Fingerprint sensing device and method of driving a fingerprint sensing plate thereof

Abstract

The present application provides a fingerprint sensing device and a driving method of a fingerprint sensing panel thereof. The driving method includes detecting whether a finger touch occurs on the fingerprint sensing panel; switching a brightness mode of the fingerprint sensing panel from a normal brightness mode to a high brightness mode during the finger touch to facilitate sensing of a fingerprint; and driving the fingerprint sensing panel to sense the fingerprint before a mode switching point at which the brightness mode of the fingerprint sensing panel is completed to the high brightness mode. The fingerprint sensing panel includes a pixel row, wherein the pixel row sequentially goes through a reset, an exposure period, and a sampling to output a row sensing result, the reset is earlier than the mode switching point, and the sampling is later than the mode switching point.

Description

Technical Field

[0001] This invention relates to an electronic device, and more particularly to a fingerprint sensing device and a driving method for the fingerprint sensing plate thereof. Background Technology

[0002] Many electronic devices can sense and recognize fingerprints, then determine whether to unlock the device based on the fingerprint recognition result. After a finger touches the fingerprint sensor, the sensor's brightness mode switches from normal brightness mode to high brightness mode (HBM) to facilitate fingerprint detection. It takes a certain amount of time (e.g., tens of milliseconds) from the moment the finger touches the sensor until the brightness mode switches to high brightness mode. Previously, optical fingerprint recognition had to wait for the high brightness mode to be ready before capturing the fingerprint (fingerprint sensing), resulting in a longer unlocking time. Summary of the Invention

[0003] The present invention provides a fingerprint sensing device and a driving method for the fingerprint sensing plate, which can sense fingerprints earlier than the mode switching point of the brightness mode.

[0004] In an embodiment of the present invention, the driving method of the fingerprint sensing plate includes: detecting whether a finger touch occurs on the fingerprint sensing plate; during the period of finger touch, switching the brightness mode of the fingerprint sensing plate from a normal brightness mode to a high brightness mode to facilitate fingerprint sensing; and driving the fingerprint sensing plate to sense the fingerprint before the mode switching point when the brightness mode of the fingerprint sensing plate completes the switch to the high brightness mode. The fingerprint sensing plate includes a first pixel row, which sequentially undergoes a first reset, a first exposure period, and a first sampling to output a first row of sensing results. The first reset occurs earlier than the mode switching point, and the first sampling occurs later than the mode switching point.

[0005] In an embodiment of the present invention, the fingerprint sensing device includes a fingerprint sensing plate and a driving circuit. The fingerprint sensing plate is used to sense fingerprints. The driving circuit is coupled to the fingerprint sensing plate to detect whether a finger touches the fingerprint sensing plate. During the period of finger touch, the driving circuit controls the fingerprint sensing plate to switch its brightness mode from a normal brightness mode to a high brightness mode to facilitate fingerprint sensing. Before the mode switching point when the fingerprint sensing plate completes the switch from brightness mode to high brightness mode, the driving circuit drives the fingerprint sensing plate to sense the fingerprint. The fingerprint sensing plate includes a first pixel row, which sequentially undergoes a first reset, a first exposure period, and a first sampling to output a first row of sensing results. The first reset occurs earlier than the mode switching point, and the first sampling occurs later than the mode switching point.

[0006] Based on the above, the driving circuit described in the embodiments of the present invention can drive the fingerprint sensing plate to switch its brightness mode when a finger touches it, in order to facilitate fingerprint sensing. Generally, it takes some time for the brightness mode to switch from normal brightness mode to high brightness mode. The driving circuit can sense the fingerprint earlier than the mode switching point. Attached Figure Description

[0007] Figure 1 This is a schematic diagram of a circuit block of a fingerprint sensing device according to an embodiment of the present invention.

[0008] Figure 2 This is a timing diagram illustrating a fingerprint sensing device performing fingerprint acquisition (fingerprint sensing) according to an embodiment.

[0009] Figure 3 This is a flowchart illustrating a driving method for a fingerprint sensing plate according to an embodiment of the present invention.

[0010] Figure 4 This is a timing diagram illustrating fingerprint acquisition (fingerprint sensing) performed by a fingerprint sensing device according to an embodiment of the present invention.

[0011] Figure 5 This is a timing diagram illustrating fingerprint acquisition (fingerprint sensing) performed by a fingerprint sensing device according to another embodiment of the present invention.

[0012] Figure 6 This is a timing diagram illustrating fingerprint acquisition (fingerprint sensing) performed by a fingerprint sensing device according to another embodiment of the present invention.

[0013] Figure 7 This is a schematic diagram illustrating the relationship between exposure time and sensing code for a pixel row of a fingerprint sensing plate during the exposure period, according to an embodiment of the present invention.

[0014] Figure 8 This is a timing diagram illustrating fingerprint acquisition (fingerprint sensing) performed by a fingerprint sensing device according to a further embodiment of the present invention.

[0015] Figure 9 This is a schematic diagram illustrating the adaptive adjustment of the sampling timing of pixel rows according to an embodiment of the present invention.

[0016] Figure 10 This is a schematic diagram illustrating the adaptive adjustment of the sampling timing of pixel rows according to another embodiment of the present invention.

[0017] Figure 11 This is a schematic diagram illustrating the adaptive adjustment of the sampling timing of pixel rows according to another embodiment of the present invention.

[0018] Figure 12 This is a schematic diagram illustrating the adaptive adjustment of the reset timing of pixel rows according to an embodiment of the present invention.

[0019] Figure 13 This is a schematic diagram illustrating the adaptive adjustment of the reset timing and sampling timing of pixel rows according to a further embodiment of the present invention.

[0020] Figure 14 This is a schematic diagram illustrating the adaptive adjustment of the reset timing of pixel rows according to another embodiment of the present invention.

[0021] Figure 15 This is a schematic diagram illustrating the adaptive adjustment of the reset timing and sampling timing of pixel rows according to another embodiment of the present invention.

[0022] Explanation of reference numerals in the attached figures

[0023] 100: Fingerprint sensor device

[0024] 110: Drive circuit

[0025] 120: Fingerprint sensor board

[0026] K: Brightness ratio

[0027] R: Reset

[0028] R1, R2, R3, R4, R5: Pixel rows

[0029] S: Sampling

[0030] S1: Reset Time Point

[0031] S2: Mode switching point

[0032] S3: Sampling time point

[0033] S310, S320, S330: Steps

[0034] Slope1: First slope

[0035] T0, T1, T2, T3: Time points

[0036] TCode: Target Sensing Code Detailed Implementation

[0037] Reference will now be made in detail to exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same element symbols are used in the drawings and description to denote the same or similar parts.

