Optical sensor, optical fingerprint module and electronic device

Abstract

This application provides an optical sensor, an optical fingerprint module, and an electronic device to reduce the difference in light response of the optical sensor to different directions and improve the fidelity of light signals. The optical sensor in this application includes: a photosensitive pixel array formed by a plurality of pixel circuit units arranged in an array; each pixel circuit unit includes a photosensitive TFT and a signal processing circuit; the signal processing circuit receives a control signal and outputs an electrical signal corresponding to the light intensity of the effective area of ​​the connected photosensitive TFT; the photosensitive TFT in the photosensitive pixel array forms a preset angle with the horizontal direction, and the distance difference between adjacent pixels in the photosensitive pixel array is smaller than the distance difference between adjacent pixels in a standard array.

Description

Technical Field

[0001] The present application relates to the technical field of optical sensors, and in particular to optical sensors, optical fingerprint modules and electronic devices. Background Art

[0002] Fingerprint recognition function is increasingly used in the field of smart phones or electronic devices. Taking the application in mobile phones as an example, the fingerprint recognition module can be used to realize functions such as unlocking, payment, and transfer.

[0003] With the demand for full-screen and thin electronic devices, optical sensors using photosensitive TFT (Thin Film Transistor) as photosensitive elements have emerged in related technologies, reducing the cost of fingerprint chips while reducing product area.

[0004] In the related art, a single pixel circuit unit includes only one photosensitive element (photosensitive TFT). Usually, the aspect ratio (W / L) of the photosensitive element is designed to be large. Each photosensitive element is often arranged in a standard array in parallel or vertically along the horizontal direction. The horizontal direction is determined according to the appearance of the chip where the photosensitive element is located. The horizontal direction is defined as the X direction and the vertical direction is defined as the Y direction. The specific distribution form of the standard array can be referred to in the attached Figure 1 , Figure 1 The standard array shown only shows four photosensitive elements that are spaced apart. Taking the photosensitive element in the pixel area in the upper left corner as a reference, the shortest distance from the reference to the horizontally adjacent (i.e., upper right corner) photosensitive element is about 10um, and the shortest distance from the reference to the vertically adjacent (i.e., lower left corner) photosensitive element is about 40um. The difference in the distance between adjacent pixels corresponding to the standard array is about 30um, which is the difference between the two shortest distances. The applicant noted that the difference in the spacing between the photosensitive elements in the horizontal and vertical directions in the standard array will lead to areas with obvious differences in the output signals. For example, when identifying the valley-ridge junction area of ​​a finger fingerprint, the photosensitive element is relatively subject to relatively large interference from adjacent pixels in the X direction, but can sensitively perceive smaller light change signals, while the interference from adjacent pixels in the Y direction is relatively small, but it is relatively insensitive to light change signals and will lose part of the signal. This difference in signals in the X and Y directions brings difficulties to the processing and comparison of the later algorithms. Summary of the invention

[0005] The embodiments of the present application provide an optical sensor, an optical fingerprint module, and an electronic device for reducing the difference in the optical sensor's response to light in different directions and improving the restoration of the optical signal.

[0006] A first aspect of an embodiment of the present application provides an optical sensor, which may include:

[0007] A photosensitive pixel array formed by a plurality of pixel circuit units arranged in an array;

[0008] Each of the pixel circuit units includes a photosensitive thin film transistor (TFT) and a signal processing circuit;

[0009] The signal processing circuit is used to receive the control signal and output an electrical signal corresponding to the light intensity of the effective area of ​​the connected photosensitive TFT;

[0010] The photosensitive TFT in the photosensitive pixel array forms a preset angle with the horizontal direction, and the difference in adjacent pixel distances corresponding to the photosensitive pixel array is smaller than the difference in adjacent pixel distances corresponding to the standard array; the standard array refers to an array formed by a plurality of pixel circuit units distributed in parallel along a horizontal direction or a vertical direction, and each pixel circuit unit in the standard array includes a photosensitive TFT; the adjacent pixel distance difference refers to the difference between the shortest distance from the same photosensitive TFT to a horizontally adjacent photosensitive TFT and the shortest distance to a vertically adjacent photosensitive TFT.

