Detection apparatus and wearable device

Abstract

Provided are a detection apparatus and a wearable device capable of improving biosignal acquisition accuracy. The present invention comprises: a sensor region (10) which has a plurality of detection regions arranged therein in a planar shape; an elastic member (EB) which is translucent and covers the sensor region (10); a light source which irradiates the sensor region (10) with light; and a detection circuit which, on the basis of data acquired from the sensor region (10), acquires a periodically changing biosignal of a subject. The sensor region (10) includes a light-shielded region (SA) in which the surface of the elastic member (EB) is covered with a light-shielding pattern (S), and an open region (OA) in which the surface of the elastic member (EB) is not covered with the light-shielding pattern (S). The detection circuit acquires, as the biosignal, the difference between a first signal acquired in the open region (OA) and a second signal acquired in the light-shielded region (SA) and scaled at a predetermined ratio.

Description

Detection apparatus and wearable device

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

[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 depending on the amount of light irradiated.

[0003] US Patent Application Publication No. 2018 / 0012069

[0004] The optical sensor is attached to, for example, the subject's finger, wrist, etc. When a detection device of this type is attached to the subject's finger or wrist to acquire a pulse wave, irregular body movement noise may occur due to the movement of the subject's finger, arm, etc., which may reduce the accuracy of acquiring the biological signal.

[0005] The present disclosure aims to provide a detection apparatus and a wearable device that can improve the accuracy of acquiring biological signals.

[0006] A detection device according to one aspect of the present disclosure comprises a sensor area having a plurality of detection regions arranged in a plane, a light-transmitting elastic member covering the sensor area, a light source that irradiates the sensor area with light, and a detection circuit that acquires a periodically fluctuating biological signal of a subject based on data acquired from the sensor area, wherein the sensor area includes a light-shielding region where the surface of the elastic member is covered with a light-shielding pattern, and an opening region where the surface of the elastic member is not covered with the light-shielding pattern, and the detection circuit acquires, as the biological signal, the difference between a first signal acquired in the opening region and a second signal acquired in the light-shielding region and scaled at a predetermined ratio.

[0007] 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.

[0008] FIG. 1 is a plan view showing a detection device according to an embodiment. FIG. 2 is a block diagram showing an example of the configuration of the detection device according to an embodiment. FIG. 3 is a circuit diagram showing the detection device according to an embodiment. FIG. 4 is a circuit diagram showing multiple detection regions. FIG. 5 is a diagram showing an example of a schematic cross-sectional configuration of an optical sensor according to an embodiment. FIG. 6 is a timing waveform diagram showing an example of operation of the detection device according to an embodiment in one frame period. FIG. 7 is a timing waveform diagram showing an example of operation of the detection device according to an embodiment in a reset period in FIG. 6. FIG. 8 is a timing waveform diagram showing an example of operation of the readout period in FIG. 6. FIG. 9 is a timing waveform diagram showing an example of operation of a drive period of one gate line included in the readout period in FIG. 6. FIG. 10 is an explanatory diagram illustrating the relationship between driving of the sensor region of the detection device according to an embodiment and the lighting operation of the light source. FIG. 11 is a schematic diagram showing a first application example of the detection device according to an embodiment. FIG. 12 is a schematic diagram showing a second application example of the detection device according to an embodiment. FIG. 13A is a plan view of a sensor region according to an embodiment. FIG. 13B is a cross-sectional view of the A-A line shown in FIG. 13A. FIG. 14A is a diagram showing an example of a time-domain signal acquired in each detection region of an aperture region. FIG. 14B is a diagram showing an example of a time domain signal acquired in each detection region in the light-blocking region. FIG. 15 is a flowchart showing an example of a biosignal acquisition processing flow in the detection device according to the embodiment. FIG. 16 is a sub-flowchart showing an example of a raw data acquisition processing. FIG. 17 is a diagram showing F frames of detection values ​​in each detection region in the sensor region. FIG. 18 is a sub-flowchart showing an example of a first signal generation processing. FIG. 19 is a sub-flowchart showing an example of a second signal scaling processing. FIG. 20 is a sub-flowchart showing an example of a biosignal generation processing. FIG. 21 is a plan view of a sensor region according to a first modified example of the embodiment. FIG. 22 is a plan view of a sensor region according to a second modified example of the embodiment. FIG. 23 is a plan view of a sensor region according to a third modified example of the embodiment. FIG. 24 is a plan view of a sensor region according to a fourth modified example of the embodiment.

