Detection apparatus and wearable device

Abstract

Provided are a detection apparatus and a wearable device which are capable of acquiring desired biological information. The detection apparatus comprises: a plurality of optical sensors (PD) arranged on a detection surface; a light source that irradiates light onto the optical sensors (PD); an AFE circuit that acquires a detection value from each of the plurality of optical sensors (PD); and a signal processing circuit that acquires prescribed biological information on the basis of first time domain data obtained by acquiring detection values in a time series. The signal processing circuit converts the first time domain data to a time domain matrix, subjects the time domain matrix to singular value decomposition, inversely calculates second time domain data on the basis of a prescribed singular value from among a plurality of singular values obtained as the results of the singular value decomposition, and uses the second time domain data to acquire, as image information, biological information that changes in a time series.

Description

[Technical Field]

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

[0002] Patent Document 1 describes an optical sensor in which a plurality of photoelectric conversion elements such as photodiodes are arranged on a semiconductor substrate. The optical sensor can detect biological information by detecting changes in the signal output from the photoelectric conversion elements according to the amount of light irradiated.

[0003] Patent Document 2 describes a configuration for obtaining blood oxygen saturation (hereinafter referred to as blood oxygen saturation (SpO2)) using a pulse wave obtained using infrared light and a pulse wave obtained using red light. 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. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US Patent Application Publication No. 2018 / 0012069 [Patent Document 2] Japanese Patent Application Publication No. 2019-180861 Summary of the Invention [Problem to be solved by the invention]

[0005] For example, when acquiring subcutaneous information such as pulse waves and blood flow, appropriate biometric information may not be obtained due to superimposition of body movement noise caused by human movement, biological signals not to be detected, or noise components of the AC frequency of commercial power (e.g., 50 [Hz], 60 [Hz]).

[0006] The present disclosure aims to provide a detection apparatus and a wearable device that can acquire desired biological information. [Means for solving the problem]

[0007] A detection device according to one aspect of the present disclosure includes a plurality of optical sensors arranged on a detection surface, a light source that irradiates the optical sensors with light, an AFE circuit that acquires detection values ​​for each of the plurality of optical sensors, and a signal processing circuit that acquires predetermined biological information based on first time-domain data obtained by acquiring the detection values ​​in a time-series manner, wherein the signal processing circuit converts the first time-domain data into a time-domain matrix and performs singular value decomposition, inversely calculates second time-domain data based on a predetermined singular value among a plurality of singular values ​​obtained as a result of the singular value decomposition, and acquires the biological information that changes in time series as image information using the second time-domain data.

[0008] A wearable device according to one aspect of the present disclosure includes the above-described detection device and has a ring-like shape that can be attached to and detached from the human body. [Brief explanation of the drawings]

[0009] [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 a detection device according to an embodiment. [Figure 4] FIG. 4 is a circuit diagram showing a plurality of partial detection regions of the detection device according to the embodiment. [Figure 5] FIG. 5 is a schematic partial cross-sectional view of the optical sensor according to the embodiment. [Figure 6] FIG. 6 is a timing waveform diagram illustrating an example of the operation of the detection device according to the embodiment. [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 readout period in FIG. [Figure 10] FIG. 10 is an explanatory diagram for explaining a first example of the relationship between the driving of the sensor region of the detection device according to the embodiment and the lighting operation of the light source. [Figure 11] FIG. 11 is a second explanatory diagram for explaining a second example of the relationship between the driving of the sensor region of the detection device according to the embodiment and the lighting operation of the light source. [Figure 12] FIG. 12 is a timing waveform diagram illustrating an example of operation in the second example shown in FIG. [Figure 13] FIG. 13 is a schematic diagram showing a device illustrating a first application example of the detection device according to the embodiment. [Figure 14] FIG. 14 is a schematic diagram showing a device illustrating a second application example of the detection device according to the embodiment. [Figure 15] FIG. 15 is a flowchart showing an example of processing in the signal processing circuit of the detection device according to the embodiment. [Figure 16] FIG. 16 is an image diagram of time domain data acquired within a detection plane for a predetermined period of time. [Figure 17] FIG. 17 is a conceptual diagram for explaining an outline of the singular value decomposition process. [Figure 18] FIG. 18 is a waveform diagram showing an example of a pulse wave. [Figure 19] FIG. 19 is an image diagram showing an example of each frequency component included in a pulse wave. [Figure 20] FIG. 20 is an image diagram showing an example of a frequency distribution obtained by FFT processing time domain data that constitutes a waveform. [Figure 21] FIG. 21 is an image diagram of FFT processing. [Figure 22] FIG. 22 is an image diagram of processing using singular value decomposition according to the embodiment. [Figure 23] FIG. 23 is a conceptual diagram showing an example of frequency components decomposed by the singular value decomposition processing according to the embodiment. [Figure 24]FIG. 24 is an image diagram showing an example of biological information acquired as image information by the detection device according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] 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 appropriately combined. 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.

[0011] 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 region 10, a gate line driving circuit 15, a signal line selection circuit 16, an AFE (Analog Front End) circuit 48, a control circuit 122, a power supply circuit 123, a first light source 61, and a second light source 62. FIG. 1 illustrates an example in which a plurality of first light sources 61 are provided on a first light source substrate 51 and a plurality of second light sources 62 are provided on a second light source substrate 52. However, 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 provided 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 sources 61 and the second light sources 62 are provided may be one or three or more. Specific examples of the arrangement of the first light sources 61 and the second light sources 62 will be described later.

[0012] The detection device 1 is electrically connected to a host. The host is, for example, a higher-level control device of an apparatus (not shown) to which the detection device 1 is applied. The detection device 1 according to the first embodiment transmits acquired biological information to the host via the output circuit 126.