[0011] Optionally, as a possible implementation, in an embodiment of the present application, the signal processing circuit includes a capacitor, a first TFT and a second TFT; the source of the first TFT is electrically connected to the gate of the photosensitive TFT, the drain of the photosensitive TFT, the gate of the second TFT and one end of the capacitor; the other end of the capacitor is electrically connected to the source of the photosensitive TFT.

[0012] Optionally, as a possible implementation, in an embodiment of the present application, the output ends of the second TFTs of at least two pixel circuit units in the same column or row in the photosensitive pixel array are connected at the same potential to form a readout point, and the readout points in the same column or row are connected through a readout line, and a row or column of pixel circuit units are selected to work in each time period.

[0013] Optionally, as a possible implementation, in an embodiment of the present application, the first TFT gates of at least two pixel circuit units in the same column or row in the photosensitive pixel array are connected at the same potential to form a common contact, and the common contacts in the same column or row are connected through a gate control line, and a row or column of pixel circuit units are selected to work in each time period.

[0014] Optionally, as a possible implementation manner, in an embodiment of the present application, the preset angle range is 15° to 75° or 105° to 165°.

[0015] A second aspect of the present application provides an optical sensor, which may include:

[0016] A photosensitive pixel array formed by a plurality of pixel circuit units arranged in an array;

[0017] Each of the pixel circuit units includes at least two parallel-connected photosensitive TFTs and a signal processing circuit;

[0018] The signal processing circuit is applied to receive the control signal and output an electrical signal corresponding to the light intensity of the effective area of ​​the connected photosensitive TFT;

[0019] The difference in distance between adjacent pixels corresponding to the photosensitive pixel array is smaller than the difference in distance between adjacent pixels corresponding to the standard array; the standard array refers to an array formed by a plurality of pixel circuit units distributed in parallel along a horizontal direction or a vertical direction, and each pixel circuit unit in the standard array includes a photosensitive TFT; the difference in distance between adjacent pixels refers to the difference between the shortest distance from the same photosensitive TFT to a horizontally adjacent photosensitive TFT and the shortest distance from the same photosensitive TFT to a vertically adjacent photosensitive TFT.

[0020] Optionally, as a possible implementation, in an embodiment of the present application, the photosensitive TFT in the photosensitive pixel array forms a preset angle with the horizontal direction.

[0021] Optionally, as a possible implementation, in an embodiment of the present application, the signal processing circuit includes a capacitor, a first TFT and a second TFT; the source of the first TFT is electrically connected to the gate of the photosensitive TFT module, the drain of the photosensitive TFT module, the gate of the second TFT and one end of the capacitor; the other end of the capacitor is electrically connected to the source of the photosensitive TFT module.

[0022] Optionally, as a possible implementation, in an embodiment of the present application, the output ends of the second TFTs of at least two pixel circuit units in the same column or row in the photosensitive pixel array are connected at the same potential to form a readout point, and the readout points in the same column or row are connected through a readout line, and a row or column of pixel circuit units are selected to work in each time period.

[0023] Optionally, as a possible implementation, in an embodiment of the present application, the first TFT gates of at least two pixel circuit units in the same row in the photosensitive pixel array are connected at the same potential to form a common contact, and the common contacts in the same row are connected through a gate control line, and a row or a column of pixel circuit units are selected to work in each time period.

[0024] Optionally, as a possible implementation manner, in an embodiment of the present application, the preset angle range is 15° to 75° or 105° to 165°.

[0025] A third aspect of an embodiment of the present application provides an optical fingerprint module, which includes a readout chip and an optical sensor including a readout line in the implementation of the first aspect or the second aspect, wherein the readout chip includes a readout channel electrically connected to the readout line.

[0026] A fourth aspect of an embodiment of the present application provides an electronic device having a fingerprint recognition area, and the electronic device includes: an optical sensor as in any possible implementation of the first aspect and the second aspect, wherein the optical sensor is arranged below the fingerprint recognition area and is used to output an electrical signal corresponding to the signal light carrying the fingerprint signal reflected back by the object being measured on the fingerprint recognition area.