[0038] The term "coupled (or connected)" as used throughout this specification (including the claims) may refer to any direct or indirect means of connection. For example, if the text describes a first device coupled (or connected) to a second device, it should be interpreted as the first device being directly connected to the second device, or the first device being indirectly connected to the second device through other devices or some means of connection. The terms "first," "second," etc., used throughout this specification (including the claims) are used to name components or distinguish different embodiments or scopes, and are not intended to limit the upper or lower limit of the number of components, nor to limit the order of components. Furthermore, wherever possible, components / components / steps using the same reference numerals in the drawings and embodiments represent the same or similar parts. Components / components / steps using the same reference numerals or the same terms in different embodiments may be referred to mutually in the relevant descriptions.

[0039] Figure 1 This is a circuit block diagram of a fingerprint sensing device 100 according to an embodiment of the present invention. The fingerprint sensing device 100 includes a driving circuit 110 and a fingerprint sensing plate 120. The fingerprint sensing plate 120 can sense fingerprints. The driving circuit 110 is coupled to the fingerprint sensing plate 120 to detect whether a finger touches the fingerprint sensing plate 120.

[0040] Depending on different design requirements, in some embodiments, the drive circuit 110 can be implemented as a hardware circuit. In other embodiments, the drive circuit 110 can be implemented as firmware, software (i.e., a program), or a combination of the two. In still other embodiments, the drive circuit 110 can be implemented as a combination of multiple hardware, firmware, and software.

[0041] In hardware terms, the driver circuit 110 can be implemented as logic circuitry on an integrated circuit. For example, the functions of the driver circuit 110 can be implemented in various logic blocks, modules, and circuits within one or more controllers, microcontrollers, microprocessors, application-specific integrated circuits (ASICs), digital signal processors (DSPs), field-programmable gate arrays (FPGAs), and / or other processing units. The functions of the driver circuit 110 can be implemented as hardware circuitry, such as various logic blocks, modules, and circuits within an integrated circuit, using hardware description languages ​​(such as Verilog HDL or VHDL) or other suitable programming languages.

[0042] In software and / or firmware form, the functions of the drive circuit 110 can be implemented as programming codes. For example, the drive circuit 110 can be implemented using common programming languages ​​(such as C, C++, or assembly language) or other suitable programming languages. The programming codes can be recorded / stored in non-transitory computer-readable medium. In some embodiments, the non-transitory computer-readable medium includes, for example, semiconductor memory and / or storage devices. The semiconductor memory includes memory cards, read-only memory (ROM), flash memory, programmable logic circuits, or other semiconductor memory. The storage devices include tape, disk, hard disk drive (HDD), solid-state drive (SSD), or other storage devices. Electronic devices (e.g., computers, central processing units (CPUs), controllers, microcontrollers, or microprocessors) can read and execute the programming codes from the non-transitory computer-readable medium to implement the functions of the drive circuit 110.

[0043] Figure 2This is a timing diagram illustrating fingerprint acquisition (fingerprint sensing) performed by a fingerprint sensing device 100 according to one embodiment. Figure 2 The horizontal axis represents time, while the vertical axis represents pixel rows (or image rows). Figure 2 The operation timing of pixel rows R1, R2, R3, R4, and R5 of the fingerprint sensing plate 120 is illustrated; however, the number of pixel rows of the fingerprint sensing plate 120 can be determined according to the actual design. Based on the control and drive of the driving circuit 110, the fingerprint sensing plate 120 can perform a rolling shutter operation to capture fingerprint images.

[0044] exist Figure 2 In the illustrated embodiment, the fingerprint sensing plate 120 has display, touch detection, and fingerprint sensing functions. The driving circuit 110 can drive the fingerprint sensing plate 120 to display a prompt light spot (the fingerprint sensing device 100 prepares the prompt light spot at time T0). The prompt light spot can indicate the fingerprint sensing area of ​​the fingerprint sensing plate 120. To avoid the prompt light spot being too bright and irritating the user's eyes, the driving circuit 110 does not activate the high brightness mode (HBM) of the fingerprint sensing plate 120 during the display of the prompt light spot; instead, it sets the brightness mode of the fingerprint sensing plate 120 to normal brightness mode. The actual brightness of the normal brightness mode can be set by the user. The actual brightness of the high brightness mode is greater than the brightness of the normal brightness mode. The actual brightness of the high brightness mode can be determined according to the actual design. For example, in some embodiments, the brightness of the high brightness mode can be the maximum brightness of the fingerprint sensing plate 120.

[0045] The driving circuit 110 can also detect whether a finger touch has occurred on the fingerprint sensing plate 120. Here, it is assumed that the user's finger touches the fingerprint sensing area of ​​the fingerprint sensing plate 120 at time T1. After the finger presses the indicator light spot (fingerprint sensing area), the driving circuit 110 can detect the finger touch via the fingerprint sensing plate 120. After confirming the finger touch, the driving circuit 110 can switch the brightness mode of the fingerprint sensing plate 120 from normal brightness mode to high brightness mode to facilitate fingerprint sensing (improving fingerprint imaging quality). Simultaneously, the driving circuit 110 will also switch the indicator light spot of the fingerprint sensing plate 120 to a fingerprint-collecting light spot (a light spot without an image) to avoid the image affecting fingerprint imaging. In practice, both the "brightness mode switching from normal brightness mode to high brightness mode" and the "light spot switching from indicator light spot to fingerprint-collecting light spot" require time.

[0046] Generally speaking, switching the light spot is faster than switching the brightness mode. Figure 2 The indicated time point T2 represents the point at which the light spot is switched to a fingerprint-collecting light spot (the fingerprint-collecting light spot is ready). Figure 2 The indicated time point T3 represents the point at which the brightness mode is switched to high brightness mode (high brightness mode is ready). For example, the time length from time point T1 to time point T2 is typically one image frame. At a frame rate of 120Hz, one image frame is approximately 8.33ms. The time length from time point T1 to time point T3 is typically several tens of milliseconds. Only after high brightness mode is ready, i.e., after time point T3, will the driving circuit 110 drive the fingerprint sensing plate 120 to capture the fingerprint image. Figure 2 In the illustrated embodiment, "R" represents a reset operation for a pixel row, "S" represents a sampling operation for a pixel row, and the time between the reset (R) and the sampling (S) represents the exposure period for a pixel row.

