Fingerprint collection circuit and display panel

Abstract

The application relates to a fingerprint collection circuit and a display panel. A photosensitive device is arranged between a power supply line and a glass layer of the display panel. In the case of a fingerprint collection requirement, a controller can control a light-emitting control circuit to operate so that a light-emitting device emits detection light outward. The detection light is received by the photosensitive device after being reflected by a to-be-detected fingerprint. The photosensitive device outputs different electrical parameters according to the different reflection intensities of the valleys and ridges of the to-be-detected fingerprint, and the electrical parameters are collected by the controller. Finally, the controller analyzes the collected electrical parameters, determines a fingerprint image of the to-be-detected fingerprint, and realizes a fingerprint collection operation. After the detection light is reflected by the to-be-detected fingerprint, the detection light does not pass through the gaps between pixel points of the display panel and is not affected by the layout of the power supply line. Even in a Micro LED type display panel, the controller can effectively receive the electrical parameters to collect the fingerprint image, thereby meeting the fingerprint collection and identification requirements of the Micro LED display panel.

Description

Technical Field

[0001] This application relates to the field of biometric technology, and in particular to a fingerprint acquisition circuit and display panel. Background Technology

[0002] As the resolution of LED (Light Emitting Diode) display panels increases, the number of pixels on the screen increases, and the gaps between pixels gradually decrease, leading to the development and application of small-sized display panels such as Micro LED (Micron-sized Light Emitting Diode).

[0003] Optical fingerprint recognition works by illuminating the finger with light generated by the display panel. The reflected light is then transmitted to the optical fingerprint sensor through gaps, enabling the acquisition and recognition of the fingerprint image. However, because Micro LED display panels require a large current during operation, the gaps between pixels are usually occupied by power metal lines, leaving very little or no area for light to pass through, which cannot meet the requirements for fingerprint acquisition and recognition. Summary of the Invention

[0004] Therefore, it is necessary to provide a fingerprint acquisition circuit and display panel to solve the problem that Micro LED display panels cannot meet the requirements for fingerprint acquisition and recognition.

[0005] A fingerprint acquisition circuit includes a light-emitting device, a light-emitting control circuit, a photosensitive device, an acquisition switch device, and a main control device. A first terminal of the light-emitting control circuit is connected to a power supply, and a second terminal of the light-emitting control circuit is connected to the first terminal of the light-emitting device, which is also connected to the power supply. The photosensitive device is disposed between the power line and the glass layer of a display panel, and its first terminal is connected to the power supply. The first terminal of the acquisition switch device is connected to the second terminal of the photosensitive device and the main control device, and its second terminal is connected to the power supply. The third terminals of the light-emitting control circuit and the acquisition switch device are respectively connected to the main control device. When fingerprint acquisition is required, the main control device controls the light-emitting device to emit detection light through the light-emitting control circuit, and acquires the electrical parameters of the detection light after it is reflected back to the photosensitive device by the fingerprint to be tested.

[0006] In one embodiment, the photosensitive device includes a photoresistor.

[0007] In one embodiment, the light-emitting control circuit includes a fingerprint switch device.

[0008] In one embodiment, the light-emitting device includes a light-emitting diode.

[0009] In one embodiment, the fingerprint acquisition circuit further includes a pixel circuit, which is connected to the main control device, the power supply, the first terminal of the light-emitting control circuit, the second terminal of the light-emitting control circuit, and the first terminal of the light-emitting device.