[0009] Modes (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by a person skilled in the art and those that are substantially identical. Furthermore, the components described below can be combined as appropriate. Furthermore, the disclosure is merely an example, and appropriate modifications that a person skilled in the art can easily conceive while maintaining the gist of the invention are naturally included within the scope of the present invention. Furthermore, for clarity of explanation, the drawings may show the width, thickness, shape, etc. of each part schematically compared to the actual embodiment. However, these are merely examples and are not intended to limit the interpretation of the present invention. Furthermore, in this specification and each figure, elements similar to those described above with reference to the previous figures may be designated by the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0010] 1 is a plan view showing a detection device according to an embodiment. In the present disclosure, the detection device 1 is configured as a detection device that is worn on, for example, a finger or wrist of a subject and detects the subject's pulse wave as biological information.

[0011] As shown in Fig. 1, the detection device 1 includes 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, an output circuit 126, a first light source 61, and a second light source 62. In the example shown in Fig. 1, the sensor region 10, the gate line driving circuit 15, and the signal line selection circuit 16 are provided on a sensor substrate 21. The AFE circuit 48 is provided on a flexible printed circuit board 71. The control circuit 122, the power supply circuit 123, and the output circuit 126 are provided on the control substrate 121. The control substrate 121 is electrically connected to the sensor substrate 21 via the flexible printed circuit board 71.

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

[0014] 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.

[0015] 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.

[0016] The output circuit 126 is, for example, a USB controller IC, and controls communication between the control circuit 122 and the host.

[0017] The sensor substrate 21 has a peripheral area GA outside the sensor area 10. The sensor area 10 is an area in which a plurality of optical sensors PD (see FIG. 4) are arranged in a matrix. The peripheral area GA is an area between the sensor area 10 and the edge of the sensor substrate 21 where no optical sensors PD are provided.

[0018] 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.

[0019] 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.

[0020] 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 terminals 124 and 125 provided on the control board 121, respectively.

[0021] 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).

[0022] The first light source 61 and the second light source 62 emit at least one of visible light, near-infrared light, and infrared light. The first light source 61 and the second light source 62 may emit light of different wavelengths or may emit light of the same wavelength. Specifically, for example, in a configuration including at least the first light source 61 (or the second light source 62), the first light emitted by the first light source 61 (or the second light source 62) may be red light or infrared light, or may be blue light or green light. Alternatively, for example, in a configuration including the first light source 61 and the second light source 62, the first light emitted by the first light source 61 may be red light, and the second light emitted by the second light source 62 may be infrared light. The present disclosure is not limited by the emission colors of the first light source 61 and the second light source 62.

[0023] In the present disclosure, light emitted from the first light source 61 and the second light source 62 is reflected by or transmitted through the surface or interior of, for example, the subject's finger or wrist, and then enters the sensor area 10. This allows the sensor area 10 to detect the subject's pulse wave.

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

[0025] 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.

[0026] 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 light source.

[0027] The gate line driving circuit 15 is a circuit that drives a plurality of gate lines GCL (see FIG. 3) based on various control signals. The gate line driving circuit 15 sequentially or simultaneously selects the plurality of 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 a plurality of photosensors PD connected to the gate lines GCL.

[0028] The signal line selection circuit 16 is a switch circuit that sequentially or simultaneously selects multiple 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 a detection signal Vdet of the photosensor PD to the detection circuit 40.

[0029] 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 to operate in synchronization with each other based on a control signal supplied from the detection control circuit 11.

[0030] 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.

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

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

[0033] The signal processing circuit 44 acquires the pulse wave of the subject based on the detection values ​​of the optical sensors PD output from the AFE circuit 48 .

[0034] The memory circuitry 46 temporarily stores the signals processed by the signal processing circuitry 44. The memory circuitry 46 may include, for example, a random access memory (RAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), etc. The memory circuitry 46 may also be a register circuit, etc.

[0035] Next, an example of the circuit configuration of the detection device 1 will be described. Fig. 3 is a circuit diagram showing the detection device according to the embodiment. As shown in Fig. 3, the sensor area 10 has a plurality of detection areas PAA arranged in a planar shape.

[0036] Specifically, the plurality of detection areas PAA are arranged in a matrix in the first direction Dx and the second direction Dy, for example. However, the present invention is not limited to this, and the plurality of detection areas PAA may be arranged in a staggered pattern in the sensor area 10.

[0037] An optical sensor PD is provided in each of the multiple detection areas PAA. The optical sensor PD outputs an electrical signal (electric potential) corresponding to the light irradiated thereon. In the following description, a configuration in which one optical sensor PD is provided in each of the multiple detection areas PAA will be described, but the number of optical sensors PD provided in each of the multiple detection areas PAA is not limited to one. A configuration in which multiple optical sensors PD are provided in each of the multiple detection areas PAA may also be used.

[0038] The gate lines GCL extend in the first direction Dx and are connected to a plurality of detection areas PAA arranged in the first direction Dx. Furthermore, a plurality of gate lines GCL(1), GCL(2), ..., GCL(8) are arranged in the 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. Although FIG. 3 shows eight gate lines GCL for ease of explanation, this is merely an example, and M gate lines GCL (M is a natural number, for example, M=256) may also be arranged.