[0013] 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 an AFE circuit 48. The control board 121 is provided with a control circuit 122, a power supply circuit 123, and an output circuit 126.

[0014] 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).

[0015] The control circuit 122 supplies control signals to the sensor area 10, the gate line driving circuit 15, and the signal line selection circuit 16 to control the detection operation of the sensor area 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.

[0016] The power supply circuit 123 supplies voltage signals such as a sensor power supply potential VDDSNS (see FIG. 4) to the sensor region 10, the gate line driving 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.

[0017] The output circuit 126 is, for example, a USB controller IC, and controls communication between the control circuit 122 and the host.

[0018] 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 area 10 are arranged in a matrix. 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.

[0019] 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 area 10 and the AFE circuit 48.

[0020] 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.

[0021] The plurality of first light sources 61 are provided on the first light source substrate 51 and arranged along the second direction Dy. The plurality of 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.

[0022] 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.

[0023] 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 area 10. As a result, the sensor area 10 can detect a fingerprint by detecting the uneven shape of the surface of the finger Fg or the like. 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 area 10. As a result, the sensor area 10 can detect information about the inside of the subject's finger, wrist, or the like. The information about the biological body 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.

[0024] The first light may have a wavelength of 420 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 area 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 area 10. This allows the sensor area 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.

[0025] 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 region 10 can detect information about the living body, such as a pulse wave, pulse rate, and blood vessel image, as well as blood oxygen concentration. 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. Note that the above-described emission colors of the first light source 61 and the second light source 62 are merely examples, and the present disclosure is not limited to the emission colors of the first light source 61 and the second light source 62.

[0026] 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 circuit 11 and a detection circuit .

[0027] The sensor region 10 has a plurality of optical sensors PD. The optical sensors PD of the sensor region 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 region 10 also performs detection in accordance with a gate drive signal Vgcl supplied from the gate line drive circuit 15.

[0028] The detection control circuit 11 is a circuit that supplies control signals to the gate line drive circuit 15, the signal line selection circuit 16, and the detection circuit 40, respectively, and controls their operations. The detection control circuit 11 supplies various control signals, such as a start signal STV, a clock signal CK, and a reset signal RST1, to the gate line drive circuit 15. The detection control circuit 11 also supplies various control signals, such as a selection signal ASW, to the signal line selection circuit 16. The detection control circuit 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.

[0029] 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.

[0030] 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 AFE circuit 48 based on a selection signal ASW supplied from the detection control circuit 11. As a result, the signal line selection circuit 16 outputs the detection signal Vdet of the photosensor PD to the detection circuit 40.

[0031] The detection circuit 40 includes an AFE circuit 48, a signal processing circuit 44, a memory circuit 46, and a detection timing control circuit 47. The detection timing control circuit 47 controls the AFE circuit 48 and the signal processing circuit 44 based on a control signal supplied from the detection control circuit 11 so that they operate in synchronization with each other.

[0032] The AFE circuit 48 detects, in time series, the detection signals of the optical sensors PD output from the sensor area 10. The AFE circuit 48 is, for example, an analog front-end IC.

[0033] The AFE circuit 48 is a signal processing circuit that has at least the functions of a detection signal amplifier circuit 42 and an A / D conversion circuit 43. The detection signal amplifier circuit 42 amplifies the detection signal Vdet. The A / D conversion circuit 43 converts the analog signal output from the detection signal amplifier circuit 42 into a digital signal at a predetermined sampling period.

[0034] In the present disclosure, the signal processing circuit 44 and the memory circuit 46 are included in the control circuit 122 .

[0035] The signal processing circuit 44 acquires biological data for generating information about the living body based on the detection values ​​of the optical sensors PD output from the AFE circuit 48. In the present disclosure, the information about the living body includes a pulse wave acquired using infrared light or red light.

[0036] The memory circuitry 46 temporarily stores signals processed by the signal processing circuitry 44. In the present disclosure, the memory circuitry 46 stores various setting information and a biometric data acquisition region set in a biometric data acquisition region setting process flow described below when the signal processing circuitry 44 acquires biometric data. The memory circuitry 46 may include, for example, a RAM (Random Access Memory), a ROM (Read Only Memory), an EEPROM (Electrically Erasable Programmable Read Only Memory), or the like. The memory circuitry 46 may also be a register circuit or the like.

[0037] 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 according to the embodiment. As shown in Fig. 3, the sensor area 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.

[0038] 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.

[0039] The signal line SGL extends in the second direction Dy and is connected to the photosensors PD of 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 simply be referred to as signal lines SGL.

[0040] 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 region 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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 the AFE circuit 48.

[0045] 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.

[0046] 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).

[0047] 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 AFE circuit 48 or the number of IC terminals.

[0048] The signal line selection circuit 16 may bundle multiple signal lines SGL and connect them to the AFE circuit 48. Specifically, the control circuit 122 (see FIG. 1) simultaneously supplies the selection signal ASW to multiple 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 AFE circuit 48. As a result, signals detected in the block units PAG1 and PAG2 are output to the AFE circuit 48. In this case, signals from multiple partial detection areas PAA (photosensors PD) included in the block units PAG1 and PAG2 are integrated and output to the AFE circuit 48.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 4 is a circuit diagram showing a plurality of partial detection areas of the detection device according to the embodiment. It should be noted that FIG. 4 also shows the circuit configuration of the AFE circuit 48. As shown in FIG. 4, the partial detection area PAA includes a photosensor PD, a capacitance element Ca, and a first switching element T r and The capacitance 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 one end of the capacitance element Ca and the anode of the photosensor PD.

