuit 22 and the third power signal PVDD of the pixel driving circuit 21 can be the same signal, and the second power signal VEE of the photosensitive circuit 22 and the fourth power signal PVEE of the pixel driving circuit 21 can be the same signal. Then, the first power signal VDD and the third power signal PVDD can share a signal line. Similarly, the second power signal VEE and the fourth power signal PVEE can share a signal line, which is conducive to simplifying the wiring of the power signal of the display panel and simplifying the panel process. In addition, this embodiment can reduce the number of power signal terminals output by the driver chip of the display panel and reduce the power consumption of the driver chip.

[0044] Figure 7 A schematic diagram of a planar structure of another display panel provided in an embodiment of the present invention, optionally, the display panel may further include: a binding area B1; the binding area B1 includes a plurality of binding pads 129; the second ends of the second transistors M12 of the plurality of light sensing circuits 22 are all connected to the first node N1; the first node N1 is electrically connected to the corresponding binding pad 129. In this embodiment, the binding area B1 includes a plurality of binding pads 129 for binding the corresponding flexible circuit board C1, and the flexible circuit board C1 is connected to the driving chip ( Figure 7 The second ends of the second transistors M12 of the plurality of light sensing circuits 22 can be connected to the first node N1, and the detection currents outputted by the second ends of the plurality of second transistors M12 can be transmitted to the first node N1. The first node N1 is connected to the corresponding binding pad 129 through a metal connection line, and is used to transmit the detection signal to the driver chip through the corresponding binding pad 129. Optionally, the second ends of the second transistors M12 of all the light sensing circuits 22 on the display panel are connected to the first node N1, and the binding area B1 can detect the ambient light by only adding one binding pad 129 on the basis of the existing process. In addition, because the first node N1 can also be connected to the second power signal VEE, the second end of the second transistor M12 can be reset. For example, if the display panel is provided with a grid-shaped second power signal line, the first node N1 is connected to the grid-shaped second power signal line.

[0045] Figure 8A structural schematic diagram of another pixel driving circuit provided in an embodiment of the present invention. Optionally, the pixel driving circuit 21 may further include a second storage capacitor C2; a first end of the second storage capacitor C2 is connected to a third power supply signal PVDD; a second end of the second storage capacitor C2 is electrically connected to a control end of the driving transistor M3; and a capacitance value of the first storage capacitor C1 is greater than a capacitance value of the second storage capacitor C2. Figure 8 The 7T1C pixel circuit is shown, which includes, in addition to the above-mentioned first light-emitting control transistor M1, driving transistor M3 and second light-emitting control transistor M6, a data writing transistor M2, a first reset transistor M5, a second reset transistor M7 and a threshold compensation transistor M4 to provide a driving current with higher precision. In addition, the pixel driving circuit 21 may also include a second storage capacitor C2, and the second storage capacitor C2 is connected between the control end of the driving transistor M3 and the third power supply signal PVDD, and is used to maintain the potential of the control end of the driving transistor M3. In this embodiment, the second storage capacitor C2 is used to maintain the potential when the transistor is turned on, and the first storage capacitor C1 is used to maintain the leakage current when the transistor is not fully turned on. The second storage capacitor C2 and the first storage capacitor C1 can be made using the same process, and the capacitance value of the first storage capacitor C1 can be set to be greater than the capacitance value of the second storage capacitor C2, thereby enhancing the effect of the first storage capacitor C1 on maintaining the potential formed by the leakage current. In addition, as Figure 8 As shown, the control end of the first reset transistor M5 is connected to the first scan signal SCAN1, and the control ends of the data writing transistor M2, the second reset transistor M7 and the threshold compensation transistor M4 are connected to the first scan signal SCAN2. That is, in this embodiment, the second transistor M12 of the light sensing circuit 22 and the first reset transistor M5 of the pixel driving circuit 21 share the first scan signal SCAN1. When the first scan signal SCAN1 outputs a valid pulse, the pixel driving circuit 21 resets the control end of the driving transistor M3, and at the same time, the second transistor M12 of the driving transistor M3 detects the leakage current and outputs the detection current sensor, thereby further reducing the number of layout lines of the first scan signal line outputting the first scan signal SCAN1. The light sensing circuit 22 does not need to add a corresponding scan signal, thereby reducing the number of settings of the scan signal of the entire display panel, thereby reducing the number of settings of the shift register circuit for generating the scan signal in the non-display area, and reducing the border width of the display panel.