[0039] The signal line SGL extends in the second direction Dy and is connected to the optical sensors PD of the multiple detection areas PAA arranged in the second direction Dy. The multiple 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 multiple 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, the present invention is not limited to this, 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 detection areas PAA arranged in the first direction Dx are selected as detection targets.

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

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

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

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

[0046] 3, the reset circuit 17 has a reference signal line Lvr, a reset signal line Lrst, and fourth switching elements TrR. The fourth switching elements TrR are provided corresponding to the multiple signal lines SGL. The reference signal line Lvr is connected to one of the sources or drains of the multiple fourth switching elements TrR. The reset signal line Lrst is connected to the gates of the multiple fourth switching elements TrR.

[0047] 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 detection areas PAA.

[0048] FIG. 4 is a circuit diagram showing multiple detection regions of the detection device according to the embodiment. FIG. 4 also shows the circuit configuration of the AFE circuit 48. As shown in FIG. 4, the detection region PAA includes a photosensor PD, a capacitive element Ca, and a first switching element Tr1. The capacitive element Ca is a capacitance (sensor capacitance) formed in the photosensor PD and is equivalently connected in parallel with the photosensor PD. Furthermore, the signal line capacitance Cc is a parasitic capacitance formed in the signal line SGL and is equivalently formed between the signal line SGL and one end of the capacitive element Ca and the anode of the photosensor PD.

[0049] 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 detection area PAA is an area surrounded by the gate lines GCL and the signal lines SGL.

[0050] 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).

[0051] The gates of the first switching elements Tr belonging to the plurality of 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 plurality of 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.

[0052] 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.

[0053] When light is irradiated onto the 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 capacitance element Ca. When the first switching element Tr is turned on, a current corresponding to the charge accumulated in the capacitance element Ca flows through the signal line SGL. The signal line SGL is connected to the 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 detection area PAA.

[0054] 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.

[0055] Next, the configuration of the optical sensor PD will be described. Fig. 5 is a diagram showing an example of a schematic cross-sectional configuration of an optical sensor according to an embodiment. The sensor region 10 of the detection device 1 includes a sensor structure 22 and a protective film 23 on a sensor substrate 20. The sensor substrate 20 is an insulating substrate formed of, for example, a film-like resin.

[0056] 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 .

[0057] Various wirings such as gate lines GCL and signal lines SGL are provided on the TFT layer 221. The sensor substrate 20 and the TFT layer 221 form a drive circuit that drives the sensor, and are also called a backplane.

[0058] 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 20.

[0059] 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, a low-molecular organic material, 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 (a derivative of perylene), or the like can be used.

[0060] 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 Laminated film with CuPc or rubrene and C ６０The 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 combines 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.

[0061] 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).

[0062] 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. The metal oxide layer is made of tungsten oxide (WO ３ ), molybdenum oxide, etc. are used.

[0063] 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.

[0064] 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 indium tin oxide (ITO). 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.

[0065] 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 can be formed of a 10 nm thick Ag thin film to have a light transmittance of about 60%. In this case, the photosensor PD can detect the first light LD irradiated from the first surface FD side, for example.

[0066] The protective film 23 is provided on the second surface 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.

[0067] 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 capacitance element Ca, is supplied from the power supply circuit 123 to the cathode of the photosensor PD, but, for example, 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 capacitance element Ca, is supplied from the power supply circuit 123 to the anode of the photosensor PD, may also be used. 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 20 .

[0068] 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).

[0069] Next, an example of operation of the detection device 1 will be described. Fig. 6 is a timing waveform diagram showing an example of operation in one frame period of the detection device according to the embodiment. Fig. 7 is a timing waveform diagram showing an example of operation in the reset period in Fig. 6. Fig. 8 is a timing waveform diagram showing an example of operation in the readout period in Fig. 6. Fig. 9 is a timing waveform diagram showing an example of operation in the drive period of one gate line included in the row readout period VR in Fig. 6. Fig. 10 is an explanatory diagram for explaining the relationship between driving of the sensor region of the detection device according to the embodiment and the lighting operation of the light source.

[0070] 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 is a signal that 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, but by applying a sensor power supply signal VDDSNS of substantially -1.25 V to the anode, the anode-cathode is reverse biased at substantially 2.0 V. After setting the reset signal RST2 to "H," the control circuit 122 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 for supplying a reset voltage by the reset signal RST2. As a result, the reference signal COM is supplied as a reset voltage to each signal line SGL. The reference signal COM is set to, for example, 0.75 V.