[0010] In one embodiment, the pixel circuit includes a first switching device, a second switching device, a third switching device, a fourth switching device, a fifth switching device, a sixth switching device, a seventh switching device, and a capacitor; a first terminal of the first switching device is connected to a first terminal of the capacitor, a first terminal of the light-emitting control circuit, and a power supply; a second terminal of the first switching device is connected to a first terminal of the second switching device and a first terminal of the third switching device; a second terminal of the third switching device and a third terminal of the third switching device are respectively connected to the main control device; a second terminal of the second switching device is connected to a first terminal of the fourth switching device and a first terminal of the fifth switching device; a third terminal of the second switching device is connected to a second terminal of the capacitor and a second terminal of the fourth switching device; a second terminal of the fourth switching device is also connected to a first terminal of the sixth switching device; a second terminal of the sixth switching device is connected to a first terminal of the seventh switching device and the main control device; a second terminal of the seventh switching device is connected to a second terminal of the fifth switching device, a first terminal of the light-emitting device, and a second terminal of the light-emitting control circuit; and the third terminals of the first, fourth, fifth, sixth, and seventh switching devices are respectively connected to the main control device.

[0011] In one embodiment, the fingerprint acquisition circuit further includes a touch detection device connected to the main control device.

[0012] A display panel includes the fingerprint acquisition circuit described in any one of the above claims, wherein the fingerprint acquisition circuit is disposed in the fingerprint control area of ​​the display panel.

[0013] In one embodiment, there are multiple fingerprint acquisition circuits, and the photosensitive device array of each fingerprint acquisition circuit is arranged between the power line and the glass layer of the display panel.

[0014] In one embodiment, the fingerprint control area includes a fingerprint recognition area. The controller scans each of the fingerprint acquisition circuits located in the fingerprint control area line by line to obtain the electrical parameters flowing through each of the photosensitive devices, and determines the fingerprint image of the fingerprint to be tested based on the electrical parameters corresponding to the fingerprint recognition area.

[0015] The aforementioned fingerprint acquisition circuit and display panel incorporate a photosensitive device positioned between the power supply line and the glass layer of the display panel. When fingerprint acquisition is required, the controller activates the light-emitting control circuit, causing the emitter to emit probe light. This probe light is reflected by the fingerprint and received by the photosensitive device. The photosensitive device outputs different electrical parameters based on the varying reflection intensities of the valleys and ridges of the fingerprint, which are then collected by the controller. Finally, the controller analyzes the collected electrical parameters to determine the fingerprint image, thus completing the fingerprint acquisition operation. This solution places the photosensitive device between the power supply line and the glass layer of the display panel—that is, on the top layer of the display panel. The probe light, after being reflected back by the fingerprint, does not need to pass through the gaps between the pixels of the display panel and is unaffected by the power supply line layout. Even in Micro LED display panels, the controller can effectively receive the electrical parameters for fingerprint image acquisition, thereby meeting the fingerprint acquisition and recognition requirements of Micro LED display panels. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the fingerprint acquisition circuit structure in one embodiment of this application;

[0018] Figure 2 This is a schematic diagram of the characteristic curve of a photoresistor in one embodiment of this application;

[0019] Figure 3 This is a schematic diagram showing the placement of a photosensitive device in a display panel according to one embodiment of this application;

[0020] Figure 4 This is a schematic diagram of the fingerprint acquisition circuit structure in another embodiment of this application;

[0021] Figure 5 This is a schematic diagram of the fingerprint acquisition circuit structure in another embodiment of this application;

[0022] Figure 6 This is a schematic diagram of pixel display control timing in one embodiment of this application;

[0023] Figure 7 This is a schematic diagram of the fingerprint acquisition control timing in one embodiment of this application;

[0024] Figure 8This is a schematic diagram of the display panel structure in one embodiment of this application. Detailed Implementation

[0025] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of this application.

[0026] Please see Figure 1 A fingerprint acquisition circuit includes a light-emitting device 110, a light-emitting control circuit 120, a photosensitive device 130, an acquisition switch device 140, and a main control device 150. A first terminal of the light-emitting control circuit 120 is connected to a power supply (not shown), and a second terminal of the light-emitting control circuit 120 is connected to the first terminal of the light-emitting device 110, which is also connected to a power supply (not shown). The photosensitive device 130 is disposed between the power line and the glass layer of the display panel (not shown), and its first terminal is connected to a power supply. The first end of the switching device 140 is connected to the second end of the photosensitive device 130 and the main control device 150, and the second end of the acquisition switching device 140 is connected to the power supply; the third end of the light emission control circuit 120 and the third end of the acquisition switching device 140 are respectively connected to the main control device 150; the main control device 150 is used to control the light emission device 110 to emit detection light through the light emission control circuit 120 when there is a need for fingerprint acquisition, and to acquire the electrical parameters of the light emission device 130 after the detection light is reflected back to the photosensitive device 130 by the fingerprint to be tested.