[0047] From time point T1 (when a finger touches the fingerprint sensor 120) to time point T3, the fingerprint sensor 120 does not perform fingerprint image acquisition. Optical fingerprint recognition requires waiting for the high-brightness mode to be ready before acquiring the fingerprint (fingerprint sensing), resulting in a longer unlocking time. If the time period from time point T1 to time point T3 can be shortened, the unlocking time can be effectively reduced. The following embodiments will illustrate that the fingerprint sensor 120 performs fingerprint sensing operation earlier when the finger touches the fingerprint sensor 120 and before the high-brightness mode is ready.

[0048] Figure 3 This is a flowchart illustrating a driving method for a fingerprint sensing plate according to an embodiment of the present invention. Please refer to... Figure 1 and Figure 3 The driving circuit 110 can detect whether a finger touch has occurred on the fingerprint sensing plate 120 (step S310). After confirming a finger touch, the driving circuit 110 can control the fingerprint sensing plate 120 to switch its brightness mode from normal brightness mode to high brightness mode during the finger touch period (step S320) to facilitate fingerprint sensing. In practice, the "brightness mode switching from normal brightness mode to high brightness mode" takes a certain amount of time. Before the mode switching point (e.g., time point T3) when the fingerprint sensing plate 120 completes the switch from brightness mode to high brightness mode, the driving circuit 110 can drive the fingerprint sensing plate 120 to sense the fingerprint (step S330).

[0049] Figure 4 This is a timing diagram illustrating fingerprint acquisition (fingerprint sensing) performed by a fingerprint sensing device 100 according to an embodiment of the present invention. Figure 4 The horizontal axis represents time, while the vertical axis represents pixel rows (image rows).

[0050] Before a finger touches the fingerprint sensor 120, the driving circuit 110 can drive the fingerprint sensor 120 to display a prompt light spot to indicate the fingerprint sensing area of ​​the fingerprint sensor 120. During the finger touch, the driving circuit 110 can drive the fingerprint sensor 120 to display a fingerprint-collecting light spot to facilitate fingerprint sensing.

[0051] Figure 4 The timing diagram shown can be referenced. Figure 2 The timing diagrams shown are explained in detail, and similar interpretations can be drawn from them; therefore, they will not be repeated here. Unlike... Figure 2 The illustrated embodiment is that, Figure 4 In the illustrated embodiment, before the high-brightness mode is ready (time point T3), the fingerprint sensing plate 120 performs the fingerprint sensing operation earlier based on the driving circuit 110 (step S330). For example, the fingerprint sensing plate 120 performs the fingerprint sensing operation in real time after the fingerprint spot is ready (time point T2). Taking the pixel row R1 of the fingerprint sensing plate 120 as an example, the pixel row R1 sequentially undergoes reset R, exposure period, and sampling S to output the row sensing result, wherein the reset R of the pixel row R1 is earlier than time point T3 (mode switching time point), and the sampling S of the pixel row R1 is later than time point T3. In this way, the fingerprint sensing device 100 can significantly reduce the image acquisition time. Figure 4 For example, it reduces the time by approximately (T3-T2).

[0052] Figure 5 This is a timing diagram illustrating fingerprint acquisition (fingerprint sensing) performed by the fingerprint sensing device 100 according to another embodiment of the present invention. Figure 5 The horizontal axis represents time, while the vertical axis represents pixel rows (image rows). Figure 5 The timing diagram shown can be referenced. Figure 4 The timing diagrams shown are explained in detail, and similar interpretations can be drawn from them; therefore, they will not be repeated here. Unlike... Figure 4 The illustrated embodiment is that, Figure 5 The fingerprint sensor 120 in the illustrated embodiment does not require a display indicator light spot. That is, the fingerprint sensing device 100 can prepare to capture a fingerprint light spot at time T0. To avoid the indicator light spot being too bright and irritating the user's eyes, the drive circuit 110 sets the brightness mode of the fingerprint sensor 120 to a normal brightness mode after time T0. In other embodiments, the fingerprint sensor 120 may not have a display function, but it has touch detection, fingerprint sensing, and light emission functions. A fingerprint sensor 120 without a display function can also be used. Figure 5 Related explanations.

[0053] After a finger presses onto the fingerprint light spot (fingerprint sensing area), that is, at time T1, the driving circuit 110 can detect the finger touch via the fingerprint sensing plate 120 (step S310). After confirming the finger touch, the driving circuit 110 can switch the brightness mode of the fingerprint sensing plate 120 from the normal brightness mode to the high brightness mode (step S320) to facilitate fingerprint sensing. It is assumed here that the fingerprint sensing plate 120 will not be ready for high brightness mode until time T3 (the mode switching point). Figure 5 In the illustrated embodiment, the fingerprint sensing plate 120 performs a fingerprint sensing operation in real time (step S330) after a finger presses the fingerprint sensing area of ​​the fingerprint sensing plate 120 (time point T1). Taking pixel row R1 of the fingerprint sensing plate 120 as an example, the reset R of pixel row R1 is earlier than time point T3 (mode switching time point), and the sampling S of pixel row R1 is later than time point T3. Compared to Figure 2 In the illustrated embodiment, the fingerprint sensing device 100 takes time to acquire an image. Figure 5 The illustrated embodiment can significantly reduce the (T3-T1) time.

[0054] Figure 6 This is a timing diagram illustrating fingerprint acquisition (fingerprint sensing) performed by the fingerprint sensing device 100 according to another embodiment of the present invention. Figure 6 The horizontal axis represents time, while the vertical axis represents pixel rows (image rows). Figure 6 The timing diagram shown can be referenced. Figure 5 The timing diagrams shown are explained in detail, and similar interpretations can be drawn from them; therefore, they will not be repeated here. Unlike... Figure 5 The illustrated embodiment is based on the control and drive of the drive circuit 110. Figure 6 The fingerprint sensing plate 120 of the illustrated embodiment can perform a global shutter operation to capture fingerprint images.

[0055] After pressing your finger on the fingerprint sensor area (the area where the fingerprint is captured), that is, when... Figure 6 At time T1, the driving circuit 110 can detect a finger touch via the fingerprint sensing plate 120 (step S310). After confirming the finger touch, the driving circuit 110 can switch the brightness mode of the fingerprint sensing plate 120 from normal brightness mode to high brightness mode (step S320) to facilitate fingerprint sensing. It is assumed here that the fingerprint sensing plate 120 until... Figure 6 High brightness mode can only be prepared at the indicated time point T3 (mode switching time). Figure 6In the illustrated embodiment, the fingerprint sensing plate 120 performs a fingerprint sensing operation in real time (step S330) after a finger presses the fingerprint sensing area of ​​the fingerprint sensing plate 120 (time point T1). Taking pixel rows R1 to R5 of the fingerprint sensing plate 120 as an example, each pixel row R1 to R5 sequentially undergoes a reset R, an exposure period, and a sampling S to output sensing results for different rows. The reset R times for pixel rows R1 to R5 are the same, and the sampling S times for pixel rows R1 to R5 are also the same. The reset R times for pixel rows R1 to R5 are earlier than time point T3 (mode switching time point), and the sampling S times for pixel rows R1 to R5 are later than time point T3.