[0071] During the reset period Prst, the gate line driving circuit 15 sequentially selects gate lines GCL based on a start signal STV, a clock signal CK, and a reset signal RST1. The gate line driving circuit 15 sequentially supplies gate driving signals Vgcl {Vgcl(1) to Vgcl(M)} to the gate lines GCL. The gate driving signal Vgcl has a pulse waveform including 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 driving signals Vgcl(1), ..., Vgcl(M) are sequentially supplied to each gate line GCL, causing the multiple first switching elements Tr to be sequentially turned on row by row and a reset voltage to be supplied. For example, the voltage of 0.75 V of the reference signal COM is supplied as the reset voltage.

[0072] Specifically, as shown in FIG. 7 , the gate line drive circuit 15 supplies a gate drive signal Vgcl(1) of a high-level voltage (power supply voltage VDD) to the gate line GCL(1) during a period V(1). The control circuit 122 supplies 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 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.

[0073] 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).

[0074] As a result, during the reset period Prst, the capacitance elements Ca in all of the detection areas PAA are sequentially electrically connected to the signal lines 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 detection area PAA by partially selecting the gate lines and signal lines SGL.

[0075] 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. Subsequently, 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 exposure is performed during the exposure period Pex. After exposure is completed, 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 line 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 capacitance element Ca, and does not include periods during which light is irradiated outside of this period. The charge stored in the capacitance element 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 capacitance element Ca. The actual exposure periods Pex(1),..., Pex(M) in the detection area PAA corresponding to each gate line GCL have different start and end times. Each exposure period Pex(1),..., Pex(M) begins when the gate drive signal Vgcl changes from the high-level power supply voltage VDD to the low-level power supply voltage VSS during the reset period Prst. Furthermore, the exposure periods Pex(1), ..., Pex(M) each end when the gate drive signal Vgcl changes from the power supply voltage VSS to the power supply voltage VDD during the readout period Pdet. The exposure times of the exposure periods Pex(1), ..., Pex(M) are equal in length.

[0076] During the exposure periods Pex {(1)...(M)}, a current flows in each detection area PAA in response to light irradiated onto the photosensor PD, resulting in charge accumulation in each capacitance element Ca.

[0077] 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.

[0078] 8, the gate line driving circuit 15 supplies a gate driving 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 during the period when the gate driving signal Vgcl(1) is at the high-level voltage (power supply voltage VDD). As a result, the signal lines SGL of the detection area PAA selected by the gate driving 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 detection area PAA.

[0079] 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), respectively, during row readout periods VR(2), ..., VR(M-1), and VR(M). That is, the gate line driving circuit 15 supplies the gate driving signal Vgcl to the gate line GCL for each row readout period VR(1), VR(2), ..., VR(M-1), and VR(M). For 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 the detection areas PAA to the AFE circuit 48 during the readout period Pdet.

[0080] An example of operation during a row readout period VR, which is the supply period of 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.

[0081] 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 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 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 detection area PAA (period t3). In the example of FIG. 9, this voltage drops from the reset voltage as shown in period t3. Thereafter, 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 detection area PAA moves to the capacitance (capacitor element Cb) of the detection signal amplifier circuit 42 of 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 capacitor element Cb. At this time, the inverting input 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. 9, the waveforms of the selection signals ASW(k), ASW(k+1), ... corresponding to the signal lines SGL of each column become high to sequentially turn on the third switching elements TrS, and similar operations are sequentially performed to sequentially read out the charges accumulated in the capacitances (capacitance elements Ca) of the detection areas PAA connected to the corresponding gate lines GCL. Note that ASW(k), ASW(k+1), ... in FIG. 9 are, for example, any of ASW1 to ASW6 in FIG.

[0082] Specifically, when a period t4 occurs during which the switch SSW is turned on, charge transfers from the capacitance (capacitor Ca) of the 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). Furthermore, the voltage of the capacitor Cb becomes a voltage corresponding to the charge accumulated in the capacitance (capacitor Ca) of the 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.

[0083] 10 , the detection device 1 executes the above-described reset period Prst, exposure period Pex{(1)...(M)}, and readout period Pdet during each of periods t(1), t(2), t(3), and t(4). 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.

[0084] 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 frame detection. However, the present invention is not limited to this. For example, the control circuit 122 may alternately turn on and off the first light source 61 and the second light source 62 every predetermined period, or may keep one of them continuously lit.

[0085] Next, application examples of the detection device 1 according to the first embodiment will be described. Fig. 11 is a schematic diagram showing a first application example of the detection device according to the embodiment. Fig. 12 is a schematic diagram showing a second application example of the detection device according to the embodiment.

[0086] 11 , the detection device 1 is a ring-shaped wearable device 200 that can be attached to or detached from the human body and is worn on a finger Fg of a subject. The finger Fg includes the thumb, index finger, middle finger, ring finger, little finger, etc. In the first application example shown in FIG. 11 , the detection device 1 according to the present disclosure acquires a pulse wave from the finger Fg on which it is worn.

