Biometric authentication device

Abstract

To provide a biometric authentication device capable of improving the S / N ratio of a signal output by the biometric authentication device.SOLUTION: A biometric authentication device according to an embodiment comprises a sensor and an illumination device. The sensor includes a first base material, a plurality of photoelectric conversion elements arranged in a matrix on the first base material to output a signal corresponding to the amount of received light, and a first control unit. The illumination device includes a second base material, a plurality of light-emitting elements arranged in a matrix on the second base material to emit light to be received by the plurality of photoelectric conversion elements, and a second control unit. When the second control unit turns on light-emitting elements located at predetermined positions of respective groups of the light-emitting elements, the first control unit controls operations of the photoelectric conversion elements so as to acquire signals from photoelectric conversion elements located at predetermined positions of the respective groups of the photoelectric conversion elements, the positions corresponding to the turned light-emitting elements.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a biometric authentication device. [Background technology]

[0002] In recent years, optical biometric authentication devices have been known as biometric authentication devices used for personal authentication and the like (for example, Patent Document 1). Patent Document 1 describes a biometric authentication device in which unit light sources included in a light source are periodically turned on in a time-division manner, and imaging operations by imaging cell groups located near the turned-on unit light sources are stopped while imaging operations are performed by imaging cell groups located far from the turned-on unit light sources. This makes it possible to reduce the reception of reflected light that can become a noise component during imaging operations.

[0003] However, there is room for improvement in the method for improving the S / N ratio of the signal output as a result of the imaging operation in the biometric authentication device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2009-31903 A Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present disclosure is to provide a biometric authentication device capable of improving the S / N ratio of a signal output from the biometric authentication device. [Means for solving the problem]

[0006] A biometric authentication device according to one embodiment includes a sensor and an illumination device. The sensor includes a first base material, a plurality of photoelectric conversion elements arranged in a matrix on the first base material and outputting a signal according to the amount of light received, and a first control unit that controls the operation of the plurality of photoelectric conversion elements. The illumination device includes a second base material, a plurality of light-emitting elements arranged in a matrix on the second base material and emitting light received by the plurality of photoelectric conversion elements, and a second control unit that controls the operation of the plurality of light-emitting elements. The plurality of photoelectric conversion elements and the plurality of light-emitting elements are divided into a plurality of groups that correspond to each other. When the second control unit turns on the light-emitting elements at predetermined positions in each group of the light-emitting elements, the first control unit controls the operation of the plurality of photoelectric conversion elements to obtain signals from the photoelectric conversion elements at predetermined positions in each group of the photoelectric conversion elements that correspond to the turned-on light-emitting elements. a first image showing an object to be authenticated based on signals acquired from the plurality of photoelectric conversion elements, a second image in which the first image is binarized based on the generated first image, and a third image in which only the center line of a black portion of the second image is drawn based on the generated second image. The second control unit controls the operation of the plurality of light-emitting elements so as to light up light-emitting elements arranged at positions overlapping with the center line drawn in the third image generated by the first control unit. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a cross-sectional view showing a schematic configuration example of a biometric authentication device according to a first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view showing another schematic configuration example of the biometric authentication device according to the embodiment. [Diagram 3] FIG. 3 is a plan view showing an example of the configuration of a sensor included in the biometric authentication device according to the embodiment. [Figure 4] FIG. 4 is a block diagram showing an example of the configuration of a sensor included in the biometric authentication device according to the embodiment. [Diagram 5] FIG. 5 is a circuit diagram showing an example of a circuit configuration of a sensor included in the biometric authentication device according to the embodiment. [Figure 6] FIG. 6 is a circuit diagram showing an example of a circuit configuration of a first pixel included in a sensor constituting the biometric authentication device according to the embodiment. [Figure 7] FIG. 7 is a plan view showing a configuration example of an illumination device included in the biometric authentication device according to the embodiment. [Figure 8]FIG. 8 is a plan view showing an example of a circuit configuration of a second pixel included in the illumination device constituting the biometric authentication device according to the embodiment. [Figure 9] FIG. 9 is a schematic diagram showing an image of a detection target generated by a general detection process. [Figure 10] FIG. 10 is a schematic diagram for explaining the first detection process executed in the biometric authentication device according to the embodiment. [Figure 11] FIG. 11 is a schematic diagram showing an image of a detection target generated by the first detection process executed in the biometric authentication device according to the embodiment. [Figure 12] FIG. 12 is a circuit diagram showing another example of the configuration of the biometric authentication device according to the embodiment. [Figure 13] FIG. 13 is a flowchart illustrating an example of the procedure of the second detection process executed in the biometric authentication device according to the second embodiment. [Figure 14] FIG. 14 is a schematic diagram for explaining the second detection process executed in the biometric authentication device according to the embodiment. [Figure 15] FIG. 15 is a schematic diagram showing another example of the shape of the biometric authentication device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment will be described with reference to the drawings. The disclosure is merely an example, and those who are skilled in the art can easily conceive of appropriate modifications while keeping the gist of the invention are naturally included in the scope of the present invention. In addition, the drawings may be shown in a schematic manner compared to the embodiment in order to make the explanation clearer, but they are merely an example and do not limit the interpretation of the present invention. In addition, in this specification and each figure, components that perform the same or similar functions as those described above with respect to the previous figures are given the same reference numerals, and duplicate detailed explanations may be omitted.

[0009] (First embodiment) Fig. 1 is a cross-sectional view showing a schematic configuration of a biometric authentication device 1 according to an embodiment. As shown in Fig. 1, the biometric authentication device 1 includes a sensor 2 and an illumination device 3, and is stacked in this order in a direction perpendicular to the surface of the sensor 2.

[0010] The light L1 emitted from the illumination device 3 passes through the sensor 2. The sensor 2 is, for example, a light reflection type optical sensor, and can detect the biometric information of the finger Fg by detecting the light L2 reflected by the finger Fg. The biometric information is, for example, a blood vessel image (vein pattern) such as a fingerprint or vein, a pulse, a pulse wave, a blood condition (blood oxygen concentration, etc.), etc. The color of the light L1 from the illumination device 3 may be different depending on the detection target. For example, in the case of fingerprint detection, the illumination device 3 can emit the light L1 of visible light (e.g., blue or green), and in the case of vein detection, the illumination device 3 can emit the light L1 of infrared light.

[0011] 1 shows the biometric authentication device 1 configured such that the illumination device 3 and the sensor 2 are stacked in this order in a direction perpendicular to the surface of the sensor 2, but the biometric authentication device 1 may be configured such that the sensor 2 and the illumination device 3 are stacked in this order in a direction perpendicular to the surface of the sensor 2 as shown in FIG. 2. In this configuration, light L1 irradiated from the illumination device 3 is reflected by the finger Fg, and the reflected light L2 passes through the illumination device 3. The sensor 2 detects the light L2 reflected by the finger Fg and transmitted through the illumination device 3, thereby detecting the biometric information of the finger Fg. 1 and 2 show the case where the detection object (authentication object) is a finger Fg, but the detection object is not limited to this and may be, for example, a palm or the like.