[0027] Specifically, the light-emitting device 110 is a device that emits light when powered on. The light-emitting control circuit 120 is a circuit that controls the light-emitting device 110 to emit light or stop emitting light under the control signal output by the controller, according to actual needs. The photosensitive device 130 is a device whose output electrical parameters change accordingly when the intensity of the received light signal changes. The acquisition switch device 140 is a switching device used to control the photosensitive device 130 to detect reflected light and output electrical parameters to the main control device 150, or to control the photosensitive device 130 to stop detecting reflected light. The main control device 150 is the controller that controls the operation of the entire fingerprint acquisition circuit. It can be understood that the specific type of the main control device 150 is not unique and can be selected differently according to actual needs. For example, in one embodiment, the main control device 150 can be a CPU (Central Processing Unit) or an MCU (Microcontroller Unit), etc., without specific limitations.

[0028] It should be noted that the specific type of control module in the main control device 150 is not unique. In one embodiment, the main control device 150 integrates a system module, a display control module, and a fingerprint control and recognition module. The system module serves as the core control module for the entire display panel. Under the operation of the system module, the display control module controls the display panel's display. The fingerprint control and recognition module, under the operation of the system module, analyzes the electrical parameters flowing through the photosensitive device 130 to obtain a fingerprint image and compares it with a preset fingerprint image to achieve fingerprint recognition. In another embodiment, the main control device 150 may also include different control devices to achieve fingerprint acquisition, recognition, and display control of the display panel, depending on the specific needs.

[0029] In the technical solution of this application, when the main control device 150 determines that the current display panel requires fingerprint collection, it can output control signals to the light-emitting control circuit 120 and the collection switch device 140 respectively, and the light-emitting control circuit 120 and the collection switch device 140 are activated. The light-emitting device 110 is connected to the power supply through the light-emitting control circuit 120, and the light-emitting device 110 emits detection light towards the user through the glass layer (or thin film layer) of the display panel. At this time, the user only needs to cover the finger to be collected on the glass layer of the display panel, and the detection light is reflected back to the display panel by the fingerprint to be collected. The reflected light, after being reflected, does not need to pass through the pixel gaps of the display panel and is directly received by the photosensitive device 130 located between the glass layer and the power line. Finally, based on the different intensity of the reflected light signal received by the photosensitive device 130, the main control device 150 collects different voltage signals at the photosensitive device 130. By analyzing this voltage signal, the fingerprint image of the fingerprint to be measured can be determined.

[0030] The main control device 150 has not a single way of determining whether there is a fingerprint collection requirement. In one embodiment, when the display panel is in the on state, the main control device 150 receives a fingerprint collection command from the system module, and the fingerprint collection and recognition module will enter the fingerprint collection state and finally start the fingerprint collection operation, such as in software unlocking or payment scenarios.

[0031] In another embodiment, when other external devices detect a user's fingerprint collection request, these devices send a collection signal to the main control device 150, and then the system module controls the fingerprint collection and recognition module to enter the fingerprint collection state. For example, when the display panel is in an off state and fingerprint collection and recognition need to be performed, fingerprint collection can be initiated by pressing a detection signal.

[0032] It should be noted that the type of electrical parameters collected by the controller from the photosensitive device 130 is not unique. Depending on the actual application scenario, the type of electrical parameters may vary depending on the type of photosensitive device 130 selected. For example, in a more detailed embodiment, the electrical parameters may be voltage parameters, current parameters, or resistance parameters of the photosensitive device 130 itself, etc., without any specific limitation.

