Detection Device

Abstract

To provide a detection device that can secure output responsiveness more easily.SOLUTION: A detection device includes a photoelectric conversion unit in which a plurality of photodiodes are disposed in a planar shape, a light source that delivers light to the photodiodes, and a heating electrode 310 that is provided to oppose the photoelectric conversion unit and generates heat to make the heat conduct to the photoelectric conversion unit.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] BACKGROUND ART There is known a detection device that can acquire a planar light-dark pattern that is visible like image data by arranging light-receiving elements that can detect light brightness in a planar manner (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-164787 Summary of the Invention [Problem to be solved by the invention]

[0004] Detection devices exhibit temperature dependency depending on the photoelectric conversion material used in the light-receiving element. Generally, the lower the temperature of a light-receiving element, the lower its output response. Output response refers to the degree of change in output in response to a change in the degree of photosensitivity. However, conventional detection devices have not considered how to respond when the temperature of the light-receiving element is too low.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a detection device that makes it easier to ensure output responsiveness. [Means for solving the problem]

[0006] A detection device according to one aspect of the present disclosure includes a photoelectric conversion unit in which a plurality of photodiodes are arranged in a planar manner, a light source that irradiates the photodiodes with light, and a heating electrode that is arranged opposite the photoelectric conversion unit, generates heat, and conducts the heat to the photoelectric conversion unit. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing the main configuration of the sensor unit. [Figure 2] FIG. 2 is a side view showing the layered structure of the detection device. [Figure 3] FIG. 3 is a perspective view showing each component included in the detection device. [Figure 4] FIG. 4 is a plan view showing the sensor unit. [Figure 5] FIG. 5 is a block diagram showing an example of the configuration of the sensor unit. [Figure 6] FIG. 6 is a circuit diagram showing the sensor unit. [Figure 7] FIG. 7 is a circuit diagram showing a plurality of partial detection areas. [Figure 8] FIG. 8 is a cross-sectional view showing a schematic cross-sectional configuration of the sensor unit. [Figure 9] FIG. 9 is a graph schematically showing the relationship between the wavelength of light incident on a photodiode and the conversion efficiency. [Figure 10] FIG. 10 is a timing waveform diagram showing an example of the operation of the sensor unit. [Figure 11] FIG. 11 is a timing waveform diagram showing an example of operation during the readout period in FIG. [Figure 12] FIG. 12 is a schematic diagram showing a mechanism of detection by the sensor unit of the embodiment. [Figure 13] FIG. 13 is a graph showing the relationship between the intensity of light irradiated onto three photodiodes at different temperatures and the level of output from the three photodiodes. [Figure 14] FIG. 14 is a flowchart showing the flow of processing related to the operation of the seat heater. [Figure 15] FIG. 15 is a flowchart showing the flow of determination regarding sensing control. [Figure 16] FIG. 16 is a side view showing the layered structure of the detection device according to the second embodiment. [Figure 17] FIG. 17 is a side view showing the layered structure of the detection device according to the third embodiment. [Figure 18]FIG. 18 is a schematic diagram showing a mechanism for controlling the voltage applied to the dual-purpose electrode. [Figure 19] FIG. 19 is a time chart showing a case where a period in which the dual-purpose electrode functions as a seat heater and a period in which the dual-purpose electrode functions as a common electrode alternate with each other. [Figure 20] FIG. 20 is a flowchart showing the flow of main operational control of the detection device according to the third embodiment. [Figure 21] FIG. 21 is a side view showing the layered structure of the detection device according to the fourth embodiment. [Figure 22] FIG. 22 is a circuit diagram showing a plurality of partial detection areas PAA in the fourth embodiment. [Figure 23] FIG. 23 is a schematic diagram showing the mechanism of detection by the sensor unit C of the fourth embodiment. [Figure 24] FIG. 24 is a side view showing the layered structure of the detection device according to the fifth embodiment. [Figure 25] FIG. 25 is a schematic diagram showing an example of the configuration of a seat heater. [Figure 26] FIG. 26 is a schematic diagram showing an example of the configuration of a seat heater. [Figure 27] FIG. 27 is a side view showing the layered structure of the detection device according to the sixth embodiment. [Figure 28] FIG. 28 is a side view showing the layered structure of the detection device according to the seventh embodiment. [Figure 29] FIG. 29 is a graph showing the relationship between the output of a photodiode that receives light from a temperature detection light source and the temperature of the photodiode. [Figure 30] FIG. 30 is a flowchart showing the flow of main operational control of the detection device according to the seventh embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Each embodiment of the present disclosure will be described below with reference to the drawings. 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 disclosure. Furthermore, to clarify the explanation, the drawings may show the width, thickness, shape, etc. of each part schematically compared to the actual embodiment, but these are merely examples and are not intended to limit the interpretation of the present disclosure. Furthermore, in this specification and each drawing, elements similar to those described above with reference to the previous drawings will be designated by the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0009] 1 is a schematic diagram showing the main configuration of the sensor unit 1. The sensor unit 1 includes a substrate 301 and a detection device 302. The substrate 301 is a substrate on one side of which the detection device 302 is mounted. Although not shown, the substrate 301 is also mounted with components for operating the seat heater 310, such as wiring connected to the seat heater 310 (described later). The photoelectric conversion unit AA, detection circuit 48, and flexible printed circuit board 71 shown in FIG. 1 will be described later.