[0012] 3 is a plan view showing a configuration example of the sensor 2 included in the biometric authentication device 1. As shown in FIG. 3, the sensor 2 includes a sensor substrate 20, a sensor unit 21, a gate line driving circuit GD1, a signal line selection circuit SD1, a detection circuit 48, a control circuit 102, and a power supply circuit 103.

[0013] A control board 101 is electrically connected to the sensor base material 20 via a flexible printed circuit board FPC1. A detection circuit 48 is provided on the flexible printed circuit board FPC1. A control circuit 102 and a power supply circuit 103 are provided on the control board 101. The control circuit 102 is, for example, an FPGA (Field Programmable Gate Array). The control circuit 102 supplies control signals to the sensor unit 21, the gate line driving circuit GD1, and the signal line selection circuit SD1 to control the detection operation of the sensor unit 21. The power supply circuit 103 supplies voltage signals such as a sensor power supply signal VDDSNS (see FIG. 6) to the sensor unit 21, the gate line driving circuit GD1, and the signal line selection circuit SD1.

[0014] The sensor substrate 20 has a detection area AA1 and a peripheral area SA1. The detection area AA1 is an area in which a plurality of first pixels PX1 constituting the sensor unit 21 are provided. The first pixels PX1 may be referred to as sensor pixels or imaging pixels. The plurality of first pixels PX1 are provided in a matrix in the first direction X and the second direction Y. Each of the plurality of first pixels PX1 is provided with a photodiode PD (see FIG. 6). The peripheral area SA1 is an area outside the detection area AA1 and does not overlap with the first pixels PX1.

[0015] The gate line driving circuit GD1 and the signal line selection circuit SD1 are provided in the peripheral area SA1. Specifically, the gate line driving circuit GD1 is provided in a region of the peripheral area SA1 extending along the second direction Y. The signal line selection circuit SD1 is provided in a region of the peripheral area SA1 extending along the first direction X, and is provided between the sensor unit 21 and the detection circuit 48.

[0016] The first direction X is a direction in a plane parallel to the sensor substrate 20. The second direction Y is a direction in a plane parallel to the sensor substrate 20, and is a direction perpendicular to the first direction X. The second direction Y may not be perpendicular to the first direction X but may intersect with it. The third direction Z is a direction perpendicular to the first direction X and the second direction Y, and is a normal direction to the sensor substrate 20.

[0017] Fig. 4 is a block diagram showing a configuration example of the sensor 2 included in the biometric authentication device 1. As shown in Fig. 4, the sensor 2 further includes a detection control unit 11 and a detection unit 40. A part or all of the functions of the detection control unit 11 are included in a control circuit 102. In addition, a part or all of the functions of the detection unit 40 other than the detection circuit 48 are included in the control circuit 102.

[0018] The sensor unit 21 is an optical sensor having a photodiode PD, which is a photoelectric conversion element. The photodiode PD of the sensor unit 21 outputs an electric signal according to the amount of light irradiated to the signal line selection circuit SD1. The signal line selection circuit SD1 sequentially selects the signal lines SLA (see FIG. 5) according to the selection signal ASW from the detection control unit 11. As a result, the above-mentioned electric signal is output to the detection unit 40 as a detection signal Vdet via the signal line selection circuit SD1. In addition, the sensor unit 21 performs detection according to the gate drive signal Vgla supplied from the gate line drive circuit GD1.

[0019] The detection control unit 11 is a circuit that supplies control signals to the gate line driving circuit GD1, the signal line selection circuit SD1, and the detection unit 40, and controls their operations. The detection control unit 11 supplies various control signals, such as a start signal STV, a clock signal CK, and a reset signal RST1, to the gate line driving circuit GD1. The detection control unit 11 also supplies various control signals, such as a selection signal ASW, to the signal line selection circuit SD1.

[0020] The gate line driving circuit GD1 is a circuit that drives multiple gate lines GLA (see FIG. 5) based on various control signals. The gate line driving circuit GD1 sequentially or simultaneously selects multiple gate lines GLA and supplies a gate driving signal Vgla to the selected gate lines GLA. In this way, the gate line driving circuit GD1 selects multiple photodiodes PD connected to the gate lines GLA.

[0021] The signal line selection circuit SD1 is a switch circuit that sequentially or simultaneously selects a plurality of signal lines SLA (see FIG. 5). The signal line selection circuit SD1 is, for example, a multiplexer. The signal line selection circuit SD1 connects the selected signal line SLA to the detection circuit 48 based on a selection signal ASW supplied from the detection control unit 11. As a result, the signal line selection circuit SD1 outputs a detection signal Vdet from the photodiode PD to the detection unit 40.

[0022] The detection unit 40 includes a detection circuit 48, a signal processing unit 44, a coordinate extraction unit 45, a storage unit 46, and a detection timing control unit 47. Based on a control signal supplied from the detection control unit 11, the detection timing control unit 47 controls the detection circuit 48, the signal processing unit 44, and the coordinate extraction unit 45 to operate in synchronization with each other.

[0023] The detection circuit 48 is, for example, an analog front-end circuit (AFE). The detection circuit 48 is, for example, a signal processing circuit having the functions of the detection signal amplifier 42 and the A / D converter 43. The detection signal amplifier 42 amplifies the detection signal Vdet. The A / D converter 43 converts the analog signal output from the detection signal amplifier 42 into a digital signal. In the following description, the signal amplified by the detection signal amplifier 42, converted from an analog signal to a digital signal by the A / D converter 43, and output may be referred to as the detection signal Vdet.

[0024] The signal processing unit 44 is a logic circuit that detects a predetermined physical quantity input to the sensor unit 21 based on an output signal from the detection circuit 48. When the finger Fg touches or approaches the detection area AA1, the signal processing unit 44 can detect unevenness on the surface of the finger Fg (i.e., a fingerprint) based on the output signal from the detection circuit 48.

[0025] The storage unit 46 temporarily stores the signal calculated by the signal processing unit 44. The storage unit may be, for example, a RAM (Random Access Memory), a register circuit, or the like.