[0033] In the aforementioned fingerprint acquisition circuit, a photosensitive device 130 is positioned between the power line and the glass layer of the display panel. When fingerprint acquisition is required, the controller can control the operation of the light-emitting control circuit 120, causing the emitter to emit detection light. This detection light is reflected by the fingerprint to be tested and then received by the photosensitive device 130. The photosensitive device 130 outputs different electrical parameters based on the varying reflection intensities of the valleys and ridges of the fingerprint, which are then acquired by the controller. Finally, the controller analyzes the acquired electrical parameters to determine the fingerprint image, thus achieving fingerprint acquisition. This solution places the photosensitive device 130 between the power line and the glass layer of the display panel, i.e., on the top layer of the display panel. The detection light, after being reflected back by the fingerprint, does not need to pass through the gaps between the pixels of the display panel and is unaffected by the layout of the power line. Even in Micro LED display panels, the controller can effectively receive the electrical parameters for fingerprint image acquisition, thereby meeting the fingerprint acquisition and recognition requirements of Micro LED display panels.

[0034] It should be noted that the specific type of photosensitive device 130 is not unique; any device capable of outputting different electrical parameters based on the intensity of the received light is acceptable. For ease of understanding of the technical solution of this application, in one embodiment, the photosensitive device 130 includes a photoresistor.

[0035] Specifically, photoresistors (or light-dependent resistors) are typically made of materials such as cadmium sulfide, selenium, aluminum sulfide, lead sulfide, and bismuth sulfide. Their resistance gradually decreases under illumination with light of a specific wavelength. More specifically, as the intensity of the light illuminating the photoresistor increases, the resistance of the photoresistor also gradually decreases. This can be further analyzed in conjunction with the specific components involved. Figure 2 Therefore, the photoresistor can be placed on the top layer of the display panel (excluding the transparent protective colloid), specifically between the glass layer and the power lines. The key is to ensure it is not affected by the layout of the power lines and can reliably receive reflected light from the detection beam. For more details, please refer to [reference needed]. Figure 3 .

[0036] In this configuration, after the probe light is reflected by the fingerprint to be tested, different resistance values ​​are generated based on the varying light reflection intensities of the ridges and valleys of the fingerprint. Subsequently, due to the voltage division between the photosensitive device 130 and the acquisition switch 140, the voltage division of the photosensitive device 130 changes with the resistance value. During fingerprint acquisition, the control device detects the voltage signal generated by the photosensitive device 130 due to the different resistance values, and finally forms a corresponding fingerprint image based on the potential difference, thus completing the fingerprint acquisition. This scheme uses a photoresistor as the photosensitive device 130, generating different voltage division values ​​based on the varying light intensities reflected by the fingerprint to achieve fingerprint image acquisition. It has the advantages of simple acquisition method, high acquisition efficiency, and high acquisition accuracy.

[0037] During fingerprint acquisition, the third terminal of the acquisition switch 140 maintains a constant potential, therefore the resistance of the acquisition switch 140 does not change. The voltage between the photoresistor and the acquisition switch 140 is determined by the following formula: V = ELVSS + (ELVDD - ELVSS) * R T8 / (R T8 +R_L), where ELVSS is the power supply voltage connected to the second terminal of the light-emitting device 110, ELVDD is the power supply voltage connected to the first terminal of the photoresistor, and R T8 To acquire the resistance value of the switching device 140, where R_L is the resistance value of the photoresistor, it can be seen that when R_L increases, V decreases, and when R_L decreases, V increases. This potential can be acquired and transmitted to the fingerprint recognition module. Based on the potential level, a corresponding fingerprint image is formed, thus completing fingerprint acquisition and fingerprint recognition.

[0038] Similarly, the specific type of the light-emitting control circuit 120 is not unique; any circuit capable of controlling the on / off state of the light-emitting device 110 under the control of the main control device 150 is acceptable. For example, in one embodiment, the light-emitting control circuit 120 includes a fingerprint switch device.