[0056] Figure 7 This is a schematic diagram illustrating the relationship between exposure time and sensing code for a pixel row of a fingerprint sensing plate 120 during the exposure period, according to an embodiment of the present invention. Figure 7 The horizontal axis represents time, while the vertical axis represents the sensing code. The sensing code corresponds to the row sensing result (exposure result) of one pixel row. Figure 4 , Figure 5 or Figure 6 Any of the pixel rows R1 to R5 shown can be referenced. Figure 7 The relevant explanations are then drawn by analogy. Figure 7 The mode switching point S2 shown can represent Figure 4 , Figure 5 or Figure 6 The time point T3 is shown. Figure 7 The time points S1 and S3 shown can represent the time points of resetting R and sampling S of a pixel row, respectively.

[0057] The drive circuit 110 can calculate the following equations (1) and (2). In equation (1), K is the brightness ratio between the high brightness mode and the normal brightness mode, and Slope1 is... Figure 7 The slope of the relationship curve shown is the first slope before the mode switching point S2, and Slope2 is... Figure 7 The relationship curve shown is the second slope after the mode switching point S2. Given that the ratio of the first slope Slope1 to the brightness K is known, the driving circuit 110 can calculate equation (1) to obtain the second slope Slope2. In equation (2), S1 is the reset point of a pixel row (the reset point of R), S2 is the mode switching point, S3 is the sampling point of a pixel row (the sampling point of S), and TCode is the target sensing code. The target sensing code TCode corresponds to the target exposure of the fingerprint sensor 120. Given that the target sensing code TCode, the mode switching point S2, the second slope Slope2, the reset point S1, and the first slope Slope1 are known, the driving circuit 110 can calculate equation (2) to obtain the sampling point S3. The sampling point S3 is the sampling point of a pixel row.

[0058] Slope2 = Slope1 * K Equation (1)

[0059] TCode=(S3-S2)*Slope2+(S2-S1)*Slope1 Equation (2)

[0060] In some application scenarios, the brightness of the normal brightness mode may be dynamically adjusted by the user, causing the first slope Slope1 to drift. When the first slope Slope1 is not determined, the driving circuit 110 can first detect the first slope Slope1 of the current normal brightness mode after time point T1 (when the finger touches the fingerprint sensor 120), and then proceed with... Figure 7 The relevant operations.

[0061] Figure 8 This is a timing diagram illustrating fingerprint acquisition (fingerprint sensing) performed by the fingerprint sensing device 100 according to a further embodiment of the present invention. Figure 8 The horizontal axis represents time, while the vertical axis represents pixel rows (image rows). Figure 8 The timing diagram shown can be referenced. Figure 5 The timing diagrams shown are explained in detail, and similar interpretations can be drawn from them; therefore, they will not be repeated here. Unlike... Figure 5 The illustrated embodiment is based on the control and drive of the drive circuit 110. Figure 8 The fingerprint sensing plate 120 of the illustrated embodiment can first detect the first slope Slope1 of the current normal brightness mode after time point T1, and then perform... Figure 5 and Figure 7 The relevant operations. Figure 8 The mode switching point S2 shown can be referenced. Figure 5 Explanation of time point T3 as shown.

[0062] Please refer to Figure 8 Before the mode switching point S2, the driving circuit 110 can drive at least one pixel row (e.g., pixel row R3) of the fingerprint sensing plate 120 to sequentially reset R and sample multiple times S to obtain multiple exposure sensing results (multiple sensing codes). The driving circuit 110 can use these exposure sensing results to calculate the first slope Slope1 of the current normal brightness mode. After determining the current first slope Slope1, the driving circuit 110 can perform... Figure 7 The sampling time point S3 of pixel row R1 is obtained through related operations. The timing of the reset R and sampling S of other pixel rows R2 to R5 can be adaptively adjusted based on the reset time point S1 and sampling time point S3 of pixel row R1 to make the equivalent exposure time of each pixel row as consistent as possible. The following embodiments will illustrate this. Figure 4 , Figure 5 or Figure 8The example shown illustrates the timing adjustment of the reset R and sampling S for pixel rows R1 to R5.

[0063] Figure 9 This is a schematic diagram illustrating the adaptive adjustment of the sampling S timing of pixel rows R1 to R5 according to an embodiment of the present invention. Figure 9 The horizontal axis represents time, while the vertical axis represents pixel rows (image rows). Figure 9 The timing diagram shown can be referenced. Figure 4 , Figure 5 or Figure 8 The relevant explanations of the timing diagram shown are analogous and will not be repeated here. Pixel rows R1 to R5 sequentially undergo reset R, exposure period, and sampling S to output the sensing results of different rows. The reset R of pixel rows R1 to R5 is earlier than the mode switching point S2, while the sampling S of pixel rows R1 to R5 is later than the mode switching point S2. Figure 9 In the embodiment shown, the timing of sampling S for pixel rows R2 to R5 can be adaptively adjusted based on the sampling time point S3 of pixel row R1, so that the equivalent exposure time of each pixel row is as consistent as possible.

[0064] exist Figure 9 In the illustrated embodiment, the brightness ratio K between the high-brightness mode and the normal-brightness mode is assumed to be 2. For example, the brightness of the high-brightness mode is 100%, while the brightness of the normal-brightness mode is 50%. The reset R of pixel row R2 is later than the reset R of pixel row R1 by one unit time, the reset R of pixel row R3 is later than the reset R of pixel row R2 by one unit time, the reset R of pixel row R4 is later than the reset R of pixel row R3 by one unit time, and the reset R of pixel row R5 is later than the reset R of pixel row R4 by one unit time. Here, one unit time can be the length of the reset R and / or the sampling S. The sampling S of pixel row R2 is half (1 / K) unit time later than the sampling S of pixel row R1, the sampling S of pixel row R3 is half a unit time later than the sampling S of pixel row R2, the sampling S of pixel row R4 is half a unit time later than the sampling S of pixel row R3, and the sampling S of pixel row R5 is half a unit time later than the sampling S of pixel row R4.