[0057] 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.

[0058] 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).

[0059] 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.

[0060] A sensor power supply signal (potential) 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 to the cathode of the optical sensor PD from the power supply circuit 123.

[0061] When light is irradiated onto the partial detection area PAA, a current corresponding to the amount of light flows through the photosensor PD, causing a charge corresponding to the amount of light to accumulate in the capacitive element Ca. When the first switching element Tr is turned on, a current corresponding to the charge accumulated in the capacitive element Ca flows through the signal line SGL. The signal line SGL is connected to the AFE 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.

[0062] In the AFE circuit 48, the switch SSW is turned on during the readout period Pdet (see FIG. 6), and the AFE circuit 48 is connected to the signal line SGL. The detection signal amplifier circuit 42 of the AFE circuit 48 converts the current supplied from the signal line SGL into a voltage and amplifies it. A reference potential (Vref) having a fixed potential is input to the non-inverting input terminal (+) of the detection signal amplifier circuit 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 circuit 42 also has a capacitance element Cb and a reset switch RSW. During the reset period Prst (see FIG. 6), the reset switch RSW is turned on, and the charge of the capacitance element Cb is reset.

[0063] Next, the configuration of the optical sensor PD will be described. Fig. 5 is a schematic partial cross-sectional view of the optical sensor according to the embodiment. The sensor region 10 of the detection device 1 includes a sensor substrate 21, a sensor structure 22, and a protective film 23. The sensor substrate 21 is an insulating substrate formed of, for example, a film-like resin.

[0064] The sensor structure 22 includes a TFT layer 221, an anode electrode (lower electrode) 222, a photosensor PD, and a cathode electrode (upper electrode) 226.

[0065] Various wirings such as gate lines GCL and signal lines SGL are provided on the TFT layer 221. The sensor substrate 21 and the TFT layer 221 form a drive circuit that drives the sensor, and are also called a backplane.

[0066] The photosensor PD has an active layer 224, an electron transport layer (lower buffer layer) 223 provided between the active layer 224 and an anode electrode (lower electrode) 222, and a hole transport layer (upper buffer layer) 225 provided between the active layer 224 and a cathode electrode (upper electrode) 226. In other words, the electron transport layer (lower buffer layer) 223, the active layer 224, and the hole transport layer (upper buffer layer) 225 of the photosensor PD are stacked in this order in a direction perpendicular to the sensor substrate 21.

[0067] The characteristics (for example, voltage-current characteristics and resistance value) of the active layer 224 change depending on the light irradiated thereto. An organic material is used as the material of the active layer 224. Specifically, the active layer 224 has a bulk heterostructure in which a p-type organic semiconductor and an n-type organic semiconductor, an n-type fullerene derivative (PCBM), are mixed. For example, C 60 (fullerene), PCBM (phenyl C61-butyric acid methyl ester), CuPc (copper phthalocyanine), F 16 CuPc (fluorinated copper phthalocyanine), rubrene (5,6,11,12-tetraphenyltetracene), PDI (perylene derivative), etc. can be used.

[0068] The active layer 224 can be formed by a vapor deposition (dry process) using these low molecular weight organic materials. In this case, the active layer 224 is formed by a vapor deposition (dry process) using, for example, CuPc and F 16 CuPc laminated film or rubrene and C 60 The active layer 224 may be a laminated film of the above-mentioned low molecular weight organic material and high molecular weight organic material. The active layer 224 may also be formed by a wet process. In this case, the active layer 224 is made of a material that is a combination of the above-mentioned low molecular weight organic material and 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 active layer 224 may be a film in which P3HT and PCBM are mixed, or a film in which F8BT and PDI are mixed.

[0069] The electron transport layer (lower buffer layer) 223 and the hole transport layer (upper buffer layer) 225 are provided to facilitate the electrons and holes generated in the active layer 224 reaching the anode electrode (lower electrode) 222 or the cathode electrode (upper electrode) 226. The electron transport layer (lower buffer layer) 223 is in direct contact with the anode electrode (lower electrode) 222. The active layer 224 is in direct contact with the electron transport layer (lower buffer layer) 223. The electron transport layer (lower buffer layer) 223 is made of ethoxylated polyethyleneimine (PEIE).

[0070] The hole transport layer (upper buffer layer) 225 is in direct contact with the active layer 224, and the cathode electrode (upper electrode) 226 is in direct contact with the hole transport layer (upper buffer layer) 225. The hole transport layer (upper buffer layer) 225 is a metal oxide layer. Tungsten oxide (WO), molybdenum oxide, or the like is used as the metal oxide layer.

[0071] The materials and manufacturing methods of the electron transport layer (lower buffer layer) 223, the active layer 224, and the hole transport layer (upper buffer layer) 225 are merely examples, and other materials and manufacturing methods may be used.

[0072] The anode electrode (lower electrode) 222 and the cathode electrode (upper electrode) 226 face each other with the photosensor PD interposed therebetween. The cathode electrode (upper electrode) 226 is made of a light-transmitting conductive material such as ITO (Indium Tin Oxide). The anode electrode (lower electrode) 222 is made of a metal material such as silver (Ag) or aluminum (Al). Alternatively, the anode electrode (lower electrode) 222 may be made of an alloy material containing at least one of these metal materials.

[0073] By controlling the film thickness of the anode electrode (lower electrode) 222, the anode electrode (lower electrode) 222 can be formed as a semi-transparent electrode having light transmittance. For example, the anode electrode (lower electrode) 222 has a light transmittance of about 60% when formed of an Ag thin film with a film thickness of 10 nm. In this case, the optical sensor PD can detect the first light LD irradiated from, for example, the first surface FD side.