[0087] 12 , the detection device 1 is a ring-shaped wearable device 200a such as a smartwatch, a wristwatch, or a wristband, and is worn on the human body HB of a subject. The human body HB includes the subject's wrist, arm, leg, etc. In the second application example shown in FIG. 12 , the detection device 1 acquires a pulse wave from the human body HB (e.g., the subject's arm) on which it is worn.

[0088] When acquiring a pulse wave by wearing a wearable device 200, 200a (see Figures 11 and 12) that employs the detection device 1 having the above-described configuration, irregular body movement noise may occur due to movements of the subject's fingers Fg, arms, etc., which may reduce the accuracy of acquiring biological signals such as pulse waves.

[0089] A specific example of processing capable of suppressing irregular body movement noise caused by movements of the subject's fingers Fg, arms, etc. will be described below.

[0090] Fig. 13A is a plan view of a sensor region according to the embodiment, and Fig. 13B is a cross-sectional view taken along line AA in Fig. 13A.

[0091] 13A and 13B , the sensor region 10 of the detection device 1 according to the embodiment has a second surface FU of the sensor substrate 21 covered with a light-transmitting elastic member EB. An example of the elastic member EB is a transparent polyurethane resin. The sensor region 10 includes a light-shielding region SA where the surface of the elastic member EB is covered with a light-shielding pattern S, and an opening region OA where the surface of the elastic member EB is not covered with the light-shielding pattern S. The light-shielding pattern S may be, for example, a black resin material, or may be, for example, formed from a light-shielding metal material.

[0092] Fig. 14A is a diagram showing an example of a time domain signal acquired in each detection region of the opening region. Fig. 14B is a diagram showing an example of a time domain signal acquired in each detection region of the light-blocking region. In Fig. 14A and Fig. 14B, the horizontal axis indicates the frame f in which the detection value for each detection region PAA is acquired, and the vertical axis indicates the detection value Raw(f) for each detection region PAA acquired for each frame.

[0093] Here, an example of acquiring a pulse wave of a subject will be described.

[0094] As described above, the sensor area 10 of the detection device 1 according to the embodiment is covered with the translucent elastic member EB, which causes fluctuations in the amount of light received by the optical sensor PD due to movements of the subject's finger Fg, arm, etc., resulting in irregular fluctuations in the detection value Raw(f).

[0095] In the opening area OA, light reflected by or transmitted through the surface or interior of the subject's finger Fg, wrist, etc. is incident on the optical sensor PD. This incident light fluctuates due to the movement of the subject's finger Fg, arm, etc. As a result, as shown in FIG. 14A , the time domain signal acquired in each detection area PAA of the opening area OA contains not only the subject's periodic pulse wave component but also irregular body movement noise components caused by the movement of the subject's finger Fg, arm, etc. FIG. 14A shows an example in which irregular body movement noise components caused by the movement of the subject's finger Fg, arm, etc. appear at the timing indicated by the dashed line.

[0096] In contrast, in the light-shielded area SA, light reflected by the light-shielding pattern S is incident on the optical sensor PD. This incident light does not contain the subject's pulse wave component. Therefore, the time-domain signal acquired in each detection area PAA in the light-shielded area SA contains only irregular body movement noise components caused by the movement of the subject's fingers Fg, arms, etc., as shown in FIG. 14B .

[0097] In the present disclosure, the body movement noise component contained in the time domain signal acquired in the shading area SA is removed from the time domain signal acquired in the opening area OA to extract the periodic pulse wave component of the subject, thereby improving the accuracy of acquiring the subject's pulse wave.

[0098] More specifically, the signal processing circuit 44 of the detection circuit 40 acquires as a first signal S1 the time-domain signal with the maximum peak value among the time-domain signals acquired in time series for each detection area PAA in the opening area OA, and generates a second signal S2 by multiplying the time-domain signal acquired at a predetermined position in the light-blocking area SA by a scaling ratio k corresponding to the detection area PAA from which the first signal S1 was acquired.Then, the signal processing circuit 44 acquires as the subject's biological signal BS the difference between the first signal S1 acquired in the opening area OA and the second signal S2 acquired at the predetermined position in the light-blocking area SA.

[0099] In the present disclosure, it is assumed that the position of the detection area PAA from which the second signal S2 is acquired is set in advance and stored in the memory circuitry 46. It is also assumed that the scaling ratio k is set in advance for each detection area PAA within the opening area OA and stored in the memory circuitry 46 so that the body movement noise component assumed to be included in the first signal S1 and the body movement noise component assumed to be included in the second signal S2 are approximate values. Here, depending on the ratio between the body movement noise component included in the time domain signal acquired at the position of the detection area PAA from which the second signal S2 is acquired and the body movement noise component included in the first signal S1, the scaling ratio k may be "1".