[0026] The coordinate extraction unit 45 is a logic circuit that determines the detection coordinates of the unevenness of the surface of the finger Fg or the like when the contact or proximity of the finger Fg is detected in the signal processing unit 44. The coordinate extraction unit 45 combines the detection signal Vdet output from the photodiode PD of the sensor unit 21 to generate two-dimensional information (e.g., an image, etc.) indicating the shape of the unevenness of the surface of the finger Fg (i.e., a fingerprint) and the shape of the blood vessel pattern of the finger Fg. This two-dimensional information is the biometric information of the user. Note that the coordinate extraction unit 45 may output the detection signal Vdet as the sensor output Vo without calculating the detection coordinates. In this case, the detection signal Vdet may be referred to as the biometric information of the user. Alternatively, the coordinate extraction unit 45 may output information about the biometric information (e.g., pulse wave data, etc.) that can be calculated based on the detection signal Vdet as the sensor output Vo without calculating the detection coordinates. In this case, the information about the biometric information that can be calculated based on the detection signal Vdet may be referred to as the biometric information of the user.

[0027] Next, an example of a circuit configuration of the sensor 2 included in the biometric authentication device 1 will be described. Fig. 5 is a circuit diagram showing the sensor 2. Fig. 6 is a circuit diagram showing a plurality of first pixels PX1 included in the sensor 2. Note that Fig. 6 also shows the circuit configuration of a detection circuit 48.

[0028] 5, the sensor unit 21 has a plurality of first pixels PX1 arranged in a matrix. Each of the first pixels PX1 is provided with a photodiode PD.

[0029] The gate line GLA extends in a first direction X and is connected to a plurality of first pixels PX1 arranged in the first direction X. The plurality of gate lines GLA1, GLA2, ..., GLA8 are arranged in a second direction Y and are each connected to a gate line driving circuit GD1. In the following description, when there is no need to distinguish between the plurality of gate lines GLA1 to GLA8, they are simply referred to as gate lines GLA. In addition, for ease of understanding, eight gate lines GLA are shown in FIG. 5, but this is merely an example, and M gate lines GLA (M is 8 or more, for example, M=256) may be arranged.

[0030] The signal line SLA extends in the second direction Y and is connected to the photodiodes PD of the first pixels PX1 arranged in the second direction Y. The signal lines SLA1, SLA2, ..., SLA12 are arranged in the first direction X and are each connected to a signal line selection circuit SD1 and a reset circuit RC. In the following description, when there is no need to distinguish between the signal lines SLA1 to SLA12, they are simply referred to as signal lines SLA. In addition, for ease of understanding, 12 signal lines SLA are shown in FIG. 5, but this is merely an example, and N signal lines SLA (N is 12 or more, for example, N=252) may be arranged.

[0031] In addition, in FIG. 5, the sensor unit 21 is provided between the signal line selection circuit SD1 and the reset circuit RC, but this is not limited to this, and the signal line selection circuit SD1 and the reset circuit RC may each be connected to the end of the signal line SLA in the same direction.

[0032] The gate line driving circuit GD1 receives various control signals, such as a start signal STV, a clock signal CK, and a reset signal RST1, from the control circuit 102. The gate line driving circuit GD1 sequentially selects the multiple gate lines GLA1 to GLA8 in a time-division manner based on the various control signals. The gate line driving circuit GD1 supplies a gate driving signal Vgla to the selected gate line GLA. As a result, the gate driving signal Vgla is supplied to multiple switching elements Tr connected to the gate line GLA, and multiple first pixels PX1 arranged in the first direction X are selected as targets from which to acquire the detection signal Vdet.

[0033] The gate line driving circuit GD1 may be driven differently for each detection mode of a fingerprint and a plurality of different pieces of biometric information (for example, pulse wave, pulse, blood vessel image, blood oxygen concentration, etc.).

[0034] The signal line selection circuit SD1 has a plurality of selection signal lines Lsel, a plurality of output signal lines Lout, and a switching element TrS. The plurality of switching elements TrS are provided corresponding to the plurality of signal lines SLA, respectively. The six signal lines SLA1 to SLA6 are connected to a common output signal line Lout1. The six signal lines SLA7 to SLA12 are connected to a common output signal line Lout2. The output signal lines Lout1 and Lout2 are each connected to a detection circuit 48.

[0035] Here, the signal lines SLA1 to SLA6 are a first signal line block, and the signal lines SLA7 to SLA12 are a second signal line block. The multiple selection signal lines Lsel are connected to the gates of the switching elements TrS included in one signal line block. Furthermore, one selection signal line Lsel is connected to the gates of the switching elements TrS of multiple signal line blocks.

[0036] Specifically, the selection signal lines Lsel1 to Lsel6 are connected to the switching elements TrS corresponding to the signal lines SLA1 to SLA6, respectively. The selection signal line Lsel1 is connected to the switching element TrS corresponding to the signal line SLA1 and the switching element TrS corresponding to the signal line SLA7. The selection signal line Lsel2 is connected to the switching element TrS corresponding to the signal line SLA2 and the switching element TrS corresponding to the signal line SLA8.

[0037] The control circuit 102 sequentially supplies the selection signal ASW to the selection signal line Lsel. As a result, the signal line selection circuit SD1 sequentially selects the signal lines SLA in one signal line block in a time-division manner by the operation of the switching element TrS. The signal line selection circuit SD1 also selects one signal line SLA each from each of the multiple signal line blocks. With this configuration, the sensor 2 can reduce the number of ICs (Integrated Circuits) including the detection circuit 48 or the number of IC terminals.

[0038] Although the example shown here is one in which six signal lines SLA are connected to one output signal line Lout to form one signal line block, the number of signal lines SLA connected to one output signal line Lout to form one signal line block can be set arbitrarily. For example, four signal lines SLA may be connected to one output signal line Lout to form one signal line block.

[0039] As shown in Fig. 5, the reset circuit RC has a reference signal line Lvr, a reset signal line Lrst, and a switching element TrR. The switching element TrR is provided corresponding to the multiple signal lines SLA. The reference signal line Lvr is connected to one of the sources or drains of the multiple switching elements TrR. The reset signal line Lrst is connected to the gates of the multiple switching elements TrR.

[0040] The control circuit 102 supplies a reset signal RST2 to the reset signal line Lrst. This turns on the multiple switching elements TrR, and the multiple signal lines SLA are electrically connected to the reference signal line Lvr. The power supply circuit 103 supplies a reference signal COM to the reference signal line Lvr. This causes the reference signal COM to be supplied to the capacitive elements Ca (see FIG. 6) included in the multiple first pixels PX1.

[0041] As shown in Fig. 6, the first pixel PX1 includes a photodiode PD, a capacitance element Ca, and a switching element Tr. In Fig. 6, two gate lines GLA(m) and GLA(m+1) arranged in the second direction Y among the multiple gate lines GLA are shown. Also, two signal lines SLA(n) and SLA(n+1) arranged in the first direction X among the multiple signal lines SLA are shown. The first pixel PX1 is disposed in an area surrounded by the gate line GLA and the signal line SLA. The switching element Tr is provided corresponding to the photodiode PD. The switching element Tr is composed of a thin film transistor, and in this example, is composed of an n-channel MOS (Metal Oxide Semiconductor) type TFT (Thin Film Transistor).

