Detection Device

Abstract

To provide a detection device capable of acquiring highly accurate data.SOLUTION: The detection device includes: a first light source for emitting light of a predetermined wavelength; a second light source for emitting light of a wavelength different from that of the light emitted by the first light source; a plurality of optical sensors provided at positions different from each other to detect and measure the light emitted by the first and second light sources; a light quantity control part for setting a light quantity of at least one of the first and second light sources so that a measurement value based on at least one of detection values of the optical sensors reaches a predetermined target value; and a biometric information detection part for, when the measurement value has reached the predetermined target value, detecting information of a living body with the plurality of optical sensors, using a light quantity for detecting biometric information that is set by the light quantity control part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] There is a known detection device that acquires blood oxygen saturation (hereinafter referred to as blood oxygen saturation (SpO2)) based on transcutaneous data acquired by shining light into the body through the skin and detecting light transmitted through or reflected from arteries. Blood oxygen saturation (SpO2) is the ratio of the amount of oxygen actually bound to hemoglobin to the total amount of oxygen assumed to be bound to all hemoglobin in the blood. When acquiring blood oxygen saturation (SpO2), for example, a pulse wave acquired using infrared light and a pulse wave acquired using red light are used (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-180861 Summary of the Invention [Problem to be solved by the invention]

[0004] Before measuring blood oxygen saturation (SpO2), the light intensity of the light source must be initially set. If the initial setting is not done properly, it may not be possible to obtain highly accurate data.

[0005] The present invention has been made in view of the above, and an object of the present invention is to provide a detection device that can acquire highly accurate data. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the objectives, a detection device according to one aspect of the present disclosure includes a first light source that emits light of a predetermined wavelength, a second light source that emits light of a wavelength different from the wavelength of the light emitted by the first light source, a plurality of optical sensors arranged at different positions to measure and detect the light emitted by the first light source and the second light source, a light intensity control unit that sets the light intensity of at least one of the first light source and the second light source so that a measurement value based on the detection value of at least one of the plurality of optical sensors reaches a predetermined target value, and a biometric information detection unit that, when the measurement value reaches the predetermined target value, detects information about the living organism using the plurality of optical sensors using the light intensity for biometric information detection set by the light intensity control unit. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a plan view showing a detection device according to an embodiment. [Figure 2] FIG. 2 is a block diagram illustrating an example of the configuration of the detection device according to the embodiment. [Figure 3] FIG. 3 is a circuit diagram showing the detection device. [Figure 4] FIG. 4 is a circuit diagram showing a plurality of partial detection regions of the detection device according to the embodiment. [Figure 5A] FIG. 5A is a cross-sectional view showing a schematic cross-sectional configuration of a sensor unit. [Figure 5B] FIG. 5B is a cross-sectional view showing a schematic cross-sectional configuration of a sensor unit of a detection device according to a first modified example. [Figure 6] FIG. 6 is a timing waveform diagram showing an example of the operation of the detection device. [Figure 7] FIG. 7 is a timing waveform diagram showing an example of operation during the reset period in FIG. [Figure 8] FIG. 8 is a timing waveform diagram showing an example of operation during the readout period in FIG. [Figure 9] FIG. 9 is a timing waveform diagram showing an example of operation during a driving period of one gate line included in the row readout period VR in FIG. [Figure 10]FIG. 10 is an explanatory diagram for explaining the relationship between the driving of the sensor unit of the detection device and the lighting operation of the light source. [Figure 11] FIG. 11 is a plan view schematically showing the relationship between the sensor unit, the first light source, and the second light source of the detection device according to the embodiment. [Figure 12] FIG. 12 is a side view of the detection device shown in FIG. 11 as seen from a first direction. [Figure 13] FIG. 13 is an explanatory diagram for explaining an example of the operation of the detection device according to the embodiment. [Figure 14] FIG. 14 is a timing waveform diagram illustrating an example of the operation of the detection device according to the embodiment. [Figure 15] FIG. 15 is a schematic diagram showing the positional relationship between the detection region of the sensor unit and the object to be detected. [Figure 16A] FIG. 16A is a diagram showing the waveform of a pulse wave acquired based on a detection signal detected in partial detection area A shown in FIG. [Figure 16B] FIG. 16B is a diagram showing the waveform of a pulse wave acquired based on a detection signal detected in partial detection region B shown in FIG. [Figure 16C] FIG. 16C is a diagram showing the waveform of a pulse wave acquired based on a detection signal detected in partial detection region C shown in FIG. [Figure 17] FIG. 17 is a diagram showing an example of a detection signal waveform. [Figure 18] FIG. 18 is a diagram showing an example of SpO2 values. [Figure 19] FIG. 19 is a diagram illustrating a first example of a configuration for initially setting the light intensity of a light source. [Figure 20] FIG. 20 is a diagram showing an example of the arrangement of light sources relative to the detection area of ​​the sensor unit. [Figure 21] FIG. 21 is a diagram showing an example of changes in the measured light amount. [Figure 22] FIG. 22 is a flowchart showing an example of a process flow for setting the initial value of the light amount. [Figure 23] FIG. 23 is a diagram illustrating a second configuration example for initially setting the light intensity of the light source. [Figure 24] FIG. 24 is a diagram for explaining the initial setting in the configuration shown in FIG. [Figure 25] FIG. 25 is a diagram for explaining the initial setting in the configuration shown in FIG. [Figure 26] FIG. 26 is a diagram for explaining the initial setting in the configuration shown in FIG. [Figure 27] FIG. 27 is a diagram for explaining the initial setting in the configuration shown in FIG. [Figure 28] FIG. 28 is a flowchart showing an example of processing in the second configuration of FIG. [Figure 29A] FIG. 29A is a diagram showing a state in which the amount of IR light reaches a target value. [Figure 29B] FIG. 29B is a diagram showing a state in which the amount of red light reaches the target value. [Figure 29C] FIG. 29C is a diagram showing a state in which the amount of red light reaches the target value. [Figure 30] FIG. 30 is a flowchart showing an example of the IR data acquisition process in FIG. [Figure 31] FIG. 31 is a flowchart showing an example of the Red data acquisition process in FIG. [Figure 32] FIG. 32 is a flowchart showing an example of a process flow for detecting a peak coordinate position. [Figure 33] FIG. 33 is a diagram showing detection values ​​for F frames in each partial detection area within the detection area temporarily stored in the storage unit. [Figure 34A] FIG. 34A is a diagram showing a specific example of time domain data in each partial detection region. [Figure 34B] FIG. 34B is a diagram showing a specific example of time domain data in each partial detection region. [Figure 35A] FIG. 35A is a diagram showing a specific example of frequency domain data in each partial detection region. [Figure 35B] FIG. 35B is a diagram showing a specific example of frequency domain data in each partial detection region. [Figure 36]FIG. 36 is a flowchart showing an example of a processing flow for setting a biometric data acquisition region in the detection device. [Figure 37] FIG. 37 is a diagram showing a modified example of the arrangement of light sources. DETAILED DESCRIPTION OF THE INVENTION

[0008] Modes (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by a person skilled in the art and those that are substantially identical. Furthermore, the components described below can be combined as appropriate. Furthermore, the disclosure is merely an example, and appropriate modifications that a person skilled in the art can easily conceive while maintaining the gist of the invention are naturally included within the scope of the present invention. Furthermore, for clarity of explanation, the drawings may show the width, thickness, shape, etc. of each part schematically compared to the actual embodiment. However, these are merely examples and are not intended to limit the interpretation of the present invention. Furthermore, in this specification and each figure, elements similar to those described above with reference to the previous figures may be designated by the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0009] FIG. 1 is a plan view showing a detection device according to an embodiment. As shown in FIG. 1, the detection device 1 includes a sensor substrate 21, a sensor unit 10, a gate line driving circuit 15, a signal line selection circuit 16, a detection circuit 48, a control circuit 122, a power supply circuit 123, a first light source 61, and a second light source 62. While FIG. 1 illustrates an example in which a first light source substrate 51 is provided with a plurality of first light sources 61 and a second light source substrate 52 is provided with a plurality of second light sources 62, the arrangement of the first light sources 61 and the second light sources 62 shown in FIG. 1 is merely an example and can be modified as appropriate. For example, a plurality of first light sources 61 and a plurality of second light sources 62 may be arranged on each of the first light source substrate 51 and the second light source substrate 52. In this case, a group including a plurality of first light sources 61 and a group including a plurality of second light sources 62 may be arranged side by side in the second direction Dy, or the first light sources 61 and the second light sources 62 may be arranged alternately in the second direction Dy. Furthermore, the number of light source substrates on which the first light source 61 and the second light source 62 are provided may be one or three or more. Specific examples of the arrangement of the first light source 61 and the second light source 62 will be described later.

[0010] The detection device 1 is electrically connected to a host 200. The host 200 is, for example, a higher-level control device of an apparatus (not shown) to which the detection device 1 is applied. The host 200 performs a predetermined process for acquiring biological information based on data output from the detection device 1.

[0011] A control board 121 is electrically connected to the sensor substrate 21 via a flexible printed circuit board 71. The flexible printed circuit board 71 is provided with a detection circuit 48. The control board 121 is provided with a control circuit 122, a power supply circuit 123, and an output circuit 126.

[0012] The control circuit 122 is, for example, a control integrated circuit (IC) that outputs a logic control signal, and may be, for example, a programmable logic device (PLD) such as a field programmable gate array (FPGA).

[0013] The control circuit 122 supplies control signals to the sensor unit 10, the gate line driving circuit 15, and the signal line selection circuit 16 to control the detection operation of the sensor unit 10. The control circuit 122 also supplies control signals to the first light source 61 and the second light source 62 to control whether the first light source 61 and the second light source 62 are turned on or off.

[0014] The power supply circuit 123 supplies voltage signals such as a sensor power supply potential VDDSNS (see FIG. 4) to the sensor unit 10, the gate line drive circuit 15, and the signal line selection circuit 16. The power supply circuit 123 also supplies a power supply voltage to the first light source 61 and the second light source 62.

[0015] The output circuit 126 is, for example, a USB controller IC, and controls communication between the control circuit 122 and the host 200 .

[0016] The sensor substrate 21 has a detection area AA and a peripheral area GA. The detection area AA is an area where a plurality of optical sensors PD (see FIG. 4) of the sensor unit 10 are provided. The peripheral area GA is an area between the outer periphery of the detection area AA and the end of the sensor substrate 21, where no optical sensors PD are provided.

[0017] The gate line driving circuit 15 and the signal line selection circuit 16 are provided in the peripheral area GA. Specifically, the gate line driving circuit 15 is provided in a region of the peripheral area GA extending along the second direction Dy. The signal line selection circuit 16 is provided in a region of the peripheral area GA extending along the first direction Dx, and is provided between the sensor unit 10 and the detection circuit 48.

[0018] The first direction Dx is a direction in a plane parallel to the sensor substrate 21. The second direction Dy is a direction in a plane parallel to the sensor substrate 21 and is a direction perpendicular to the first direction Dx. The second direction Dy may intersect with the first direction Dx without being perpendicular to it. The third direction Dz is a direction perpendicular to the first direction Dx and the second direction Dy and is a normal direction to the sensor substrate 21.

[0019] The multiple first light sources 61 are provided on the first light source substrate 51 and arranged along the second direction Dy. The multiple second light sources 62 are provided on the second light source substrate 52 and arranged along the second direction Dy. The first light source substrate 51 and the second light source substrate 52 are electrically connected to the control circuit 122 and the power supply circuit 123 via terminal portions 124 and 125 provided on the control board 121, respectively.

[0020] The plurality of first light sources 61 and the plurality of second light sources 62 may be, for example, inorganic light emitting diodes (LEDs) or organic light emitting diodes (OLEDs). The plurality of first light sources 61 and the plurality of second light sources 62 emit first light and second light of different wavelengths, respectively.

[0021] The first light emitted from the first light source 61 is reflected by the surface of the object to be detected, such as the subject's finger or wrist, and enters the sensor unit 10. This allows the sensor unit 10 to detect the shape of the projections and recesses on the surface of the finger Fg or the like, thereby detecting a fingerprint. The second light emitted from the second light source 62 is reflected by the inside of the finger Fg or the like, or passes through the finger Fg or the like, and enters the sensor unit 10. This allows the sensor unit 10 to detect information about the inside of the subject's finger, wrist, or the like. The information about the body of the subject is, for example, the subject's pulse wave, pulse rate, blood vessel image, etc. That is, the detection device 1 may be configured as a fingerprint detection device that detects fingerprints, or a vein detection device that detects blood vessel patterns such as veins.

[0022] The first light may have a wavelength of 520 nm or more and 600 nm or less, for example, approximately 500 nm, and the second light may have a wavelength of 780 nm or more and 950 nm or less, for example, approximately 850 nm. In this case, the first light is blue or green visible light (blue light or green light), and the second light is infrared light. The sensor unit 10 can detect a fingerprint based on the first light emitted from the first light source 61. The second light emitted from the second light source 62 is reflected or transmitted / absorbed inside the object to be detected and then enters the sensor unit 10. This allows the sensor unit 10 to detect biometric data such as a pulse wave and a blood vessel image (blood vessel pattern) as information about the internal living body of the subject's finger, wrist, etc.

[0023] Alternatively, the first light may have a wavelength of 600 nm or more and 700 nm or less, for example, approximately 660 nm, and the second light may have a wavelength of 780 nm or more and 950 nm or less, for example, approximately 850 nm. In this case, based on the first light emitted from the first light source 61 and the second light emitted from the second light source 62, the sensor unit 10 can detect information about the living body, such as pulse waves, pulse rates, and blood vessel images, as well as blood oxygen levels. In this way, the detection device 1 has the first light source 61 and multiple second light sources 62, and can detect various pieces of information about the living body by performing detection based on the first light and detection based on the second light.