[0100] A specific example of the biological signal acquisition process according to the embodiment will be described below.

[0101] 15 is a flowchart showing an example of a biological signal acquisition process flow in the detection device according to the embodiment. The processes shown in FIG. 15 are mainly executed by the signal processing circuit 44 of the detection circuit 40.

[0102] In the following description, n is a variable representing the number N of detection areas PAA aligned in the first direction Dx, m is a variable representing the number M of detection areas PAA aligned in the second direction Dy, and X<n,m> is a variable in the nth column, mth row of the detection area PAA. The variable X<n,m> includes coordinate information of the detection area PAA from which the variable X<n,m> was obtained. Furthermore, X(f)<n,m> is the variable X<n,m> for the fth frame.

[0103] In the biosignal acquisition processing flow shown in Figure 15, first, the signal processing circuit 44 executes the Raw data acquisition processing shown in Figure 16 to acquire detection values ​​Raw(f)<n, m> for multiple frames in each detection area PAA of the sensor area 10 (Figure 15, step S100).

[0104] 16 is a sub-flowchart showing an example of the raw data acquisition process. As a prerequisite for the raw data acquisition process, it is assumed that the variable f representing the number of frames F, the variable n representing the number N of detection areas PAA aligned in the first direction Dx, and the variable m representing the number M of detection areas PAA aligned in the second direction Dy are reset (f=0, n=0, m=0).

[0105] The number of frames F when acquiring detection values ​​Raw(f)<n,m> for multiple frames is set to a number that allows multiple (e.g., approximately 10) pulse wave peaks to be acquired. The number of frames F is defined by the following equation (1), where P is the acquisition period for the detection values ​​Raw(f)<n,m> and t is the sampling period. The acquisition period P for the detection values ​​Raw(f)<n,m> is set to, for example, 10 to 20 seconds. The number of frames F is stored in, for example, the memory circuitry 46.

[0106] F=P / t...(1)

[0107] 16, the signal processing circuit 44 sets the initial frame f to 1 (f=1) (step S101), sets n=1 and m=1 (step S102), acquires the detection value Raw(f)<n,m> (step S103), and stores the acquired detection value Raw(f)<n,m> in the memory circuit 46 (step S104). Fig. 17 is a diagram showing the detection values ​​for F frames in each detection area within the sensor area.

[0108] Next, the signal processing circuit 44 sets n=n+1 (step S105) and determines whether n is N (n=N) (step S106). If n is less than N (n<N) (step S106; No), the process returns to step S103.

[0109] When n becomes N (n=N) (step S106; Yes), the signal processing circuit 44 then sets m=m+1 (step S107) and determines whether m is M (m=M) (step S108). If m is less than M (m<M) (step S108; No), the process returns to step S103.

[0110] When m becomes M (m=M) (step S108; Yes), the signal processing circuit 44 then sets f=f+1 (step S109) and determines whether f is F (f=F) (step S110). If f is less than F (f<F) (step S110; No), the process returns to step S102.

[0111] By repeating the processes from step S102 to step S110 F times, the detection values ​​Raw(f)<n, m> for F frames in each detection area PAA are stored in the memory circuit 46.

[0112] When f becomes F (f = F) (step S110; Yes), the signal processing circuit 44 resets the variable f for the number of frames F, the variable n for the number N of detection areas PAA lined up in the first direction Dx, and the variable m for the number M of detection areas PAA lined up in the second direction Dy (f = 0, n = 0, m = 0, step S111), returns to the biological signal acquisition processing flow shown in Figure 15, and executes the first signal generation processing (step S200).

[0113] 18 is a sub-flowchart showing an example of the first signal generation process. As a precondition for the first signal generation process, a variable n representing the number N of detection areas PAA arranged in the first direction Dx, a variable m representing the number M of detection areas PAA arranged in the second direction Dy, and the maximum peak value WHmax of the time domain signal S(n, m) are reset (n=0, m=0, WHmax=0).

[0114] 18, the signal processing circuit 44 sets m=m+1 (step S201) and n=n+1 (step S202), and determines whether the detection area PAA is within the opening area OA (step S203). If the detection area PAA is not within the opening area OA (step S203; No), the signal processing circuit 44 repeatedly executes the processes from step S202 onward. If the detection area PAA is within the opening area OA (step S203; Yes), the signal processing circuit 44 reads out the time domain signal S(n, m) (= (Raw(1)<n, m>, Raw(2)<n, m>, ..., Raw(F)<n, m>)) corresponding to the variable (n, m) from the memory circuit 46 (step S204), calculates the peak value WH(n, m) of the time domain signal S(n, m) (step S205), and determines whether the calculated peak value WH(n, m) is greater than the maximum peak value WHmax (step S206).