[0010] FIG. 2 is a side view showing the layered structure of the detection device 302. FIG. 3 is a perspective view showing each component included in the detection device 302. The detection device 302 has a layered structure in which the seat heater 310, the sensor unit 10, and the collimator 303 are layered in this order from one side to the other side. In the following description, the layering direction in the layered structure of the detection device 302 is referred to as the third direction Dz. Furthermore, one of two directions perpendicular to the third direction Dz is referred to as the first direction Dx, and the other is referred to as the second direction Dy. The substrate 301 is located on one side of the seat heater 310.

[0011] The sheet heater 310 is a film sheet heater that is capable of heating the sensor unit 10. Specifically, the sheet heater 310 has a sheet-like configuration including a heat-generating portion that generates heat through electrical resistance in response to the application of voltage. The heat-generating portion is made of, for example, ITO (Indium Tin Oxide), molybdenum chromium (MoCr), silver (Ag), IZO (Indium Zinc Oxide), tungsten (W), molybdenum (Mo), tantalum (Ta), or titanium (Ti), but is not limited to these. Any material that can be processed into a sheet shape and generates heat in response to the application of voltage may be used. The sheet heater 310 is provided so as to cover the photoelectric conversion unit AA from a planar perspective. The planar perspective is a perspective obtained by viewing a plane perpendicular to the third direction Dz from the front.

[0012] The sensor unit 10 has a layered structure in which a circuit board 320, a photodiode PD, and a common electrode 322 are layered in this order from one surface to the other. The structure of the sensor unit 10 will be described with reference to FIGS. 4 to 11.

[0013] Fig. 4 is a plan view showing the sensor unit 1. As shown in Fig. 4, the sensor unit 1 includes a sensor substrate 21, a sensor section 10, a gate line driving circuit 15, a signal line selection circuit 16, a detection circuit 48, a control circuit 122, a power supply circuit 123, a first light source substrate 51, a second light source substrate 52, a first light source 61, a second light source 62, and a temperature detection section 331.

[0014] The control board 121 is electrically connected to the sensor board 21 via a flexible printed circuit board 71. The flexible printed circuit board 71 is provided with a detection circuit 48. The control board 121 is provided with a control circuit 122 and a power supply circuit 123. The control circuit 122 is, for example, an FPGA (Field Programmable Gate Array). The control circuit 122 supplies control signals to the sensor unit 10, the gate line driving circuit 15, and the signal line selection circuit 16 to control the detection operation of the sensor unit 10. The control circuit 122 also supplies control signals to the first light source 61 and the second light source 62 to control the lighting or non-lighting of the first light source 61 and the second light source 62. The power supply circuit 123 also supplies voltage signals such as a sensor power supply signal VDDSNS (see FIG. 7) to the sensor unit 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.

[0015] The sensor substrate 21 has a photoelectric conversion unit AA and a peripheral unit GA. The photoelectric conversion unit AA is an area where a plurality of photodiodes PD (see FIG. 7) of the sensor unit 10 are provided. The peripheral unit GA is an area between the outer periphery of the photoelectric conversion unit AA and the end of the sensor substrate 21, and is an area that does not overlap with the photodiodes PD.

[0016] The position overlapping one of the four sides of the photoelectric conversion unit AA that forms the boundary between the rectangular photoelectric conversion unit AA and the peripheral portion GA becomes the connection portion CP1 shown in Fig. 2. Also, the position overlapping the other side of the photoelectric conversion unit AA that is opposite to the one side across the photoelectric conversion unit AA becomes the connection portion CP2 shown in Fig. 2.

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

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

[0019] The 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.

[0020] The first light sources 61 and the second light sources 62 may be, for example, inorganic light emitting diodes (LEDs) or organic light emitting diodes (OLEDs). The first light sources 61 and the second light sources 62 emit first light and second light, respectively, having different wavelengths. That is, the first light has a first maximum emission wavelength, and the second light has a second maximum emission wavelength that is different from the first maximum emission wavelength. The maximum emission wavelength is the wavelength that exhibits the maximum emission intensity in an emission spectrum that indicates the relationship between the wavelength and emission intensity of each of the first light and the second light.

[0021] For example, the first light has a first maximum emission wavelength of 520 nm or more and 600 nm or less, for example, about 500 nm, and the second light has a second maximum emission wavelength of 600 nm or more and 700 nm or less, for example, about 660 nm. That is, the second maximum emission wavelength of the second light is longer than the first maximum emission wavelength of the first light. In this case, the first light and the second light are visible light. The first light is blue or green light, and the second light is red light.

[0022] The first light emitted from the first light source 61 is reflected by the surface of the object to be detected, such as a finger Fg, and enters the sensor unit 10. This allows the sensor unit 10 to detect the shape of the projections and recesses on the surface of the finger Fg, etc., thereby detecting a fingerprint. The second light emitted from the second light source 62 is reflected by the inside of the finger Fg, etc., or passes through the finger Fg, etc., and enters the sensor unit 10. This allows the sensor unit 10 to detect information about the living body inside the finger Fg, etc. The information about the living body is, for example, the pulse of the finger Fg or the palm, etc.