[0042] The gates of the switching elements Tr belonging to the first pixels PX1 aligned in the first direction X are connected to the gate line GLA. The sources of the switching elements Tr belonging to the first pixels PX1 aligned in the second direction Y are connected to the signal line SLA. The drains of the switching elements Tr are connected to the cathodes of the photodiodes PD and the capacitive elements Ca.

[0043] A sensor power supply signal VDDSNS is supplied to the anode of the photodiode PD from the power supply circuit 103. In addition, a reference signal COM, which becomes the initial potential of the signal line SLA and the capacitance element Ca, is supplied from the power supply circuit 103 to the signal line SLA and the capacitance element Ca.

[0044] When light is applied to the first pixel PX1, a current corresponding to the amount of light flows through the photodiode PD included in the first pixel PX1. This causes charge to accumulate in the capacitance element Ca. When the switching element Tr is turned on, a current flows through the signal line SLA according to the charge accumulated in the capacitance element Ca. The signal line SLA is connected to the detection circuit 48 via the switching element TrS of the signal line selection circuit SD1. This allows the sensor 2 to detect a signal corresponding to the amount of light applied to the photodiode PD for each first pixel PX1.

[0045] In the detection circuit 48, the switch SSW is turned on during the readout period, and the detection circuit 48 is connected to the signal line SLA. The detection signal amplifier 42 of the detection circuit 48 converts the fluctuation in current supplied from the signal line SLA into a fluctuation in voltage and amplifies it. A reference potential (Vref) having a fixed potential is input to the non-inverting input terminal (+) of the detection signal amplifier 42, and the signal line SLA is connected to the inverting input terminal (-). Here, a signal that is the same as the reference signal COM is input as the reference potential (Vref). The detection signal amplifier 42 also has a capacitance element Cb and a reset switch RSW. In the reset period following the readout period, the reset switch RSW is turned on, and the charge of the capacitance element Cb is reset.

[0046] Next, a description will be given of the illumination device 3 included in the biometric authentication device 1. Fig. 7 is a plan view showing a configuration example of the illumination device 3 included in the biometric authentication device 1. The illumination device 3 includes a light source base material 30, a light-emitting unit 31, a light source gate line driving circuit GD2, a light source signal line selection circuit SD2, a control circuit 112, and a power supply circuit 113.

[0047] A control board 111 is electrically connected to the light source base material 30 via a flexible printed circuit board FPC2. The control board 111 is provided with a control circuit 112 and a power supply circuit 113. The control circuit 112 is, for example, an FPGA. The control circuit 112 supplies control signals to the light-emitting unit 31, the light source gate line driving circuit GD2, and the light source signal line selection circuit SD2 to control the lighting operation of the multiple light-emitting elements LED included in the light-emitting unit 31. The power supply circuit 103 supplies voltage signals such as a light source power supply signal to the light-emitting unit 31, the light source gate line driving circuit GD2, and the light source signal line selection circuit SD2.

[0048] The light source substrate 30 has a light-emitting area AA2 and a peripheral area SA2. In the case of the biometric authentication device 1 having the configuration shown in FIG. 1 and FIG. 2, the light-emitting area AA2 of the light source substrate 30 overlaps with the detection area AA1 of the sensor substrate 20 in a planar view. The peripheral area SA2 of the light source substrate 30 overlaps with the peripheral area SA2 of the sensor substrate 20 in a planar view. The light-emitting area AA2 is an area in which a plurality of second pixels PX2 constituting the light-emitting unit 31 are provided. The plurality of second pixels PX2 are provided in a matrix shape in the first direction X and the second direction Y. Each of the plurality of second pixels PX2 is provided with a light-emitting element LED (see FIG. 8). The light-emitting element LED is, for example, a micro LED or a mini LED, and irradiates light toward the finger Fg that is the detection target. The peripheral area SA2 is an area outside the light-emitting area AA2 and does not overlap with the second pixels PX2.

[0049] The light source gate line driving circuit GD2 and the light source signal line selection circuit SD2 are provided in the peripheral area SA2. Specifically, the light source gate line driving circuit GD2 is provided in an area of ​​the peripheral area SA2 extending along the second direction Y. The light source signal line selection circuit SD2 is provided in an area of ​​the peripheral area SA2 extending along the first direction X.

[0050] The light source gate line drive circuit GD2 is a circuit that drives a plurality of light source gate lines GLB (see FIG. 8) based on various control signals. The light source gate line drive circuit GD2 sequentially or simultaneously selects a plurality of light source gate lines GLB and supplies a gate drive signal to the selected light source gate line GLB. In this way, the light source gate line drive circuit GD2 selects a plurality of light emitting elements LED connected to the light source gate line GLB.

[0051] The light source signal line selection circuit SD2 is a switch circuit that sequentially or simultaneously selects multiple light source signal lines SLB (see FIG. 8). The light source signal line selection circuit SD2 is, for example, a multiplexer. The light source signal line selection circuit SD2 sequentially or simultaneously selects multiple light source signal lines SLB and supplies a selection signal to the selected light source signal line SLB. As a result, the light source signal line selection circuit SD2 selects one or multiple light-emitting elements LED from the multiple light-emitting elements LED selected by the light source gate line drive circuit GD2.

[0052] 8, the second pixel PX2 is disposed in an area surrounded by the light source gate line GLB and the light source signal line SLB. Each of the second pixels PX2 is connected to the light source gate line GLB extending along the first direction X and arranged at intervals in the second direction Y, and the light source signal line SLB extending along the second direction Y and arranged at intervals in the first direction X. The light-emitting elements LED included in the second pixels PX2 are selectively turned on by control signals supplied from the light source gate line drive circuit GD2 and the light source signal line selection circuit SD2.

[0053] Here, a process for detecting biometric information (hereinafter, simply referred to as detection process) executed in a general biometric authentication device will be described. In a general detection process, first, a plurality of light-emitting elements provided in an illumination device are simultaneously turned on, and the plurality of light-emitting elements irradiate light toward a finger or palm of a detection target. The light irradiated from the plurality of light-emitting elements is diffusely reflected by the finger or palm of a detection target. Then, a plurality of photodiodes provided in a sensor receive the light diffusely reflected by the finger or palm of a detection target, and output a detection signal according to the amount of light received. This allows the biometric authentication device to detect biometric information based on the detection signals from the plurality of photodiodes.