[0065] Taking pixel row R1 as an example, assuming the exposure time before and after the mode switch point S2 is 50ms and 50ms respectively, the equivalent exposure time at 100% brightness is 50 / 2 + 50 = 75ms. Here, we assume a unit time is 2ms. Figure 9The sampling S of pixel row R2 is advanced by half a unit of time. Therefore, the exposure times before and after the mode switch point S2 are 48ms and 51ms respectively, which is equivalent to an exposure time of 48 / 2 + 51 = 75ms at 100% brightness. The other pixel rows R3 to R5 can be deduced by referring to the relevant explanation for pixel row R2, as follows... Figure 9 As shown. Based on this, each pixel row R1 to R5 is equivalent to an exposure time of 75ms at 100% brightness, so the driving circuit 110 can capture a uniform fingerprint image.

[0066] Figure 10 This is a schematic diagram illustrating the adaptive adjustment of the sampling S timing of pixel rows R1 to R5 according to another embodiment of the present invention. Figure 10 The horizontal axis represents time, while the vertical axis represents pixel rows (image rows). Figure 10 The timing diagram shown can be referenced. Figure 4 , Figure 5 , Figure 8 or Figure 9 The relevant explanations of the timing diagrams shown are provided and can be extrapolated from here on out, so they will not be repeated here. Figure 10 The pixel rows R1 to R5 shown can be referenced. Figure 9 The following is a description of pixel rows R1 to R5. (Different from...) Figure 9 The illustrated embodiment is characterized in that, Figure 10 The reset R and sampling S of pixel row R5 shown are both later than the mode switching point S2. Figure 10 In the illustrated embodiment, the reset R of pixel row R5 is one unit time later than the reset R of pixel row R4, and the sampling S of pixel row R5 is one unit time later than the sampling S of pixel row R4. Figure 10 In the embodiment shown, the timing of sampling S for pixel rows R2 to R5 can be adaptively adjusted based on the sampling time point S3 of pixel row R1, so that the equivalent exposure time of each pixel row is as consistent as possible.

[0067] Taking pixel row R1 as an example, assuming the exposure time before and after the mode switch point S2 is 6ms and 72ms respectively, the equivalent exposure time at 100% brightness is 6 / 2 + 72 = 75ms. Here, we assume a unit time of 2ms, with high brightness mode having a brightness of 100% and normal brightness mode having a brightness of 50%. Figure 10The sampling S of pixel row R2 is advanced by half a unit of time. Therefore, the exposure times before and after the mode switch point S2 are 4ms and 73ms, respectively, which is equivalent to an exposure time of 4 / 2 + 73 = 75ms at 100% brightness. For pixel row R3, the exposure times before and after the mode switch point S2 are 2ms and 74ms, respectively, which is equivalent to an exposure time of 2 / 2 + 74 = 75ms at 100% brightness. For pixel row R4, the exposure times before and after the mode switch point S2 are 0ms and 75ms, respectively, which is equivalent to an exposure time of 0 / 2 + 75 = 75ms at 100% brightness. Since pixel row R5 is reset after the mode switch point S2, the sampling S of pixel row R5 does not need to be advanced by half a unit of time. Therefore, each pixel row R1 to R5 is equivalent to an exposure time of 75ms at 100% brightness, so the driving circuit 110 can capture a uniform fingerprint image.

[0068] Figure 11 This is a schematic diagram illustrating the adaptive adjustment of the sampling S timing of pixel rows R1 to R5 according to another embodiment of the present invention. Figure 11 The horizontal axis represents time, while the vertical axis represents pixel rows (image rows). Figure 11 The timing diagram shown can be referenced. Figure 4 , Figure 5 , Figure 8 or Figure 9 The relevant explanations of the timing diagrams shown are provided and can be extrapolated from here on out, so they will not be repeated here. Figure 11 The pixel rows R1 to R5 shown can be referenced. Figure 9 The following is a description of pixel rows R1 to R5. (Different from...) Figure 9 The illustrated embodiment is characterized in that, Figure 11 The reset R and sampling S of pixel rows R1 to R2 shown are both earlier than the mode switching point S2. Figure 11 In the illustrated embodiment, the reset R of pixel row R2 is one unit time earlier than the reset R of pixel row R3, the reset R of pixel row R1 is one unit time earlier than the reset R of pixel row R2, the sampling S of pixel row R2 is one unit time earlier than the sampling S of pixel row R3, and the sampling S of pixel row R1 is one unit time earlier than the sampling S of pixel row R2. Figure 11 In the embodiment shown, the timing of sampling S for pixel rows R2 to R5 can be adaptively adjusted based on the sampling time point S3 of pixel row R1, so that the equivalent exposure time of each pixel row is as consistent as possible.

[0069] Taking pixel rows R1 to R3 as an example, assuming the exposure time before and after the mode switch point S2 is 150ms and 0ms respectively, the equivalent exposure time at 100% brightness is 150 / 2 + 0 = 75ms. Here, we assume a unit time of 2ms, that the brightness in high brightness mode is 100%, and the brightness in normal brightness mode is 50%. Figure 11 The sampling S of pixel row R4 is advanced by half a unit of time. Therefore, the exposure time before and after the mode switching point S2 is 148ms and 1ms respectively, which is equivalent to an exposure time of 148 / 2 + 1 = 75ms at 100% brightness. For pixel row R5, the exposure time before and after the mode switching point S2 is 146ms and 2ms respectively, which is equivalent to an exposure time of 146 / 2 + 2 = 75ms at 100% brightness. Based on this, the equivalent exposure time for each pixel row R1 to R5 at 100% brightness is 75ms, so the driving circuit 110 can capture a uniform fingerprint image.

[0070] Figure 12 This is a schematic diagram illustrating the adaptive adjustment of the reset timing of pixel rows R1 to R5 according to an embodiment of the present invention. Figure 12 The horizontal axis represents time, while the vertical axis represents pixel rows (image rows). Figure 12 The timing diagram shown can be referenced. Figure 4 , Figure 5 or Figure 8 The relevant explanations of the timing diagrams shown are provided and can be extrapolated from here on out, so they will not be repeated here. Figure 12 The pixel rows R1 to R5, as shown, sequentially undergo reset R, exposure period, and sampling S to output the sensing results for different rows. The reset R for pixel rows R1 to R5 is earlier than the mode switching point S2, while the sampling S for pixel rows R1 to R5 is later than the mode switching point S2. Figure 12 In the embodiment shown, the timing of the reset R of pixel rows R2 to R5 can be adaptively adjusted based on the reset time S1 of pixel row R1 so that the equivalent exposure time of each pixel row is as consistent as possible.