[0039] Specifically, the fingerprint switch device is a switch device that controls the activation of the fingerprint acquisition function. The specific type of fingerprint switch device is not unique. In one embodiment, it can be any one of a MOS (Metal Oxide Semiconductor), a transistor, and an insulated gate bipolar transistor. There is no specific limitation, as long as it can turn on or off the light-emitting device 110 under the control command output by the main control device 150.

[0040] In one embodiment, the light-emitting device 110 includes a light-emitting diode.

[0041] Specifically, a light-emitting diode (LED) is a commonly used light-emitting device 110 that emits light by releasing energy through the recombination of electrons and holes. In this embodiment, an LED is used as the light-emitting device 110 in the fingerprint acquisition circuit. This LED can emit light not only for display purposes when the display panel requires it, but also to perform fingerprint acquisition when the display panel requires it. Using an LED as the light-emitting device 110 in this solution effectively saves device resources and reduces the size of the display panel.

[0042] Accordingly, in one embodiment, to avoid affecting the normal display operation of the display panel, the data writing and reset operations for display operation should be staggered from the fingerprint acquisition operation in the fingerprint acquisition area. That is, during the effective period of the light-emitting control circuit 120, that is, when the light-emitting control circuit 120 inputs a valid finger_emit signal, causing the light-emitting control circuit 120 to turn on the light-emitting device 110 and the power supply, the data writing and reset operations for display operation are stopped. During the ineffective period of the light-emitting control circuit 120, the data writing and reset operations are started to realize the display operation.

[0043] Please refer to the following: Figure 4 In one embodiment, the fingerprint acquisition circuit further includes a pixel circuit 410, which is connected to the main control device 150 (not shown), the power supply (not shown), the first terminal of the light-emitting control circuit 120, the second terminal of the light-emitting control circuit 120, and the first terminal of the light-emitting device 110.

[0044] Specifically, the pixel circuit 410 is a circuit that enables the light-emitting devices 110 in each fingerprint acquisition circuit to operate through data writing and reset operations, ultimately displaying different text or images on the display panel. In this embodiment, the light-emitting devices 110 in the pixel circuit 410 are reused with the light-emitting devices 110 in the fingerprint acquisition circuit, and the reset and data writing operations need to avoid the effective time of the fingerprint_emit signal of the light-emitting control circuit 120.

[0045] It is understood that the specific structure of the pixel circuit 410 is not unique; please refer to [link / reference needed]. Figure 5In one embodiment, the pixel circuit 410 includes a first switching device T1, a second switching device T2, a third switching device T3, a fourth switching device T4, a fifth switching device T5, a sixth switching device T6, a seventh switching device T7, and a capacitor C. The first terminal of the first switching device T1 is connected to the first terminal of the capacitor C, the first terminal of the light-emitting control circuit 120, and a power supply. The second terminal of the first switching device T1 is connected to the first terminals of the second switching device T2 and the third switching device T3. The second terminals of the third switching device T3 are respectively connected to the main control device 150. The second terminal of the second switching device T2 is connected to the first terminal of the fourth switching device T4 and the fifth switching device T7. The first terminal of T5, the third terminal of the second switching device T2 is connected to the second terminal of capacitor C and the second terminal of the fourth switching device T4. The second terminal of the fourth switching device T4 is also connected to the first terminal of the sixth switching device T6. The second terminal of the sixth switching device T6 is connected to the first terminal of the seventh switching device T7 and the main control device 150. The second terminal of the seventh switching device T7 is connected to the second terminal of the fifth switching device T5, the first terminal of the light-emitting device 110 and the second terminal of the light-emitting control circuit 120. The third terminals of the first switching device T1, the fourth switching device T4, the fifth switching device T5, the sixth switching device T6 and the seventh switching device T7 are respectively connected to the main control device 150.