[0023] The wavelengths of the first light and the second light are not limited to the above examples and can be changed as appropriate. For example, the first light may have a first emission maximum wavelength of 520 nm or more and 600 nm or less, e.g., approximately 500 nm, and the second light may have a second emission maximum wavelength of 780 nm or more and 900 nm or less, e.g., approximately 850 nm. In this case, the first light is blue or green visible light, and the second light is infrared light. The sensor unit 10 can detect a fingerprint based on the first light emitted from the first light source 61. The second light emitted from the second light source 62 is reflected from the inside of the detection object such as a finger Fg or passes through the finger Fg or the like before entering the sensor unit 10. This allows the sensor unit 10 to detect a blood vessel image (vein pattern) as information about the biological body inside the finger Fg or the like.

[0024] Alternatively, the first light may have a first emission maximum wavelength of 600 nm or more and 700 nm or less, for example, about 660 nm, and the second light may have a second emission maximum wavelength of 780 nm or more and 900 nm or less, for example, about 850 nm. In this case, based on the first light emitted from the first light source 61 and the second light emitted from the second light source 62, the sensor unit 10 can detect information about the living body, such as the pulse rate and blood vessel image, as well as the blood oxygen concentration. In this way, the sensor unit 1 has the first light source 61 and multiple second light sources 62, and therefore can detect various information about the living body by performing detection based on the first light and detection based on the second light.

[0025] 4 is merely an example and can be modified as appropriate. For example, a plurality of first light sources 61 and a plurality of second light sources 62 may be arranged on each of the first light source substrate 51 and the second light source substrate 52. In this case, a group including a plurality of first light sources 61 and a group including a plurality of second light sources 62 may be arranged side by side in the second direction Dy, or the first light sources 61 and the second light sources 62 may be arranged alternately in the second direction Dy. Furthermore, the number of light source substrates on which the first light sources 61 and the second light sources 62 are provided may be one or three or more.

[0026] Fig. 5 is a block diagram showing an example configuration of the sensor unit 1. As shown in Fig. 5, the sensor unit 1 further includes a detection control unit 11 and a detection unit 40. Some or all of the functions of the detection control unit 11 are included in a control circuit 122. In addition, some or all of the functions of the detection unit 40 other than the detection circuit 48 are included in the control circuit 122.

[0027] The sensor unit 10 is an optical sensor having a photodiode PD, which is a photoelectric conversion element. The photodiode PD of the sensor unit 10 outputs an electrical signal corresponding to the incident light as a detection signal Vdet to the signal line selection circuit 16. The sensor unit 10 also performs detection in accordance with a gate drive signal Vgcl supplied from the gate line drive circuit 15.

[0028] The detection control unit 11 is a circuit that supplies control signals to the gate line driving circuit 15, the signal line selection circuit 16, and the detection unit 40, respectively, and controls their operations. The detection control unit 11 supplies various control signals, such as a start signal STV, a clock signal CK, and a reset signal RST1, to the gate line driving circuit 15. The detection control unit 11 also supplies various control signals, such as a selection signal ASW, to the signal line selection circuit 16. The detection control unit 11 also supplies various control signals to the first light source 61 and the second light source 62, and controls the lighting and non-lighting of each.

[0029] The gate line driving circuit 15 is a circuit that drives multiple gate lines GCL (see FIG. 6) based on various control signals. The gate line driving circuit 15 selects the multiple gate lines GCL sequentially or simultaneously and supplies a gate driving signal Vgcl to the selected gate lines GCL. In this way, the gate line driving circuit 15 selects multiple photodiodes 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. 6 ). The signal line selection circuit 16 is, for example, a multiplexer. The signal line selection circuit 16 connects the selected signal line SGL to the detection circuit 48 based on a selection signal ASW supplied from the detection control unit 11. As a result, the signal line selection circuit 16 outputs a detection signal Vdet of the photodiode PD to the detection unit 40.

[0031] The detection unit 40 includes a detection circuit 48, a signal processing unit 44, a coordinate extraction unit 45, a storage unit 46, a detection timing control unit 47, and an image processing unit 49. Based on a control signal supplied from the detection control unit 11, the detection timing control unit 47 controls the detection circuit 48, the signal processing unit 44, the coordinate extraction unit 45, and the image processing unit 49 so that they operate in synchronization.

[0032] The detection circuit 48 is, for example, an analog front end (AFE) circuit. The detection circuit 48 is a signal processing circuit having at least the functions of a detection signal amplifier 42 and an A / D converter 43. The detection signal amplifier 42 amplifies the detection signal Vdet. The A / D converter 43 converts the analog signal output from the detection signal amplifier 42 into a digital signal.

[0033] The signal processing unit 44 is a logic circuit that detects a predetermined physical quantity input to the sensor unit 10 based on the output signal of the detection circuit 48. When the finger Fg comes into contact with or close to the detection surface, the signal processing unit 44 can detect unevenness on the surface of the finger Fg or palm based on the signal from the detection circuit 48. The signal processing unit 44 can also detect information about the living body based on the signal from the detection circuit 48. The information about the living body includes, for example, blood vessel images of the finger Fg or palm, pulse waves, pulse rate, and blood oxygen concentration. The signal processing unit 44 may also acquire detection signals Vdet (information about the living body) simultaneously detected by multiple photodiodes PD and average these signals. In this case, the detection unit 40 can suppress measurement errors caused by noise and relative positional deviation between the sensor unit 10 and the object to be detected, such as the finger Fg, thereby enabling stable detection.