[0024] 2 is a block diagram showing an example of the configuration of the detection device according to the embodiment. As shown in FIG. 2, the detection device 1 further includes a detection control unit 11 and a detection unit 40.

[0025] The sensor unit 10 has a plurality of optical sensors PD. The optical sensors PD of the sensor unit 10 are organic photodiodes (OPDs), and output an electrical signal corresponding to irradiated light as a detection signal Vdet to the signal line selection circuit 16. The sensor unit 10 also performs detection in accordance with a gate drive signal Vgcl supplied from the gate line drive circuit 15.

[0026] The detection control unit 11 is a circuit that supplies control signals to the gate line driving circuit 15, the signal line selection circuit 16, and the detection unit 40, respectively, 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 15. The detection control unit 11 also supplies various control signals, such as a selection signal ASW, to the signal line selection circuit 16. The detection control unit 11 also supplies various control signals to the first light source 61 and the second light source 62, and controls the lighting and non-lighting of each.

[0027] The gate line driving circuit 15 is a circuit that drives multiple gate lines GCL (see FIG. 3) based on various control signals. The gate line driving circuit 15 sequentially or simultaneously selects the multiple gate lines GCL and supplies a gate driving signal Vgcl to the selected gate lines GCL. In this way, the gate line driving circuit 15 selects multiple photosensors PD connected to the gate lines GCL.

[0028] The signal line selection circuit 16 is a switch circuit that sequentially or simultaneously selects a plurality of signal lines SGL (see FIG. 3). The signal line selection circuit 16 is, for example, a multiplexer. The signal line selection circuit 16 electrically connects the selected signal line SGL 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 16 outputs the detection signal Vdet of the photosensor PD to the detection unit 40.

[0029] The detection unit 40 includes a detection circuit 48, a signal processing unit 44, a storage unit 46, and a detection timing control unit 47. The detection timing control unit 47 controls the detection circuit 48 and the signal processing unit 44 based on a control signal supplied from the detection control unit 11 so that they operate in synchronization with each other.

[0030] The detection circuit 48 generates a detection value of each optical sensor PD based on the detection signal of each optical sensor PD output from the sensor unit 10. The detection circuit 48 is, for example, an analog front end (AFE).

[0031] The detection circuit 48 is a signal processing circuit that has at least the functions of a detection signal amplifier 42 and an 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.

[0032] In the present disclosure, the signal processing unit 44 and the storage unit 46 are included in the control circuit 122 .

[0033] The signal processing unit 44 acquires biological data for generating information about the living body based on the detection values ​​of each optical sensor PD output from the detection circuit 48. In the present disclosure, the information about the living body includes a pulse wave acquired using infrared light or red light.

[0034] The storage unit 46 temporarily stores signals processed by the signal processing unit 44. In the present disclosure, the storage unit 46 stores various setting information and a biometric data acquisition area set in a biometric data acquisition area setting process flow described below when the signal processing unit 44 acquires biometric data. The storage unit 46 may include, for example, a RAM (Random Access Memory), a ROM (Read Only Memory), an EEPROM (Electrically Erasable Programmable Read Only Memory), etc. The storage unit 46 may also be a register circuit, etc.

[0035] Next, an example of the circuit configuration of the detection device 1 will be described. Fig. 3 is a circuit diagram showing the detection device. As shown in Fig. 3, the sensor unit 10 has a plurality of partial detection areas PAA arranged in a matrix. Each of the plurality of partial detection areas PAA is provided with an optical sensor PD.

[0036] The gate lines GCL extend in a first direction Dx and are connected to a plurality of partial detection areas PAA arranged in the first direction Dx. Furthermore, a plurality of gate lines GCL(1), GCL(2), ..., GCL(8) are arranged in a second direction Dy and are each connected to a gate line driving circuit 15. In the following description, when it is not necessary to distinguish between the plurality of gate lines GCL(1), GCL(2), ..., GCL(8), they will simply be referred to as gate lines GCL. Furthermore, for ease of understanding, eight gate lines GCL are shown in FIG. 3, but this is merely an example, and M gate lines GCL (M is a natural number, for example, M=256) may be arranged.

[0037] The signal line SGL extends in the second direction Dy and is connected to the photosensors PD in the partial detection areas PAA arranged in the second direction Dy. The signal lines SGL(1), SGL(2), ..., SGL(12) are arranged in the first direction Dx and are each connected to the signal line selection circuit 16 and the reset circuit 17. In the following description, when it is not necessary to distinguish between the signal lines SGL(1), SGL(2), ..., SGL(12), they will be simply referred to as signal lines SGL.

[0038] For ease of understanding, 12 signal lines SGL are shown, but this is merely an example, and N signal lines SGL (N is a natural number, for example, N=252) may be arranged. In addition, in Fig. 3, the sensor unit 10 is provided between the signal line selection circuit 16 and the reset circuit 17. However, this is not limiting, and the signal line selection circuit 16 and the reset circuit 17 may be connected to ends of the signal lines SGL in the same direction.

[0039] The gate line driving circuit 15 receives various control signals, such as a start signal STV, a clock signal CK, and a reset signal RST1, from the control circuit 122 (see FIG. 1). Based on the various control signals, the gate line driving circuit 15 sequentially selects multiple gate lines GCL(1), GCL(2), ..., GCL(8) in a time-division manner. The gate line driving circuit 15 supplies a gate driving signal Vgcl to the selected gate line GCL. As a result, the gate driving signal Vgcl is supplied to multiple first switching elements Tr connected to the gate line GCL, and multiple partial detection areas PAA arranged in the first direction Dx are selected as detection targets.

[0040] The gate line driving circuit 15 may perform different driving for each detection mode of a fingerprint and a plurality of different pieces of biometric information (pulse wave, pulse, blood vessel image, blood oxygen concentration, etc., hereinafter simply referred to as "biometric information"). For example, the gate line driving circuit 15 may drive a plurality of gate lines GCL in a bundle.

[0041] Specifically, the gate line driving circuit 15 simultaneously selects a predetermined number of gate lines GCL from among the gate lines GCL(1), GCL(2), ..., GCL(8) based on a control signal. For example, the gate line driving circuit 15 simultaneously selects six gate lines GCL(1) to GCL(6) and supplies the gate driving signal Vgcl to them. The gate line driving circuit 15 supplies the gate driving signal Vgcl to a plurality of first switching elements Tr via the six selected gate lines GCL. As a result, block units PAG1 and PAG2, each including a plurality of partial detection areas PAA arranged in the first direction Dx and the second direction Dy, are selected as detection targets. The gate line driving circuit 15 drives the predetermined number of gate lines GCL in a bundle and sequentially supplies the gate driving signal Vgcl to each of the predetermined number of gate lines GCL.

[0042] The signal line selection circuit 16 has a plurality of selection signal lines Lsel, a plurality of output signal lines Lout, and a third switching element TrS. The plurality of third switching elements TrS are provided corresponding to the plurality of signal lines SGL, respectively. The six signal lines SGL(1), SGL(2), ..., SGL(6) are connected to a common output signal line Lout1. The six signal lines SGL(7), SGL(8), ..., SGL(12) are connected to a common output signal line Lout2. The output signal lines Lout1 and Lout2 are each connected to a detection circuit 48.

[0043] Here, the signal lines SGL(1), SGL(2), ..., SGL(6) are defined as a first signal line block, and the signal lines SGL(7), SGL(8), ..., SGL(12) are defined as a second signal line block. The multiple selection signal lines Lsel are connected to the gates of the third switching elements TrS included in one signal line block. Furthermore, one selection signal line Lsel is connected to the gates of the third switching elements TrS of multiple signal line blocks.

[0044] Specifically, the selection signal lines Lsel1, Lsel2, ..., Lsel6 are connected to the third switching elements TrS corresponding to the signal lines SGL(1), SGL(2), ..., SGL(6), respectively. The selection signal line Lsel1 is connected to the third switching element TrS corresponding to the signal line SGL(1) and the third switching element TrS corresponding to the signal line SGL(7). The selection signal line Lsel2 is connected to the third switching element TrS corresponding to the signal line SGL(2) and the third switching element TrS corresponding to the signal line SGL(8).

[0045] The control circuit 122 (see FIG. 1) sequentially supplies the selection signal ASW to the selection signal line Lsel. As a result, the signal line selection circuit 16 sequentially selects the signal lines SGL in one signal line block in a time-division manner through the operation of the third switching element TrS. The signal line selection circuit 16 also selects one signal line SGL from each of the multiple signal line blocks. With this configuration, the detection device 1 can reduce the number of ICs (Integrated Circuits) including the detection circuit 48 or the number of IC terminals.

[0046] The signal line selection circuit 16 may bundle multiple signal lines SGL and connect them to the detection circuit 48. Specifically, the control circuit 122 (see FIG. 1) simultaneously supplies selection signals ASW to the selection signal lines Lsel. The signal line selection circuit 16 selects multiple signal lines SGL (e.g., six signal lines SGL) in one signal line block by operation of the third switching element TrS and connects the multiple signal lines SGL to the detection circuit 48. As a result, signals detected in the block units PAG1 and PAG2 are output to the detection circuit 48. In this case, signals from multiple partial detection areas PAA (photo sensors PD) included in the block units PAG1 and PAG2 are integrated and output to the detection circuit 48.

[0047] By performing detection for each block unit PAG1, PAG2 through the operation of the gate line driving circuit 15 and the signal line selection circuit 16, the strength of the detection signal Vdet obtained in one detection is improved, thereby improving the sensor sensitivity.

[0048] In the present disclosure, the detection device 1 can change the number of partial detection areas PAA (optical sensors PD) included in the block units PAG1 and PAG2, thereby enabling the resolution per inch (ppi (pixels per inch) value, hereinafter referred to as "resolution") to be set according to the information to be acquired.

[0049] For example, the number of partial detection areas PAA (optical sensors PD) included in the block units PAG1 and PAG2 is relatively reduced. This increases the detection time and results in a low frame rate (e.g., 20 fps or less), but enables high-resolution detection (e.g., 300 ppi or more). Hereinafter, the mode that performs low frame rate and high-resolution detection will be referred to as the "first mode." By selecting the first mode that performs low frame rate and high-resolution detection, for example, it is possible to acquire a fingerprint on the surface of a finger with high resolution.

[0050] Also, for example, the number of partial detection areas PAA (optical sensors PD) included in the block units PAG1 and PAG2 is relatively increased. This results in low resolution (for example, 50 ppi or less), but allows detection to be performed at a high frame rate (for example, 100 fps or more) that allows detection to be performed repeatedly within a short period of time within one frame. Hereinafter, the mode that performs detection at a high frame rate and low resolution is referred to as the "second mode." By selecting the second mode that performs detection at a high frame rate and low resolution, for example, it is possible to accurately detect changes in the pulse wave over time. Furthermore, in this second mode, by using pulse waves acquired at a higher frame rate (for example, 1000 fps or more), it becomes possible to calculate pulse wave velocity, blood pressure, etc.

[0051] Furthermore, for example, when acquiring a blood vessel image (vein pattern), the number of partial detection areas PAA (optical sensors PD) included in the block units PAG1 and PAG2 is set to an intermediate value between the first mode and the second mode. This enables detection to be performed at a medium frame rate (e.g., greater than 20 fps and less than 100 fps) that is higher than the first mode but lower than the second mode, and at a medium resolution (e.g., greater than 50 ppi and less than 300 ppi) that is lower than the first mode but higher than the second mode. Hereinafter, the mode that performs detection at a medium frame rate and medium resolution will be referred to as the "third mode." This third mode, which performs detection at a medium frame rate and medium resolution, is suitable for acquiring a blood vessel pattern such as veins, for example.

[0052] 3, the reset circuit 17 includes a reference signal line Lvr, a reset signal line Lrst, and a fourth switching element TrR. The fourth switching element TrR is provided corresponding to the plurality of signal lines SGL. The reference signal line Lvr is connected to one of the sources or drains of the plurality of fourth switching elements TrR. The reset signal line Lrst is connected to the gates of the plurality of fourth switching elements TrR.

[0053] The control circuit 122 supplies a reset signal RST2 to the reset signal line Lrst. This turns on the multiple fourth switching elements TrR, and the multiple signal lines SGL are electrically connected to the reference signal line Lvr. The power supply circuit 123 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. 4) included in the multiple partial detection areas PAA.

[0054] FIG. 4 is a circuit diagram showing multiple partial detection areas of the detection device according to the embodiment. FIG. 4 also shows the circuit configuration of a detection circuit 48. As shown in FIG. 4, the partial detection area PAA includes a photosensor PD, a capacitive element Ca, and a first switching element Tr1. The capacitive element Ca is a capacitance (sensor capacitance) formed in the photosensor PD and is equivalently connected in parallel with the photosensor PD. Furthermore, the signal line capacitance Cc is a parasitic capacitance formed in the signal line SGL and is equivalently formed between the signal line SGL and the anode of the photosensor PD and one end of the capacitive element Ca.

[0055] 4 shows two gate lines GCL(m) and GCL(m+1) aligned in the second direction Dy among the multiple gate lines GCL. Also, two signal lines SGL(n) and SGL(n+1) aligned in the first direction Dx among the multiple signal lines SGL. The partial detection area PAA is an area surrounded by the gate lines GCL and the signal lines SGL.

[0056] The first switching element Tr is provided corresponding to the optical sensor PD. The first switching element Tr is configured by a thin film transistor, and in this example, is configured by an n-channel MOS (Metal Oxide Semiconductor) TFT (Thin Film Transistor).