[0054] However, in the above-mentioned general detection process, since the multiple light emitting elements provided in the illumination device are turned on at the same time, the multiple light beams diffusely reflected at various positions on the finger or palm of the detection target are mixed and enter each of the multiple photodiodes provided in the sensor. This causes a problem that the S / N ratio of the detection signal from the multiple photodiodes is reduced. In addition, if the S / N ratio of the detection signal is reduced, there is also a problem that the time change of the biological information (e.g., pulse wave data) cannot be detected with high accuracy. Furthermore, if the S / N ratio of the detection signal is reduced, for example, even if an image is generated based on the detection signal, a blurred image I1 with low contrast is generated as shown in FIG. 9.

[0055] Therefore, in the biometric authentication device 1 of this embodiment, the control circuit 112 of the illumination device 3 has a function of dividing the multiple second pixels PX2 provided in the illumination device 3 into multiple groups, and controlling the operation of the light source gate drive circuit GD2 and the light source signal line selection circuit SD2 so that only the light-emitting element LED included in the second pixel PX2 at a predetermined position in each group is turned on.

[0056] In addition, the control circuit 102 of the sensor 2 has a function of dividing a plurality of first pixels PX1 provided in the sensor 2 into a plurality of groups, and controlling the operation of the gate line driving circuit GD1 and the signal line selection circuit SD1 so that the detection signal Vdet is acquired only from the photodiode PD included in the first pixel PX1 at a predetermined position of each group.

[0057] The control circuit 112 of the lighting device 3 and the control circuit 102 of the sensor 2 operate in synchronization with each other. Also, here, it is assumed that the number of the second pixels PX2 provided in the lighting device 3 is the same as the number of the first pixels PX1 provided in the sensor 2, and the grouping of the second pixels PX2 by the control circuit 112 of the lighting device 3 and the grouping of the first pixels PX1 by the control circuit 102 of the sensor 2 are performed correspondingly (the area of ​​one group of the second pixels PX2 is the same as the area of ​​one group of the first pixels PX1, and the grouping is performed such that one group of the first pixels PX1 exists for one group of the second pixels PX2).

[0058] Fig. 10 is a schematic diagram for explaining the above-mentioned functions of the control circuit 112 of the illumination device 3 and the above-mentioned functions of the control circuit 102 of the sensor 2. Fig. 10 shows a case where a plurality of second pixels PX2 provided in the illumination device 3 and a plurality of first pixels PX1 provided in the sensor 2 are both grouped into 4 x 4 = 16 pixels. Note that, hereinafter, a series of processes described with reference to Fig. 10 will be referred to as a first detection process.

[0059] As shown in the upper part of Fig. 10(a), the control circuit 112 of the illumination device 3 controls the operation of the light source gate drive circuit GD2 and the light source signal line selection circuit SD2 so as to simultaneously light up the light-emitting element LED included in the second pixel PX2 located in the first row and first column of each group (hereinafter referred to as the first light-emitting element LED). At this time, the light-emitting element LED included in the other second pixels PX2 of each group (i.e., the 15 second pixels PX2 located in the first row, second column to the fourth row, fourth column) is not lighted and is maintained in an unlit state. As a result, as shown in the upper part of Fig. 10(a), only the first light-emitting element LED of each group is lighted up.

[0060] In synchronization with the timing when the first light-emitting element LED of each group of the illumination device 3 is turned on, the control circuit 102 of the sensor 2 controls the operation of the gate line driving circuit GD1 and the signal line selection circuit SD1 so as to simultaneously acquire the detection signal Vdet from the photodiode PD (hereinafter referred to as the first photodiode PD) included in the first pixel PX1 located in the first row and first column of each group. At this time, the detection signal Vdet is not acquired from the photodiode PD included in the other first pixels PX1 of each group (that is, the 15 first pixels PX1 located in the first row, second column to the fourth row, fourth column). According to this, as shown in the lower part of FIG. 10(a), the detection signal Vdet is acquired only from the first photodiode PD of each group. The acquired detection signal Vdet is stored in the storage unit 46.

[0061] Next, as shown in the upper part of Fig. 10(b), the control circuit 112 of the illumination device 3 controls the operation of the light source gate drive circuit GD2 and the light source signal line selection circuit SD2 so as to turn off the first light-emitting element LED of each group and simultaneously turn on the light-emitting element LED (hereinafter referred to as the second light-emitting element LED) included in the second pixel PX2 located in the first row and second column of each group. At this time, the light-emitting element LED included in the other second pixels PX2 of each group (i.e., the 15 second pixels PX2 located in the first row, first column, the first row, third column to the fourth row, fourth column) is not turned on and is maintained in the turned off state. As a result, as shown in the upper part of Fig. 10(b), only the second light-emitting element LED of each group is turned on.

[0062] In synchronization with the timing when the second light-emitting element LED of each group of the illumination device 3 is turned on, the control circuit 102 of the sensor 2 controls the operation of the gate line driving circuit GD1 and the signal line selection circuit SD1 so that the detection signal Vdet is simultaneously acquired from the photodiode PD (hereinafter referred to as the second photodiode PD) included in the first pixel PX1 located in the first row and second column of each group. At this time, the detection signal Vdet is not acquired from the photodiode PD included in the other first pixels PX1 of each group (that is, the 15 first pixels PX1 located in the first row and first column, the third column of the first row to the fourth row and fourth column). According to this, as shown in the lower part of FIG. 10(b), the detection signal Vdet is acquired only from the second photodiode PD of each group. The acquired detection signal Vdet is stored in the storage unit 46.

[0063] Thereafter, the control circuit 112 of the lighting device 3 performs similar control on the light-emitting element LED included in the second pixel PX2 located in the 3rd column of the 1st row and the 4th column of the 1st row, and the control circuit 102 of the sensor 2 performs similar control on the photodiode PD included in the first pixel PX1 located in the 3rd column of the 1st row and the 4th column of the 1st row.

[0064] The control circuit 112 of the illumination device 3 and the control circuit 102 of the sensor 2 execute the above-mentioned control for the first row, first column to the first row, fourth column (each column of the first row) of each group, and then execute similar control for each column of the next row. That is, the control circuit 112 of the illumination device 3 executes similar control for the light-emitting element LED included in the second pixel PX2 located in the second row, first column to the second row, fourth column, and the control circuit 102 of the sensor 2 executes similar control for the photodiode PD included in the first pixel PX1 located in the second row, first column to the second row, fourth column.

[0065] Furthermore, the control circuit 112 of the illumination device 3 and the control circuit 102 of the sensor 2 execute the above-mentioned control in the 2nd row, 1st column to the 2nd row, 4th column (each of the 2nd rows and columns) of each group, and then execute similar control for each column of the next row. That is, the control circuit 112 of the illumination device 3 executes similar control for the light-emitting element LED included in the second pixel PX2 located in the 3rd row, 1st column to the 3rd row, 4th column, and the control circuit 102 of the sensor 2 executes similar control for the photodiode PD included in the first pixel PX1 located in the 3rd row, 1st column to the 3rd row, 4th column.