[0034] The storage unit 46 temporarily stores the signals calculated by the signal processing unit 44. The storage unit 46 may be, for example, a RAM (Random Access Memory), a register circuit, or the like.

[0035] The coordinate extraction unit 45 is a logic circuit that calculates the detected coordinates of the unevenness of the surface of the finger or the like when the signal processing unit 44 detects contact or proximity of a finger. The coordinate extraction unit 45 is also a logic circuit that calculates the detected coordinates of the blood vessels of the finger Fg or the palm. The image processing unit 49 combines the detection signals Vdet output from each photodiode PD of the sensor unit 10 to generate two-dimensional information indicating the shape of the unevenness of the surface of the finger Fg or the like and two-dimensional information indicating the shape of the blood vessels of the finger Fg or the palm. The coordinate extraction unit 45 may output the detection signal Vdet as the sensor output Vo without calculating the detection coordinates. The coordinate extraction unit 45 and the image processing unit 49 may not be included in the detection unit 40.

[0036] Next, an example of the circuit configuration of the sensor unit 10 will be described. Fig. 6 is a circuit diagram showing the sensor unit 10. Fig. 7 is a circuit diagram showing a plurality of partial detection areas PAA. Fig. 7 also shows the circuit configuration of the detection circuit 48.

[0037] 6, the sensor unit 10 has a plurality of partial detection areas PAA arranged in a matrix. A photodiode PD is provided in each of the partial detection areas PAA.

[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. 6, but this is merely an example, and M gate lines GCL (M is 8 or more, for example, M=256) may be arranged.

[0039] The signal line SGL extends in the second direction Dy and is connected to the photodiodes PD of the plurality of partial detection areas PAA arranged in the second direction Dy. The plurality of 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 plurality of 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 12 or more, for example, N=252) may be arranged. In addition, in Fig. 6, the sensor unit 10 is provided between the signal line selection circuit 16 and the reset circuit 17. However, this is not limiting, and the signal line selection circuit 16 and the reset circuit 17 may be connected to ends of the signal lines SGL in the same direction.

[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. 5). 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 biological information (pulse wave, pulse, blood vessel image, blood oxygen concentration, etc.) 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 the 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, detection area groups 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 a detection 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. 4) 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 sensor unit 1 can reduce the number of ICs (Integrated Circuits) including the detection 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 detection circuit 48. Specifically, the control circuit 122 (see FIG. 4) simultaneously supplies selection signals ASW to the selection signal lines Lsel. As a result, the signal line selection circuit 16 selects multiple signal lines SGL (e.g., six signal lines SGL) in one signal line block through the operation of the third switching element TrS and connects the multiple signal lines SGL to the detection circuit 48. As a result, signals detected in the detection area groups PAG1 and PAG2 are output to the detection circuit 48. In this case, signals from multiple partial detection areas PAA (photodiodes PD) included in the detection area groups PAG1 and PAG2 are integrated and output to the detection circuit 48.

[0049] By performing detection for each of the detection area groups PAG1 and PAG2 through the operation of the gate line drive 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. Furthermore, the time required for detection can be shortened. Therefore, the sensor unit 1 can repeatedly perform detection in a short period of time, improving the S / N ratio and enabling accurate detection of temporal changes in information related to a living body, such as pulse waves.

[0050] 6, 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.

[0051] 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. 7) included in the multiple partial detection areas PAA.

[0052] As shown in FIG. 7, the partial detection area PAA includes a photodiode PD, a capacitance element Ca, and a first switching element Tr. In FIG. 7, two gate lines GCL(m) and GCL(m+1) arranged in the second direction Dy are shown among the multiple gate lines GCL. Also shown are two signal lines SGL(n) and SGL(n+1) arranged 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. The first switching element Tr is provided corresponding to the photodiode PD. The first switching element Tr is formed of a thin-film transistor, and in this example, is formed of an n-channel MOS (Metal Oxide Semiconductor) TFT (Thin Film Transistor).

[0053] 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 photodiodes PD and the capacitance elements Ca.

[0054] The photodiode PD is supplied with a sensor power supply signal VDDSNS from the power supply circuit 123. In addition, the signal line SGL and the capacitance element Ca are supplied with a reference signal COM from the power supply circuit 123, which serves as the initial potential of the signal line SGL and the capacitance element Ca.

[0055] When light is irradiated onto the partial detection area PAA, a current corresponding to the amount of light flows through the photodiode PD, causing charge to accumulate in the capacitance element Ca. When the first switching element Tr is turned on, a current corresponding to the charge accumulated in the capacitance element Ca flows through the signal line SGL. The signal line SGL is connected to the detection circuit 48 via the third switching element TrS of the signal line selection circuit 16. This allows the sensor unit 10 to detect a signal corresponding to the amount of light irradiated onto the photodiode PD for each partial detection area PAA or for each detection area group PAG1, PAG2.