[0115] If the peak value WH(n, m) is greater than the maximum peak value WHmax (step S206; Yes), the peak value WH(n, m) is updated as the maximum peak value WHmax (step S207), the time domain signal S(n, m) corresponding to the peak value WH(n, m) is held as the first signal S1 (= (Raw1(1), Raw1(2), ..., Raw1(F))) (step S208), and the process proceeds to step S209. If the peak value WH(n, m) is less than or equal to the maximum peak value WHmax (step S206; No), the maximum peak value WHmax is not updated and the process proceeds to step S209.

[0116] The signal processing circuit 44 determines whether n=N (step S209), and if n=N is not true (step S209; No), repeats the processing from step S202 onward. If n=N is true (step S209; Yes), the signal processing circuit 44 resets the variable n (n=0, step S210).

[0117] Next, the signal processing circuit 44 determines whether m=M (step S211), and if m=M is ​​not true (step S211; No), repeats the processing from step S201 onward. If m=M is ​​true (step S211; Yes), the signal processing circuit 44 resets the variable m (m=0, step S212), returns to the biological signal acquisition processing flow shown in FIG. 15, and executes the second signal scaling processing (step S300).

[0118] 19 is a sub-flowchart showing an example of the second signal scaling process. As a precondition for the second signal scaling process, it is assumed that the variable f of the number of frames F is reset (f=0).

[0119] The signal processing circuit 44 reads out the scaling ratio k corresponding to the detection area PAA from which the first signal S1 (= (Raw1(1), Raw1(2), ..., Raw1(F))) was acquired from the memory circuit 46 (step S301), increments the variable f of the frame number F (step S302), calculates the second signal S2 (= k × Raw2(f)) (step S303), and stores the calculated second signal S2 (= k × Raw2(f)) in the memory circuit 46 (step S304).

[0120] Next, the signal processing circuit 44 determines whether f = F (step S305), and if f = F is not true (step S305; No), repeats the processing from step S302 onwards. If f = F is true (step S305; Yes), the signal processing circuit 44 resets the variable f (f = 0, step S306), returns to the biosignal acquisition processing flow shown in Fig. 15, and executes the biosignal generation processing (step S400).

[0121] 20 is a sub-flowchart showing an example of the biosignal generation process. As a precondition for the biosignal generation process, it is assumed that the variable f of the frame number F is reset (f=0).

[0122] The signal processing circuit 44 increments the variable f of the frame number F (step S401), calculates the difference RawBS(f) between the first signal S1 (=Raw1(f)) and the second signal S2 (=k×Raw2(f)) (step S402), and stores the calculated difference RawBS(f) as the biological signal BS (=RawBS(f)) in the memory circuit 46 (step S403).

[0123] Next, the signal processing circuit 44 determines whether f = F (step S404), and if f = F is not true (step S404; No), repeats the processing from step S401 onwards. If f = F is true (step S404; Yes), the signal processing circuit 44 resets the variable f (f = 0, step S405), returns to the biological signal acquisition processing flow shown in Fig. 15, and ends the biological signal acquisition processing flow.

[0124] The above-described processing makes it possible to acquire highly accurate biological signals in which irregular body movement noise components caused by movements of the subject's fingers Fg, arms, etc. are suppressed.

[0125] Specific examples of the light-shielding area SA and the opening area OA in the sensor area 10 will be described below. Fig. 21 is a plan view of a sensor area according to a first modified example of the embodiment. Fig. 22 is a plan view of a sensor area according to a second modified example of the embodiment. Fig. 23 is a plan view of a sensor area according to a third modified example of the embodiment. Fig. 24 is a plan view of a sensor area according to a fourth modified example of the embodiment.

[0126] 21, 22, 23, and 24, the opening area OA includes a plurality of partial opening areas POA. The light-shielding area SA includes a plurality of partial light-shielding areas PSA. The partial opening area POA and the partial light-shielding area PSA are areas that include a plurality of detection areas PAA in the first direction Dx and the second direction Dy, respectively.

[0127] 21, the sensor area 10a may have partial opening areas POA and partial light-shielding areas PSA arranged alternately in the first direction Dx, whereby the light-shielding pattern S becomes a vertical stripe-shaped light-shielding pattern.

[0128] 22, the sensor area 10b may have partial opening areas POA and partial light-shielding areas PSA arranged alternately in the second direction Dy, thereby forming the light-shielding pattern S in a horizontal stripe shape.

[0129] 23, the sensor area 10c may have partial opening areas POA and partial light-shielding areas PSA arranged alternately in the first direction Dx, and partial opening areas POA and partial light-shielding areas PSA arranged alternately in the second direction Dy, thereby forming a checkerboard-shaped light-shielding pattern S.