[0027] It can be seen from the above technical solutions that the embodiments of the present application have the following advantages:

[0028] In the embodiment of the present application, compared with the related art in which each pixel circuit unit includes a photosensitive element and is distributed parallel or vertically along the horizontal direction, the photosensitive TFT in the photosensitive pixel array in the embodiment of the present application is at a preset angle to the horizontal direction, and / or a single pixel circuit unit includes multiple photosensitive elements, which can reduce the difference in distance between adjacent pixels in the photosensitive pixel array, reduce the difference in the optical sensor's response to light in different directions, and improve the restoration of the light signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of the distribution of photosensitive elements corresponding to a standard array in the related art;

[0030] Figure 2 This is a schematic diagram of a photosensitive element in an optical sensor in an embodiment of the present application being distributed at 45° with respect to the horizontal direction;

[0031] Figure 3 A schematic diagram comparing the structure of the photosensitive TFT in the embodiment of the present application and the conventional TFT;

[0032] Figure 4 Schematic diagram of optional shapes of the photosensitive TFT in the embodiment of the present application;

[0033] Figure 5 This is a schematic diagram of a circuit structure of a pixel circuit unit in an embodiment of the present application;

[0034] Figure 6 This is a schematic diagram of a local circuit structure of another photosensitive pixel array in an embodiment of the present application;

[0035] Figure 7 This is a schematic diagram of the distribution of photosensitive elements in an embodiment of the present application;

[0036] Figure 8 This is another schematic diagram of the distribution of photosensitive elements in the embodiment of the present application;

[0037] Fig. 9 This is a schematic diagram of another circuit structure of a pixel circuit unit in an embodiment of the present application;

[0038] Fig.10 This is a schematic diagram of an electronic device in an embodiment of the present application. DETAILED DESCRIPTION

[0039] The embodiments of the present application provide an optical sensor, an optical fingerprint module, and an electronic device for reducing the difference in the optical sensor's response to light in different directions and improving the restoration of the optical signal.

[0040] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0041] The terms "first", "second", "third", "fourth", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0042] To solve Figure 1 In order to solve the problem of output signal difference caused by the distance difference in the X and Y directions of the photosensitive elements in the standard array shown, the embodiments of the present application change the angle between the photosensitive elements in a single pixel circuit unit and the horizontal direction, and / or increase the number of photosensitive elements in a single pixel circuit unit to reduce the difference in the distance between adjacent pixels and reduce the difference in the optical sensor's response to light in different directions.

[0043] The optical sensor in the embodiment of the present application will be described below from the perspective of changing the angle between the photosensitive element in a single pixel circuit unit and the horizontal direction. The optical sensor in one embodiment of the present application may include: a photosensitive pixel array formed by a number of pixel circuit units; each pixel circuit unit includes a photosensitive thin film transistor (TFT for short) and a signal processing circuit. Among them, the photosensitive TFT in each photosensitive pixel array is at a preset angle with the horizontal direction, and the signal processing circuit is used to receive a control signal and output an electrical signal corresponding to the light intensity of the effective area of ​​the connected photosensitive TFT.

[0044] It should be noted that the photosensitive TFT in the photosensitive pixel array is at a preset angle to the horizontal direction. Optionally, the preset angle ranges from 15° to 75° or from 105° to 165°. Figure 1 The photosensitive TFTs in the standard array shown are rotated so that the photosensitive TFTs are arranged at 45° to the horizontal direction. Figure 2 As shown, at this time, the photosensitive element in the pixel area in the upper left corner is used as a reference object. The shortest distance from the reference object to the horizontally adjacent (i.e., upper right corner) photosensitive element is about 25um, and the shortest distance from the reference object to the vertically adjacent (i.e., lower left corner) photosensitive element is also about 25um. Then, the difference in distance between adjacent pixels in the array is about 0.