[0066] Furthermore, the control circuit 112 of the lighting device 3 and the control circuit 102 of the sensor 2 execute the above-mentioned control for the 3rd row, 1st column to the 3rd row, 4th column (each of the three rows) of each group, and then execute similar control for each column of the next row. That is, the control circuit 112 of the lighting device 3 executes similar control for the light-emitting element LED included in the second pixel PX2 located in the 4th row, 1st column to the 4th row, 4th column, and the control circuit 102 of the sensor 2 executes similar control for the photodiode PD included in the first pixel PX1 located in the 4th row, 1st column to the 4th row, 4th column. Hereinafter, the control executed for the 4th row, 4th column of each group will be described in detail with reference to FIG. 10(c).

[0067] As shown in the upper part of Fig. 10(c), the control circuit 112 of the illumination device 3 controls the operation of the light source gate drive circuit GD2 and the light source signal line selection circuit SD2 so as to turn off the 15th light-emitting element LED of each group and simultaneously turn on the light-emitting element LED included in the second pixel PX2 located in the 4th row and 4th column of each group (hereinafter referred to as the 16th light-emitting element LED). At this time, the light-emitting element LED included in the other second pixels PX2 of each group (i.e., the 15 second pixels PX2 located in the 1st row, 1st column to the 4th row, 3rd column) is not turned on and is maintained in an off state. As a result, as shown in the upper part of Fig. 10(c), only the 16th light-emitting element LED of each group is turned on.

[0068] In synchronization with the timing when the 16th light-emitting element LED of each group of the illumination device 3 is turned on, the control circuit 102 of the sensor 2 controls the operation of the gate line driving circuit GD1 and the signal line selection circuit SD1 so that the detection signal Vdet is simultaneously acquired from the photodiode PD (hereinafter, referred to as the 16th photodiode PD) included in the first pixel PX1 located in the 4th row and 4th column of each group. At this time, the detection signal Vdet is not acquired from the photodiode PD included in the other first pixels PX1 of each group (that is, the 15 first pixels PX1 located in the 1st row, 1st column to the 4th row, 3rd column). According to this, as shown in the lower part of FIG. 10(c), the detection signal Vdet is acquired only from the 16th photodiode PD of each group. The acquired detection signal Vdet is stored in the storage unit 46.

[0069] When the series of controls as described above is executed and the detection signals Vdet acquired from the 1st to 16th photodiodes PD of each group are stored in the memory unit 46, the coordinate extraction unit 45, which is one function of the control circuit 102 of the sensor 2, generates an image I2 (see FIG. 11) showing the shape of the vascular pattern of the finger Fg to be detected, based on the detection signals Vdet of the 1st to 16th photodiodes PD of each group stored in the memory unit 46.

[0070] In the first detection process executed in the biometric authentication device 1 according to the present embodiment described above, the second pixels PX2 provided in the illumination device 3 and the first pixels PX1 provided in the sensor 2 are both divided into a plurality of groups corresponding to each other. Then, in the illumination device 3, one light-emitting element LED for each group is controlled to be turned on. In other words, the light-emitting elements LED other than one of the multiple light-emitting elements LED included in each group are controlled to be turned off. This makes it possible to prevent light from the other light-emitting elements LED included in each group from entering the photodiode PD, which operates in synchronization with the turned-on light-emitting element LED, as stray light.

[0071] In addition, in the first detection process executed in the biometric authentication device 1 according to the present embodiment, one light-emitting element LED is controlled to be turned on for each group, and the light-emitting element LED turned on in one group is grouped so that it is sufficiently spaced from the light-emitting element LED turned on in a group adjacent to the one group (for example, in FIG. 10, it is grouped so that it is separated by four pixels). Therefore, it is possible to allow the n-th photodiode PD of each group to mainly receive light from the n-th light-emitting element LED of each group that overlaps in plan view. In other words, according to the first detection process according to the present embodiment, it is possible to prevent the light from the n-th light-emitting element LED of another group that does not overlap in plan view from entering the n-th photodiode PD of each group as stray light.

[0072] In this manner, it is possible to suppress a decrease in the S / N ratio of the detection signal Vdet from the photodiodes PD by suppressing stray light from entering the photodiodes PD. As a result, the biometric authentication device 1 according to this embodiment can generate an image I2 showing the shape of a blood vessel pattern, for example, as shown in Fig. 11, and can generate an image with higher contrast than the general biometric authentication device described above.

[0073] In this embodiment, it is assumed that the multiple second pixels PX2 provided in the lighting device 3 and the multiple first pixels PX1 provided in the sensor 2 are grouped into groups of 4 x 4 = 16 pixels, but the number of pixels into which the second pixels PX2 and the first pixels PX1 are divided is not limited to this, and the groups may be divided into any number of pixels as long as the light-emitting element LED that lights up in one group and the light-emitting element LED that lights up in the group adjacent to that group are separated by a distance such that light from the light-emitting element LED that lights up in that group does not enter the photodiode PD that overlaps with the light-emitting element LED that lights up in the adjacent group in a planar view as stray light.

[0074] In addition, in this embodiment, a case has been described in which the number of pixels of the multiple second pixels PX2 provided in the lighting device 3 is the same as the number of pixels of the multiple first pixels PX1 provided in the sensor 2, but this is not limited to this, and the number of pixels of the second pixels PX2 provided in the lighting device 3 may be different from the number of pixels of the first pixels PX1 provided in the sensor 2.

[0075] For example, the first pixels PX1 of the sensor 2 may be arranged at a pitch of 235 μm, whereas the second pixels PX2 of the illumination device 3 may be arranged at a pitch of 100 μm. That is, the number of second pixels PX2 of the illumination device 3 may be greater than the number of first pixels PX1 of the sensor 2. However, even in this case, it is preferable that one group of the first pixels PX1 and one group of the second pixels PX2 have the same area (that is, although the number of pixels included in one group is different, it is preferable that the area of ​​one group is the same).

[0076] In this case, the control circuit 112 of the lighting device 3 controls the operation of the light source gate line driving circuit GD2 and the light source signal line selection circuit SD2 so as to turn on the light-emitting element LED included in a plurality of second pixels PX2 corresponding to one of the plurality of first pixels PX1 provided in the sensor 2 (i.e., a plurality of second pixels PX2 overlapping one first pixel PX1 in a planar view).

[0077] The control circuit 102 of the sensor 2 controls the operation of the gate line driving circuit GD1 and the signal line selection circuit SD1 so as to acquire a detection signal Vdet from a photodiode PD included in a first pixel PX1 corresponding to the second pixels PX2 including the lit light-emitting elements LED in synchronization with the timing at which the light-emitting elements LED included in the second pixels PX2 provided in the lighting device 3 are lit.