[0057] The gates of the first switching elements Tr belonging to the partial detection areas PAA aligned in the first direction Dx are connected to the gate line GCL, the sources of the first switching elements Tr belonging to the partial detection areas PAA aligned in the second direction Dy are connected to the signal line SGL, and the drains of the first switching elements Tr are connected to the cathodes of the photosensors PD and the capacitive elements Ca.

[0058] A sensor power supply signal VDDSNS is supplied to the anode of the optical sensor PD from the power supply circuit 123. In addition, a reference signal COM, which becomes the initial potential of the signal line SGL and the capacitive element Ca, is supplied from the power supply circuit 123 to the signal line SGL and the capacitive element Ca.

[0059] When light is irradiated onto the partial detection area PAA, a current corresponding to the amount of light flows through the photosensor PD, causing charge to accumulate in the capacitance element Ca. When the first switching element Tr is turned on, a current corresponding to the charge accumulated in the capacitance element Ca flows through the signal line SGL. The signal line SGL is connected to the detection circuit 48 via the third switching element TrS of the signal line selection circuit 16. This allows the detection device 1 to detect a signal corresponding to the amount of light irradiated onto the photosensor PD for each partial detection area PAA or for each block unit PAG1 or PAG2. The initial setting of the light intensity of the first light source 61 and the second light source 62 will be described later.

[0060] In the detection circuit 48, the switch SSW is turned on during the readout period Pdet (see FIG. 6), and the detection circuit 48 is connected to the signal line SGL. The detection signal amplifier 42 of the detection circuit 48 converts fluctuations in current supplied from the signal line SGL into fluctuations in voltage and amplifies the voltage. 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 SGL is connected to the inverting input terminal (-). In this embodiment, a signal identical to the reference signal COM is input as the reference potential (Vref) voltage. The detection signal amplifier 42 also has a capacitance element Cb and a reset switch RSW. In the reset period Prst (see FIG. 6), the reset switch RSW is turned on, and the charge of the capacitance element Cb is reset.

[0061] Next, the configuration of the optical sensor PD will be described. FIG. 5A is a cross-sectional view showing a schematic cross-sectional configuration of the sensor unit. As shown in FIG. 5A, the sensor unit 10 includes a sensor substrate 21, a TFT layer 22, an insulating layer 23, an optical sensor PD, and insulating layers 24a, 24b, 24c, and 25. The sensor substrate 21 is an insulating substrate made of, for example, glass or a resin material. The sensor substrate 21 is not limited to a flat plate shape and may have a curved surface. In this case, the sensor substrate 21 may be a film-like resin. The sensor substrate 21 has a first surface and a second surface opposite the first surface. The TFT layer 22, the insulating layer 23, the optical sensor PD, and the insulating layers 24 and 25 are stacked in this order on the first surface.

[0062] The TFT layer 22 is provided with circuits such as the gate line driving circuit 15 and signal line selection circuit 16 described above. The TFT layer 22 is also provided with TFTs (Thin Film Transistors) such as the first switching element Tr, and various wirings such as gate lines GCL and signal lines SGL. The sensor substrate 21 and the TFT layer 22 are a driving circuit board that drives sensors for each predetermined detection area, and are also called a backplane or array substrate.

[0063] The insulating layer 23 is an organic insulating layer and is provided on the TFT layer 22. The insulating layer 23 is a planarizing layer that flattens unevenness formed by the first switching element Tr formed in the TFT layer 22 and various conductive layers.

[0064] The photosensor PD is provided on the insulating layer 23. The photosensor PD has a lower electrode 35, a semiconductor layer 31, and an upper electrode 34, which are laminated in this order.

[0065] The lower electrode 35 is provided on the insulating layer 23 and is electrically connected to the first switching element Tr of the TFT layer 22 through a contact hole H1. The lower electrode 35 is the cathode of the photosensor PD and is an electrode for reading out the detection signal Vdet. The lower electrode 35 is made of a metal material such as molybdenum (Mo) or aluminum (Al). Alternatively, the lower electrode 35 may be a laminated film in which a plurality of these metal materials are laminated. The lower electrode 35 may also be made of a light-transmitting conductive material such as ITO (Indium Tin Oxide).

[0066] The semiconductor layer 31 is made of amorphous silicon (a-Si). The semiconductor layer 31 includes an i-type semiconductor layer 32a, a p-type semiconductor layer 32b, and an n-type semiconductor layer 32c. The i-type semiconductor layer 32a, the p-type semiconductor layer 32b, and the n-type semiconductor layer 32c are a specific example of a photoelectric conversion element. In FIG. 5A, the n-type semiconductor layer 32c, the i-type semiconductor layer 32a, and the p-type semiconductor layer 32b are stacked in this order in the direction perpendicular to the surface of the sensor substrate 21. However, the opposite configuration, that is, the p-type semiconductor layer 32b, the i-type semiconductor layer 32a, and the n-type semiconductor layer 32c may also be used. The semiconductor layer 31 may also be a photoelectric conversion element made of an organic semiconductor.

[0067] The n-type semiconductor layer 32c is formed by doping impurities into a-Si to form an n+ region. The p-type semiconductor layer 32b is formed by doping impurities into a-Si to form a p+ region. The i-type semiconductor layer 32a is, for example, an undoped intrinsic semiconductor and has lower conductivity than the p-type semiconductor layer 32b and the n-type semiconductor layer 32c.

[0068] The upper electrode 34 is an anode of the photosensor PD and is an electrode for supplying a power supply signal VDDSNS to the photoelectric conversion layer. The upper electrode 34 is a light-transmitting conductive layer such as ITO, and is provided in common to all the photosensors PD.

[0069] Insulating layers 24a and 24b are provided on insulating layer 23. Insulating layer 24a covers the periphery of upper electrode 34, and has an opening provided at a position overlapping with upper electrode 34. Connection wiring 36 is connected to upper electrode 34 at a portion of upper electrode 34 where insulating layer 24a is not provided. Insulating layer 24b is provided on insulating layer 24a, covering upper electrode 34 and connection wiring 36. Insulating layer 24c, which is a planarizing layer, is provided on insulating layer 24b. Insulating layer 25 is provided on insulating layer 24c. However, insulating layer 25 is not necessary.

[0070] 5B is a cross-sectional view showing a schematic cross-sectional configuration of a sensor unit of a detection device according to a first modification. As shown in FIG. 5B, in a detection device 1A according to the first modification, an optical sensor PDA is provided on an insulating layer 23a. The insulating layer 23a is an inorganic insulating layer provided to cover the insulating layer 23, and is formed of, for example, silicon nitride (SiN). The optical sensor PDA has a photoelectric conversion layer 31A, a lower electrode 35 (cathode electrode), and an upper electrode 34 (anode electrode). The lower electrode 35, the photoelectric conversion layer 31A, and the upper electrode 34 are stacked in this order in a direction perpendicular to the first surface S1 of the sensor substrate 21.

[0071] The photoelectric conversion layer 31A changes its characteristics (for example, voltage-current characteristics and resistance value) depending on the light irradiated thereon. An organic material is used as the material for the photoelectric conversion layer 31A. Specifically, for example, low-molecular organic materials such as C60 (fullerene), PCBM (phenyl C61-butyric acid methyl ester), CuPc (copper phthalocyanine), F16CuPc (fluorinated copper phthalocyanine), rubrene (5,6,11,12-tetraphenyltetracene), and PDI (a perylene derivative) can be used as the photoelectric conversion layer 31A.

[0072] The photoelectric conversion layer 31A can be formed by a vapor deposition method (dry process) using these low-molecular-weight organic materials. In this case, the photoelectric conversion layer 31A may be, for example, a laminated film of CuPc and F16CuPc, or a laminated film of rubrene and C60. The photoelectric conversion layer 31A can also be formed by a coating method (wet process). In this case, the photoelectric conversion layer 31A is made of a material that combines the above-mentioned low-molecular-weight organic material with a high-molecular-weight organic material. Examples of high-molecular-weight organic materials that can be used include P3HT (poly(3-hexylthiophene)) and F8BT (F8-alt-benzothiadiazole). The photoelectric conversion layer 31A can be a film in which P3HT and PCBM are mixed, or a film in which F8BT and PDI are mixed.

[0073] The lower electrode 35 and the upper electrode 34 face each other with the photoelectric conversion layer 31A interposed therebetween. The upper electrode 34 is made of a light-transmitting conductive material such as ITO (Indium Tin Oxide). The lower electrode 35 is made of a metal material such as silver (Ag) or aluminum (Al). Alternatively, the lower electrode 35 may be made of an alloy material containing at least one of these metal materials.

[0074] By controlling the film thickness of the lower electrode 35, the lower electrode 35 can be formed as a semi-transparent electrode having light transmittance. For example, by forming the lower electrode 35 from a 10 nm-thick Ag thin film, the lower electrode 35 has a light transmittance of about 60%. In this case, the optical sensor PDA can detect light irradiated from both sides of the sensor substrate 21, for example, light L1 irradiated from the first surface S1 side and light irradiated from the second surface S2 side.

[0075] 5B, an insulating layer 24 may be provided to cover the upper electrode 34. The insulating layer is a passivation film, and is provided to protect the photosensor PDA.

[0076] 5B, a first switching element Tr electrically connected to the photosensor PDA is provided in the TFT layer 22. The first switching element Tr has a semiconductor layer 81, a source electrode 82, a drain electrode 83, and gate electrodes 84 and 85. The lower electrode 35 of the photosensor PDA is electrically connected to the drain electrode 83 of the first switching element Tr through a contact hole H11 provided in the insulating layers 23 and 23a.

[0077] The first switching element Tr has a so-called dual gate structure in which gate electrodes 84, 85 are provided on both the upper and lower sides of the semiconductor layer 81. However, the first switching element Tr is not limited to this, and may have a top gate structure or a bottom gate structure.

[0078] 5B schematically illustrates the second switching element TrA and the terminal portion 72 provided in the peripheral area GA. The second switching element TrA is, for example, a switching element provided in the gate line driving circuit 15 (see FIG. 1). The second switching element TrA has a semiconductor layer 86, a source electrode 87, a drain electrode 88, and a gate electrode 89. The second switching element TrA has a so-called top-gate structure in which the gate electrode 89 is provided above the semiconductor layer 86. A light-shielding layer 90 is provided below the semiconductor layer 86, between the semiconductor layer 86 and the sensor substrate 21. However, the second switching element TrA is not limited to this, and may have a bottom-gate structure or a dual-gate structure.

[0079] The semiconductor layer 81 of the first switching element Tr and the semiconductor layer 86 of the second switching element TrA are provided in different layers. The semiconductor layer 81 of the first switching element Tr is made of, for example, an oxide semiconductor. The semiconductor layer 86 of the second switching element TrA is made of, for example, polysilicon.

[0080] Next, an example of the operation of the detection device 1 will be described. Fig. 6 is a timing waveform diagram showing an example of the operation of the detection device. Fig. 7 is a timing waveform diagram showing an example of the operation during the reset period in Fig. 6. Fig. 8 is a timing waveform diagram showing an example of the operation during the readout period in Fig. 6. Fig. 9 is a timing waveform diagram showing an example of the operation during the drive period of one gate line included in the row readout period VR in Fig. 6. Fig. 10 is an explanatory diagram for explaining the relationship between the drive of the sensor unit of the detection device and the lighting operation of the light source.

[0081] As shown in FIG. 6, the detection device 1 has a reset period Prst, an exposure period Pex, and a readout period Pdet. The power supply circuit 123 supplies a sensor power supply signal VDDSNS to the anode of the photosensor PD throughout the reset period Prst, the exposure period Pex, and the readout period Pdet. The sensor power supply signal VDDSNS applies a reverse bias between the anode and cathode of the photosensor PD. For example, a reference signal COM of substantially 0.75 V is applied to the cathode of the photosensor PD. Applying a sensor power supply signal VDDSNS of substantially -1.25 V to the anode reverse-biasssed at substantially 2.0 V between the anode and cathode. The control circuit 122 sets the reset signal RST2 to "H" and then supplies a start signal STV and a clock signal CK to the gate line driving circuit 15, starting the reset period Prst. During the reset period Prst, the control circuit 122 supplies the reference signal COM to the reset circuit 17 and turns on the fourth switching element TrR, which supplies a reset voltage using the reset signal RST2. As a result, the reference signal COM is supplied to each signal line SGL as a reset voltage. The reference signal COM is set to, for example, 0.75V.

[0082] During the reset period Prst, the gate line drive circuit 15 sequentially selects the gate lines GCL based on the start signal STV, the clock signal CK, and the reset signal RST1. The gate line drive circuit 15 sequentially supplies gate drive signals Vgcl {Vgcl(1) to Vgcl(M)} to the gate lines GCL. The gate drive signal Vgcl has a pulse waveform having a power supply voltage VDD, which is a high-level voltage, and a power supply voltage VSS, which is a low-level voltage. In FIG. 6, M (e.g., M=256) gate lines GCL are provided, and gate drive signals Vgcl(1), ..., Vgcl(M) are sequentially supplied to each gate line GCL, and the multiple first switching elements Tr are sequentially turned on row by row, and a reset voltage is supplied. For example, the voltage of 0.75V of the reference signal COM is supplied as the reset voltage.

[0083] Specifically, as shown in FIG. 7, the gate line drive circuit 15 supplies a gate drive signal Vgcl(1) of a high-level voltage (power supply voltage VDD) to the gate line GCL(1) during a period V(1). The control circuit 122 supplies one of the selection signals ASW1, ..., ASW6 (selection signal ASW1 in FIG. 7) to the signal line selection circuit 16 during the period when the gate drive signal Vgcl(1) is at the high-level voltage (power supply voltage VDD). As a result, the signal line SGL of the partial detection area PAA selected by the gate drive signal Vgcl(1) is connected to the detection circuit 48. As a result, the reset voltage (reference signal COM) is also supplied to the connection wiring between the third switching element TrS and the detection circuit 48.