[0074] The protective film 23 is provided on the second face FU to cover the cathode electrode (upper electrode) 226. The protective film 23 is a passivation film, and is provided to protect the photosensor PD.

[0075] 4 illustrates a configuration in which the sensor power supply signal VDDSNS is supplied from the power supply circuit 123 to the anode of the photosensor PD, and the reference signal COM, which serves as the initial potential of the signal line SGL and the capacitive element Ca, is supplied from the power supply circuit 123 to the cathode of the photosensor PD, but it may also be a configuration in which the sensor power supply signal VDDSNS is supplied from the power supply circuit 123 to the cathode of the photosensor PD, and the reference signal COM, which serves as the initial potential of the signal line SGL and the capacitive element Ca, is supplied from the power supply circuit 123 to the anode of the photosensor PD. In this case, unlike the configuration described above, the photosensor PD has an active layer 224, a hole transport layer (lower buffer layer) 223 provided between the active layer 224 and the cathode electrode (lower electrode) 222, and an electron transport layer (upper buffer layer) 225 provided between the active layer 224 and the anode electrode (upper electrode) 226. In other words, the hole transport layer (lower buffer layer) 223, the active layer 224, and the electron transport layer (upper buffer layer) 225 of the photosensor PD are stacked in this order in a direction perpendicular to the sensor substrate 21.

[0076] In addition, in the present disclosure, the photosensor PD is not limited to an organic photodiode (OPD), and may be, for example, a silicon photodiode (SiPD).

[0077] Next, an operation example of the detection device 1 will be described. FIG. 6 is a timing waveform diagram showing an operation example of the detection device according to the embodiment. FIG. 7 is a timing waveform diagram showing an operation example of the reset period in FIG. 6. FIG. 8 is a timing waveform diagram showing an operation example of the readout period in FIG. 6. FIG. 9 is a timing waveform diagram showing an operation example of 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 a first example of the relationship between the drive of the sensor region of the detection device according to the embodiment and the lighting operation of the light source.

[0078] 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 creates a reverse bias of 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 drive 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.

[0079] 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.

[0080] 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 at least one of 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 a high-level voltage (power supply voltage VDD). As a result, the signal line SGL of the partial detection area PAA selected by the selection signal ASW1 is connected to the AFE 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 AFE circuit 48.

[0081] 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).

[0082] 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.

[0083] 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 actual exposure period, which is the period during which the photosensor PD charges the capacitor Ca. It does not include periods during which light is irradiated outside of this period. The charge stored in the capacitor Ca during the reset period Prst flows through 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 area PAA corresponding to each gate line GCL have different start and end times. Each exposure period 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 exposure period 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.

[0084] 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.

[0085] 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.

[0086] Specifically, as shown in FIG. 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 the 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 the 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 connected to the AFE circuit 48. As a result, the detection signal Vdet is supplied to the AFE circuit 48 for each partial detection area PAA. Note that a predetermined number of the selection signals ASW1, ..., ASW6 may be simultaneously supplied to the signal line selection circuit 16. In this case, a predetermined number of signal lines SGL of the partial detection area PAA selected by the gate drive signal Vgcl(1) are simultaneously connected to the AFE circuit 48.

[0087] 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 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 or simultaneously selects the signal lines SGL based on the selection signal ASW. The signal line selection circuit 16 sequentially or simultaneously connects each signal line SGL to one AFE circuit 48. This allows the detection device 1 to output the detection signals Vdet of all partial detection areas PAA to the AFE circuit 48 during the readout period Pdet.

[0088] 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.

[0089] 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 AFE circuit 48 and the capacitance (capacitor element Ca) of the partial detection area PAA are electrically connected via the third switching element TrS. As a result, the output (Vout) of the third switching element TrS (see FIG. 4) changes 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 circuit 42 in the AFE circuit 48, and the output voltage of the detection signal amplifier circuit 42 becomes a voltage corresponding to the charge accumulated in the capacitance element Cb. At this time, the inverting input terminal of the detection signal amplifier circuit 42 becomes the imaginary short potential of the operational amplifier, and therefore becomes the reference potential (Vref). The output voltage of the detection signal amplifier circuit 42 is read by the A / D conversion circuit 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. In addition, ASW(k), ASW(k+1)... in FIG. 8 It is one of ASW1 to ASW6 in the above.

[0090] 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 circuit 42 of the AFE circuit 48. At this time, the non-inverting input (+) of the detection signal amplifier circuit 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 circuit 42 causes the output (Vout) of the third switching element TrS to also become the reference potential (Vref) voltage. 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 at the point 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 circuit 42 becomes a voltage corresponding to the capacitance of the capacitor Cb. The output voltage of the detection signal amplifier circuit 42 is read by the A / D conversion circuit 43. The voltage of the capacitance element Cb is, for example, the voltage between two electrodes provided in the capacitor that constitutes the capacitance element Cb.

[0091] 10, the detection device 1 executes the above-described reset period Prst, exposure period Pex{(1)...(M)}, and readout period Pdet during periods t(1), t(2), t(3), and t(4), respectively. 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 periods t(1), t(2), t(3), and t(4), i.e., 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.

[0092] 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 first 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 detection of one frame. 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.

[0093] 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 AFE circuit 48. Furthermore, the gate line driving circuit 15 may scan a plurality of gate lines GCL by thinning them out.

[0094] As shown in FIG. 8, in 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.

[0095] 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.

[0096] As a specific example of information about a living body acquired by the detection device 1, 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 below.