[0045] It is understandable that the size of the preset angle between the photosensitive TFT in the photosensitive pixel array and the horizontal direction can be adjusted according to the application requirements in the actual chip design process, but the following conditions must be met: each photosensitive TFT in the photosensitive pixel array rotates in the same direction at the same angle. The distance difference between each pixel and its adjacent pixel in the photosensitive pixel array formed by the rotation formed by the preset angle will be smaller than the distance difference between adjacent pixels corresponding to the standard array. This ensures that the pixel density (PPI) remains unchanged in the output of the final overall image, and at the same time, the difference in the horizontal and vertical directions is small, that is, the crosstalk between adjacent pixels is guaranteed to be at a reasonable level, and at the same time, there is no obvious difference in the XY direction when the pixel array detects the signal. The signal restoration is guaranteed. Among them, the standard array refers to an array formed by the parallel distribution of pixel circuit units containing a photosensitive TFT in the horizontal or vertical direction; the difference in the distance between adjacent pixels refers to the difference between the shortest distance from the same photosensitive TFT to the horizontally adjacent photosensitive TFT and the shortest distance to the vertically adjacent photosensitive TFT.

[0046] It should be noted that the photosensitive TFT in the present application is produced based on a conventional TFT (Thin Film Transistor) process, which may be an a-Si process, or a LPTS (Low Temperature Poly-silicon) process, an IGZO (indium gallium zinc oxide) process, etc. In this embodiment, Figure 3 As shown, the photosensitive TFT can open the effective area larger than the conventional TFT, and can increase the amplitude of the response to changes in external light. Since the conventional TFT also has a certain response to light, this will generate additional noise. In order to reduce this effect, in this embodiment, a mask is covered on the conventional TFT to block the influence of external light.

[0047] In addition, the shape of the photosensitive TFT in this application is set according to actual needs, and can be used as follows: Figure 4 The various polygons shown are not specifically limited here.

[0048] Compared with the related art in which the photosensitive elements are distributed parallel or vertically along the horizontal direction, each photosensitive TFT in the photosensitive pixel array in the embodiment of the present application is at a preset angle to the horizontal direction, which can reduce the difference in the distance between adjacent pixels in the photosensitive pixel array, reduce the difference in the optical sensor's response to light in different directions, and improve the restoration of the light signal.

[0049] Further, the signal processing circuit in the embodiment of the present application will be described below in conjunction with a specific application embodiment. In an optional embodiment of the present application, Figure 5 As shown, the signal processing circuit may include a capacitor Cst, a first TFT (T1), a second TFT (T2) and a photosensitive TFT (TFT sensor); one end of the capacitor Cst is respectively connected to the source of the first TFT, the gate of the photosensitive TFT, the drain of the photosensitive TFT, and the gate of the second TFT; the other end of the capacitor Cst and the source of the photosensitive TFT are respectively grounded.

[0050] T1 and T2 are conventional TFT tubes used for controlling signals, and the TFT sensor is used as a photosensitive device. The signal processing circuit used in this embodiment is referred to as a 3T1 circuit.

[0051] It should be noted that, for the sake of convenience, the source and drain of T1 and T2 are marked in the composition description of the above signal processing circuit, but the functions of the source and drain of the TFT tube can be interchanged. In actual applications, the source and drain of T1 and T2 can be marked according to the application scenario. Figure 5 The source and drain of T1 and T2 in are re-marked, and the specific details are not limited here.

[0052] The following will Figure 5The working process of the pixel circuit unit shown is explained. T1 and T2 can receive corresponding control signals respectively. T1 can reset the voltage of C_node according to the gate control signal (i.e. charge the capacitor Cst). After the reset operation, T1 is turned off and the voltage of the upper end C_node of the capacitor is Vdd. At this time, the charge on the capacitor Cst is discharged through the TFT sensor, and the voltage of C_node drops. After a preset time, the rear circuit reads the changed voltage signal through T2 and processes it to obtain a gray value, thereby obtaining the required fingerprint signal. In different light environments, the drop voltage value of C_node is different. In the light environment, the TFT sensor responds to light, and the current passing through the TFT sensor is significantly increased compared to the dark environment, so the voltage of C_node drops more. The valley ridges of the finger will reflect different light intensities on the screen surface, and the gray value obtained by the rear circuit is different for different light intensities. Therefore, the TFT sensor can detect this difference area and obtain the fingerprint pattern image.