[0046] Specifically, in this embodiment, the first terminal of the first switching device T1, the first terminal of the light-emitting control circuit 120, and the first terminal of the photosensitive device 130 are connected to the power supply ELVDD, while the second terminal of the acquisition switching device 140 and the second terminal of the light-emitting device 110 are connected to the power supply ELVSS. The third terminal of the first switching device T1 and the third terminal of the fifth switching device T5 are respectively connected to the main control device 150 for inputting EM control signals. The second and third terminals of the third switching device T3 and the third terminal of the fourth switching device T4 are used to input Gate control signals, and the third terminal of the sixth unlocking device and the third terminal of the seventh switching device T7 are used to input Rest control signals.

[0047] In a more detailed embodiment, there are multiple fingerprint acquisition circuits, and the photosensitive devices 130 of each fingerprint acquisition circuit are arranged in an array between the glass layer of the display panel and the power line. In actual operation, the display function is achieved by scanning line by line. For specific control timing, please refer to the relevant documentation. Figure 6In each row of photosensitive devices 130, the control signal timing is identical in the corresponding pixel acquisition circuit. Each row's process includes three stages: reset (reset active), write data (gate active), and emit light (EM active). After the first row completes reset and write data, the second row begins reset and write data, and so on. Furthermore, during the active period of the finger_emit signal, the first terminal of ELVDD is connected to the emitter 110 via the emitter control circuit 120. This affects the reset operation of the pixels in that row, thus affecting the normal operation of the pixel circuit 410. Therefore, the reset and write data operations must be avoided during the active period of finger_emit.

[0048] When the fingerprint acquisition circuit performs fingerprint acquisition, please refer to [the relevant documentation]. Figure 7 The main control device 150 needs to input a valid finger_emit signal to the light emission control circuit 120. During the valid period of finger_emit, finger_collect is turned on row by row, that is, the acquisition switch device 140 is turned on row by row, and the electrical parameters output by each photosensitive device 130 are detected row by row and output through the finger_sense port. Finally, after the electrical parameters of each row are acquired, the fingerprint image of the fingerprint to be tested can be determined.

[0049] The fingerprint acquisition circuit built through this embodiment can complete the fingerprint acquisition work within a valid Finger_emit time period under the control of the main control device 150, thereby achieving fast fingerprint acquisition within one frame and having high fingerprint acquisition efficiency.

[0050] It should be noted that the specific types of each switching device in the fingerprint acquisition circuit are not unique. In a more detailed embodiment, the first switching device T1, the second switching device T2, the third switching device T3, the fourth switching device T4, the fifth switching device T5, the sixth switching device T6, and the seventh switching device T7 are of the same type and are all thin film transistors (TFTs).

[0051] Understandably, in one embodiment, the display panel has a display area and a fingerprint control area. The fingerprint control area is located within the display area, and the fingerprint acquisition circuit is located within the fingerprint control area of ​​the display panel. This fingerprint acquisition circuit includes a pixel circuit 410. The fingerprint control area can perform both display and fingerprint recognition operations. In the display area outside the fingerprint control area, only the pixel circuit 410 and the light-emitting device 110 as described in the previous embodiment need to be provided. The display operation can be achieved through the pixel circuit 410 and the light-emitting device 110.

[0052] In one embodiment, the fingerprint acquisition circuit further includes a touch detection device connected to the main control device 150.

[0053] Specifically, the touch detection device is a device that detects user touch operations on the display panel, enabling touch interaction between the user and the display panel. In this embodiment, the touch detection device is placed in the fingerprint control area of ​​the display panel. When the display panel is in the off state, the touch detection device can detect the user's touch operations on the display panel, thereby triggering fingerprint recognition, making the display panel suitable for applications such as fingerprint unlocking.

[0054] This application embodiment also provides a display panel including any of the above-mentioned fingerprint acquisition circuits, wherein the fingerprint acquisition circuit is disposed in the fingerprint control area of ​​the display panel.

[0055] Specifically, the entire display area of ​​the display panel is equipped with pixel circuits 410 and light-emitting devices 110. The display area outside the fingerprint control area does not require fingerprint recognition, so only pixel circuits 410 and light-emitting devices 110 are needed. However, in the fingerprint control area, since fingerprint acquisition is required, a fingerprint acquisition circuit is necessary. It can be understood that this fingerprint acquisition circuit may not include pixel circuits 410; in this case, only fingerprint acquisition is required in the fingerprint control area. In another embodiment, the fingerprint control area is equipped with a fingerprint acquisition circuit including pixel circuits 410, thus enabling both display and fingerprint acquisition functions in the fingerprint control area.