[0097] When acquiring a pulse wave for calculating blood oxygen saturation (SpO2), for example, the first light emitted from the first light source 61 is 600 nm or more and 700 nm or less, specifically, red visible light (red light) of about 660 nm, and the second light emitted from the second light source 62 is 780 nm or more and 950 nm or less, specifically, infrared light of about 850 nm. When acquiring a human's blood oxygen saturation (SpO2), the pulse wave acquired using the first light (red light) and the pulse wave acquired using the second light (infrared light) are used.

[0098] 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).

[0099] 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).

[0100] 10, in detecting one frame in period t(1), the control circuit 122 (detection control circuit 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 circuit 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.

[0101] 10, 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. As a result, a first detection value detected by the optical sensor PD based on the first light and a second detection value detected by the optical sensor PD based on the second light are output to the AFE circuit 48 in a time-division manner.

[0102] Here, 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 to minimize the difference in detection timing between the first detection value detected by the first light and the second detection value detected by the second light. Below, an example of operation that can minimize the difference in detection timing between the first detection value detected by the first light and the second detection value detected by the second light will be described with reference to FIGS. 11 and 12.

[0103] Fig. 11 is a second explanatory diagram for explaining a second example of the relationship between the driving of the sensor region of the detection device according to the embodiment and the lighting operation of the light source, and Fig. 12 is a timing waveform diagram showing an example of operation in the second example shown in Fig. 11.

[0104] In the second example shown in Fig. 11, the first light is red light and the second light is infrared light. In the second example shown in Fig. 11, the first reset period Prst1 in the detection operation using the first light and the second reset period Prst2 in the detection operation using the second light are indicated by solid arrows, and the first readout period Pdet1 in the detection operation using the first light and the second readout period Pdet2 in the detection operation using the second light are indicated by dashed arrows.

[0105] In the second example shown in FIG. 11, a detection operation using the first light is performed during periods t(1), t(3), and so on, and a detection operation using the second light is performed during periods t(2), t(4), and so on. Hereinafter, the periods t(1), t(3), and so on during which the detection operation using the first light is performed will also be referred to as the "first light detection period," and the periods t(2), t(4), and so on during which the detection operation using the second light is performed will also be referred to as the "second light detection period." Furthermore, the first exposure period Pex1 of the first light detection period, the first readout period Pdet1 of the first light detection period, the second exposure period Pex2 of the second light detection period, and the second readout period Pdet2 of the second light detection period form one frame (1F) to detect the first and second detection values ​​used to calculate blood oxygen saturation (SpO2). In the second example shown in FIGS. 11 and 12, the light emission period of the first light source 61 and the first exposure period Pex1 of the first light detection period approximately coincide with each other. In the second example shown in FIGS. 11 and 12, the light emission period of the second light source 62 and the second exposure period Pex2 in the second light detection period are approximately the same.

[0106] 11, the first reset period Prst1 in the first light detection period and the second readout period Pdet2 in the second light detection period of the previous frame are executed in parallel. Also, in one frame (1F), the second reset period Prst2 in the second light detection period and the first readout period Pdet1 in the first light detection period are executed in parallel. This makes it possible to reduce the difference ΔPt in the detection timing between the first detection value and the second detection value used to calculate blood oxygen saturation (SpO2).

[0107] 11, a gate drive signal Vgcl is supplied to the gate line GCL for each row, and multiple first switching elements Tr belonging to a given row are turned on. Specifically, as shown in FIG. 12, 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.

[0108] 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 the 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 the connected state, and the signal line selection circuit 16 connects the multiple signal lines SGL to the AFE circuit 48 in a predetermined order for each column. As a result, the detection signal Vdet is supplied to the AFE circuit 48 for each partial detection area PAA.

[0109] 12, in the second example, 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.

[0110] 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).

[0111] 12, 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.

[0112] Thereafter, at time t23, the gate line driving circuit 15 sets the gate driving signal Vgcl(1) to a low level voltage. As a result, the plurality of first switching elements Tr in a predetermined row are put into a non-connected state. At time t24, the control circuit 122 sets the reset signal RST2 to a low level voltage. As a result, the readout period Pdet and reset period Prst of the first row end. In addition, between times t22 and t24, the reset switch RSW is changed from the OFF state to the ON state, and then to the OFF state. AFE The capacitance Cb of the circuit 48 is reset.

[0113] 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, the readout period Pdet and 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 detecting one frame (1F).

[0114] In the second example shown in FIGS. 11 and 12 , as described above, the first reset period Prst1 in the first light detection period (t(1), t(3), . . .) and the second readout period Pdet2 in the second light detection period of the previous frame are executed in parallel. Also, the second reset period Prst2 in the second light detection period (t(2), t(4), . . .) and the first readout period Pdet1 in the first light detection period are executed in parallel. Then, the first detection value and the second detection value used to calculate the blood oxygen saturation (SpO2) are detected, with the first exposure period Pex1 in the first light detection period, the first readout period Pdet1 in the first light detection period, the second exposure period Pex2 in the second light detection period, and the second readout period Pdet2 in the second light detection period forming one frame (1F). 11 and 12, the first reset period Prst1 and the second readout period Pdet2 are executed in parallel, and the second reset period Prst2 and the first readout period Pdet1 are executed in parallel. This makes it possible to reduce the deviation (time difference) ΔPt in the detection timing of the first detection value and the second detection value used to calculate the blood oxygen saturation (SpO2) compared to the first example shown in FIG.

[0115] Next, an application example of the detection device 1 according to the first embodiment will be described.