[0071] exist Figure 12In the illustrated embodiment, the brightness ratio K between the high-brightness mode and the normal-brightness mode is assumed to be 2. For example, the brightness of the high-brightness mode is 100%, while the brightness of the normal-brightness mode is 50%. The reset R of pixel row R2 is later than the reset R of pixel row R1 by K units of time, the reset R of pixel row R3 is later than the reset R of pixel row R2 by K units of time, the reset R of pixel row R4 is later than the reset R of pixel row R3 by K units of time, and the reset R of pixel row R5 is later than the reset R of pixel row R4 by K units of time. Here, one unit of time can be the time of reset R and / or sampling S. The sampling S of pixel row R2 is later than the sampling S of pixel row R1 by one unit of time, the sampling S of pixel row R3 is later than the sampling S of pixel row R2 by one unit of time, the sampling S of pixel row R4 is later than the sampling S of pixel row R3 by one unit of time, and the sampling S of pixel row R5 is later than the sampling S of pixel row R4 by one unit of time.

[0072] Taking pixel row R1 as an example, assuming the exposure time before and after the mode switch point S2 is 50ms and 50ms respectively, the equivalent exposure time at 100% brightness is 50 / 2 + 50 = 75ms. Here, we assume a unit time is 2ms. Figure 12 The reset R of pixel row R2 is delayed by one unit time (K-1 unit time). Therefore, the exposure times before and after the mode switch point S2 are 46ms and 52ms respectively, which is equivalent to an exposure time of 46 / 2 + 52 = 75ms at 100% brightness. The other pixel rows R3 to R5 can be deduced by referring to the relevant explanation for pixel row R2, such as... Figure 12 As shown. Based on this, each pixel row R1 to R5 is equivalent to an exposure time of 75ms at 100% brightness, so the driving circuit 110 can capture a uniform fingerprint image.

[0073] Figure 13 This is a schematic diagram illustrating the adaptive adjustment of the reset R timing and sampling S timing of pixel rows R1 to R5 according to a further embodiment of the present invention. Figure 13 The horizontal axis represents time, while the vertical axis represents pixel rows (image rows). Figure 13 The timing diagram shown can be referenced. Figure 4 , Figure 5 , Figure 8 or Figure 12 The relevant explanations of the timing diagrams shown are provided and can be extrapolated from here on out, so they will not be repeated here. Figure 13 The pixel rows R1 to R5 shown can be referenced. Figure 12 The following is a description of pixel rows R1 to R5. (Different from...) Figure 12 The illustrated embodiment is characterized in that, Figure 13 The reset R and sampling S of pixel rows R4 to R5 shown are both later than the mode switching point S2. Figure 13In the illustrated embodiment, the reset R of pixel row R4 is two units of time (K units of time) later than the reset R of pixel row R3, the reset R of pixel row R5 is two units of time later than the reset R of pixel row R4, the sampling S of pixel row R4 is two units of time later than the sampling S of pixel row R3 (K units of time), and the sampling S of pixel row R5 is two units of time later than the sampling S of pixel row R4.

[0074] Taking pixel row R1 as an example, assuming the exposure time before and after the mode switch point S2 is 8ms and 71ms respectively, the equivalent exposure time at 100% brightness is 8 / 2 + 71 = 75ms. Here, we assume a unit time of 2ms, that the brightness in high brightness mode is 100%, and the brightness in normal brightness mode is 50%. Figure 13 The reset R of pixel row R2 is delayed by one unit time (K-1 unit time), so the exposure time before and after the mode switching point S2 is 4ms and 73ms respectively, which is equivalent to an exposure time of 4 / 2 + 73 = 75ms at 100% brightness. For pixel row R3, the exposure time before and after the mode switching point S2 is 0ms and 75ms respectively, which is equivalent to an exposure time of 0 / 2 + 75 = 75ms at 100% brightness. Since the reset R of pixel rows R4 to R5 is performed after the mode switching point S2, the sampling S of pixel rows R4 to R5 is also delayed by one unit time (K-1 unit time). Based on this, the equivalent exposure time of each pixel row R1 to R5 at 100% brightness is 75ms, so the driving circuit 110 can capture a uniform fingerprint image.

[0075] Figure 14 This is a schematic diagram illustrating the adaptive adjustment of the reset timing of pixel rows R1 to R5 according to another embodiment of the present invention. Figure 14 The horizontal axis represents time, while the vertical axis represents pixel rows (image rows). Figure 14 The timing diagram shown can be referenced. Figure 4 , Figure 5 , Figure 8 or Figure 12 The relevant explanations of the timing diagrams shown are provided and can be extrapolated from here on out, so they will not be repeated here. Figure 14 The pixel rows R1 to R5 shown can be referenced. Figure 12 The following is a description of pixel rows R1 to R5. (Different from...) Figure 12 The illustrated embodiment is characterized in that, Figure 14 The reset R and sampling S of pixel rows R4 to R5 shown are both later than the mode switching point S2. Figure 14In the illustrated embodiment, the reset R of pixel row R4 is later than the reset R of pixel row R3 by one unit time, the reset R of pixel row R5 is later than the reset R of pixel row R4 by one unit time, the sampling S of pixel row R4 is later than the sampling S of pixel row R3 by one unit time, and the sampling S of pixel row R5 is later than the sampling S of pixel row R4 by one unit time.

[0076] Taking pixel row R1 as an example, assuming the exposure time before and after the mode switch point S2 is 8ms and 71ms respectively, the equivalent exposure time at 100% brightness is 8 / 2 + 71 = 75ms. Here, we assume a unit time of 2ms, that the brightness in high brightness mode is 100%, and the brightness in normal brightness mode is 50%. Figure 14 The reset R of pixel row R2 is delayed by one unit time (K-1 unit time), so the exposure time before and after the mode switching point S2 is 4ms and 73ms respectively, which is equivalent to an exposure time of 4 / 2 + 73 = 75ms at 100% brightness. For pixel row R3, the exposure time before and after the mode switching point S2 is 0ms and 75ms respectively, which is equivalent to an exposure time of 0 / 2 + 75 = 75ms at 100% brightness. Since the reset R of pixel rows R4 to R5 is performed after the mode switching point S2, the reset R and sampling S of pixel rows R4 to R5 are not delayed. Based on this, the equivalent exposure time of each pixel row R1 to R5 at 100% brightness is 75ms, so the driving circuit 110 can capture a uniform fingerprint image.