[0078] Even in this configuration, only the light-emitting element LED included in one region of each group is controlled to be lit, and the light-emitting element LED in other regions is controlled to be turned off, so that it is possible to prevent light from the light-emitting element LED included in other regions of each group from entering the photodiode PD, which operates in synchronization with the lit light-emitting element LED, as stray light.

[0079] Furthermore, since the elements are still grouped so that there is a sufficient distance between the area in which the light-emitting element LED is lit in one group and the area in which the light-emitting element LED is lit in the group adjacent to that group, it is also possible to prevent light from the light-emitting element LED that is lit in the group adjacent to that group from entering as stray light into the photodiode PD corresponding to the area in which the light-emitting element LED is lit in that group.

[0080] In other words, even if the number of first pixels PX1 provided in the sensor 2 is different from the number of second pixels PX2 provided in the lighting device 3, the above-mentioned series of first detection processes can prevent stray light from entering the multiple photodiodes PD and can prevent a decrease in the S / N ratio of the detection signals Vdet from the multiple photodiodes PD, and ultimately makes it possible to generate a high-contrast image based on the above-mentioned detection signals Vdet.

[0081] Furthermore, in this embodiment, the control of the first pixel PX1 and the second pixel PX2 in each group is performed in the order of row 1, column 1 to row 1, column 4, row 2, column 1 to row 2, column 4, row 3, column 1 to row 3, column 4, and row 4, column 1 to row 4, column 4, but the order in which the first pixel PX1 and the second pixel PX2 in each group are controlled is not limited to this.

[0082] In the present embodiment described above, the biometric authentication device 1 has a configuration in which the sensor 2 and the lighting device 3 are stacked (the sensor 2 and the lighting device 3 are provided on different substrates). However, this is not limited to this, and the biometric authentication device 1 may have a configuration in which the sensor 2 and the lighting device 3 are provided on the same substrate.

[0083] 12 is a circuit diagram showing an example of a circuit configuration of a biometric authentication device 1 in which the photodiode PD of the sensor 2 and the light-emitting element LED of the illumination device 3 are provided on the same substrate. In this case, as shown in FIG. 12, the gate lines GLA for selecting the photodiodes PD extend along the first direction X and are arranged at intervals in the second direction Y. Furthermore, the signal lines SLA for selecting the photodiodes PD extend along the second direction Y and are arranged at intervals in the first direction X. The light source gate line GLB for selecting the light-emitting element LED extends in a direction parallel to the gate line GLA for selecting the photodiode PD. Furthermore, the light source signal line SLB for selecting the light-emitting element LED extends in a direction parallel to the signal line SLA for selecting the photodiode PD. In this case, an area surrounded by the gate line GLA, the light source gate line GLB, the signal line SLA, and the light source signal line SLB corresponds to one pixel.

[0084] Even in such a configuration, the biometric authentication device 1 operates such that a plurality of pixels arranged in a matrix are grouped, one light-emitting element LED is turned on for each group, and a detection signal Vdet is acquired from one photodiode PD included in the same pixel as the turned-on light-emitting element LED. In other words, even when the sensor 2 and the illumination device 3 are provided on the same substrate, the above-described series of first detection processes can prevent stray light from entering the plurality of photodiodes PD, and can prevent a decrease in the S / N ratio of the detection signals Vdet from the plurality of photodiodes PD, and can also generate a high-contrast image based on the above-described detection signal Vdet.

[0085] According to the first embodiment described above, the biometric authentication device 1 does not simultaneously light up the light-emitting element LED included in each of the multiple second pixels PX2 provided in the illumination device 3 and simultaneously acquire the detection signal Vdet from the photodiode PD included in each of the multiple first pixels PX1 provided in the sensor 2, but rather groups the first pixels PX1 and the second pixels PX2 by the series of first detection processes described above, and then lights up only the light-emitting element LED included in the second pixel PX2 at a predetermined position in each group and acquires the detection signal Vdet only from the photodiode PD included in the first pixel PX1 corresponding to the second pixel PX2 that includes the light-emitting element LED that has been turned on.

[0086] This makes it possible to prevent stray light from entering the multiple photodiodes PD, and to prevent a decrease in the S / N ratio of the detection signals Vdet from the multiple photodiodes PD. Ultimately, it is also possible to generate a high-contrast image based on the above-mentioned detection signals Vdet.

[0087] Second embodiment Next, a second embodiment will be described. In the above-mentioned first embodiment, the first detection process capable of improving the contrast of an image generated based on the detection signal Vdet from the photodiode PD was mainly described, but in this embodiment, a detection process (hereinafter, referred to as a second detection process) capable of accurately detecting a temporal change in biological information (e.g., pulse wave data) calculated based on the detection signal Vdet from the photodiode PD will be described.

[0088] Since the configuration of the biometric authentication device 1 is similar to that of the first embodiment described above, a detailed description thereof will be omitted here, and the following description will mainly focus on the second detection process described above.

[0089] FIG. 13 is a flowchart showing an example of the procedure of the second detection process executed in the biometric authentication device 1 according to this embodiment. First, when the biometric authentication device 1 detects contact or proximity of a detection target such as a finger Fg, the sensor 2 and the illumination device 3 constituting the biometric authentication device 1 generate an image of the detection target by the first detection process shown in the first embodiment (step S1). Here, it is assumed that, for example, a gradation image I2 shown in FIG. 14(b) is generated by the process of step S1.

[0090] Next, the control circuit 102 of the sensor 2 generates an image by binarizing the image generated by the processing of step S1 (step S2). As a result, the control circuit 102 can obtain, for example, a binarized image I3 shown in FIG. 14(c).

[0091] Next, the control circuit 102 of the sensor 2 extracts the center line of the black part of the binarized image generated by the processing of step S2, and generates an image in which only the extracted center line is drawn (step S3). In this way, the control circuit 102 can obtain, for example, a line image I4 shown in FIG. 14(d).

[0092] When the line image shown in FIG. 14(d) is generated by the control circuit 102 of the sensor 2, the control circuit 112 of the lighting device 3 controls the operation of the light source gate line driving circuit GD2 and the light source signal line selection circuit SD2 so as to turn on the light-emitting element LED included in the second pixel PX2, which is positioned at a position overlapping with the center line drawn in the line image (step S4).

[0093] It is assumed here that the control circuit 102 of the sensor 2 and the control circuit 112 of the lighting device 3 operate in synchronization with each other and can share information with each other by sending and receiving signals. According to this, as shown in the processing of step S4, the control circuit 112 of the lighting device 3 can select the second pixel PX2 that causes the light-emitting element LED to light up, with reference to the line image I4 generated by the control circuit 102 of the sensor 2.