[0053] Therefore, the pixel circuit unit can respond to different light intensities through the TFT sensor and output different fingerprint signals.

[0054] Understandably, Figure 5 The signal processing circuit in the pixel circuit unit shown is merely exemplary. Other pixel circuits may be used in practical applications, such as 2T1C circuits, 7T1C circuits, etc. The number of photosensitive TFTs and conventional TFTs may be designed according to practical applications, and no specific limitation is made here.

[0055] In order to reduce the wiring in the photosensitive pixel array and reduce the hardware cost, in an optional embodiment of the present application, Figure 6 As shown, the output ends of the second TFTs (T2) of at least two pixel circuit units in the same column or row in the photosensitive pixel array in the optical sensor are connected at the same potential to form a readout point, and the readout points in the same column or row are connected through a readout line.

[0056] In order to reduce the wiring in the photosensitive pixel array and reduce the hardware cost, in an optional embodiment of the present application, Figure 6 As shown, the gates of the first TFTs (T1) of at least two pixel circuit units in the same row in the photosensitive pixel array of the optical sensor are connected to form a common point, and the common points in the same column or row are connected through a gate control line. A row or column of pixel circuit units can be selected to work in each time period.

[0057] The four groups of pixel arrays arranged in a plane are arranged in parallel in two rows. Each group of pixel arrays includes two conventional TFTs, one photosensitive TFT and one capacitor, that is, the aforementioned 3T1C circuit structure. The gates of the TFT tubes arranged in the same row receive the same Gatedriver drive signal, the drains of T1 arranged in the same row receive the same Vdd signal, and the drains of T2 arranged in the same row receive the same Bias signal, and only one row of pixels is selected as the working row at a time. The pixels in each column are read out from the Readout end through the amplifier configured for the corresponding column (marked with Amplifler&multipexer in the figure), and data is collected and output through reading circuits such as ROIC by selecting different columns.

[0058] The above control timing is realized by chips and circuits outside the pixel array, and finally a whole frame of data under the required exposure time can be obtained, and then subsequent processing is performed to obtain fingerprint image data.

[0059] In order to meet the diverse needs of users, in an optional embodiment of the present application, the substrate material in the photosensitive pixel array is glass or a flexible material. The optical sensor obtained when the substrate material is a flexible material can be applied to the curved surface of a curved screen.

[0060] The above embodiment solves the problem in the background art by changing the angle between the photosensitive element in a single pixel circuit unit and the horizontal direction. The following describes an embodiment of increasing the number of photosensitive elements in a single pixel circuit unit in the present application.

[0061] An optical sensor in an optional embodiment of the present application may include: a photosensitive pixel array formed by a plurality of pixel circuit units arranged in an array; each pixel circuit unit includes at least two parallel photosensitive thin film transistors and a signal processing circuit. The signal processing circuit is applied to receive a control signal and output an electrical signal corresponding to the light intensity of the effective area of ​​the connected photosensitive TFT.

[0062] It should be noted that the number of parallel-connected photosensitive thin-film transistors contained in each pixel circuit unit can be adjusted according to the application requirements in the actual chip design process, but the following conditions must be met: the difference in adjacent pixel distances corresponding to the photosensitive pixel array is smaller than the difference in adjacent pixel distances corresponding to the standard array; the standard array refers to an array formed by pixel circuit units containing a photosensitive TFT distributed in parallel along the horizontal or vertical direction; the difference in adjacent pixel distances refers to the difference between the shortest distance from the same photosensitive TFT to a horizontally adjacent photosensitive TFT and the shortest distance to a vertically adjacent photosensitive TFT.

[0063] For example, Figure 1 The standard array shown is for comparison, e.g. Figure 7As shown, the number of photosensitive TFTs in each pixel circuit unit in the standard array is increased to 3, forming a Figure 7 The photosensitive pixel array shown in the figure, the photosensitive elements in the same pixel area are regarded as a whole pixel. Figure 7 It can be seen that the shortest distance between the photosensitive elements in the same pixel area is about 5um, the distance between the lowest photosensitive element in the upper left corner and the photosensitive element in the lower left corner is about 10um, and the distance between the photosensitive element in the upper left corner and the photosensitive element in the upper right corner is about 10um, so the difference in the distance between adjacent pixels corresponding to the standard array is about 0. Compared with the difference in the distance between adjacent pixels in the background technology (30um), it is greatly reduced.