[0116] Fig. 13 is a schematic diagram showing a device illustrating a first application example of a detection device according to an embodiment. The device 200 shown in Fig. 13 is a ring-shaped wearable device that can be attached to and detached from the human body, and is worn on a finger Fg of the human body. The finger Fg includes the thumb, index finger, middle finger, ring finger, little finger, etc. The detection device 1 can detect biometric information about the living body from the finger Fg on which it is worn.

[0117] 14 is a schematic diagram showing a device illustrating a second application example of the detection device according to the embodiment. The device 200a shown in FIG. 14 may be a ring-shaped wearable device such as a smart watch, a wristwatch, or a wristband. The device 200a is worn on the arm of a human body HB. The human body HB includes a wrist, an arm, a leg, etc. The detection device 1 can detect biological information about the living body from the human body HB to which the device 200a is worn.

[0118] To obtain biological information such as pulse waves and blood flow, it is necessary to acquire time domain data in which detection values ​​acquired by the optical sensor PD are arranged in time series. In this embodiment, a specific example of processing that can acquire biological information that changes over time, such as pulse waves and blood flow, as image information within the detection plane in devices 200, 200a (see FIGS. 13 and 14) that employ the detection apparatus 1 having the above-described configuration will be described.

[0119] FIG. 15 is a flowchart showing an example of processing in the signal processing circuit of the detection device according to the embodiment.

[0120] The signal processing circuit 44 first stores the detection values ​​of the optical sensors PD acquired by the AFE circuit 48 during the predetermined period P in the storage circuit 46 as first time domain data (first time domain data acquisition process, step S100).

[0121] The predetermined period P during which the detection values ​​for each optical sensor PD are acquired is set to a length suitable for the pulsation frequency of the biological information to be detected by the detection device 1. Specifically, when the biological information to be detected by the detection device 1 is a pulse wave or blood flow, the predetermined period P during which the detection values ​​for each optical sensor PD are acquired is set to, for example, 10 to 20 seconds. When the biological information to be detected by the detection device 1 is a pulse wave, the pulsation frequency is, for example, about 1 to 1.5 Hz. When the biological information to be detected by the detection device 1 is blood flow, the pulsation frequency is, for example, about 0.05 to 0.15 Hz.

[0122] Fig. 16 is an image diagram of time domain data acquired within a predetermined period within the detection surface. In the example shown in Fig. 16, each detection value (n, m, p) corresponding to the optical sensor PD of n columns and m rows is acquired at a sampling period t of the A / D conversion circuit 43 within a predetermined period P (n is a natural number from 1 to N, m is a natural number from 1 to M, and p is a natural number from 1 to P / t).

[0123] The signal processing circuit 44 converts the acquired first time domain data into a time domain matrix A having elements each of the detected values ​​(n, m, p) in (P / t) columns and (N×M) rows shown in the following formula (1) (matrix conversion process, step S200). In the time domain matrix A, the detected values ​​(n, m, p) are arranged in descending order of time along the rows, and the detected values ​​(n, m, p) are arranged in spatial order along the columns. The order of the detected values ​​(n, m, p) along the columns in the time domain matrix A is not limited to the order shown in the following formula (1).

[0124]

number

[0125] Furthermore, the signal processing circuit 44 reads out the first time domain data acquired in time series for each optical sensor PD from the memory circuit 46, and performs FFT processing on the first time domain data for each unit frequency set in advance to calculate the power spectral density (PSD) (power spectral analysis processing, step S300).

[0126] Based on the result of the power spectrum analysis process, the signal processing circuit 44 performs singular value decomposition (SVD) on the time domain matrix A shown in the above equation (1) as shown in the following equation (2) (singular value decomposition process, step S400).

[0127]

number

[0128] The matrix S shown in the above equation (2) is expressed in descending order as λ1, λ2, . . . , λ K are arranged as diagonal elements, and the non-diagonal elements are "0". k is the singular value of the time domain matrix A that indicates the unit frequency in the power spectrum analysis process, and the singular value λ kThe number K is a value determined according to the unit frequency in the power spectrum analysis process.

[0129] Furthermore, U in the above equation (2) indicates the spatial distribution, and the singular value λ k Each element u corresponding to * k indicates the left singular vectors arranged in the row direction.

[0130] In addition, V in the above equation (2) represents the time distribution, and the singular value λ k Each element v corresponding to * k indicates right singular vectors arranged in the column direction.

[0131] Fig. 17 is a conceptual diagram for explaining an outline of the singular value decomposition process. As shown in Fig. 17, the matrix U indicating the spatial distribution can be expressed as an orthogonal matrix with K columns (N × M) rows. Furthermore, the matrix V indicating the temporal distribution can be expressed as an orthogonal matrix with P / t columns and K rows.

[0132] The orthogonal matrix U that represents the spatial distribution has singular values ​​λ k Each element u corresponding to * k is the descending order of power spectral density (u * 1,u * 2,···,u * K ) are arranged in the orthogonal matrix U. * k is the singular value λ k The spatial component u of the fluctuation in the component corresponding to k are arranged in the column direction (space (N × M) direction) in the same order as the column direction of the time domain matrix A.

[0133] The orthogonal matrix V representing the time distribution has singular values ​​λ k Each element v corresponding to * k is the descending order of power spectral density in the column direction (v * 1,v * 2,···v * K ) are arranged in the orthogonal matrix V.* k is the singular value λ k The time period component v of the fluctuation in the component corresponding to k are arranged in chronological order in the row direction (time (P / t) direction).