[0056] In one embodiment, there are multiple fingerprint acquisition circuits, and the photosensitive devices 130 of each fingerprint acquisition circuit are arranged in an array between the power line and the glass layer of the display panel.

[0057] Specifically, in this embodiment, the display function is implemented using a line-by-line scanning method. During fingerprint acquisition, while Finger_emit is active, Finger_collect is activated line by line to acquire the electrical parameters output by each column of photosensitive devices 130. Within one active Finger_emit period, all pixels output their potentials. In non-fingerprint acquisition mode, finger_emit and Finger_collect remain in an inactive state (i.e., the high-level state shown in the diagram), ensuring that the acquisition switch 140 and the light-emitting control circuit 120 are in the off state.

[0058] Please see Figure 8 In one embodiment, the fingerprint control area includes a fingerprint recognition area. The controller scans each fingerprint acquisition circuit located in the fingerprint control area line by line to obtain the electrical parameters flowing through each photosensitive device 130, and determines the fingerprint image of the fingerprint to be tested based on the electrical parameters corresponding to the fingerprint recognition area.

[0059] Specifically, the fingerprint recognition area is the region where electrical parameters are actually collected to determine the area of ​​the fingerprint image to be tested. In this embodiment, to ensure consistent received light intensity and improve fingerprint acquisition accuracy, a fingerprint recognition area smaller than the fingerprint control area is further set within the fingerprint control area. Assume row x is the effective start time of `Finger_emit`, and row y is the effective end time of `Finger_emit`. The starting row number of the area controlled by `finger_emit` is x and y, and the starting and ending row numbers of fingerprint recognition are between x and y. That is, when `Finger_emit` is effective, electrical parameters are not immediately collected for fingerprint image recognition. Instead, fingerprint image recognition is performed based on the scanning results of subsequent photosensitive devices 130 after at least one row of photosensitive devices 130 has finished scanning. Furthermore, the fingerprint image recognition operation does not end only when `Finger_emit` is effective; fingerprint image recognition is performed based on the already scanned electrical parameters while at least one row of photosensitive devices 130 remains to be scanned.

[0060] In a more detailed embodiment, the starting and ending rows of fingerprint recognition are located at a point less than or equal to 1 / 3 of the distance between x and y. In a more specific embodiment, the 1 / 3 point can be selected to achieve optimal consistency in received light intensity. For example, if the effective starting row of Finger_emit is row 10 and the effective ending row of Finger_emit is row 34, then the electrical parameters output by the photosensitive device 130 can be acquired starting from row 18 and ending at row 26. Finally, the fingerprint image of the fingerprint to be tested is determined by the electrical parameters acquired row by row from row 18 to row 26, and fingerprint recognition is performed accordingly.

[0061] In the aforementioned display panel, a photosensitive device 130 is positioned between the power line and the glass layer. When fingerprint acquisition is required, the controller activates the light-emitting control circuit 120, causing the emitter to emit probe light. This probe light is reflected by the fingerprint and received by the photosensitive device 130. The photosensitive device 130 outputs different electrical parameters based on the varying reflection intensities of the valleys and ridges of the fingerprint, which are then collected by the controller. Finally, the controller analyzes the collected electrical parameters to determine the fingerprint image, thus enabling fingerprint acquisition. This solution places the photosensitive device 130 between the power line and the glass layer of the display panel, i.e., on the top layer. The probe light, reflected by the fingerprint, does not pass through the gaps between the pixels of the display panel and is unaffected by the power line layout. Even in Micro LED display panels, the controller can effectively receive the electrical parameters for fingerprint image acquisition, thereby meeting the fingerprint acquisition and recognition requirements of Micro LED display panels.