[0046] Optionally, all transistors in the pixel driving circuit 21 may be first-type transistors T1 , so that the transistors in the pixel driving circuit 21 are not affected by leakage current, and more accurate control of the corresponding light-emitting element D1 can be achieved.

[0047] On the basis of the above embodiment, optionally, the width-to-length ratio of the first transistor M11 can be greater than the width-to-length ratio of the second transistor M12; and / or, the width-to-length ratio of the first transistor M11 is less than the width-to-length ratio of the driving transistor M3. Because the first transistor M11 needs to output leakage current, the first transistor M11 has a larger width-to-length ratio relative to the second transistor M12, and the first transistor M11 has a larger leakage current, which is convenient for analyzing and obtaining ambient light parameters according to the leakage current, improving the accuracy of the display panel's analysis of ambient light, and thus improving the display panel's brightness adjustment effect on the display screen according to ambient light. Or, optionally, the width-to-length ratio of the driving transistor M3 can be greater than the width-to-length ratio of the first transistor M11, and the driving transistor M3 needs to output a larger driving current, so it needs to set a larger width-to-length ratio. The width-to-length ratio of the first transistor M11 is less than that of the driving transistor M3, and the first transistor M11 can occupy a smaller layout space, reserving a larger space for the part of the light-transmitting area A3, thereby improving the light transmittance of the transparent display panel. In addition, the aspect ratio of the first transistor M11 may be greater than that of the second transistor M12 and smaller than that of the driving transistor M3 to improve the ambient light detection accuracy while reducing the layout space of the first transistor M11.

[0048] Fig. 9 A schematic diagram of the planar structure of another display panel provided in an embodiment of the present invention, optionally, a plurality of sub-pixel units 31 can be arranged along a first direction X to form a sub-pixel unit row 32; the sub-pixel unit 31 includes a first sub-pixel unit 311 and a second sub-pixel unit 312; the first sub-pixel unit 311 includes a pixel circuit area A1, a photosensitive area A2 and a light-transmitting area A3; the second sub-pixel unit 312 includes a pixel circuit area A1 and a light-transmitting area A3; the display panel also includes a first scanning signal line 23 extending along the first direction X; the first scanning signal line 23 is used to output a first scanning signal to the first sub-pixel unit 311 and the second sub-pixel unit 312 corresponding to the sub-pixel unit row 32.

[0049] The first direction X is a direction parallel to the substrate, and along the first direction X, a plurality of sub-pixel units 31 may be arranged along the first direction X to form a sub-pixel unit row 32. The sub-pixel unit 31 may include a first sub-pixel unit 311 and a second sub-pixel unit 312, wherein the first sub-pixel unit 311 includes a pixel circuit area (including a pixel driving circuit) A1, a photosensitive area (including a photosensitive circuit) A2 and a light-transmitting area A3, and the second sub-pixel unit 312 includes a pixel circuit area (including a pixel driving circuit) A1 and a light-transmitting area A3, that is, not all sub-pixel units 31 are provided with a photosensitive area A2, and the photosensitive area A2 is only provided in part of the sub-pixel units 31. Of course, each sub-pixel unit 31 may include a pixel circuit area A1 and a light-transmitting area A3 to achieve transparent display. The display panel also includes a first scanning signal line 23 extending along the first direction X, exemplarily, as Fig. 9 As shown, the first scan signal line 23 is sequentially provided with first scan signal lines SCAN_1, SCAN_2, SCAN_3...SCAN_n along the second direction Y, where n is a positive integer. Optionally, the second direction Y is a direction parallel to the substrate, and the second direction Y intersects with the first direction X. Preferably, the second direction Y and the first direction X can be arranged perpendicularly. The number of the first scan signal lines 23 is the same as the number of the sub-pixel unit rows 32. The first scan signal line 23 is used to output the first scan signal (SCAN1, SCAN2, SCAN3...SCANn) to the pixel driving circuit 21 and the photosensitive circuit 22 of the first sub-pixel unit 311 and the second sub-pixel unit 312 of the corresponding sub-pixel unit row 32. Then, the display panel only needs to set a shift register circuit VSR that outputs the first scan signal, and does not need to set another shift register circuit to provide a scan signal for the photosensitive circuit 22, thereby simplifying the circuit design of the display panel and improving the uniformity of light transmission of the transparent display screen.