[0056] In the detection circuit 48, the switch SSW is turned on during the readout period Pdet (see FIG. 10), and the detection circuit 48 is connected to the signal line SGL. The detection signal amplifier 42 of the detection circuit 48 converts fluctuations in current supplied from the signal line SGL into fluctuations in voltage and amplifies the voltage. A reference voltage Vref having a fixed potential is input to the non-inverting input terminal (+) of the detection signal amplifier 42, and the signal line SGL is connected to the inverting input terminal (-). In this embodiment, a signal identical to the reference signal COM is input as the reference voltage Vref. The detection signal amplifier 42 also has a capacitance element Cb and a reset switch RSW. During the reset period Prst (see FIG. 10), the reset switch RSW is turned on, and the charge of the capacitance element Cb is reset.

[0057] Next, the configuration of the photodiode PD will be described. Fig. 8 is a cross-sectional view showing a schematic cross-sectional configuration of the sensor unit. Fig. 9 is a graph showing a schematic relationship between the wavelength of light incident on the photodiode and the conversion efficiency.

[0058] 8, the sensor unit 10 includes a sensor substrate 21, a TFT layer 22, individual electrodes 321, a photodiode PD, and a common electrode 322. The sensor substrate 21 is a flexible insulating base material, such as a film-like resin. The sensor substrate 21 has a first surface 211 and a second surface 212 opposite the first surface 211. The TFT layer 22, the individual electrodes 321, the photodiode PD, and the common electrode 322 are stacked on the first surface 211 in this order.

[0059] The TFT layer 22 is provided with circuits such as the gate line driving circuit 15 and signal line selection circuit 16 described above. Also provided in the TFT layer 22 are TFTs (Thin Film Transistors) such as the first switching element Tr, and various wirings such as the gate lines GCL and signal lines SGL. The sensor substrate 21 and the TFT layer 22 are a driving circuit substrate that drives sensors for each predetermined detection area, and are also called a backplane.

[0060] The individual electrode 321 is connected to the signal line SGL via the first switching element Tr. The individual electrode 321 is individually provided for each partial detection area PAA. The individual electrode 321 is made of a metal material such as silver (Ag) or aluminum (Al). Alternatively, the individual electrode 321 may be made of an alloy material containing at least one of these metal materials. By controlling the film thickness of the individual electrode 321, the individual electrode 321 can be formed as a translucent semi-transparent electrode. For example, the individual electrode 321 can be formed of a 10 nm-thick Ag thin film to have a translucency of approximately 60%. In this case, the photodiode PD can detect light irradiated from both sides of the sensor substrate 21, for example, first light irradiated from the first surface 211 side and second light irradiated from the second surface 212 side.

[0061] The circuit board 320 shown in Figures 2, 3, etc. is the part of the sensor board 21 that is included within the photoelectric conversion unit AA, excluding the other side of the individual electrode 321 (the photodiode PD and the configuration above the photodiode PD).

[0062] Although not shown, an insulating layer is provided between the TFT layer 22 and the individual electrode 321. The insulating layer is an inorganic insulating layer. For example, an oxide such as silicon oxide (SiO2) or a nitride such as silicon nitride (SiN) is used for the insulating layer. A contact hole is provided in the insulating layer to connect the first switching element Tr of the TFT layer 22 and the individual electrode 321.

[0063] The photodiode PD is provided on the individual electrode 321. The photodiode PD has a photoelectric conversion layer 31, a hole transport layer 35, and an electron transport layer 34. The hole transport layer 35, the photoelectric conversion layer 31, and the electron transport layer 34 are stacked in this order in a direction perpendicular to the first surface 211 of the sensor substrate 21. Note that the photodiode PD may also be stacked in the order of the electron transport layer 34, the photoelectric conversion layer 31, and the hole transport layer 35.

[0064] The photoelectric conversion layer 31 changes its characteristics (for example, voltage-current characteristics and resistance value) depending on the light irradiated thereon. An organic material is used as the material for the photoelectric conversion layer 31. Specifically, the photoelectric conversion layer 31 is made of, 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 (perylene derivative), etc. can be used.

[0065] The photoelectric conversion layer 31 can be formed by a vapor deposition (dry process) using these low-molecular organic materials. In this case, the photoelectric conversion layer 31 is formed by, for example, CuPc and F 16 CuPc laminated film or rubrene and C 60The photoelectric conversion layer 31 may be a laminated film of the above-mentioned low molecular weight organic material and high molecular weight organic material. The photoelectric conversion layer 31 may also be formed by a coating process (wet process). In this case, the photoelectric conversion layer 31 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 photoelectric conversion layer 31 may be a film in which P3HT and PCBM are mixed, or a film in which F8BT and PDI are mixed.

[0066] The hole transport layer 35 and the electron transport layer 34 face each other with the photoelectric conversion layer 31 interposed therebetween. The hole transport layer 35 is provided on the anode side of the photodiode PD. The hole transport layer 35 is formed from, for example, zinc oxide (ZnO), titanium dioxide (TiO2), titanium nitride (TiN), or IGZO (registered trademark), that is, a substance composed of indium, gallium, zinc, and oxygen. The electron transport layer 34 is provided on the cathode side of the photodiode PD. The electron transport layer 34 is formed from, for example, tungsten trioxide (WO3) or molybdenum trioxide.

[0067] The common electrode 322 is a thin-film electrode provided to cover the photoelectric conversion unit AA in a plan view. The common electrode 322 is made of a light-transmitting conductive material such as ITO (Indium Tin Oxide).