[0064] Furthermore, on the basis of increasing the number of photosensitive elements in a single pixel circuit unit, the angle between the photosensitive elements in the single pixel circuit unit and the horizontal direction can also be changed to reduce the distance difference between adjacent pixels. Optionally, the preset angle range is 15° to 75° or 105° to 165°. For example, Figure 8 As shown, the number of photosensitive TFTs in each pixel circuit unit in the standard array can be increased to 2, and the two photosensitive TFTs are arranged at 45° with respect to the horizontal direction to form a Figure 8 The photosensitive pixel array shown, it is obvious that the adjacent pixel distance difference corresponding to the photosensitive pixel array at this time is smaller than the adjacent pixel distance difference in the background technology.

[0065] Accordingly, when a single pixel circuit unit includes multiple photosensitive elements, in a possible embodiment of the present application, as Fig. 9 As shown, the signal processing circuit may include a capacitor (Cst), a first TFT (T1) and a second TFT (T2); the source of the first TFT is electrically connected to the gate of the photosensitive TFT module (three parallel TFT sensors), the drain of the photosensitive TFT module, the gate of the second TFT and one end of the capacitor; the other end of the capacitor and the source of the photosensitive TFT are grounded.

[0066] In order to reduce the wiring in the photosensitive pixel array and reduce the hardware cost, in an optional embodiment of the present application, the output ends of the second TFTs of at least two pixel circuit units in the same column or row in the photosensitive pixel array are connected to the same potential to form a readout point, and the readout points in the same column or row are connected through a readout line. Optionally, the gates of the first TFTs of at least two pixel circuit units in the same column or row in the photosensitive pixel array are connected to the same potential to form a common point, and the common points in the same column or row are connected through a gate control line. A row or column of pixel circuit units can be selected to work in each time period.

[0067] The present application also provides an optical fingerprint module, which includes a readout chip and the aforementioned optical sensor including a readout line, wherein the readout chip includes a readout channel electrically connected to the readout line.

[0068] Please refer to Fig.10 Based on the optical sensor provided in the above embodiment, the present application also provides an electronic device. The electronic device 1 has a fingerprint recognition area, and further includes: the optical sensor described in the above embodiment, the optical sensor is arranged below the fingerprint recognition area, and is used to output an electrical signal corresponding to the signal light carrying the fingerprint signal reflected back by the object under test on the fingerprint recognition area. In a specific usage scenario, the electronic device may include: a memory 11, a processor 12 and a display 13. Among them, the fingerprint recognition area can be arranged in the display.

[0069] Optionally, in some embodiments, the display may be an LED display, a liquid crystal display, an OLED (Organic Light-Emitting Diode) display, a touch display, etc. The display may also be referred to as a display unit, which is used to display information processed in the electronic device 1 and to display a visual user interface.

[0070] In some embodiments, the processor 12 may be a central processing unit (CPU), a controller, a microcontroller, a microprocessor or other data processing chip, used to run program codes or process data stored in the memory 11, such as executing the computer program 01.

[0071] Fig.10 Only the electronic device 1 having components 11-13 is shown, and those skilled in the art will understand that Fig.10 The structure shown does not constitute a limitation on the electronic device 1 , and may include fewer or more components than shown in the figure, or combine certain components, or arrange the components differently.

[0072] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An optical sensor, characterized in that: include: A photosensitive pixel array formed by a plurality of pixel circuit units arranged in an array; Each of the pixel circuit units includes a photosensitive thin film transistor (TFT) and a signal processing circuit; The signal processing circuit is used to receive the control signal and output an electrical signal corresponding to the light intensity of the effective area of ​​the connected photosensitive TFT; The photosensitive TFT in the photosensitive pixel array forms a preset angle with the horizontal direction, and the difference in adjacent pixel distances corresponding to the photosensitive pixel array is smaller than the difference in adjacent pixel distances corresponding to the standard array; the standard array refers to an array formed by a plurality of pixel circuit units distributed in parallel along a horizontal direction or a vertical direction, and each pixel circuit unit in the standard array includes a photosensitive TFT; the adjacent pixel distance difference refers to the difference between the shortest distance from the same photosensitive TFT to a horizontally adjacent photosensitive TFT and the shortest distance to a vertically adjacent photosensitive TFT.