[0050] Continue to refer Fig. 9 Optionally, a plurality of photosensitive areas A2 may be arranged along the second direction Y to form a photosensitive area column 33; the display panel further includes: a sensing signal line 24 extending along the second direction Y; the sensing signal line 24 is arranged in a one-to-one correspondence with the photosensitive area column 33, and is used to connect the second end of the second transistor M12 of the photosensitive circuit 22 of the corresponding photosensitive area column 33. In this embodiment, a plurality of photosensitive areas A2 may be arranged along the second direction Y to form a photosensitive area column 33, and a sensing signal line 24 is further arranged in a one-to-one correspondence with the photosensitive area column 33, and the sensing signal line 24 is electrically connected to the second end of the second transistor M12 of each photosensitive circuit 22 in the corresponding photosensitive area column 33, and is used to access the second power supply signal VEE or output the detection current sensor.

[0051] Fig.10A schematic diagram of a planar structure of another display panel provided by an embodiment of the present invention, optionally, a plurality of pixel circuit regions A1 may be arranged along the second direction Y to form a pixel circuit region column 34; a plurality of photosensitive regions A2 may be arranged along the second direction Y to form a photosensitive region column 33; N pixel circuit regions A1 are arranged between adjacent photosensitive region columns 33; N is an integer greater than 1. In addition to the photosensitive region column 33 extending along the second direction Y, this embodiment may also include a pixel circuit region column 34 extending along the second direction Y, and N pixel circuit regions A1 are arranged between adjacent photosensitive region columns 33. For example, Fig.10 As shown, two pixel circuit areas A1 can be set between adjacent photosensitive area columns 33. In this embodiment, in order to increase the PPI of the pixel and improve the fineness of the picture, the number of N can be increased. When the user needs to check the ambient light more, the setting of N can be smaller. In addition, multiple light-transmitting areas A3 are arranged along the second direction Y to form a light-transmitting area column 35. M light-transmitting areas A3 can be set between adjacent photosensitive area columns 33. Similarly, the user can set the number of M according to the light transmittance requirements of the display panel. Optionally, in order to achieve a good light transmittance of the display panel, M=N can be set. For example, Fig.10 As shown, two light-transmitting areas A3 may be arranged between adjacent light-sensitive area columns 33 .