[0068] Although not shown, a protective film may be provided between the common electrode 322 and the collimator 303. The protective film is, for example, a passivation film, and is provided to protect the photodiode PD located opposite the protective film across the common electrode 322.

[0069] Fig. 9 is a graph showing a relationship between the wavelength of light incident on a photodiode and its efficiency. The horizontal axis of the graph shown in Fig. 9 represents the wavelength of light incident on the photodiode PD, and the vertical axis represents the external quantum efficiency of the photodiode PD. The external quantum efficiency is expressed, for example, as the ratio between the number of photons of light incident on the photodiode PD and the current flowing from the photodiode PD to an external detection circuit 48.

[0070] 9, the photodiode PD has good efficiency in a wavelength band of about 300 nm to 1000 nm. That is, the photodiode PD has sensitivity to both the wavelengths of the first light emitted from the first light source 61 and the second light emitted from the second light source 62. Therefore, one photodiode PD can detect a plurality of lights having different wavelengths.

[0071] Next, a description will be given of an example of operation of the sensor unit 10. Fig. 10 is a timing waveform diagram showing an example of operation of the sensor unit 10. Fig. 11 is a timing waveform diagram showing an example of operation during the readout period in Fig. 10.

[0072] As shown in Figure 10, the sensor unit 10 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 photodiode PD throughout the reset period Prst, the exposure period Pex, and the readout period Pdet. Before the reset period Prst begins, the control circuit 122 supplies a reference signal COM and a high-level voltage reset signal RST2 to the reset circuit 17. At this time, the reference signal COM is set to 0.75V. The control circuit 122 supplies a start signal STV to the gate line drive circuit 15, and the reset period Prst begins.

[0073] During the reset period Prst, the gate line driving 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 driving circuit 15 sequentially supplies the gate lines GCL with a gate driving signal Vgcl. The gate driving 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. 10, 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.

[0074] As a result, during the reset period Prst, the capacitive elements Ca in all the partial detection areas PAA are sequentially electrically connected to the signal line SGL and supplied with the reference signal COM, thereby resetting the capacitance of the capacitive elements Ca.

[0075] The exposure period Pex begins after the gate drive signal Vgcl(M) is supplied to the gate line GCL. Note that the actual exposure periods Pex(1), ..., Pex(M) in the partial detection areas PAA corresponding to each gate line GCL have different start and end times. The exposure periods Pex(1), ..., Pex(M) each begin 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. 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.

[0076] During the exposure period Pex, a current flows in each partial detection area PAA in response to light irradiated on the photodiode PD, and as a result, charge is accumulated 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, which stops the operation of the reset circuit 17. During the readout period Pdet, similar to 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] 11, 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 t(1). The control circuit 122 sequentially supplies selection signals ASW1, ..., ASW6 to the signal line selection circuit 16 while the gate drive signal Vgcl(1) is at a high-level voltage (power supply voltage VDD). As a result, the signal lines SGL of the partial detection area PAA selected by the gate drive signal Vgcl(1) are sequentially or simultaneously connected to the detection circuit 48. As a result, the detection signal Vdet is supplied to the detection circuit 48 for each partial detection area PAA.

[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 periods t(2), ..., t(M-1), and t(M). That is, the gate line driving circuit 15 supplies the gate driving signal Vgcl to the gate line GCL during periods t(1), t(2), ..., t(M-1), and t(M). During each period in which each gate driving signal Vgcl is at a high-level voltage, the signal line selection circuit 16 sequentially selects the signal lines SGL based on the selection signal ASW. The signal line selection circuit 16 sequentially connects each signal line SGL to one detection circuit 48. This allows the sensor unit 10 to output detection signals Vdet for all partial detection areas PAA to the detection circuit 48 during the readout period Pdet.

[0080] 11 shows an example in which the gate line driving circuit 15 selects one gate line GCL for each period t, but this is not limiting. The gate line driving circuit 15 may simultaneously select two or more predetermined number of gate lines GCL 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 two or more predetermined number of signal lines SGL to one detection circuit 48. Furthermore, the gate line driving circuit 15 may scan a plurality of gate lines GCL by thinning them out.

[0081] 10 has been described on the assumption that gate drive signals Vgcl(1), Vgcl(2), ..., Vgcl(M-1), and Vgcl(M) are supplied to gate lines GCL(1), GCL(2), ..., GCL(M-1), and GCL(M), but the operation of the sensor unit 10 in the embodiment is not limited to this. For example, an operation mode including multiple sequences in which gate drive signals are supplied to some of these gate lines may be employed.

[0082] The temperature detection unit 331 detects the temperature of the photoelectric conversion unit AA. The temperature detection unit 331 is provided to be able to detect temperature based on the relationship between temperature and electrical resistance, such as a thermistor or a resistance temperature detector. As shown in FIG. 4, the temperature detection unit 331 is electrically connected to the control circuit 122 and the power supply circuit 123 via terminal units 332 provided on the control board 121. Note that in FIG. 4, the temperature detection unit 331 is shown separated from the sensor board 21, but in reality, the temperature detection unit 331 abuts against the sensor board 21. Specifically, the temperature detection unit 331 abuts against the sensor board 21 at a position that does not prevent light from entering both surfaces of the photoelectric conversion unit AA and is as close as possible to the photoelectric conversion unit AA.