[0062] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0063] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A fingerprint acquisition circuit, characterized in that, The circuit, applied to a Micro LED display panel, includes: Light-emitting devices; A light-emitting control circuit, wherein a first terminal of the light-emitting control circuit is connected to a power supply, a second terminal of the light-emitting control circuit is connected to a first terminal of the light-emitting device, and a second terminal of the light-emitting device is connected to a power supply. A photosensitive device is disposed between the power line and the glass layer of the display panel, and the first end of the photosensitive device is connected to the power supply. A data acquisition switch device, wherein the first end of the data acquisition switch device is connected to the second end of the photosensitive device and the main control device, and the second end of the data acquisition switch device is connected to a power supply; The main control device is connected to the third terminal of the light-emitting control circuit and the third terminal of the acquisition switch device respectively. The main control device is used to control the light-emitting device to emit detection light through the light-emitting control circuit when there is a need for fingerprint acquisition, and to collect the electrical parameters of the light-emitting device after the detection light is reflected back to the photosensitive device by the fingerprint to be tested. Specifically, when a valid signal is input to the light-emitting control circuit, causing the light-emitting control circuit to turn on the light-emitting device and the power supply, the data writing and reset operation for display operation stops; during the period when the light-emitting control circuit is inactive, the data writing and reset operation is started.

2. The fingerprint acquisition circuit according to claim 1, characterized in that, The photosensitive device includes a photoresistor.

3. The fingerprint acquisition circuit according to claim 1, characterized in that, The light-emitting control circuit includes a fingerprint switch device.

4. The fingerprint acquisition circuit according to claim 1, characterized in that, The light-emitting device includes a light-emitting diode.

5. The fingerprint acquisition circuit according to any one of claims 1-4, characterized in that, It also includes a pixel circuit, which is connected to the main control device, the power supply, the first terminal of the light-emitting control circuit, the second terminal of the light-emitting control circuit, and the first terminal of the light-emitting device.

6. The fingerprint acquisition circuit according to claim 5, characterized in that, The pixel circuit includes a first switching device, a second switching device, a third switching device, a fourth switching device, a fifth switching device, a sixth switching device, a seventh switching device, and a capacitor. The first terminal of the first switching device is connected to the first terminal of the capacitor, the first terminal of the light-emitting control circuit, and a power supply. The second terminal of the first switching device is connected to the first terminals of the second and third switching devices. The second and third terminals of the third switching device are respectively connected to the main control device. The second terminal of the second switching device is connected to the first terminals of the fourth and fifth switching devices. The third terminal of the second switching device is connected to the second terminals of the capacitor and the second terminal of the fourth switching device. The second terminal of the fourth switching device is also connected to the first terminal of the sixth switching device. The second terminal of the sixth switching device is connected to the first terminal of the seventh switching device and the main control device. The second terminal of the seventh switching device is connected to the second terminal of the fifth switching device, the first terminal of the light-emitting device, and the second terminal of the light-emitting control circuit. The third terminals of the first, fourth, fifth, sixth, and seventh switching devices are respectively connected to the main control device.

7. The fingerprint acquisition circuit according to any one of claims 1-4, characterized in that, It also includes a touch detection device, which is connected to the main control device.

8. A display panel, characterized in that, The device includes the fingerprint acquisition circuit according to any one of claims 1-7, wherein the fingerprint acquisition circuit is disposed in the fingerprint control area of ​​the display panel.

9. The display panel according to claim 8, characterized in that, The number of fingerprint acquisition circuits is multiple, and the photosensitive device array of each fingerprint acquisition circuit is arranged between the power line and the glass layer of the display panel.

10. The display panel according to claim 9, characterized in that, The fingerprint control area includes a fingerprint recognition area. The main control device scans each of the fingerprint acquisition circuits located in the fingerprint control area line by line to obtain the electrical parameters flowing through each of the photosensitive devices, and determines the fingerprint image of the fingerprint to be tested based on the electrical parameters corresponding to the fingerprint recognition area.

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