[0052] Fig.11 A schematic diagram of the planar structure of another display panel provided in an embodiment of the present invention, optionally, along a first direction X, the display panel may include a central area AA1 and edge areas AA2 arranged on opposite sides of the central area AA1; the first direction X intersects with the second direction Y, and in the central area AA1, P pixel circuit area columns 34 are arranged between adjacent photosensitive area columns 33; in the edge area AA2, Q pixel circuit area columns 34 are arranged between adjacent photosensitive area columns 33; wherein P>Q≥N, P and Q are integers. In this embodiment, the display area of ​​the display panel may be provided with a central area AA1 and edge areas AA2 arranged on opposite sides of the central area AA1 along the first direction X. According to the visual habits of the user, the main visual area of ​​the retina is generally concentrated in the central area AA1, such as Fig.11 As shown, Fig.11 The middle visual area AA3 is concentrated in the central area AA1. In the central area AA1, the arrangement density of the photosensitive area A2 may be smaller than that of the photosensitive area A2 in the edge area AA2. Specifically, in the central area AA1, P pixel circuit area columns 34 may be arranged between adjacent photosensitive area columns 33. In the edge area AA2, Q pixel circuit area columns 34 may be arranged between adjacent photosensitive area columns 33. P>Q. Fig.11As shown, P=2, Q=1, then within the same area, the number of pixel circuit areas A1 set in the central area AA1 is large, and the number of pixel circuit areas A1 set in the edge area AA2 is small, that is, the setting density of the pixel circuit area A1 in the central area AA1 is greater than the setting density of the pixel circuit area A1 in the edge area AA2. Similarly, it can be obtained that the setting density of the photosensitive area A2 in the central area AA1 is less than the setting density of the photosensitive area A2 in the edge area AA2. Because the greater the setting density of the pixel circuit area A1, the greater the setting density of the light-emitting element, the photosensitive area A2 will occupy the layout space of the pixel driving circuit 21, thereby affecting and reducing the PPI of the display panel. In this embodiment, the setting density of the light-emitting element in the central area AA1 is increased, and the PPI of the central area AA1 is improved, so that the user can obtain a clearer and more delicate display picture, and more photosensitive areas A2 can be set in the edge area AA2 to improve the transmittance of the display panel, thereby improving the display effect of the display screen and the light transmittance of the display panel.

[0053] Continue to refer Figure 2 Optionally, the display panel may further include: a driving circuit layer 12, which is arranged on one side of the substrate 11; the driving circuit layer 12 includes a pixel driving circuit 21 and a photosensitive circuit 22; a metal bonding layer 13, which is arranged on the side of the driving circuit layer 12 away from the substrate 11; the metal bonding layer 13 includes a first electrode block 131 and a second electrode block 132; the pixel driving circuit 21 is electrically connected to the first electrode block 131; a light-emitting element D1 is arranged on the side of the metal bonding layer 13 away from the substrate 11; the first pole of the light-emitting element D1 is electrically connected to the first electrode block 131; the second pole of the light-emitting element D1 is electrically connected to the second electrode block 132. Optionally, in this embodiment, the light-emitting element D1 may be a microchip such as an LED chip, Mini-LED or Micro-LED, and is attached to the substrate through the metal bonding layer 13. When the light-emitting element 113 is the above-mentioned microdevice, the light-emitting element D1 has the advantages of smaller size, faster response speed, higher luminous efficiency, stronger stability and longer service life. At the same time, a higher PPI can also be achieved. In addition, the display panel film layer and process are simpler, which is conducive to achieving a transparent display effect.

[0054] Fig.12A schematic diagram of the cross-sectional structure of another display panel provided in an embodiment of the present invention, optionally, the driving circuit layer 12 may further include: a metal shielding layer 16; the metal shielding layer 16 is disposed between the first source and drain electrode layer 125 and the metal bonding layer 13; in a plane parallel to the substrate 11, the metal shielding layer 16 at least partially overlaps with the first active layer 121. The metal shielding layer 16 may be an alloy of one or more metals selected from chromium, molybdenum, aluminum, titanium, niobium, and copper, and the metal shielding layer 16 at least partially overlaps with the first active layer 121, or the projection of the metal shielding layer 16 on the plane where the substrate 11 is located may cover the first active layer 121, thereby further preventing ambient light from entering the panel from the side close to the light-emitting element D1, avoiding the influence of external light on the pixel driving circuit 21, improving the control accuracy of the pixel driving circuit 21 on the light-emitting element D1, and improving the picture display effect of the transparent display panel.