[0084] Similarly, the gate line driving circuit 15 supplies high-level voltage gate driving signals Vgcl(2), ..., Vgcl(M-1), Vgcl(M) to the gate lines GCL(2), ..., GCL(M-1), GCL(M), respectively, during periods V(2), ..., V(M-1), V(M).

[0085] As a result, during the reset period Prst, the capacitance elements Ca in all partial detection areas PAA are sequentially electrically connected to the signal line SGL and the reference signal COM is supplied. As a result, the capacitance of the capacitance elements Ca is reset. Note that it is also possible to reset the capacitance of some of the capacitance elements Ca in the partial detection area PAA by partially selecting the gate lines and signal lines SGL.

[0086] Examples of exposure timing include a gate line non-selection exposure control method and a constant exposure control method. In the gate line non-selection exposure control method, gate drive signals {Vgcl(1) to (M)} are sequentially supplied to all gate lines GCL connected to the photosensors PD to be detected, and a reset voltage is supplied to all photosensors PD to be detected. After that, when all gate lines GCL connected to the photosensors PD to be detected are at a low voltage (the first switching element Tr is off), exposure begins and is performed during the exposure period Pex. After exposure ends, as described above, gate drive signals {Vgcl(1) to (M)} are sequentially supplied to the gate lines GCL connected to the photosensors PD to be detected, and readout is performed during the readout period Pdet. In the constant exposure control method, it is also possible to control exposure during the reset period Prst and the readout period Pdet (constant exposure control). In this case, the exposure period Pex(1) begins after the gate drive signal Vgcl(1) is supplied to the gate lines GCL during the reset period Prst. Here, the exposure period Pex{(1)...(M)} is the period during which the photosensor PD charges the capacitor Ca. During the reset period Prst, the charge stored in the capacitor Ca flows in the photosensor PD as a reverse current (from cathode to anode) due to light irradiation, reducing the potential difference across the capacitor Ca. The actual exposure periods Pex(1), ..., Pex(M) in the partial detection areas PAA corresponding to each gate line GCL have different start and end times. Each of the exposure periods Pex(1), ..., Pex(M) begins during the reset period Prst when the gate drive signal Vgcl changes from the high-level power supply voltage VDD to the low-level power supply voltage VSS. Each of the exposure periods Pex(1), ..., Pex(M) ends during the readout period Pdet when the gate drive signal Vgcl changes from the power supply voltage VSS to the power supply voltage VDD. The exposure periods Pex(1), . . . , Pex(M) have the same exposure time length.

[0087] During the exposure periods Pex{(1)...(M)}, a current flows in each partial detection area PAA in response to the light irradiated to the photosensor PD, and as a result, charge is accumulated in each capacitive element Ca.

[0088] Before the readout period Pdet starts, the control circuit 122 sets the reset signal RST2 to a low-level voltage. This stops the operation of the reset circuit 17. The reset signal may be set to a high-level voltage only during the reset period Prst. During the readout period Pdet, as in the reset period Prst, the gate line drive circuit 15 sequentially supplies gate drive signals Vgcl(1), ..., Vgcl(M) to the gate lines GCL.

[0089] 8, the gate line drive circuit 15 supplies a gate drive signal Vgcl(1) of a high-level voltage (power supply voltage VDD) to the gate line GCL(1) during a row readout period VR(1). The control circuit 122 sequentially supplies selection signals ASW1, ..., ASW6 to the signal line selection circuit 16 while the gate drive signal Vgcl(1) is at a high-level voltage (power supply voltage VDD). As a result, the signal lines SGL of the partial detection area PAA selected by the gate drive signal Vgcl(1) are sequentially or simultaneously connected to the detection circuit 48. As a result, the detection signal Vdet is supplied to the detection circuit 48 for each partial detection area PAA.

[0090] Similarly, the gate line driving circuit 15 supplies high-level voltage gate driving signals Vgcl(2), ..., Vgcl(M-1), and Vgcl(M) to the gate lines GCL(2), ..., GCL(M-1), and GCL(M) during the row readout periods VR(2), ..., VR(M-1), and VR(M), respectively. That is, the gate line driving circuit 15 supplies the gate driving signal Vgcl to the gate line GCL during each row readout period VR(1), VR(2), ..., VR(M-1), and VR(M). During each period in which each gate driving signal Vgcl is at a high-level voltage, the signal line selection circuit 16 sequentially selects the signal lines SGL based on the selection signal ASW. The signal line selection circuit 16 sequentially connects each signal line SGL to one detection circuit 48. This allows the detection device 1 to output the detection signals Vdet for all partial detection areas PAA to the detection circuit 48 during the readout period Pdet.

[0091] An example of operation during a row readout period VR, which is the supply period for one gate drive signal Vgcl(j) in Fig. 6, will be described below with reference to Fig. 9. In Fig. 6, the first gate drive signal Vgcl(1) is labeled with the row readout period VR, but the same applies to the other gate drive signals Vgcl(2), ..., Vgcl(M). j is a natural number from 1 to M.

[0092] As shown in FIGS. 9 and 4, the output (Vout) of the third switching element TrS is reset to a reference potential (Vref) voltage. The reference potential (Vref) voltage is a reset voltage, e.g., 0.75 V. Next, the gate drive signal Vgcl(j) goes high, turning on the first switching element Tr of the corresponding row, and the signal line SGL of each row goes to a voltage corresponding to the charge accumulated in the capacitance (capacitor element Ca) of the corresponding partial detection area PAA. After a period t1 has elapsed since the rising edge of the gate drive signal Vgcl(j), a period t2 occurs during which the selection signal ASW(k) goes high. When the selection signal ASW(k) goes high and the third switching element TrS turns on, the charge stored in the capacitance (capacitor element Ca) of the partial detection area PAA, which is connected to the detection circuit 48 via the third switching element TrS, causes the output (Vout) of the third switching element TrS (see FIG. 4) to change to a voltage corresponding to the charge accumulated in the capacitance (capacitor element Ca) of the corresponding partial detection area PAA (period t3). In the example of FIG. 9, this voltage drops from the reset voltage as shown in period t3. After that, when the switch SSW is turned on (period t4 when the SSW signal is at a high level), the charge accumulated in the capacitance (capacitor element Ca) of the partial detection area PAA is transferred to the capacitance (capacitor element Cb) of the detection signal amplifier 42 of the detection circuit 48, and the output voltage of the detection signal amplifier 42 becomes a voltage corresponding to the charge accumulated in the capacitance element Cb. At this time, the inverting input of the detection signal amplifier 42 becomes the imaginary short potential of the operational amplifier, returning to the reference potential (Vref). The output voltage of the detection signal amplifier 42 is read by the A / D converter 43. In the example of FIG. 9, the waveforms of the selection signals ASW(k), ASW(k+1), ... corresponding to the signal lines SGL of each column become high, sequentially turning on the third switching elements TrS. By performing similar operations sequentially, the charge accumulated in the capacitance (capacitor element Ca) of the partial detection area PAA connected to the gate line GCL is sequentially read out. 9 are, for example, any of ASW1 to ASW6 in FIG.

[0093] Specifically, when a period t4 occurs during which the switch SSW is turned on, charge transfers from the capacitance (capacitor Ca) of the partial detection area PAA to the capacitance (capacitor Cb) of the detection signal amplifier 42 of the detection circuit 48. At this time, the non-inverting input (+) of the detection signal amplifier 42 is biased to a reference potential (Vref) voltage (e.g., 0.75 V). Therefore, an imaginary short circuit between the inputs of the detection signal amplifier 42 causes the output (Vout) of the third switching element TrS to also become the reference potential (Vref). Furthermore, the voltage of the capacitor Cb becomes a voltage corresponding to the charge accumulated in the capacitance (capacitor Ca) of the partial detection area PAA where the third switching element TrS is turned on in response to the selection signal ASW(k). After the output (Vout) of the third switching element TrS becomes the reference potential (Vref) voltage due to the imaginary short circuit, the output of the detection signal amplifier 42 becomes a voltage corresponding to the capacitance of the capacitor Cb, and this output voltage is read by the A / D converter 43. The voltage of the capacitance element Cb is, for example, the voltage between two electrodes provided in a capacitor that constitutes the capacitance element Cb.

[0094] The period t1 is, for example, 20 μs, the period t2 is, for example, 60 μs, the period t3 is, for example, 44.7 μs, and the period t4 is, for example, 0.98 μs.

[0095] 10, during periods t(1), t(2), t(3), and t(4), the detection device 1 executes the reset period Prst, exposure period Pex{(1)...(M)}, and readout period Pdet described above. During the reset period Prst and readout period Pdet, the gate line driving circuit 15 sequentially scans the gate lines GCL(1) to GCL(M). In the following description, detection during each period t, that is, scanning the gate lines GCL(1) to GCL(M) during the reset period Prst and readout period Pdet and acquiring the detection signal Vdet from the signal line SGL of each column, is referred to as detection of one frame.

[0096] The control circuit 122 can control the lighting and non-lighting of the light sources depending on the detection target. Fig. 10 shows an example in which the first light source 61 is turned on during periods t(1) and t(3), and the second light source 62 is turned on during periods t(2) and t(4). That is, in the example shown in Fig. 10, the control circuit 122 alternately turns on and off the first light source 61 and the second light source 62 for each frame detection. However, the present invention is not limited to this. For example, the control circuit 122 may alternately turn on and off the first light source 61 and the second light source 62 every predetermined period, or may keep one of them continuously lit.

[0097] 6 to 10 show an example in which the gate line driving circuit 15 selects the gate lines GCL individually, but this is not limiting. The gate line driving circuit 15 may simultaneously select a predetermined number of gate lines GCL (two or more) and sequentially supply the gate driving signal Vgcl to each of the predetermined number of gate lines GCL. The signal line selection circuit 16 may also simultaneously connect a predetermined number of signal lines SGL (two or more) to one detection circuit 48. Furthermore, the gate line driving circuit 15 may scan a plurality of gate lines GCL by thinning them out.

[0098] 8, during the row readout period VR(1), while the gate drive signal Vgcl(1) is at a high-level voltage (power supply voltage VDD), the selection signals ASW1, ..., ASW6 are sequentially supplied to the signal line selection circuit 16. That is, even after the selection signal ASW1 becomes a low-level voltage at time t11, exposure continues during the exposure period Pex-1 until the gate drive signal Vgcl(1) becomes a low-level voltage at time t13. Charges corresponding to the exposure period Pex-1 are stored from the photosensor PD in the signal line SGL(1) corresponding to the selection signal ASW1.

[0099] Similarly, electric charges are stored in each signal line SGL during exposure periods Pex-1, ..., Pex-6 corresponding to each selection signal ASW1, ..., ASW6. For example, exposure period Pex-6 is the period from when selection signal ASW6 becomes a low-level voltage at time t12 until when gate drive signal Vgcl(1) becomes a low-level voltage at time t13, and exposure period Pex differs for each column.

[0100] Then, in the next row readout period VR(2), a signal obtained by adding together the charge accumulated during the exposure periods Pex-1(SGL(1))...Pex-6(SGL(6)) of the previous row readout period VR(1) to the detection signal Vdet of the second row is supplied to the detection circuit 48.

[0101] As described above, the detection device 1 is configured to include, for example, multiple types of light sources (first light source 61, second light source 62) that emit light with different wavelengths, making it possible to obtain fingerprints obtained by detecting light reflected from the surface of the subject's finger, and various types of biometric information obtained by detecting light reflected from or transmitted inside the subject's finger, wrist, etc.

[0102] Hereinafter, an example of acquiring a pulse wave, which is biological information for calculating oxygen saturation in the blood (hereinafter referred to as blood oxygen saturation (SpO2)), will be described as a specific example of biological information acquired by the detection device 1. Fig. 11 is a plan view schematically showing the relationship between the sensor unit, the first light source, and the second light source of the detection device according to the embodiment.

[0103] 11 , the detection device 1 has a filter 63. The filter 63 is arranged in the scanning direction SCAN, overlapping with the detection area AA from one end to the other end of the sensor unit 10. The filter 63 has a transmission band that transmits the first light emitted from the first light source 61 and the second light emitted from the second light source 62. In the configuration according to the first embodiment, the filter 63 is not necessarily required, and the configuration may not include the filter 63.

[0104] 11, the scanning direction SCAN is the direction in which the gate line driving circuit 15 scans the gate lines GCL. That is, one gate line GCL is provided extending in the first direction Dx in the detection area AA and connected to multiple partial detection areas PAA provided in the detection area AA. Furthermore, one signal line SGL is provided extending in the second direction Dy in the detection area AA and connected to multiple photosensors PD in the detection area AA.

[0105] The first light source substrate 51 and the second light source substrate 52 face each other in the first direction Dx with the detection area AA interposed therebetween in a plan view. A plurality of first light sources 61 and a plurality of second light sources 62 are provided on the surface of the first light source substrate 51 facing the second light source substrate 52. Furthermore, the plurality of first light sources 61 and a plurality of second light sources 62 are provided on the surface of the second light source substrate 52 facing the first light source substrate 51. The plurality of first light sources 61 and the plurality of second light sources 62 are aligned in the first direction Dx along the periphery of the detection area AA and are provided alternately in the second direction Dy on each of the first light source substrate 51 and the second light source substrate 52.

[0106] The first light source 61 emits a first light in a direction parallel to the first direction Dx. This causes the first light to be irradiated onto the detection area AA. The second light source 62 emits a second light in a direction parallel to the first direction Dx. This causes the second light to be irradiated onto the detection area AA.