[0083] FIG. 12 is a schematic diagram illustrating a detection mechanism by the sensor unit 10 of the embodiment. In the sensor unit 10 of the embodiment, light from at least one of the first light source 61 and the second light source 62 coming from the common electrode 322 side is detected by the photodiode PD. Specifically, when a detection target that affects light, such as a finger Fg, is located near the photodiode PD, the degree to which light L61 from the first light source 61 reaches the photodiode PD varies depending on the detection target. Furthermore, when the detection target is located near the photodiode PD, light L62 from the second light source 62 is reflected by the detection target and enters the photodiode PD, and the degree to which light L62 from the second light source 62 reaches the photodiode PD varies depending on the detection target. In this way, by using the photodiode PD to detect the degree of light arrival, which varies depending on the relationship with the detection target, the sensor unit 10 can acquire information about the detection target as a light brightness pattern.

[0084] Although not shown in FIG. 12, the light L61 and the light L62 pass through the light guide hole 303a provided in the collimator 303 shown in FIG. 3 and reach the photodiode PD from the common electrode 322 side. The collimator 303 is a member that blocks light. The light guide hole 303a is an insertion hole provided in the collimator 303. By limiting the light (e.g., the light L61 and the light L62) that reaches the photodiode PD to light that has passed through the light guide hole 303a, the light that is detected by the photodiode PD can be limited to light along the third direction Dz or, even if it is light in a direction that intersects the third direction Dz, light that has almost no intersecting angle with the third direction Dz. The larger the intersecting angle with the third direction Dz, the more the light is blocked by the side wall of the light guide hole 303a, even if it enters the light guide hole 303a. In addition, when viewed from a plan view, the arrangement of the light guide holes 303a and the arrangement of the individual electrodes 321 overlap each other.

[0085] The photodiode PD receives a voltage Vr1 from the sensor power supply signal VDDSNS via the individual electrode 321. The voltage Vr1 acts as a reverse bias for the photodiode PD. Specifically, the voltage Vr1 applies a relatively high voltage to the common electrode 322 and a relatively low voltage to the individual electrode 321. The anode of the photodiode PD is connected to the individual electrode 321. The cathode of the photodiode PD is connected to the common electrode 322. The photodiode PD has a hole transport layer 35 on the anode side and an electron transport layer 34 on the cathode side, sandwiching the photoelectric conversion layer 31 between them. Therefore, the individual electrode 321 and the hole transport layer 35 are in contact with each other, and the common electrode 322 and the electron transport layer 34 are in contact with each other. The voltage Vr1 is, for example, 2 volts (V), but is not limited to this and can be changed as appropriate depending on various conditions, such as the materials used in the photodiode PD. The voltage Vr1 is supplied from the power supply circuit 123.

[0086] As described above, when an organic material is used for the photoelectric conversion layer 31, the photodiode PD exhibits temperature dependency, in which sensitivity changes depending on temperature. Hereinafter, this temperature dependency will be described with reference to FIG.

[0087] Fig. 13 is a graph showing the relationship between the intensity of light irradiated onto three photodiodes PD having different temperatures and the level of output from the three photodiodes PD. Graph 401 shown in Fig. 13 is a graph showing the relationship between the intensity of light irradiated onto the photodiode PD with the lowest temperature among the three photodiodes PD having different temperatures and the level of output from the three photodiodes PD. Graph 403 is a graph showing the relationship between the intensity of light irradiated onto the photodiode PD with the highest temperature among the three photodiodes PD having different temperatures and the level of output from the three photodiodes PD. Graph 402 is a graph showing the relationship between the intensity of light irradiated onto the photodiode PD with the intermediate temperature among the three photodiodes PD having different temperatures and the level of output from the three photodiodes PD.

[0088] 13, the photodiode PD exhibits temperature dependency such that the lower the temperature, the slower the responsiveness of the output corresponding to the intensity of light irradiated onto the photodiode PD. Therefore, if the temperature of the photodiode PD is too low, it may be difficult to properly identify the presence or absence of a detection target such as a finger Fg shown in FIG.

[0089] The organic material used in the photodiode PD of the embodiment can provide output responsiveness sufficient to distinguish the intensity of light irradiating the photodiode PD, as shown in graphs 402 and 403 in FIG. 13 , if the temperature exceeds 25°C. Therefore, in the embodiment, the temperature of the sensor substrate 21 on which the photodiode PD included in the photoelectric conversion unit AA is provided is detected by the temperature detection unit 331, and sensing is performed when the temperature of the sensor substrate 21 exceeds 25°C. Sensing refers to the acquisition of a light and dark pattern within the photoelectric conversion unit AA by the operation of the photodiode PD described with reference to FIGS. 10 and 11 . That is, the first light source 61 and the second light source 62 are turned on during sensing. In other words, the first light source 61 and the second light source 62 are not turned on except during sensing. In the embodiment, the temperature of the sensor substrate 21 detected by the temperature detection unit 331 is treated as the temperature of the photoelectric conversion unit AA and the photodiode PD included in the photoelectric conversion unit AA.