[0094] The control circuit 102 of the sensor 2 controls the operation of the gate line driving circuit GD1 and the signal line selection circuit SD1 so as to acquire a detection signal Vdet from a photodiode PD included in a first pixel PX1 corresponding to a second pixel PX2 including the lit light-emitting element LED (more specifically, the first pixel PX1 overlapping in a planar view with the second pixel PX2 including the lit light-emitting element LED) (step S5).

[0095] Thereafter, the control circuit 102 of the sensor 2 calculates biological information (pulse wave data) based on the acquired detection signal Vdet (step S6), and ends the series of second detection processes. By repeatedly executing such a series of second detection processes, it is possible to accurately detect the change over time in the biological information calculated based on the detection signal Vdet.

[0096] According to the second embodiment described above, the biometric authentication device 1 generates a binary image I3 based on the gradation image I2, which is a high-contrast image, by the second detection process described above, generates a line image I4 based on the binary image I3, and then lights up only the light-emitting element LED included in the second pixel PX2 that is positioned at a position overlapping with the center line drawn in the line image I4, and acquires a detection signal Vdet only from the photodiode PD included in the first pixel PX1 corresponding to the second pixel PX2 that includes the lit light-emitting element LED.

[0097] According to this, since the light of the light-emitting element LED can be irradiated only to the position where the target of the biometric information to be calculated (for example, a vein) passes, it is possible to improve the S / N ratio of the detection signal Vdet obtained from the photodiode PD compared to the case where the light-emitting element LED provided in the illumination device 3 is fully lit. This makes it possible to accurately detect the temporal change in the biometric information calculated based on the detection signal Vdet.

[0098] In the first and second embodiments described above, as shown in Figs. 1 and 2, it is assumed that the biometric authentication device 1 is flat, but the shape of the biometric authentication device 1 is not limited to this, and may be ring-shaped, for example, as shown in Fig. 15(a). In this case, as shown in Fig. 15(a), a finger Fg is placed inside the ring of the ring-shaped biometric authentication device 1, and as shown in Fig. 15(b), light irradiated from the light-emitting element LED toward the finger Fg can be detected by the photodiode PD arranged opposite to the finger Fg. Even in such a configuration, the above-mentioned first and second detection processes are executed, and it is possible to obtain the same effects as those shown in the first and second embodiments. In addition, since the biometric authentication device 1 is ring-shaped and the light-emitting element LED and the photodiode PD are arranged around the entire ring, it is possible to calculate the detection coordinates of both sides of the finger Fg (the surface (fingerprint side) and the back side (nail side) of the finger Fg), and it is also possible to generate three-dimensional information (three-dimensional image).

[0099] According to at least one of the embodiments described above, it is possible to provide a biometric authentication device 1 capable of improving the S / N ratio of the detection signal Vdet outputted from the biometric authentication device 1.

[0100] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0101] 1...biometric authentication device, 2...sensor, 3...lighting device, L1, L2...light, Fg...finger.

Claims

1. A sensor including a first base material, a plurality of photoelectric conversion elements arranged in a matrix on the first base material, the photoelectric conversion elements outputting a signal corresponding to an amount of received light, and a first control unit controlling an operation of the plurality of photoelectric conversion elements; A lighting device including a second base material, a plurality of light-emitting elements arranged in a matrix on the second base material and configured to irradiate light to be received by the plurality of photoelectric conversion elements, and a second control unit configured to control an operation of the plurality of light-emitting elements; Equipped with The plurality of photoelectric conversion elements and the plurality of light emitting elements are divided into a plurality of groups corresponding to each other, The first control unit is When the second control unit turns on each of the light-emitting elements at a predetermined position in each group of the light-emitting elements, the second control unit controls the operation of the plurality of photoelectric conversion elements so as to obtain signals from the photoelectric conversion elements at the predetermined positions in each group of the photoelectric conversion elements and at positions corresponding to the turned-on light-emitting elements, generating a first image representing an object to be authenticated based on signals acquired from the plurality of photoelectric conversion elements; generating a second image in which the first image is binarized based on the generated first image, and generating a third image in which only the center lines of the black portions of the second image are drawn based on the generated second image; The second control unit is controlling operations of the plurality of light-emitting elements so as to light up light-emitting elements arranged at positions overlapping with a center line drawn on the third image generated by the first control unit; Biometric authentication device.

2. The light-on light-emitting element and the photoelectric conversion element at a position corresponding to the light-on light-emitting element overlap each other in a plan view. The biometric authentication device according to claim 1 .

3. The second control unit is controlling the operation of the plurality of light-emitting elements so that the plurality of light-emitting elements included in each group of the light-emitting elements are sequentially turned on as the light-emitting element at the predetermined position; The biometric authentication device according to claim 1 or 2.

4. The number of the plurality of light-emitting elements included in each group of the light-emitting elements is the same as the number of the plurality of photoelectric conversion elements included in each group of the photoelectric conversion elements, and one light-emitting element is arranged so as to overlap one photoelectric conversion element in a plan view. The biometric authentication device according to any one of claims 1 to 3.

5. the number of the plurality of light-emitting elements included in each group of the light-emitting elements is different from the number of the plurality of photoelectric conversion elements included in each group of the photoelectric conversion elements, and the plurality of light-emitting elements are arranged so as to overlap with one photoelectric conversion element in a plan view; The biometric authentication device according to any one of claims 1 to 3.

6. The sensor includes: the pixel circuit further includes a plurality of first gate lines extending along a first direction and spaced apart in a second direction intersecting the first direction, a plurality of first signal lines extending along the second direction and spaced apart in the first direction, a first gate line driving circuit connected to the plurality of first gate lines, and a first signal line selection circuit connected to the plurality of first signal lines, The lighting device includes: a plurality of second gate lines extending along the first direction and spaced apart in the second direction; a plurality of second signal lines extending along the second direction and spaced apart in the first direction; a second gate line driving circuit connected to the plurality of second gate lines; and a second signal line selection circuit connected to the plurality of second signal lines, the plurality of photoelectric conversion elements are provided in an area surrounded by the first gate line and the first signal line, the plurality of light emitting elements are provided in an area surrounded by the second gate line and the second signal line, the first control unit controls operations of the first gate line driving circuit and the first signal line selection circuit to control operations of the plurality of photoelectric conversion elements; the second control unit controls operations of the second gate line driving circuit and the second signal line selection circuit to control operations of the plurality of light emitting elements; The biometric authentication device according to any one of claims 1 to 5.

7. the photoelectric conversion element is a photodiode, The light emitting element is a micro LED. The biometric authentication device according to any one of claims 1 to 6.

Images