[0055] Fig.13 A schematic diagram of the cross-sectional structure of another display panel provided by an embodiment of the present invention, optionally, the driving circuit layer 12 may further include: a non-metallic shielding layer 17; the non-metallic shielding layer 17 is disposed on a side of the driving circuit layer 12 away from the substrate 11; in a plane parallel to the substrate 11, the non-metallic shielding layer 17 at least partially overlaps with the first active layer 121 of the first type transistor T1; and the non-metallic shielding layer 17 does not overlap with the light-emitting element D1. This embodiment may also be on a side of the driving circuit layer 12 away from the substrate 11, exemplarily, such as Fig.13 As shown, the non-metal shielding layer 17 can be arranged on the side of the metal bonding layer 13 away from the substrate, and the non-metal shielding layer 17 at least partially overlaps with the first active layer 121 of the first type transistor T1 to prevent external light from affecting the pixel driving circuit 21, improve the control accuracy of the pixel driving circuit 21 on the light-emitting element D1, and improve the picture display effect of the transparent display panel. Fig.14 Optionally, in a plane parallel to the substrate 11, a non-metallic shielding layer 17 can be disposed around the light emitting element D1, so that the non-metallic shielding layer 17 and the light emitting element D1 together form a shielding structure to prevent external light from affecting the first type transistor T1.

[0056] Based on the same concept, an embodiment of the present invention further provides a display device. Fig.14 A schematic diagram of a display device according to an embodiment of the present invention is shown in FIG. Fig.14 As shown, the display device provided by the embodiment of the present invention may include the display panel 200 of any embodiment of the present invention. The display device may be as follows Fig.14 The display device of the mobile phone shown in the figure may also be a display device of an electronic device such as a computer, a television, a smart wearable device, etc., and this embodiment does not specifically limit this.

[0057] The display device provided by the embodiment of the present invention includes the technical features of the display panel provided by any embodiment of the present invention, and has the beneficial effects of the corresponding technical features.

[0058] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A display panel, characterized in that: include: substrate; Pixel circuit area and photosensitive area; The pixel circuit area includes a pixel driving circuit and a light emitting element electrically connected to the pixel driving circuit; The photosensitive area includes a photosensitive circuit; A first type of transistor and a second type of transistor located on the substrate; the first type of transistor comprises a first active layer, a first top gate structure and a first source-drain layer arranged in sequence away from the substrate; a light shielding layer is arranged on a side of the first active layer close to the substrate; in a direction perpendicular to the plane where the substrate is located, the light shielding layer at least partially overlaps with the first active layer; the second type of transistor comprises a second active layer, a second top gate structure and a second source-drain layer arranged in sequence away from the substrate; Wherein, the pixel driving circuit includes at least the first type of transistors; and the photosensitive circuit includes at least the second type of transistors.

2. The display panel according to claim 1, characterized in that: The light shielding layer is reused as a first bottom gate structure of the first type of transistor.

3. The display panel according to claim 1, characterized in that: The light sensing circuit comprises: a first transistor and a second transistor; The control end and the first end of the first transistor are connected to a first power supply signal; the second end of the first transistor is electrically connected to the first end of the second transistor; the control end of the second transistor is connected to a first scanning signal; the second end of the second transistor is used to connect to a second power supply signal or output a detection current.

4. The display panel according to claim 3, characterized in that: The light sensing circuit further includes: a first storage capacitor; a first end of the first storage capacitor is electrically connected to a second end of the first transistor; and a second end of the first storage capacitor is connected to the first power signal.

5. The display panel according to claim 4, characterized in that: The pixel driving circuit at least includes: a first light emitting control transistor, a driving transistor and a second light emitting control transistor; The first end of the first light-emitting control transistor is connected to a third power supply signal; the second end of the first light-emitting control transistor is electrically connected to the first end of the driving transistor; the second end of the driving transistor is electrically connected to the first end of the second light-emitting control transistor; the second end of the second light-emitting control transistor is electrically connected to the first end of the light-emitting element; the second end of the light-emitting element is connected to a fourth power supply signal; The first power signal of the photosensitive circuit and the third power signal of the pixel driving circuit are the same signal; the second power signal of the photosensitive circuit and the fourth power signal of the pixel driving circuit are the same signal.