2. The optical sensor according to claim 1, characterized in that The signal processing circuit includes a capacitor, a first TFT and a second TFT; the source of the first TFT is electrically connected to the gate of the photosensitive TFT, the drain of the photosensitive TFT, the gate of the second TFT and one end of the capacitor; the other end of the capacitor is electrically connected to the source of the photosensitive TFT.

3. The optical sensor according to claim 2, characterized in that The output ends of the second TFTs of at least two pixel circuit units in the same column or row in the photosensitive pixel array are connected at the same potential to form a readout point. The readout points in the same column or row are connected through a readout line, and a row or column of pixel circuit units is selected to work in each time period.

4. The optical sensor according to claim 3, characterized in that The first TFT gates of at least two pixel circuit units in the same column or row in the photosensitive pixel array are connected at the same potential to form a common contact point, and the common contacts in the same column or row are connected through a gate control line, and a row or column of pixel circuit units are selected to work in each time period.

5. The optical sensor according to any one of claims 1 to 4, characterized in that The preset angle range is 15° to 75° or 105° to 165°.

6. An optical sensor, characterized in that: include: A photosensitive pixel array formed by a plurality of pixel circuit units arranged in an array; Each of the pixel circuit units includes at least two parallel-connected photosensitive TFTs and a signal processing circuit; The signal processing circuit is applied to receive the control signal and output an electrical signal corresponding to the light intensity of the effective area of ​​the connected photosensitive TFT; The difference in distance between adjacent pixels corresponding to the photosensitive pixel array is smaller than the difference in distance between adjacent pixels corresponding to the standard array; the standard array refers to an array formed by a plurality of pixel circuit units distributed in parallel along a horizontal direction or a vertical direction, and each pixel circuit unit in the standard array includes a photosensitive TFT; the difference in distance between adjacent pixels refers to the difference between the shortest distance from the same photosensitive TFT to a horizontally adjacent photosensitive TFT and the shortest distance from the same photosensitive TFT to a vertically adjacent photosensitive TFT.

7. The optical sensor according to claim 6, characterized in that The photosensitive TFTs in the photosensitive pixel array form a preset angle with the horizontal direction.

8. The optical sensor according to claim 6 or 7, characterized in that: The signal processing circuit includes a capacitor, a first TFT and a second TFT; the source of the first TFT is electrically connected to the gate of the photosensitive TFT module, the drain of the photosensitive TFT module, the gate of the second TFT and one end of the capacitor; the other end of the capacitor is electrically connected to the source of the photosensitive TFT module.

9. The optical sensor according to claim 7, characterized in that The output ends of the second TFTs of at least two pixel circuit units in the same column or row in the photosensitive pixel array are connected at the same potential to form a readout point. The readout points in the same column or row are connected through a readout line, and a row or column of pixel circuit units is selected to work in each time period.

10. The optical sensor according to claim 6 or 7, characterized in that: The first TFT gates of at least two pixel circuit units in the same row in the photosensitive pixel array are connected at the same potential to form a common contact point, and the common contact points in the same row are connected through a gate control line. A row or a column of pixel circuit units are selected to work in each time period.

11. The optical sensor according to claim 7, characterized in that The preset angle range is 15° to 75° or 105° to 165°.

12. An optical fingerprint module, characterized in that: include: A readout chip and an optical sensor as claimed in any one of claims 3 or 9; the readout chip comprises a readout channel electrically connected to the readout line.

13. An electronic device having a fingerprint recognition area, characterized in that: include: The optical sensor according to any one of claims 1 to 11, wherein the optical sensor is disposed below the fingerprint recognition area and is used to output an electrical signal corresponding to the signal light carrying the fingerprint signal reflected by the object under test on the fingerprint recognition area.

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