[0107] Fig. 12 is a side view of the detection device shown in Fig. 11 as viewed from a first direction Dx. As shown in Fig. 12, a detection object such as a subject's finger Fg or wrist comes into contact with or is close to the sensor unit 10 via a filter 63. The first light source 61 and the second light source 62 are arranged above the sensor unit 10 and the filter 63, and are arranged to sandwich the detection object such as the subject's finger Fg or wrist in the first direction Dx.

[0108] Here, for example, the first light emitted from the first light source 61 is red visible light (red light) of 600 nm or more and 700 nm or less, specifically, approximately 660 nm, and the second light emitted from the second light source 62 is infrared light of 780 nm or more and 950 nm or less, specifically, approximately 850 nm. When acquiring a person's blood oxygen saturation (SpO2), a pulse wave acquired using the first light (red light) and a pulse wave acquired using the second light (infrared light) are used.

[0109] Since the amount of light absorbed by hemoglobin changes depending on the amount of oxygen absorbed by the hemoglobin, the optical sensor PD detects the amount of light obtained by subtracting the light absorbed by the blood (hemoglobin) from the irradiated first and second lights. Most of the oxygen in the blood is reversibly bound to the hemoglobin in red blood cells, with a small portion dissolved in the plasma. More specifically, the percentage of oxygen that is bound to the blood's overall capacity is called oxygen saturation (SpO2). Using the two wavelengths of the first and second lights, it is possible to calculate blood oxygen saturation from the amount of irradiated light minus the light absorbed by the blood (hemoglobin).

[0110] Oxygen saturation (SpO2) is determined by the ratio of hemoglobin in the blood when it is bound to oxygen (O2Hb: oxygenated hemoglobin) to when it is not bound to oxygen (HHb: reduced hemoglobin). The absorption characteristics of red light are HHb >> O2Hb, with HHb having significantly greater absorbance, whereas the absorption characteristics of infrared light are HHb ≒ O2Hb, with O2Hb having slightly greater absorbance.

[0111] The first light emitted from the first light source 61 travels in a direction parallel to the first direction Dx and is incident on the subject's finger Fg or wrist. The first light emitted from the first light source 61 penetrates into the living body and is reflected by the inside of the subject's finger Fg or wrist. The reflected light reflected by the inside of the subject's finger Fg or wrist travels in a third direction Dz, passes through the filter 63, and is incident on the detection area AA of the sensor unit 10.

[0112] The second light emitted from the second light source 62 travels in a direction parallel to the first direction Dx and is incident on the subject's finger Fg or wrist. The second light emitted from the second light source 62 penetrates into the living body and is reflected by the inside of the subject's finger Fg or wrist. The reflected light reflected by the inside of the subject's finger Fg or wrist travels in a third direction Dz, passes through the filter 63, and is incident on the detection area AA of the sensor unit 10.

[0113] The arrangement of the multiple first light sources 61 and the multiple second light sources 62 is not limited to the examples shown in Fig. 11 and Fig. 12. For example, the first light or the second light may be irradiated from above the object to be detected, such as the subject's finger Fg or wrist, shown in Fig. 12, specifically from the third direction Dz. Alternatively, the multiple first light sources 61 and the multiple second light sources 62 may be so-called direct light sources provided directly below the detection area AA.

[0114] 10, a reset period Prst, an exposure period Pex, and a readout period Pdet are provided for detecting one frame in each of periods t(1), t(2), t(3), and t(4). During the reset period Prst and the readout period Pdet, the gate line driving circuit 15 sequentially scans the gate lines GCL(1) to GCL(M).

[0115] 10, in detecting one frame in period t(1), the control circuit 122 (detection control unit 11) turns on the first light source 61 and turns off the second light source 62 during the exposure period Pex. In addition, in detecting one frame in period t(2), the control circuit 122 (detection control unit 11) turns off the first light source 61 and turns on the second light source 62 during the exposure period Pex. Similarly, in detecting one frame in period t(3), the first light source 61 is turned on and the second light source 62 is turned off during the exposure period Pex, and in detecting one frame in period t(4), the first light source 61 is turned off and the second light source 62 is turned on during the exposure period Pex.

[0116] In this way, the first light source 61 and the second light source 62 are controlled to be turned on or off in a time-division manner for each detection of one frame, whereby a first detection signal detected by the optical sensor PD due to the first light and a second detection signal detected by the optical sensor PD due to the second light are output to the detection circuit 48 in a time-division manner.

[0117] In addition, since the calculation of blood oxygen saturation (SpO2) uses the pulse wave acquired by the first light and the pulse wave acquired by the second light, it is desirable that the difference in detection timing between the first detection signal detected by the first light and the second detection signal detected by the second light is small. Below, an operation example that can reduce the difference in detection timing between the first detection signal detected by the first light and the second detection signal detected by the second light will be described with reference to Figures 13 and 14.

[0118] Fig. 13 is an explanatory diagram for explaining an example of operation of the detection device according to the embodiment. Fig. 14 is a timing waveform diagram showing an example of operation of the detection device according to the embodiment. In the example shown in Fig. 13, the reset periods Prst of the periods t(1), t(2), t(3), and t(4) are indicated by solid arrows, and the readout periods Pdet are indicated by dashed arrows.

[0119] 13, the reset period Prst of period t(1), which includes period T1 during which the first light source 61 is turned on, and the readout period Pdet of the previous frame are executed in parallel. The reset period Prst of period t(2), which includes period T2 during which the second light source 62 is turned on, and the readout period Pdet of the previous frame are executed in parallel. Similarly, the reset period Prst of period t(3), which includes period T3 during which the first light source 61 is turned on, and the readout period Pdet of the previous frame are executed in parallel. The reset period Prst of period t(4), which includes period T4 during which the second light source 62 is turned on, and the readout period Pdet of the previous frame are executed in parallel. Specifically, for example, immediately after reading out each row of the frame of period t(1), the row of the frame of period t(2) is reset and illuminated with light in period T2. Thereafter, immediately after reading out each row of the frame of period t(2), the row of the frame of period t(3) is reset and then irradiated with light in period T3. Thereafter, the same operation is repeated. This makes it possible to reduce the timing difference between detection by the first light emitted from the first light source 61 and detection by the first light emitted from the second light source 62 for each row.

[0120] In the operation example shown in Fig. 13, a gate drive signal Vgcl is supplied to the gate line GCL for each row, and multiple first switching elements Tr belonging to a specific row are turned on. Specifically, as shown in Fig. 14, at time t21, the gate line drive circuit 15 supplies a gate drive signal Vgcl(1) of a high-level voltage (power supply voltage VDD) to the gate line GCL(1). The row readout period VR(1) starts at time t21, when the gate drive signal Vgcl(1) becomes a high-level voltage.

[0121] Specifically, the control circuit 122 sequentially supplies selection signals ASW1, ..., ASW6 to the signal line selection circuit 16 while the gate drive signal Vgcl(1) is at a high-level voltage (power supply voltage VDD). The third switching elements TrS are sequentially switched to a connected state in response to the selection signals ASW1, ..., ASW6. That is, during a row-by-row readout period (row readout period VR(1)), the multiple first switching elements Tr of a predetermined row are in a connected state, and the signal line selection circuit 16 connects the multiple signal lines SGL to the detection circuit 48 in a predetermined order for each column. As a result, the detection signal Vdet is supplied to the detection circuit 48 for each partial detection area PAA.

[0122] 14, the selection signals ASW1, ..., ASW6 are supplied in a time-division manner in the order of periods T11, ..., T16. At time t22, the control circuit 122 sets the selection signal ASW6 to a low-level voltage, completing the readout of the last column. In other words, the row readout period VR(1) ends when the gate drive signal Vgcl(1) is at a high-level voltage and the selection signal ASW6 transitions to a low-level voltage.

[0123] After the readout period for a given row (row readout period VR(1)) is completed and before the readout period for the next row (row readout period VR(2)) for the given row begins, a reset potential (reference signal COM) is supplied to the photosensors PD and signal lines SGL belonging to the given row. Specifically, the control circuit 122 supplies a reset signal RST2 to the reset signal line Lrst at time t22. This turns on the fourth switching elements TrR, and the reference signal COM is supplied to the photosensors PD and signal lines SGL corresponding to the gate line GCL(1).

[0124] 14, the timing at which the reset signal RST2 becomes a high-level voltage and the timing at which the selection signal ASW6 becomes a low-level voltage coincide at time t22. However, this is not limiting, and the reset signal RST2 may be set to a high-level voltage after a predetermined period has elapsed since the selection signal ASW6 became a low-level voltage.

[0125] Then, at time t23, the gate line drive circuit 15 sets the gate drive signal Vgcl(1) to a low-level voltage. This causes the first switching elements Tr in a predetermined row to be in a disconnected state. At time t24, the control circuit 122 sets the reset signal RST2 to a low-level voltage. This ends the readout period Pdet and reset period Prst for the first row.

[0126] After that, at time t25, the gate line drive circuit 15 supplies a gate drive signal Vgcl(2) of a high-level voltage (power supply voltage VDD) to the gate line GCL(2) of the second row. Thereafter, as with the first row, a readout period Pdet and a reset period Prst for the second row are executed from time t26 to time t28. This operation is repeated until the final row (gate line GCL(256)) is scanned, thereby completing one frame of detection.

[0127] During periods T1, T2, T3, and T4 (see FIG. 13) when each light source is turned on, none of the gate lines GCL are selected (the gate drive signal Vgcl is at a low-level voltage). That is, the light source is turned off during the row readout period VR when the first switching element Tr of a specific row is in the connected state, and the light source is turned on during periods T1, T2, T3, and T4 when all the first switching elements Tr are in the disconnected state.

[0128] 13 and 14, as described above, the readout period Pdet and the reset period Prst in the detection of the two frames before and after are executed in parallel, which makes it possible to reduce the difference in detection timing between the first detection signal detected by the first light and the second detection signal detected by the second light.

[0129] 15 is a schematic diagram showing the positional relationship between the detection region of the sensor unit and the object to be detected, in which the object to be detected is a subject's finger Fg.

[0130] Fig. 16A is a diagram showing the waveform of a pulse wave acquired based on a detection signal detected in partial detection area A shown in Fig. 15. Fig. 16B is a diagram showing the waveform of a pulse wave acquired based on a detection signal detected in partial detection area B shown in Fig. 15. Fig. 16C is a diagram showing the waveform of a pulse wave acquired based on a detection signal detected in partial detection area C shown in Fig. 15. In Figs. 16A, 16B, and 16C, the horizontal axis represents time, and the vertical axis represents the data value of the pulse wave data.

[0131] 17 is a diagram showing an example of a detection signal waveform, in which the horizontal axis represents time and the vertical axis represents the data value of the detection signal Vdet after A / D conversion.

[0132] In the following description, the magnitude of the PP (Peak to Peak) value of the data values ​​in FIGS. 16A, 16B, 16C, and 17 will be referred to as "signal strength."

[0133] The strength of the signal detected in each partial detection area PAA within the detection area AA varies depending on the distribution of blood vessels under the skin of the subject's finger Fg. Specifically, for example, the signal strength of the pulse wave acquired based on the detection signal Vdet detected in partial detection area B shown in Fig. 15 (Fig. 16B) is relatively greater than the signal strength of the pulse wave acquired based on the detection signal Vdet detected in partial detection area A shown in Fig. 15 (Fig. 16A) and the signal strength of the pulse wave acquired based on the detection signal Vdet detected in partial detection area C shown in Fig. 15 (Fig. 16C).

[0134] Furthermore, the detection signal Vdet detected in each partial detection area PAA within the detection area AA contains noise components due to disturbances and body movements of the subject, as shown in FIG.

[0135] In the present disclosure, as a preprocessing for acquiring pulse wave data, partial detection areas PAA within the detection area AA are extracted, and the signal strength of the data acquired in each partial detection area PAA is relatively high. Then, data related to the living body (here, pulse wave data) is acquired based on the detection signal Vdet detected in the biological data acquisition area BAA including the extracted partial detection area PAA. This makes it possible to acquire highly accurate data related to the living body.

[0136] (SpO2 measurement) SpO2, which is biological information, can be obtained by measuring light passing through a living body such as a finger. For example, SpO2 can be measured using the following equation (1).

number

[0137] In the above formula (1), "a" and "b" are predetermined coefficients. In formula (1), R is defined by the following formula (2).

number

[0138] In the above formula (2), AC Red is the AC component of the measurement value of Red light, and DC Red is the DC component of the measurement value of Red light, and AC IR is the AC component of the measurement value of IR light, and DC IR is the DC component of the measurement value of IR light. The AC component is the component of the pulse wave that appears in the direct current.

[0139] More specifically, the value of SpO2 can be obtained as follows. That is, the value of SpO2 corresponding to the above value of R is measured in advance, and the value of SpO2 is obtained based on the curve of the measurement value. The curve of the measurement value is, for example, as shown in FIG. 18. FIG. 18 is a diagram showing an example of the value of SpO2. In FIG. 18, the horizontal axis is the calculated value of the above R, and the vertical axis is the value of SpO2. When Ir light is greater than Red light (Ir>Red), R becomes a value less than 1.0, and when Red light is greater than Ir light (Ir<Red), R becomes a value greater than 1.0.

[0140] As shown in FIG. 18, by calculating the value of the above R, the value of SpO2 corresponding to the value of R can be obtained. For example, by using the curve C1 in FIG. 18, when the value of R is 0.9, the value of SpO2 can be obtained as about 83%. Also, for example, by using the curve C2 in FIG. 18, when the value of R is 0.9, the value of SpO2 can be obtained as about 87%.