6. The display panel according to claim 5, characterized in that: The pixel driving circuit further includes a second storage capacitor; a first end of the second storage capacitor is connected to the third power signal; a second end of the second storage capacitor is electrically connected to the control end of the driving transistor; The capacitance value of the first storage capacitor is greater than the capacitance value of the second storage capacitor.

7. The display panel according to claim 5, characterized in that: The width-to-length ratio of the first transistor is greater than the width-to-length ratio of the second transistor; and / or, The width-to-length ratio of the first transistor is smaller than the width-to-length ratio of the driving transistor.

8. The display panel according to claim 1, characterized in that: The transistors in the pixel driving circuit are all first type transistors.

9. The display panel according to claim 3, characterized in that: The first transistor is a second type transistor; the second transistor is a first type transistor.

10. The display panel according to claim 3, characterized in that: Also includes: A binding area; the binding area includes a plurality of binding pads; The second ends of the second transistors of the plurality of light sensing circuits are all connected to the first node; The first node is electrically connected to the corresponding bonding pad.

11. The display panel according to claim 3, characterized in that: A plurality of sub-pixel units are arranged along a first direction to form a sub-pixel unit row; the sub-pixel unit includes a first sub-pixel unit and a second sub-pixel unit; the first sub-pixel unit includes the pixel circuit area, the photosensitive area and the light-transmitting area; the second sub-pixel unit includes the pixel circuit area and the light-transmitting area; The display panel further includes a first scanning signal line extending along the first direction; the first scanning signal line is used to output the first scanning signal to the first sub-pixel unit and the second sub-pixel unit corresponding to the sub-pixel unit row.

12. The display panel according to claim 3, characterized in that: The plurality of photosensitive regions are arranged along the second direction to form a photosensitive region row; The display panel further includes: a sensing signal line extending along the second direction; the sensing signal line is arranged in a one-to-one correspondence with the photosensitive area columns and is used to connect the second end of the second transistor of the photosensitive circuit corresponding to the photosensitive area column.

13. The display panel according to claim 1, characterized in that: A plurality of the pixel circuit regions are arranged along the second direction to form a pixel circuit region column; a plurality of the photosensitive regions are arranged along the second direction to form a photosensitive region column; N pixel circuit area columns are arranged between adjacent photosensitive area columns; N≥1, and N is an integer.

14. The display panel according to claim 13, characterized in that: Along a first direction, the display panel includes a central area and edge areas arranged on both sides of the central area; the first direction intersects with the second direction; In the central area, P pixel circuit area columns are arranged between adjacent photosensitive area columns; in the edge area, Q pixel circuit area columns are arranged between adjacent photosensitive area columns; wherein P>Q≥N, P and Q are integers.

15. The display panel according to claim 1, characterized in that: Also includes: A driving circuit layer, disposed on one side of the substrate; the driving circuit layer includes the pixel driving circuit and the light sensing circuit; A metal bonding layer is arranged on a side of the driving circuit layer away from the substrate; the metal bonding layer comprises a first electrode block and a second electrode block; the pixel driving circuit is electrically connected to the first electrode block; The light emitting element is arranged on a side of the metal bonding layer away from the substrate; the first electrode of the light emitting element is electrically connected to the first electrode block; and the second electrode of the light emitting element is electrically connected to the second electrode block.

16. The display panel according to claim 15, characterized in that: The driving circuit layer further includes: a metal shielding layer; The metal shielding layer is arranged between the first source and drain electrode layer and the metal bonding layer; In a plane parallel to the substrate, the metal shielding layer at least partially overlaps with the first active layer.

17. The display panel according to claim 15, characterized in that: Also includes: Non-metal Occlusion layer; The non-metal shielding layer is arranged on a side of the driving circuit layer away from the substrate; In a plane parallel to the substrate, the non-metallic blocking layer at least partially overlaps with the first active layer of the first type of transistor; and the non-metallic blocking layer does not overlap with the light-emitting element.

18. A display device, characterized in that: A display panel comprising any one of claims 1 to 17.

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