[0077] Figure 15 This is a schematic diagram illustrating the adaptive adjustment of the reset R timing and sampling S timing of pixel rows R1 to R5 according to another embodiment of the present invention. Figure 15 The horizontal axis represents time, while the vertical axis represents pixel rows (image rows). Figure 15 The timing diagram shown can be referenced. Figure 4 , Figure 5 , Figure 8 or Figure 12 The relevant explanations of the timing diagrams shown are provided and can be extrapolated from here on out, so they will not be repeated here. Figure 15 The pixel rows R1 to R5 shown can be referenced. Figure 12 The following is a description of pixel rows R1 to R5. (Different from...) Figure 12 The illustrated embodiment is characterized in that, Figure 15 The reset R and sampling S of pixel rows R1 to R3 shown are both earlier than the mode switching point S2. Figure 15In the illustrated embodiment, the reset R of pixel row R3 is two units of time (K units of time) earlier than the reset R of pixel row R4, the reset R of pixel row R2 is two units of time earlier than the reset R of pixel row R3, the reset R of pixel row R1 is two units of time earlier than the reset R of pixel row R2, the sampling S of pixel row R3 is two units of time earlier than the sampling S of pixel row R4 (K units of time), the sampling S of pixel row R2 is two units of time earlier than the sampling S of pixel row R3, and the sampling S of pixel row R1 is two units of time earlier than the sampling S of pixel row R2. Figure 15 In the embodiment shown, the timing of sampling S for pixel rows R2 to R5 can be adaptively adjusted based on the sampling time point S3 of pixel row R1, so that the equivalent exposure time of each pixel row is as consistent as possible.

[0078] Taking pixel rows R1 to R4 as an example, assuming the exposure time before and after the mode switch point S2 is 150ms and 0ms respectively, the equivalent exposure time at 100% brightness is 150 / 2 + 0 = 75ms. Here, we assume a unit time of 2ms, that the brightness in high brightness mode is 100%, and the brightness in normal brightness mode is 50%. Figure 15 The reset R of pixel row R5 is delayed by one unit time (K-1 unit time), while the sampling S of pixel row R5 is not delayed. Therefore, the exposure time before and after the mode switching point S2 is 146ms and 2ms respectively, which is equivalent to an exposure time of 146 / 2+2=75ms at 100% brightness. Based on this, the exposure time of each pixel row R1 to R5 is equivalent to 75ms at 100% brightness, so the driving circuit 110 can capture a uniform fingerprint image.

[0079] In summary, when a finger touches the fingerprint sensor 120, the driving circuit 110 described in the above embodiments can drive the fingerprint sensor 120 to switch the brightness mode of the fingerprint sensor 120 to facilitate fingerprint sensing. Generally, it takes some time for the brightness mode to switch from normal brightness mode to high brightness mode. The driving circuit 110 can sense the fingerprint earlier than the mode switching point S2 (time point T3).

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A driving method for a fingerprint sensing plate, characterized in that, The driving method includes: Detects whether a finger touches the fingerprint sensor. During the period of finger contact, the brightness mode of the fingerprint sensor is switched from normal brightness mode to high brightness mode to facilitate fingerprint sensing; and Before the mode switching point when the brightness mode of the fingerprint sensing plate completes the switch to the high brightness mode, the fingerprint sensing plate is driven to sense the fingerprint. The fingerprint sensing plate includes a first pixel row, and the first pixel row sequentially undergoes a first reset, a first exposure period, and a first sampling to output a first row of sensing results. The first reset is earlier than the mode switching point, and the first sampling is later than the mode switching point.

2. The driving method according to claim 1, characterized in that, The driving method further includes: Before the fingerprint sensor is touched, the fingerprint sensor is driven to display a prompt light spot to indicate the fingerprint sensing area of ​​the fingerprint sensor; and During the period of finger touch, the fingerprint sensing plate is driven to display a fingerprint spot in order to detect the fingerprint.

3. The driving method according to claim 1, characterized in that, The driving method further includes: Calculate Slope2 = Slope1 * K, where K is the brightness ratio of the high-brightness mode to the normal-brightness mode, Slope1 is the first slope of the exposure time versus sensor code curve before the mode switching point, the sensor code corresponds to the first row of sensing results, and Slope2 is the second slope of the curve after the mode switching point; and Calculate TCode = (S3-S2)*Slope2 + (S2-S1)*Slope1, where S1 is the first reset time point of the first pixel row, S2 is the mode switching time point, S3 is the sampling time point of the first sampling of the first pixel row, TCode is the target sensing code, and the target sensing code corresponds to the target exposure of the fingerprint sensing plate.

4. The driving method according to claim 3, characterized in that, The driving method further includes: Prior to the mode switching point, at least one pixel row of the fingerprint sensing plate is driven to sequentially perform a second reset and multiple second samplings to obtain multiple exposure sensing results; and The first slope Slope1 is calculated using the multiple exposure sensing results.

5. The driving method according to claim 1, characterized in that, The fingerprint sensing plate further includes a second pixel row adjacent to the first pixel row. The second pixel row sequentially undergoes a second reset, a second exposure period, and a second sampling to output a second row of sensing results. The timing of the second reset is the same as the timing of the first reset, and the timing of the second sampling is the same as the timing of the first sampling.

6. The driving method according to claim 1, characterized in that, The brightness ratio of the high brightness mode to the normal brightness mode is K. The fingerprint sensing plate further includes a second pixel row adjacent to the first pixel row. The second pixel row sequentially undergoes a second reset, a second exposure period, and a second sampling to output a second row of sensing results. The second reset is earlier than the mode switching time, the second reset is later than the first reset by one unit time, and the second sampling is later than the first sampling by one-Kth of a unit time.

7. The driving method according to claim 6, characterized in that, The fingerprint sensing plate further includes a third pixel row adjacent to the second pixel row. The third pixel row sequentially undergoes a third reset, a third exposure period, and a third sampling to output a third row of sensing results. The third reset and the third sampling are both later than the mode switching time. The third reset is later than the second reset by one unit time, and the third sampling is later than the second sampling by one unit time.

8. The driving method according to claim 6, characterized in that, The fingerprint sensing plate further includes a third pixel row adjacent to the first pixel row. The third pixel row sequentially undergoes a third reset, a third exposure period, and a third sampling to output a third row of sensing results. The third reset and the third sampling are both earlier than the mode switching time. The third reset is earlier than the first reset by one unit of time, and the third sampling is earlier than the first sampling by one unit of time.

9. The driving method according to claim 1, characterized in that, The brightness ratio of the high brightness mode to the normal brightness mode is K. The fingerprint sensing plate further includes a second pixel row adjacent to the first pixel row. The second pixel row sequentially undergoes a second reset, a second exposure period, and a second sampling to output a second row of sensing results. The second reset is earlier than the mode switching time, the second reset is later than the first reset by K units of time, and the second sampling is later than the first sampling by one unit of time.