[0141] Also, by determining the above coefficients a and b so as to be an approximation formula of curve C1 or curve C2, the value of SpO2 can also be obtained using formula (1).

[0142] Since SpO2, which is biological information, is defined by formula (1) and formula (2), when the light amount is too small, the AC component cannot be detected and only the DC component remains, and high-precision data cannot be obtained. Also, since the ratio of the measurement value of IR light to the measurement value of Red light is used, if either is too large or too small, the correct value cannot be obtained. Therefore, it is necessary to perform appropriate initial settings before measurement.

[0143] If only one sensor is installed, the initial setting can be completed by adjusting the light intensity of the light source. For example, if the IR light received by the sensor is stronger than the red light, the amount of red light can be increased to make the amount of red light and the amount of IR light the same.

[0144] In contrast, when there are multiple sensors as shown in Figure 3, that is, when there are multiple (partial detection areas PAA) in the detection area AA as described above, there are issues such as light distribution, making it difficult to adjust the light intensity to be the same for all sensors.

[0145] (Initial light source intensity setting) Setting of the initial values ​​of the light intensity for the first light source 61 and the second light source 62 will be described. By appropriately setting the initial values ​​of the light intensity for the first light source 61 and the second light source 62, it becomes possible to acquire highly accurate data about a living body. Setting of the initial values ​​of the light intensity for the first light source 61 and the second light source 62 will be described below.

[0146] (Initial setting example 1) A description will be given of an example of initial setting of the light intensity of the first light source 61 and the second light source 62. Fig. 19 is a diagram illustrating a first example of a configuration for initial setting of the light intensity of the light sources.

[0147] Referring to FIG. 19, the first configuration for performing the initial setting includes a first light source 61, a second light source 62, a sensor unit 10, a light amount control unit 13a, and a biological information detection unit 14.

[0148] The first light source 61 emits light of a predetermined wavelength. The second light source 62 emits light of a wavelength different from the wavelength of the light emitted by the first light source 61. In other words, the first light source 61 and the second light source 62 emit light of different wavelengths.

[0149] In this example, the first light source 61 is a light source that emits infrared light (hereinafter referred to as IR light), and the second light source 62 is a light source that emits red light (hereinafter referred to as Red light).

[0150] The sensor unit 10 includes the detection area AA described with reference to Fig. 1. As described above, the detection area AA includes partial detection areas PAA, each of which functions as a sensor. In other words, the sensor unit 10 includes a plurality of optical sensors. The plurality of optical sensors are provided at different positions to detect light emitted by the first light source 61 and the second light source 62.

[0151] The light intensity control unit 13 controls the light intensity of the first light source 61 and the second light source 62. It includes a first light intensity control unit 131 and a second light intensity control unit 132. The first light intensity control unit 131 sets the light intensity of the first light source 61. The first light intensity control unit 131 changes the light intensity of the first light source 61. The second light intensity control unit 132 sets the light intensity of the second light source 62. The second light intensity control unit 132 changes the light intensity of the second light source 62.

[0152] The light intensity control unit 13 also includes a light intensity storage unit 134. When the increased light intensity of the first light source 61 and the increased light intensity of the second light source 62 both reach predetermined target values, the light intensity storage unit 134 stores the light intensity set by the first light intensity control unit 131 and the light intensity set by the second light intensity control unit 132 as the light intensity for biological information detection. That is, the light intensity storage unit 134 does not store the light intensity set by the first light intensity control unit 131 and the second light intensity control unit 132 in advance, but stores the light intensity set by the first light intensity control unit 131 and the second light intensity control unit 132 when the average value of the measurement value by the partial detection area PAA1 and the measurement value by the partial detection area PAA2 of the sensor unit 10 reaches the target value. The light intensity stored in the light intensity storage unit 134 becomes the initial light intensity when the biological information detection unit 14 detects biological information. That is, the light intensity for biological information detection is stored in the light intensity storage unit 134.

[0153] The biological information detection unit 14 detects biological information based on light emitted from the first light source 61 and the second light source 62 according to the light amount for biological information detection stored in the light amount storage unit 134.

[0154] Fig. 20 is a diagram showing an example of the arrangement of light sources relative to the detection area AA of the sensor unit 10. As shown in Fig. 20, in this example, the detection area AA is provided between a first light source 61 and a second light source 62. That is, the first light source 61 and the second light source 62 are provided at positions sandwiching the detection area AA of the sensor unit 10.

[0155] In this example, attention is focused on partial detection areas PAA1 and PAA2 of the detection area AA of the sensor unit 10. Of the detection area AA, partial detection area PAA1 is provided at a position close to the first light source substrate 51. Of the detection area AA, partial detection area PAA2 is provided at a position close to the second light source substrate 52. In this example, an average value of the measurement values ​​from partial detection areas PAA1 and PAA2 is calculated.

[0156] The positions of partial detection areas PAA1 and PAA2 shown in Fig. 20 are just an example, and the average of measurement values ​​obtained by partial detection area PAA at two other positions may be calculated. Also, the average of measurement values ​​obtained by partial detection area PAA at three or more positions may be calculated.

[0157] Returning to FIG. 19 , the first light intensity control unit 131 increases the intensity of IR light from the first light source 61 (hereinafter referred to as the IR light intensity) until the average value of the measurement values ​​from the partial detection areas PAA1 and PAA2 reaches the target value. That is, the first light intensity control unit 131 increases the intensity of IR light until the average value of the measurement values ​​from the multiple optical sensors reaches the target value. Furthermore, the second light intensity control unit 132 increases the intensity of Red light from the second light source 62 (hereinafter referred to as the Red light intensity) until the average value of the measurement values ​​from the partial detection areas PAA1 and PAA2 reaches the target value. That is, the second light intensity control unit 132 increases the Red light intensity until the average value of the measurement values ​​from the multiple optical sensors reaches the target value. The light intensity of the light source is controlled by setting a PWM value. The target value is, for example, 80% of the maximum detection value of the optical sensor.

[0158] The first light intensity control unit 131 sets the light intensity of the first light source 61 by changing the duty ratio of the pulse of the voltage applied to the first light source 61. The second light intensity control unit 132 sets the light intensity of the second light source 62 by changing the duty ratio of the pulse of the voltage applied to the second light source 62.

[0159] Fig. 21 is a diagram showing an example of changes in the measured light intensity. In Fig. 21, the vertical axis represents the measured value, and the horizontal axis represents the number of measurements. As shown in Fig. 21, measurements are repeated while increasing the light intensity until the measured value falls within a predetermined threshold range R1 centered on the target value tv. In the following explanation, reaching the predetermined threshold range R1 will be referred to as reaching the target value.

[0160] In Figure 21, each measurement value is the average value of the measurement values ​​obtained by the partial detection areas PAA1 and PAA2. As shown in Figure 21, the first measurement value v1 and the second measurement value v2 are lower than the predetermined threshold range R1. The third measurement value v3 is higher than the predetermined threshold range R1. The fourth measurement value v4 is lower than the predetermined threshold range R1. All of the first to fourth measurement values ​​v1 to v4 are outside the predetermined threshold range R1.

[0161] Of these measurement values, the fifth measurement value v5 is a value within the predetermined threshold range R1. Since the measurement value has reached the target value, the light amount set by the light amount control unit 13 at that time is stored as the initial setting value.

[0162] In FIG. 21, when the light intensity changes from increasing to decreasing (or decreasing to increasing), it is preferable to set the width smaller than the previous increase width (or decrease width) by a predetermined value. For example, it is sufficient to set the width to about half the previous increase width (or decrease width). If the width is set to the same as the previous increase width (or decrease width), there is a possibility that the light intensity adjustment will straddle the upper or lower limit value of the predetermined threshold range R1. In contrast, if the width is set to about half the previous increase width (or decrease width) as described above, such a possibility will be eliminated.

[0163] Returning to FIG. 19 , the biological information detection unit 14 detects information about a living organism using the sensor unit 10. At this time, the light intensity memory unit 134 stores the light intensity set by the light intensity control unit 13, i.e., the light intensity for biological information detection, when the average value of the measurement values ​​from the partial detection areas PAA1 and PAA2 of the sensor unit 10 reaches the target value. The biological information detection unit 14 detects biological information based on light from the first light source 61 and the second light source 62, which emit light at the light intensity for biological information detection stored in the light intensity memory unit 134. By focusing on the average value of the measurement values ​​as described above, the initial light intensity values ​​for the first light source 61 and the second light source 62 can be appropriately set. This allows for appropriate measurement of SpO2.

[0164] 22 is a flowchart showing an example of a process flow for setting the initial value of the light amount. The processes shown in FIG.

[0165] 22, first, the light intensity of the second light source 62 is set to zero (step S500). That is, the red light is set to off. Next, the first light intensity control unit 131 sets the light intensity of the first light source 61 (step S501). IR light is emitted from the first light source 61 at the set light intensity and measured, and the average value is detected (step S502).

[0166] Next, it is determined whether the detected average value is within a threshold range centered on the target value (step S503). If the result of the determination in step S503 is that the value is not within the threshold range (No in step S503), the light intensity of the first light source 61 is increased (step S504). Next, it is determined whether the light intensity is at its maximum value (step S505). When the above-mentioned duty ratio is 100%, the light intensity of the first light source 61 is at its maximum value.

[0167] If, as a result of the determination in step S505, the light quantity is at the maximum value (Yes in step S505), the value cnt of the counter for error determination is incremented (step S506), and it is determined whether the value cnt of the counter is a predetermined value N (step S507). If the state where the target value is not reached continues for N times even when the light quantity reaches the maximum value, it is determined as an error. For example, when there is no living body such as a finger, it is determined as an error.

[0168] If, as a result of the determination in step S507, the value cnt of the counter is the predetermined value N (cnt = N), it is regarded that reaching the target value is impossible, and a lower target value is set as the new target value (step S508). Here, the value N is a natural number. For example, the value N is "3".

[0169] Next, it is determined whether a Red flag indicating that the processing for Red light has ended is on (step S509). If, as a result of the determination in step S509, the Red flag is on (Yes in step S509), the process returns to step S501.

[0170] If, as a result of the determination in step S505, the light quantity is not at the maximum value (No in step S505), the process proceeds to step S600. If, as a result of the determination in step S507, the value cnt of the counter is not the predetermined value N (cnt < N), the process proceeds to step S600. If, as a result of the determination in step S509, the Red flag is not on (No in step S509), the process proceeds to step S600.

[0171] In step S600, the light quantity of the first light source 61 is set to zero (step S600). That is, the Ir light is turned off. Next, the light quantity of the second light source 62 is set by the second light quantity control unit 132 (step S601). Red light is emitted from the second light source 62 at the set light quantity for measurement, and the average value is detected (step S602).

[0172] Next, it is determined whether or not the detected average value is within the threshold range centered on the target value (step S603). As a result of the determination in step S603, if it is not within the threshold range (No in step S603), the light amount of the second light source 62 is increased (step S604). Next, it is determined whether or not the light amount is the maximum value (step S605). When the duty ratio described above is 100%, the light amount of the second light source 62 becomes the maximum value.

[0173] As a result of the determination in step S605, if the light amount is the maximum value (Yes in step S605), the value cnt of the counter for error determination is incremented (step S606), and it is determined whether or not the value cnt of the counter is a predetermined value N (step S607). If the state where the target value is not reached even when the light amount reaches the maximum value continues for N times, it is determined as an error. For example, when there is no living body such as a finger, it is determined as an error.

[0174] As a result of the determination in step S607, if the value cnt of the counter is the predetermined value N (cnt = N), it is regarded that it is impossible to reach the target value, and a lower target value is set as the new target value (step S608). Here, the value N is a natural number. For example, the value N is "3".

[0175] Next, it is determined whether or not an IR flag indicating that the processing for IR light has ended is on (step S609). As a result of the determination in step S609, if the IR flag is on (Yes in step S609), the process returns to step S601.

[0176] As a result of the determination in step S605, if the light amount is not the maximum value (No in step S605), the process proceeds to step S500. As a result of the determination in step S607, if the value cnt of the counter is not the predetermined value N (cnt < N), the process proceeds to step S500. As a result of the determination in step S609, if the IR flag is not on (No in step S609), the process proceeds to step S500.

[0177] If the result of the determination in step S503 is that the value is within the threshold range (Yes in step S503), the IR flag is turned on (step S510). Then, it is determined whether or not both the IR flag and the Red flag are on (step S511). If the result of the determination in step S511 is that neither flag is on (No in step S511), the process proceeds to step S600.

[0178] If the result of the determination in step S603 is that the value is within the threshold range (Yes in step S603), the Red flag is turned on (step S610). Then, it is determined whether both the IR flag and the Red flag are on (step S611). If the result of the determination in step S611 is that neither flag is on (No in step S611), the process proceeds to step S500.

[0179] If the result of the judgment in step S511 is that both flags are on (Yes in step S511), or if the result of the judgment in step S611 is that both flags are on (Yes in step S611), the measurement ends, and the light intensity at that time is stored in light intensity memory unit 134 as the light intensity when detecting biometric information (step S612), and the processing ends.

[0180] 22, if neither the IR flag nor the Red flag is on (No in step S509, No in step S609), the processes of steps S501 to S509 and steps S601 to S609 are performed alternately. That is, measurement of the IR light intensity and measurement of the Red light intensity are performed alternately. In order to measure the light intensity alternately, the Red light is set to off when measuring the IR light intensity, and the IR light is set to off when measuring the Red light intensity.

[0181] As described above, by focusing on the average value of the measured values ​​of a plurality of sensors and initially setting the light intensity so that the measured values ​​fall within a similar range of target values, highly accurate data can be obtained.