[0134] The left side (time domain matrix A) and the right side (USV T ) can be mutually converted. In this disclosure, the right-hand side (USV T ) and apply predetermined biometric information acquisition conditions to the

[0135] In the present disclosure, acquisition conditions for acquiring desired biological information such as pulse waves and blood flow are stored in advance as biological information acquisition conditions in the memory circuitry 46. The signal processing circuitry 44 reads out the biological information acquisition conditions stored in the memory circuitry 46, and performs inverse calculation of second time domain data that satisfies the biological information acquisition conditions using the above equations (1) and (2) (second time domain data inverse calculation process, step S500).

[0136] The signal processing circuit 44 calculates the singular values ​​λ1, λ2, . . . , λ2 included in the singular value matrix S in the above equation (2). K The second time domain data is inversely calculated based on the singular values ​​that satisfy the above-mentioned biometric information acquisition conditions. More specifically, the singular values ​​λ1, λ2, . . . , λ2 included in the singular value matrix S are K Among these, singular values ​​that satisfy the above-mentioned biometric information acquisition conditions are kept, and singular values ​​that do not satisfy the biometric information acquisition conditions are set to "0", and the time domain matrix A shown in the above equation (1) is inversely calculated. Then, the obtained time domain matrix A is inversely transformed into second time domain data in the form shown in FIG.

[0137] The biometric information acquisition conditions are set according to the characteristics of the human body. For example, the biometric information acquisition conditions for measuring blood flow velocity may be a frequency range in which the time when the phase of outputs at two points, determined from the known blood flow velocity for each attachment site, falls within a predetermined range, and singular values ​​corresponding to other frequencies are set to "0". Also, for example, the biometric information acquisition conditions for measuring pulse waves may be a frequency range in which a predetermined frequency range including the frequency of the waveform peak is set, and singular values ​​corresponding to other frequencies are set to "0". In this case, the predetermined frequency range is set within a range that can be considered as a human pulse wave. Alternatively, for example, frequency components that can be identified in advance as noise components (for example, singular values ​​λ 1 shown in FIG. 24 (described later)) may be set. b The frequency component (which is considered to be a power supply noise component multiplied by one frame period in the detection device 1) may be configured so that the singular value corresponding to this frequency component is "0".

[0138] The signal processing circuit 44 generates biometric information to be detected by the detection device 1 using the second time domain data for each optical sensor PD obtained by the second time domain data inverse operation process (biometric information generation process, step S600).

[0139] The above-described processing can remove noise components other than the biological information to be detected by the detection device 1, such as pulse waves and blood flow (for example, body movement noise caused by human movement, biological signals not to be detected, or noise components of the AC frequency of the commercial power supply (for example, 50 [Hz], 60 [Hz])).

[0140] Fig. 18 is a waveform diagram showing an example of a pulse wave. Fig. 19 is an image diagram showing an example of each frequency component included in a pulse wave. Fig. 20 is an image diagram showing an example of a frequency distribution obtained by FFT processing of time domain data constituting the waveform.

[0141] As shown in Figures 18, 19, and 20, the pulse wave contains multiple frequency components. butIf the period of the frequency components constituting the pulse wave overlaps with the period of noise components other than the biological information to be detected by the detection device 1, or if the frequencies of the frequency components of the pulse wave and the noise components are close to each other, it may not be possible to distinguish the frequency components of the pulse wave from the noise components using FFT processing.

[0142] Fig. 21 is an image diagram of FFT processing. Fig. 22 is an image diagram of processing using singular value decomposition according to an embodiment. Figs. 21 and 22 show frequency components of a pulse wave as biological information to be detected by the detection device 1.

[0143] FFT processing can obtain the magnitude (amplitude) of the frequency components of the pulse wave contained in the pulse waveform, but there is a possibility that an appropriate amplitude value cannot be obtained due to noise components being superimposed on the pulse wave components, as shown in Figure 21. Furthermore, it is not possible to obtain the phase difference components of the detected values ​​within the detection plane, i.e., the time-series changes of each detected value within the detection plane, as image information.

[0144] In contrast, in the processing according to the above-described embodiment, it is possible to remove noise components other than the desired frequency components by singular value decomposition, as shown in Fig. 22, and it is possible to acquire the biological information to be detected as image information within the detection plane using the time domain data (second time domain data) for each optical sensor PD after the noise components have been removed. Hereinafter, the concept of obtaining the time domain data (second time domain data) for each optical sensor PD from which the frequency components other than the desired frequency components have been removed in the processing according to the above-described embodiment will be described.

[0145] FIG. 23 is a conceptual diagram showing an example of frequency components decomposed by the singular value decomposition processing according to the embodiment.

[0146] In the process according to the present embodiment described above, the singular value decomposition process (step S400 in FIG. 15) is performed to obtain K singular values ​​λ kAt this time, among the K singular values ​​included in the singular value matrix S, singular values ​​that do not satisfy the above-mentioned biometric information acquisition condition are set to "0", and singular values ​​that satisfy the biometric information acquisition condition are left, and the second time domain data inverse operation process (step S500 in FIG. 15) is executed. Specifically, in the example shown in FIG. 23, for example, the singular value λ a Frequency components and singular values ​​λ c are frequency components that form the biological information to be detected by the detection device 1, and the singular value λ b When the frequency components of other singular values ​​including a and the singular value λ c and the singular value λ b The other singular values ​​including λ are set to "0", and the second time domain data inverse operation process (step S500 in FIG. 15) is performed. b The time domain data (second time domain data) is obtained by removing the frequency components of other singular values ​​including the singular value λ. a Frequency components and singular values ​​λ c The time domain matrix A obtained by the frequency components of a+c can be expressed by the following equation (3).