[0130] 24, the sensor area 10d may be configured such that the partial opening areas POA alternately sandwich the partial shielding areas PSA in the first direction Dx, the partial opening areas POA alternately sandwich the partial shielding areas PSA in the second direction Dy, and the partial shielding areas PSA are arranged side by side in the first direction Dx and the second direction Dy, thereby forming a lattice-shaped shielding pattern S.

[0131] In the above-described embodiment, an example of acquiring a pulse wave as a biological signal has been described, but the scope of application of the detection device 1 according to the present disclosure is not limited to a pulse wave, and it can be widely applied to configurations for acquiring a periodically fluctuating biological signal of a subject.

[0132] 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 gist of each of the above-described embodiments and modifications.

[0133] 1 Detection device 10, 10a, 10b, 10c, 10d Sensor region 11 Detection control circuit 15 Gate line driving circuit 16 Signal line selection circuit 20 Sensor substrate 21 Sensor substrate 22 Sensor structure 23 Protective film 40 Detection circuit 42 Detection signal amplification circuit 43 A / D conversion circuit 44 Signal processing circuit 46 Memory circuit 47 Detection timing control circuit 48 AFE circuit 61 First light source (light source) 62 Second light source (light source) 122 Control circuit 123 Power supply circuit 126 Output circuit 200, 200a Wearable device 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)) EB Elastic member GA Peripheral region GCL Gate line OA Opening region PAA Detection region PD Photosensor Pdet Readout period Pex Exposure period POA Partial opening region PSA Partially shielded region RSW Reset switch SA Light shielded region SGL Signal line

Claims

1. A detection device comprising: a sensor region having a plurality of detection regions arranged in a planar shape; an elastic member having translucency and covering the sensor region; a light source that irradiates light onto the sensor region; and a detection circuit that acquires a periodically varying biological signal of a subject based on data obtained from the sensor region, wherein the sensor region includes a light-shielding region in which the surface of the elastic member is covered with a light-shielding pattern, and an opening region in which the surface of the elastic member is not covered with a light-shielding pattern, and the detection circuit acquires, as the biological signal, a difference between a first signal acquired in the opening region and a second signal acquired in the light-shielding region and scaled at a predetermined ratio.

2. The detection device according to claim 1, wherein the detection circuit acquires, as the first signal, a time-domain signal having the maximum peak value among the time-domain signals for each detection region acquired in time series in the opening region.

3. The detection device according to claim 2, wherein the detection circuit generates the second signal by multiplying the time-domain signal acquired at a predetermined position in the light-shielding region by a scaling ratio corresponding to the detection region in which the first signal is acquired.

4. The detection device according to any one of claims 1 to 3, wherein one or more optical sensors are provided in each of the plurality of detection regions.

5. The detection device according to claim 4, wherein the optical sensor is an organic photodiode.

6. The detection device according to any one of claims 1 to 3, wherein the opening region includes a plurality of partial opening regions, the light-shielding region includes a plurality of partial light-shielding regions, a first direction and a second direction intersecting the first direction are defined in the sensor region, and the partial opening regions and the partial light-shielding regions are alternately arranged in the first direction.

7. The detection device according to any one of claims 1 to 3, wherein the opening region includes a plurality of partial opening regions, the light-shielding region includes a plurality of partial light-shielding regions, a first direction and a second direction intersecting the first direction are defined in the sensor region, and the partial opening regions and the partial light-shielding regions are alternately arranged in the second direction.

8. The opening region includes a plurality of partial opening regions, the light-shielding region includes a plurality of partial light-shielding regions, a first direction and a second direction intersecting the first direction are defined in the sensor region, the partial opening regions and the partial light-shielding regions are alternately arranged in the first direction, and the partial opening regions and the partial light-shielding regions are alternately arranged in the second direction. The detection device according to any one of claims 1 to 3.

9. The opening region includes a plurality of partial opening regions, the light-shielding region includes a plurality of partial light-shielding regions, a first direction and a second direction intersecting the first direction are defined in the sensor region, the partial opening regions are alternately arranged with the partial light-shielding regions interposed therebetween in the first direction, the partial opening regions are alternately arranged with the partial light-shielding regions interposed therebetween in the second direction, the partial light-shielding regions are arranged in the first direction, and the partial light-shielding regions are arranged in the second direction. The detection device according to any one of claims 1 to 3.

10. A wearable device having a ring-shaped form that can be attached to and detached from a human body and including the detection device according to any one of claims 1 to 3.

11. The wearable device according to claim 10, which is worn on a finger of a human body.

12. The wearable device according to claim 10, which is worn on a wrist or an arm of a human body.

13. The wearable device according to claim 10, which is worn on a foot of a human body.

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