[0182] (Initial setting example 2) A description will be given of another example of the initial setting of the light intensity of the first light source 61 and the second light source 62. Fig. 23 is a diagram illustrating a second example of the configuration for initial setting of the light intensity of the light sources.

[0183] In the first configuration example described above, the light intensity is initially set so that the average value of the measurement values ​​of the multiple sensors becomes the target value. In contrast, in the second configuration example described below, the initial setting is performed as follows. That is, the light intensity of the first light source 61 is set so that the measurement value of the sensor at a provisionally determined arbitrary coordinate position becomes the target value. Then, focusing on the optical sensor at the peak coordinate position with the highest measurement value, the light intensity of the second light source 62 is set so that the measurement value at the peak coordinate position reaches the target value.

[0184] 23, the second configuration for performing initial setting includes a light intensity control unit 13a instead of the light intensity control unit 13 of the first configuration described with reference to FIG. 19. The light intensity control unit 13a includes a first light intensity control unit 131a, a second light intensity control unit 132a, a peak coordinate acquisition unit 133, and a light intensity storage unit 134a. In this example, the first light source 61 is a light source that emits IR light. In this example, the second light source 62 is a light source that emits Red light.

[0185] The first light intensity control unit 131a sets the light intensity of the first light source 61. The first light intensity control unit 131a changes the light intensity of the first light source 61. The first light intensity control unit 131a increases the IR light intensity until the measurement value of an optical sensor at a predetermined coordinate position among the multiple optical sensors reaches a target value.

[0186] When the measurement value at the predetermined coordinate position reaches the target value, the peak coordinate acquisition unit 133 acquires the peak coordinate position with the highest measurement value among the multiple optical sensors. The peak coordinate acquisition unit 133 acquires the position where the amplitude of the pulse wave is the largest as the peak coordinate position. The process of detecting the peak coordinate position will be described later.

[0187] The second light intensity control unit 132a sets the light intensity of the second light source 62. The second light intensity control unit 132a changes the light intensity of the second light source 62. The second light intensity control unit 132a increases the red light intensity until the measurement value of the peak coordinate position acquired by the peak coordinate acquisition unit 133 reaches the target value.

[0188] When the measurement value of the optical sensor at the peak coordinate position reaches the target value, the light intensity storage unit 134a stores the light intensity set by the first light intensity control unit 131a and the light intensity set by the second light intensity control unit 132a as the light intensity for detecting biological information. The light intensity stored in the light intensity storage unit 134a becomes the initial light intensity when the biological information detection unit 14a detects biological information. In other words, the light intensity for detecting biological information is stored in the light intensity storage unit 134a.

[0189] The biological information detector 14a detects biological information based on light emitted from the first light source 61 and the second light source 62 according to the light amount for biological information detection stored in the light amount storage unit 134a.

[0190] 24 to 27 are diagrams illustrating the initial setting using the configuration shown in Fig. 23. In Fig. 24, a partial detection area PAA3 within the detection area AA is assumed to be a sensor at a provisionally determined arbitrary coordinate position. The sensor at the coordinate position of this partial detection area PAA3 is set as the measurement target, and the first light intensity control unit 131a sets the light intensity of the first light source 61 (i.e., the IR light source) so that the measurement value becomes a target value.

[0191] 25, the measurement value of the sensor at the coordinate position of the partial detection area PAA3 increases due to the light intensity setting of the first light intensity control unit 131a. When the measurement value reaches the target value tv as shown in FIG. 26, the peak coordinate acquisition unit 133 acquires the peak coordinate position with the highest measurement value.

[0192] In this example, the first light intensity control unit 131a sets the light intensity of the first light source 61, and as a result, the partial detection area PAA4 shown in FIG. 26 is acquired as the peak coordinate position. The second light intensity control unit 132a measures the partial detection area PAA4 at this peak coordinate position while setting the light intensity of the second light source 62 (i.e., the Red light source). That is, the second light intensity control unit 132a increases the light intensity of the second light source 62 until the measurement value at the peak coordinate position reaches the target value. At this time, the Ir light of the first light source 61 is set to off.

[0193] As shown in Fig. 27, the measurement value of the sensor at the coordinate position of the partial detection area PAA4 increases due to the light intensity setting of the second light intensity control unit 132a. When the measurement value reaches the target value tv as shown in Fig. 27, the biological information detection unit 14a detects information related to the biological organism by setting the IR light intensity of the first light intensity control unit 131a as the light intensity of the first light source 61 and the Red light intensity of the second light intensity control unit 132a as the light intensity of the second light source 62.

[0194] As shown in FIG. 22, the IR light may be measured by using the sensors on the entire surface of the detection area AA as the measurement target, without determining a specific partial detection area PAA3.

[0195] The processing of the second configuration in Fig. 23, which has been described with reference to Fig. 24 to Fig. 27, will be further described with reference to Fig. 28 to Fig. 31. Fig. 28 is a flowchart showing an example of the processing of the second configuration in Fig. 23. The processing shown in Fig. 28 includes processing S7 by the signal processing unit 44 and processing S8 by the control circuit 122.

[0196] 28, first, the signal processing unit 44 transmits a luminance adjustment command for adjusting the luminance (step S701). The luminance adjustment command includes a target value and coordinates.

[0197] When the control circuit 122 receives a brightness adjustment command (step S801), it performs an IR data acquisition process to acquire a measured value of the IR light intensity (step S802). The IR data acquisition process will be described later. When the IR light intensity reaches the target value (step S803), it outputs an IR arrival completion notification to notify the fact.

[0198] When the signal processing unit 44 receives the IR arrival completion notification, it starts processing to acquire peak coordinates (step S702). The processing to acquire peak coordinates will be described later. When the peak coordinates are acquired by the processing of the signal processing unit 44 (step S703), the signal processing unit 44 transmits the peak coordinates.

[0199] When the control circuit 122 receives the peak coordinates, it resets the peak coordinates as the coordinates of the measurement target (step S804). Next, the control circuit 122 performs a Red data acquisition process to acquire the measured value of the Red light intensity (step S805). The Red data acquisition process will be described later. When the measured value of the Red light intensity reaches the target value (step S806), a Red reach completion notification indicating this is output.

[0200] When the signal processing unit 44 receives the Red arrival completion notification, the control circuit 122 proceeds to a process of detecting information related to the living body (step S704). In this example, an SpO2 acquisition process of measuring SpO2 is performed.

[0201] The control circuit 122 sets the IR light intensity of the first light intensity control unit 131a as the light intensity of the first light source 61 and stores the Red light intensity of the second light intensity control unit 132a as the light intensity of the second light source 62 in the light intensity storage unit 134a (step S807). Through the above processing, the initial setting of the light intensity for measuring SpO2 is completed, and the control circuit 122 performs SpO2 acquisition processing to measure SpO2 (step S808).

[0202] FIG. 29A is a diagram showing the state in which the IR light intensity reaches the target value. FIG. 29A is a waveform diagram illustrating an example of the processing in step S803 of FIG. 28. As shown in FIG. 29A, when the IR light intensity level is increased, the measured value increases as shown by the voltage value indicated by the solid line Ja. The measured value increases and reaches the target value tv. Since the measured value has reached the target value tv, the IR light intensity level is maintained, and a measured value of the Red light intensity is obtained in steps S805 and S806 of FIG. 28.

[0203] 29B and 29C are diagrams illustrating the state in which the red light intensity reaches the target value. FIGS. 29B and 29C are waveform diagrams illustrating an example of the processing in steps S805 and S806. In FIG. 29B, a pulse wave indicated by a dashed line Ha is added to the DC voltage indicated by a solid line Ja. The voltage value of the pulse wave fluctuates over time. The peak coordinate acquisition unit 133 acquires the position where the pulse wave has the largest amplitude as the peak coordinate position. The frequency of this pulse wave is, for example, 0.5 Hz or more and 3 Hz or less. The measured value of the red light intensity, including the fluctuating pulse wave, must reach the target value. In the case of FIG. 29C as well, a pulse wave with a small amplitude indicated by a dashed line Hs is added to the DC voltage indicated by the solid line Ja. In this case as well, the measured value of the red light intensity, including the fluctuating pulse wave, must reach the target value.

[0204] Fig. 30 is a flowchart showing an example of the IR data acquisition process (step S802) in Fig. 28. In Fig. 30, first, the light intensity of the second light source 62 is set to zero (step S500). That is, the red light is set to off. Next, the first light intensity control unit 131 sets the light intensity of the first light source 61 (step S501). IR light is emitted from the first light source 61 at the set light intensity and measured (step S502a).

[0205] Next, it is determined whether the measured value is within the threshold range centered on the target value (step S503). As a result of the determination in step S503, if it is not within the threshold range (No in step S503), the light amount of the first light source 61 is increased (step S504). Next, it is determined whether the light amount is the maximum value (step S505). When the above-described duty ratio is 100%, the light amount of the first light source 61 becomes the maximum value.

[0206] As a result of the determination in step S505, if the light amount is the maximum value (Yes in step S505), the value cnt of the counter for error determination is incremented (step S506), and it is determined whether the value cnt of the counter is a predetermined value N (step S507).

[0207] As a result of the determination in step S507, if the value cnt of the counter is the predetermined value N (cnt = N), it is considered that it is impossible to reach the target value, and a lower target value is set as the new target value (step S508). Then, the process returns to step S501. Here, the value N is a natural number. For example, the value N is "3".

[0208] As a result of the determination in step S505, if the light amount is not the maximum value (No in step S505), the process returns to step S501.

[0209] As a result of the determination in step S507, if the value cnt of the counter is not the predetermined value N (cnt < N), the process returns to step S501.

[0210] As a result of the determination in step S503, if it is within the threshold range (Yes in step S503), the measurement is terminated and the process returns to the original process (step S513).

[0211] FIG. 31 is a flowchart showing an example of the Red data acquisition process (step S805) in FIG. 28. In FIG. 31, first, the light amount of the first light source 61 is set to zero (step S600). That is, the Ir light is turned off. Next, the second light amount control unit 132 sets the light amount of the second light source 62 (step S601). Red light is emitted from the second light source 62 at the set light amount and measured (step S602a).

[0212] Next, it is determined whether the measured value is within the threshold range centered on the target value (step S603). As a result of the determination in step S603, if the value is not within the threshold range (No in step S603), the light amount of the second light source 62 is increased (step S604). Next, it is determined whether the light amount is the maximum value (step S605). When the above-described duty ratio is 100%, the light amount of the second light source 62 becomes the maximum value.

[0213] As a result of the determination in step S605, if the light amount is the maximum value (Yes in step S605), the value cnt of the counter for error determination is incremented (step S606), and it is determined whether the value cnt of the counter is a predetermined value N (step S607).

[0214] As a result of the determination in step S607, if the value cnt of the counter is the predetermined value N (cnt = N), it is considered that the target value cannot be reached, and a lower target value is set as the new target value (step S608). Then, the process returns to step S601. Here, the value N is a natural number. For example, the value N is "3".

[0215] As a result of the determination in step S605, if the light amount is not the maximum value (No in step S605), the process returns to step S601.

[0216] As a result of the determination in step S607, if the value cnt of the counter is not the predetermined value N (cnt < N), the process returns to step S601.

[0217] If the result of the determination in step S603 is that the value is within the threshold range (Yes in step S603), the measurement ends and the process returns to the original step (step S613).

[0218] As described above, highly accurate data can be obtained by focusing on the measurement value of the sensor at the position where the measurement value is maximum and initially setting the light intensity so that the measurement value falls within a similar target value range. For living organisms, the transmittance of IR light is higher than that of red light. Therefore, it is more likely that the target value will be reached for IR light before it is for red light. Therefore, by adopting the order of setting the IR light intensity first and then the red light intensity as described above, initial setting can be performed more efficiently than if it were performed in the reverse order.

[0219] (Process to detect peak coordinate position) Next, a process for detecting a peak coordinate position will be described. Fig. 32 is a flowchart showing an example of a process flow for detecting a peak coordinate position. The processes shown in Fig. 32 are mainly executed by the signal processing unit 44 of the detection unit 40.

[0220] In the following description, X<m,n> indicates a variable in the partial detection area PAA at the mth column and nth row.<m,n> is the variable X<m,n> It also includes the coordinate information of the partial detection area PAA where X(f) was acquired.<m,n> is the variable X in the fth frame.<m,n> This shows:

[0221] In the detection process flow shown in FIG. 32, first, the signal processing unit 44 calculates the detection values ​​Raw(f) for a plurality of frames in each partial detection area PAA within the detection area AA.<m,n> Obtain the detection value Raw(f) for multiple frames.<m,n> The number of frames F when acquiring the pulse wave peak is set to a number that allows multiple (for example, about 10) pulse wave peaks to be acquired. The number of frames F is stored in the storage unit 46, for example.

[0222] Also, in the processes from step S102 to step S110 of the detection process flow shown in FIG. 32, the control circuit 122 continuously lights either the first light source 61 or the second light source 62, for example, during periods t(1), t(2), t(3), and t(4) shown in FIG. 10. Each detection value Raw(f)<m,n> is temporarily stored in the storage unit 46, for example. FIG. 33 is a diagram showing the detection values for the F frames in each partial detection area within the detection area temporarily stored in the storage unit.

[0223] The signal processing unit 44 sets the initial frame f to 1 (f = 1) (step S101). The signal processing unit 44 sets m = 1 and n = 1 (step S102), acquires the detection value Raw(f)<m,n> (step S103), and temporarily stores the acquired detection value Raw(f)<m,n> in the storage unit 46 (step S104).

[0224] Subsequently, the signal processing unit 44 sets m = m + 1 (step S105) and determines whether m is equal to M (m = M) (step S106). If m is less than M (m < M) (step S106; No), the process returns to the process of step S103.