10. The driving method according to claim 9, characterized in that, The fingerprint sensing plate further includes a third pixel row adjacent to the second pixel row. The third pixel row sequentially undergoes a third reset, a third exposure period, and a third sampling to output a third row of sensing results. The third reset and the third sampling are both later than the mode switching time. The third reset is later than the second reset by K units of time, and the third sampling is later than the second sampling by K units of time.

11. The driving method according to claim 9, characterized in that, The fingerprint sensing plate further includes a third pixel row adjacent to the second pixel row. The third pixel row sequentially undergoes a third reset, a third exposure period, and a third sampling to output a third row of sensing results. The third reset and the third sampling are both later than the mode switching time. The third reset is later than the second reset by one unit time, and the third sampling is later than the second sampling by one unit time.

12. The driving method according to claim 9, characterized in that, The fingerprint sensing plate further includes a third pixel row adjacent to the first pixel row. The third pixel row sequentially undergoes a third reset, a third exposure period, and a third sampling to output a third row of sensing results. The third reset and the third sampling are both earlier than the mode switching time. The third reset is earlier than the first reset by K units of time, and the third sampling is earlier than the first sampling by K units of time.

13. A fingerprint sensing device, characterized in that, The fingerprint sensing device includes: A fingerprint sensor plate, used to detect fingerprints; and A driving circuit is coupled to the fingerprint sensor plate to detect whether a finger touches the fingerprint sensor plate, wherein... The driving circuit controls the fingerprint sensing plate to switch its brightness mode from normal brightness mode to high brightness mode during the period when the finger touches it, so as to facilitate the sensing of the fingerprint. The driving circuit drives the fingerprint sensing plate to sense the fingerprint before the fingerprint sensing plate completes the mode switch from the brightness mode to the high brightness mode. The fingerprint sensing plate includes a first pixel row, which sequentially undergoes a first reset, a first exposure period, and a first sampling to output a first row of sensing results. The first reset is earlier than the mode switching time, and the first sampling is later than the mode switching time.

14. The fingerprint sensing device according to claim 13, characterized in that, Before the fingerprint sensor is touched, the driving circuit drives the fingerprint sensor to display a prompt light spot to indicate the fingerprint sensing area of ​​the fingerprint sensor. as well as During the period of finger contact, the driving circuit drives the fingerprint sensing plate to display a fingerprint spot in order to sense the fingerprint.

15. The fingerprint sensing device according to claim 13, characterized in that, The driving circuit calculates Slope2 = Slope1 * K, where K is the brightness ratio of the high-brightness mode to the normal-brightness mode, Slope1 is the first slope of the exposure time versus sensing code curve before the mode switching point, the sensing code corresponds to the first row of sensing results, and Slope2 is the second slope of the curve after the mode switching point; and The driving circuit calculates TCode = (S3-S2)*Slope2 + (S2-S1)*Slope1, where S1 is the first reset time point of the first pixel row, S2 is the mode switching time point, S3 is the sampling time point of the first sampling of the first pixel row, TCode is the target sensing code, and the target sensing code corresponds to the target exposure of the fingerprint sensing plate.

16. The fingerprint sensing device according to claim 15, characterized in that, Before the mode switching point, the driving circuit drives at least one pixel row of the fingerprint sensing plate to sequentially perform a second reset and multiple second samplings to obtain multiple exposure sensing results. as well as The driving circuit uses the plurality of exposure sensing results to calculate the first slope Slope1.

17. The fingerprint sensing device according to claim 13, characterized in that, The fingerprint sensing plate further includes a second pixel row adjacent to the first pixel row. The second pixel row sequentially undergoes a second reset, a second exposure period, and a second sampling to output a second row of sensing results. The timing of the second reset is the same as the timing of the first reset, and the timing of the second sampling is the same as the timing of the first sampling.

18. The fingerprint sensing device according to claim 13, characterized in that, The brightness ratio of the high brightness mode to the normal brightness mode is K. The fingerprint sensing plate further includes a second pixel row adjacent to the first pixel row. The second pixel row sequentially undergoes a second reset, a second exposure period, and a second sampling to output a second row of sensing results. The second reset is earlier than the mode switching time, the second reset is later than the first reset by one unit time, and the second sampling is later than the first sampling by one-Kth of a unit time.

19. The fingerprint sensing device according to claim 18, characterized in that, The fingerprint sensing plate further includes a third pixel row adjacent to the second pixel row. The third pixel row sequentially undergoes a third reset, a third exposure period, and a third sampling to output a third row of sensing results. The third reset and the third sampling are both later than the mode switching time. The third reset is later than the second reset by one unit time, and the third sampling is later than the second sampling by one unit time.

20. The fingerprint sensing device according to claim 18, characterized in that, The fingerprint sensing plate further includes a third pixel row adjacent to the first pixel row. The third pixel row sequentially undergoes a third reset, a third exposure period, and a third sampling to output a third row of sensing results. The third reset and the third sampling are both earlier than the mode switching time. The third reset is earlier than the first reset by one unit of time, and the third sampling is earlier than the first sampling by one unit of time.

21. The fingerprint sensing device according to claim 13, characterized in that, The brightness ratio of the high brightness mode to the normal brightness mode is K. The fingerprint sensing plate further includes a second pixel row adjacent to the first pixel row. The second pixel row sequentially undergoes a second reset, a second exposure period, and a second sampling to output a second row of sensing results. The second reset is earlier than the mode switching time, the second reset is later than the first reset by K units of time, and the second sampling is later than the first sampling by one unit of time.

22. The fingerprint sensing device according to claim 21, characterized in that, The fingerprint sensing plate further includes a third pixel row adjacent to the second pixel row. The third pixel row sequentially undergoes a third reset, a third exposure period, and a third sampling to output a third row of sensing results. The third reset and the third sampling are both later than the mode switching time. The third reset is later than the second reset by K units of time, and the third sampling is later than the second sampling by K units of time.

23. The fingerprint sensing device according to claim 21, characterized in that, The fingerprint sensing plate further includes a third pixel row adjacent to the second pixel row. The third pixel row sequentially undergoes a third reset, a third exposure period, and a third sampling to output a third row of sensing results. The third reset and the third sampling are both later than the mode switching time. The third reset is later than the second reset by one unit time, and the third sampling is later than the second sampling by one unit time.

24. The fingerprint sensing device according to claim 21, characterized in that, The fingerprint sensing plate further includes a third pixel row adjacent to the first pixel row. The third pixel row sequentially undergoes a third reset, a third exposure period, and a third sampling to output a third row of sensing results. The third reset and the third sampling are both earlier than the mode switching time. The third reset is earlier than the first reset by K units of time, and the third sampling is earlier than the first sampling by K units of time.

Images