[0147] A a+c =λ a u * a v * a +λ c u * c v * c ···(3)

[0148] 24 is a conceptual diagram showing an example of biological information acquired as image information by the detection device according to the embodiment. In the conceptual diagram shown in FIG. 24, a singular value λ , which is a noise component, b The frequency components of the singular values ​​λ , which form the biological information to be detected by the detection device 1, are removed. a Frequency components and singular values ​​λ c10 illustrates an image diagram of image information based on frequency components.

[0149] Then, the time domain data (second time domain data) for each optical sensor PD obtained by the second time domain data inverse operation process is used to execute the biometric information generation process (step S600 in FIG. 15). b The biological information from which the frequency components are removed can be acquired as image information within the detection plane.

[0150] By the above-described processing, desired biological information such as pulse waves and blood flow can be acquired as image information within the detection plane.

[0151] In the above-described embodiment, an example has been described in which the biometric information generation process (step S600 in FIG. 15) is executed in the signal processing circuit 44. However, it is also possible to transmit the time domain data (second time domain data) for each optical sensor PD after removing the noise components to the host via the output circuit 126, and generate the biometric information on the host side.

[0152] Although preferred embodiments of the present invention have been described above, the present invention is not limited to such embodiments. The contents disclosed in the embodiments are merely examples, and various modifications are possible without departing from the spirit of the present invention. Appropriate modifications made without departing from the spirit of the present invention naturally fall within the technical scope of the present invention. At least one of various omissions, substitutions, and modifications of components can be made without departing from the spirit of each of the above-described embodiments and modifications. [Explanation of symbols]

[0153] 1. Detection device 10 Sensor Area 11 Detection control circuit 15 Gate line driving circuit 16 Signal line selection circuit 21 Sensor substrate 22 Sensor structure 23 Protective film 40 Detection circuit 42 Detection signal amplifier circuit 43 A / D conversion circuit 44 Signal Processing Circuit 46 Memory circuit 47 Detection timing control circuit 48 AFE circuits 61 1st light source (light source) 62 Second light source (light source) 122 control circuit 123 Power supply circuit 126 Output circuit 200,200a devices 221 TFT layer 222 Anode electrode (lower electrode) (or cathode electrode (lower electrode)) 223 Electron transport layer (lower buffer layer) (or hole transport layer (lower buffer layer)) 224 Active layer 225 Hole transport layer (upper buffer layer) (or electron transport layer (upper buffer layer)) 226 Cathode electrode (upper electrode) (or anode electrode (upper electrode)) AA detection area GA peripheral area GCL Gate line PD light sensor Pdet read period Pdet1 First read period Pdet2 Second read period Pex, Pex1, Pex2 exposure period Pex1 First exposure period Pex2 Second exposure period RSW Reset switch SGL signal line

Claims

1. a plurality of optical sensors arranged on the detection surface; a light source that irradiates the optical sensor with light; an AFE circuit that acquires detection values ​​for each of the plurality of optical sensors; a signal processing circuit that acquires predetermined biological information based on first time domain data acquired in time series of the detection values; Equipped with The signal processing circuit transforming the first time domain data into a time domain matrix and performing singular value decomposition on the transformed data; and inversely computing second time domain data based on a predetermined singular value among a plurality of singular values ​​obtained as a result of the singular value decomposition; acquiring the biological information that changes over time as image information using the second time domain data; The signal processing circuit performing a power spectrum analysis of the first time domain data; generating a singular value matrix in which a plurality of singular values ​​are arranged as diagonal elements in descending order of the power spectral density obtained by the power spectral analysis processing; In the singular value decomposition, left singular vectors are generated which indicate a spatial distribution in which elements corresponding to the plurality of singular values ​​are arranged in a row direction in descending order of power spectral density, and right singular vectors are generated which indicate a time distribution in which elements corresponding to the plurality of singular values ​​are arranged in a column direction in descending order of power spectral density, The singular value decomposition is When the time domain matrix is ​​A, the singular value matrix is ​​S, the left singular vector is U, the right singular vector is V, the singular values ​​that are the elements of the singular value matrix S are λ k (k is a natural number from 1 to K), each element of the left singular vector U is u * k , and each element of the right singular vector V is v * k , then it can be expressed using the following equation (1): Detection device. [Equation 1]

2. the light sensor is an organic photodiode; an active layer; an upper electrode provided with an upper buffer layer sandwiched between the upper electrode and the active layer; a lower electrode provided with a lower buffer layer sandwiched between the lower electrode and the active layer; having The detection device according to claim 1 .

3. Further comprising a memory circuit storing biometric information acquisition conditions for acquiring the biometric information, the signal processing circuit reads out the biological information acquisition condition from the storage circuit, and performs an inverse calculation on the second time domain data that satisfies the biological information acquisition condition using the above formula (1).

3. The detection device according to claim 1 or 2.

4. The signal processing circuit performing an inverse operation on the second time domain data by setting singular values ​​that do not match the biometric information acquisition condition, among the K singular values ​​included in the singular value matrix, to zero; The detection device according to claim 3 .

5. The light source is a first light source that irradiates at least the optical sensor with first light; The detection device according to claim 1 .

6. the first light is red light or infrared light; The detection device according to claim 5 .

7. the first light is blue light or green light; The detection device according to claim 5 .

8. The light source is a first light source that irradiates the optical sensor with first light; a second light source that irradiates the optical sensor with second light; Including, The detection device according to claim 1 .

9. the first light is red light, the second light is infrared light; The detection device according to claim 8.

10. A detection device according to claim 1, It has a ring-shaped shape that can be attached to and detached from the human body. Wearable device.

11. It is worn on the human finger, The wearable device of claim 10.

12. Worn on the wrist or arm of a human body, The wearable device of claim 10.

13. It is attached to the human foot, The wearable device of claim 10.

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