[0225] When m becomes M (m = M) (step S106; Yes), subsequently, the signal processing unit 44 sets n = n + 1 (step S107) and determines whether n is equal to N (n = N) (step S108). If n is less than N (n < N) (step S108; No), the process returns to the process of step S103.

[0226] When n becomes N (n = N) (step S108; Yes), subsequently, the signal processing unit 44 sets f = f + 1 (step S109) and determines whether f is equal to F (f = F) (step S110). If f is less than F (f < F) (step S110; No), the process returns to the process of step S102.

[0227] By repeating the processes from step S102 to step S110 F times, the detection values Raw(f)<m,n> for F frames in each partial detection region PAA within the detection region AA shown in FIG. 33 are temporarily stored in the storage unit 46.

[0228] When f becomes F (f = F) (step S110; Yes), subsequently, the signal processing unit 44 sets m = 1 and n = 1 (step S111), sets the initial frame f to 1 (f = 1) (step S112), and reads the detection value Raw(f)<m,n> from the storage unit 46 (step S113). Further, the signal processing unit 44 sets f = f + 1 (step S114) and determines whether f is F (f = F) (step S115). If f is less than F (f < F) (step S115; No), the process returns to step S113.

[0229] Through the processes from step S113 to step S115, the detection values Raw(f)<m,n> for F frames in the partial detection region PAA at the m-th column and n-th row are read out.

[0230] When f becomes F (f = F) (step S115; Yes), the signal processing unit 44 generates the time-domain data Det<m,n> in the partial detection region PAA at the m-th column and n-th row based on the detection values Raw(f)<m,n> for F frames read from the storage unit 46 (step S116). FIGS. 34A and 34B are diagrams showing specific examples of the time-domain data in each partial detection region. In FIG. 34A, the time-domain data in the partial detection region A shown in FIG. 15 is illustrated. In FIG. 34B, the time-domain data in the partial detection region B shown in FIG. 15 is illustrated.

[0231] The signal processing unit 44 performs a Fourier transform process (here, FFT (Fast Fourier Transform) process) on the time-domain data Det<m,n> in the generated m-th row and n-th column partial detection region PAA, and generates frequency-domain data Sdet<m,n> (step S117). FIGS. 35A and 35B are diagrams showing specific examples of the frequency-domain data in each partial detection region. In FIG. 35A, the frequency-domain data in the partial detection region A shown in FIG. 15 is illustrated. In FIG. 35B, the frequency-domain data in the partial detection region B shown in FIG. 15 is illustrated.

[0232] The signal processing unit 44 extracts the signal intensity Speak<m,n> of the peak value in the frequency range of the first frequency f1 or more and the second frequency f2 less than the frequency-domain data shown in FIGS. 35A and 35B (step S118). The first frequency f1 is, for example, 0.5 [Hz] (f1 = 0.5 [Hz]), and the second frequency f2 is, for example, 3 [Hz] (f2 = 3 [Hz]). The signal processing unit 44 temporarily stores the extracted signal intensity Speak<m,n> of the peak value in the storage unit 46 as the signal intensity in the m-th row and n-th column partial detection region PAA (step S119).

[0233] Then, the signal processing unit 44 sets m = m + 1 (step S120), and determines whether m is equal to M (m = M) (step S121). If m is less than M (m < M) (step S121; No), the process returns to the process of step S112.

[0234] When m becomes M (m = M) (step S121; Yes), subsequently, the signal processing unit 44 sets n = n + 1 (step S122), and determines whether n is equal to N (n = N) (step S123). If n is less than N (n < N) (step S123; No), the process returns to the process of step S112.

[0235] By repeating the processes from step S112 to step S123 M×N times, the signal intensity Speak for each partial detection area PAA in the detection area AA is calculated.<m,n> is temporarily stored in the storage unit 46. After the processes from step S112 to step S123 are repeated M×N times (step S123; Yes), the process proceeds to step S124.

[0236] The signal processing unit 44 calculates the signal intensity Speak for each partial detection area PAA in the detection area AA extracted by the above processing.<m,n> Based on this, a biological data acquisition region for acquiring pulse wave data is set (step S124).

[0237] FIG. 36 is a flowchart showing an example of a processing flow for setting a biometric data acquisition region in the detection device.

[0238] In the biological data acquisition area setting process flow shown in FIG. 36, first, the signal processing unit 44 calculates the signal intensity Speak<m,n> The signal strength is calculated by comparing the<m,n> The coordinates of the position of the partial detection area PAA where is the maximum are extracted.

[0239] The signal processing unit 44 detects the maximum signal strength Speak_max<m,n> to 0(Speak_max<m,n> = 0) (step S201). The signal processing unit 44 sets m=1 and n=1 (step S202), and calculates the signal intensity Speak<m,n> is read out (step S203).

[0240] The signal processing unit 44 reads out the signal intensity Speak<m,n> is the maximum signal strength Speak_max<m,n> Speak<m,n> >Speak_max<m,n> ) (Step S204).<m,n> is the maximum signal strength Speak_max<m,n> Below (Speak<m,n> ≦Speak_max<m,n> ) (step S204; No), the process proceeds to step S206.

[0241] When the read signal intensity Speak<m,n> is greater than the maximum signal intensity Speak_max<m,n> (Speak<m,n>>Speak_max<m,n>) (step S204; Yes), the signal processing unit 44 replaces the maximum signal intensity Speak_max<m,n> with the signal intensity Speak<m,n> (Speak_max<m,n>=Speak<m,n>) and temporarily stores it in the storage unit 46 (step S205).

[0242] Subsequently, the signal processing unit 44 sets m=m+1 (step S206) and determines whether m is equal to M (m=M) (step S207). If m is less than M (m<M) (step S207; No), the process returns to the process of step S203.

[0243] When m becomes M (m=M) (step S207; Yes), subsequently, the signal processing unit 44 sets n=n+1 (step S208) and determines whether n is equal to N (n=N) (step S209). If n is less than N (n<N) (step S209; No), the process returns to the process of step S203.

[0244] By repeating the processes from step S203 to step S209 M×N times, the maximum signal intensity Speak_max<m,n> in the detection area AA and the coordinate information of the partial detection area PAA where the maximum signal intensity Speak_max<m,n> is obtained are temporarily stored in the storage unit 46.

[0245] When n becomes N (n=N) (step S209; Yes), the signal processing unit 44 reads out the maximum signal intensity Speak_max<m,n> temporarily stored in the storage unit 46 (step S210) and stores the coordinates of the partial detection area PAA where the maximum signal intensity Speak_max<m,n> is obtained in the storage unit 46 as the signal intensity maximum coordinates Smax(m,n) (step S211).

[0246] The signal processing unit 44 sets a predetermined area having the signal strength maximum coordinate Smax(m,n) as its center coordinate as a biometric data acquisition area BAA (step S212). The set biometric data acquisition area BAA is stored in the storage unit 46.

[0247] Returning to Figure 32, in the biometric data acquisition process (step S125), the signal processing unit 44 reads out the biometric data acquisition area BAA stored in the memory unit 46, and acquires pulse wave data based on the detection signal Vdet detected in the partial detection area PAA included in the biometric data acquisition area BAA.

[0248] If multiple biological data acquisition areas BAA are set within the detection area AA, the signal processing unit 44 averages the detection signals Vdet output from multiple partial detection areas PAA within the biological data acquisition area BAA to acquire pulse wave data, which is expected to improve the quality of the pulse wave data.

[0249] As described above, the strength of the signal detected in each partial detection area PAA within the detection area AA varies depending on the distribution of blood vessels under the skin of the subject's finger Fg. The detection device 1 according to this embodiment extracts a partial detection area PAA within the detection area AA where the signal strength of the data acquired in that partial detection area PAA is relatively high, and acquires pulse wave data based on the detection signal Vdet detected in the biological data acquisition area BAA that includes the extracted partial detection area PAA. This enables highly accurate acquisition of pulse wave data.

[0250] (Variation 1) In the example described with reference to FIGS. 20 and 24 , the first light source 61 and the second light source 62 are provided at positions sandwiching the detection area AA of the sensor unit 10. However, light sources may be provided around the detection area AA so as to surround the detection area AA. FIG. 37 is a diagram showing a modified arrangement of light sources. Referring to FIG. 37 , a first light source substrate 51, a second light source substrate 52, a third light source substrate 53, and a fourth light source substrate 54 are provided so as to surround the detection area AA. By providing the first light source 61 and the second light source 62 so as to surround the detection area AA, a high amount of light can be maintained at each portion of the detection area AA. As shown in FIG. 37 , the second light source 62 may be provided on the first light source substrate 51 and the second light source substrate 52 facing each other, and the first light source 61 may be provided on the third light source substrate 53 and the fourth light source substrate 54 facing each other. In this manner, the first light source 61 and the second light source 62 may be arranged around the plurality of optical sensors.

[0251] (Variation 2) The detection area AA detected by the multiple optical sensors may be divided into multiple areas, and the light intensity control unit 13 or the light intensity control unit 13a may perform processing for each of the multiple divided areas. For example, as described with reference to FIG. 3, the detection area AA may be divided into block units PAG1 and PAG2, respectively, as the detection target. This allows for more efficient processing than when the entire detection area AA is the detection target. When peak coordinates are acquired by the peak coordinate acquisition unit 133 of the light intensity control unit 13a, biological information can be detected using the block unit containing the peak coordinates, allowing for more efficient processing. [Explanation of symbols]

[0252] 1. Detection device 10 Sensor section 11 Detection control section 13, 13a Light quantity control section 14, 14a Biometric information detection unit 40 Detector 44 Signal Processing Section 48 Detection circuit 61 1st light source 62 Second light source 131, 131a First light quantity control section 132, 132a Second light quantity control section 133 Peak coordinate acquisition unit 134, 134a Light quantity memory unit AA detection area PAA, PAA1 to PAA4 partial detection area

Claims

1. a first light source that emits light of a predetermined wavelength; a second light source that emits light of a wavelength different from the wavelength of the light emitted by the first light source; and a plurality of optical sensors provided at different positions to measure and detect the light emitted by the first light source and the second light source; a light amount control unit that sets the light amount of at least one of the first light source and the second light source so that a measurement value based on a detection value of at least one of the plurality of optical sensors reaches a predetermined target value; a biological information detection unit that detects information about the living body using the plurality of optical sensors, using the amount of light for biological information detection set by the light amount control unit, when the measurement value reaches a predetermined target value; Including, The light amount control unit a first light amount control unit that increases the light amount of the first light source until an average value of measurement values ​​based on detection values ​​of the plurality of optical sensors reaches a predetermined target value; and a second light amount control unit that increases the light amount of the second light source until an average value of measurement values ​​based on detection values ​​of the plurality of optical sensors reaches the target value. a light intensity storage unit that stores the light intensity set by the first light intensity control unit and the light intensity set by the second light intensity control unit as the light intensity for detecting biological information when the increased light intensity of the first light source and the increased light intensity of the second light source both reach predetermined target values, A detection region detected by the plurality of optical sensors is divided into a plurality of areas, and processing is performed by the first light amount control unit and the second light amount control unit for each of the plurality of divided areas. Detection device.

2. a first light source that emits light of a predetermined wavelength; a second light source that emits light of a wavelength different from the wavelength of the light emitted by the first light source; and a plurality of optical sensors provided at different positions to measure and detect the light emitted by the first light source and the second light source; a light amount control unit that sets the light amount of at least one of the first light source and the second light source so that a measurement value based on a detection value of at least one of the plurality of optical sensors reaches a predetermined target value; a biological information detection unit that detects information about the living body using the plurality of optical sensors, using the amount of light for biological information detection set by the light amount control unit, when the measurement value reaches a predetermined target value; Including, The light amount control unit a first light amount control unit that increases the light amount of the first light source until a measurement value of an optical sensor at a predetermined coordinate position among the plurality of optical sensors reaches a predetermined target value; a peak coordinate acquiring unit that acquires a peak coordinate position having the highest measurement value among the plurality of optical sensors when the measurement value at the predetermined coordinate position reaches the target value; a second light amount control unit that increases the light amount of the second light source until the measurement value of the peak coordinate position acquired by the peak coordinate acquisition unit reaches the target value; a light intensity memory unit that stores the light intensity set by the first light intensity control unit and the light intensity set by the second light intensity control unit as the light intensity for detecting the biological information when the measured value of the peak coordinate position reaches the target value.

3. The detection device according to claim 2 , wherein the peak coordinate acquisition unit acquires the position where the amplitude of the pulse wave is greatest as the peak coordinate position.

4. The detection device according to claim 3 , wherein the frequency of the pulse wave is equal to or greater than 0.5 Hz and equal to or less than 3 Hz.

5. 5. The detection device according to claim 1, wherein, when the measurement value does not reach the target value, the first light intensity control unit and the second light intensity control unit reset a target value lower than the target value as a new target value and then increase the light intensity.

6. The first light amount control unit and the second light amount control unit reset the lower target value as a new target value when the number of times the measured value does not reach the target value reaches a predetermined value. The detection device according to claim 5 .

7. 7. The detection device according to claim 2, wherein a detection region detected by the plurality of optical sensors is divided into a plurality of areas, and processing is performed by the first light intensity control unit and the second light intensity control unit for each of the plurality of divided areas.

8. the first light source is a light source that emits infrared light, The second light source is a light source that emits red light.

8. A detection device according to any one of claims 1 to 7.

9. The detection device according to claim 1 , wherein the first light source and the second light source are arranged around the plurality of optical sensors.

10. The detection device according to claim 1 , wherein the information about the living body detected by the living body information detection unit is blood oxygen saturation.

11. 11. The detection device according to claim 1, wherein the optical sensor is an organic photodiode.

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