[0090] Furthermore, in the embodiment, the photodiode PD is heated by operating the seat heater 310 under a predetermined temperature condition in order to more reliably ensure an operating environment for the photodiode PD of 25°C or higher. Hereinafter, the term "temperature condition" simply refers to the predetermined temperature condition. The temperature condition is, for example, that the temperature of the photodiode PD is lower than 30°C. By operating the seat heater 310 from the point in time when it is detected that the temperature is lower than 30°C, it is possible to more reliably bring about a state in which the temperature of the photodiode PD exceeds 25°C.

[0091] Furthermore, in the embodiment, sensing is not performed even when the temperature of the photodiode PD is too high. In the embodiment, the operations of the seat heater 310 and the photodiode PD are controlled by a combination of the temperature condition for operating the seat heater 310 described above and the temperature range in which sensing is performed based on the temperature condition.

[0092] Specifically, let the temperature for operating the seat heater 310 determined by the temperature condition be Ts °C. Ts ° is, for example, 30 °C described above. The temperature range is a range of ±td ° centered on Ts °. td is, for example, 5. Therefore, in the embodiment, the temperature range is set so that Ts ° - td ° = 25 °C.

[0093] FIG. 14 is a flowchart showing the flow of processing related to the operation of the seat heater 310. First, the temperature condition is set by the control circuit 122 (step S1). Specifically, the control circuit 122 reads the data indicating the above-mentioned Ts ° held in an external storage circuit (not shown) that is held in the control circuit 122 or can be read from the control circuit 122.

[0094] Next, the control circuit 122 measures the temperature of the photodiode PD (step S2). Specifically, the control circuit 122 measures the temperature of the sensor substrate 21 provided with the photoelectric conversion unit AA, that is, the temperature treated as the temperature of the photodiode PD in the embodiment, based on the output of the temperature detection unit 331. The control circuit 122 sets the temperature of the photodiode PD obtained in the process of step S2 as Tm °C.

[0095] The control circuit 122 determines whether Tm < Ts holds (step S3). If Tm < Ts holds (step S3; Yes), the control circuit 122 operates the seat heater 310 (step S4). On the other hand, if Tm < Ts does not hold (step S3; No), the control circuit 122 does not operate the seat heater 310 (step S5).

[0096] FIG. 15 is a flowchart showing a determination flow regarding the control of sensing. In the determination regarding the control of sensing, it is assumed that the processing regarding the operation of the seat heater 310 described with reference to FIG. 14 has already been performed. Further, within the elapsed time during which the validity of the temperature of the photodiode PD obtained in the process of step S2 included in the process regarding the operation of the seat heater 310 is not lost, the determination regarding the control of sensing described with reference to FIG. 15 is made.

[0097] First, the temperature range is set by the control circuit 122 (step S11). Specifically, the control circuit 122 reads the data indicating the above-mentioned td, which is held in an external storage circuit (not shown) that can be held in the control circuit 122 or read from the control circuit 122.

[0098] The control circuit 122 determines whether Ts - td < Tm < Ts + Td holds (step S12). Ts in the process of step S12 is Ts of the temperature condition (Ts °C) set in the process of step S1 shown in FIG. 14. Also, Tm in the process of step S12 is Tm of the temperature (Tm °C) of the photodiode PD obtained in the process of step S2 shown in FIG. 14. When Ts - td < Tm < Ts + Td holds (step S12; Yes), sensing is performed (step S13). On the other hand, when Ts - td < Tm < Ts + Td does not hold (step S12; No), the process of step S13 is not performed. That is, when Ts - td < Tm < Ts + Td does not hold, sensing is not performed.

[0099] Note that the embodiment of the detection device according to the present disclosure is not limited to the form described with reference to FIGS. 1 to 15. Hereinafter, other embodiments will be described.

[0100] (Embodiment 2) 16 is a side view showing the layered structure of a detection device 302A according to embodiment 2. Unlike the detection device 302 described with reference to FIG. 2, the detection device 302A has a layered structure in which the sensor unit 10, the seat heater 310, and the collimator 303 are layered in this order from one side to the other side. That is, in the detection device 302A, the seat heater 310 is interposed between the collimator 303 and the sensor unit 10.

[0101] In the second embodiment, the seat heater 310 is located on the path of light entering the photodiode PD from the collimator 303 side. Therefore, the seat heater 310 of the second embodiment is translucent. Such a seat heater 310 can be realized by using a conductive material exhibiting translucency, such as the above-mentioned ITO or IZO, as its material. As described above, except for the points noted above, the detection device 302A of the second embodiment is the same as the detection device 302 of the first embodiment.

[0102] (Embodiment 3) 17 is a side view showing the layered structure of a detection device 302B according to the third embodiment. The detection device 302B has a layered structure in which a sensor unit 10A and a collimator 303 are layered in this order from one surface to the other. The sensor unit 10A has a layered structure in which a circuit board 320, a photodiode PD, and a dual-purpose electrode 341 are layered in this order from one surface to the other. The dual-purpose electrode 341 is an integrated structure of the seat heater 310 according to the second embodiment described with reference to FIG. 16 and the common electrode 322 according to the first embodiment described with reference to FIGS. 1 to 15.

[0103] 18 is a schematic diagram showing a mechanism for controlling the voltage applied to dual-purpose electrode 341. As shown in FIG. 18, in the third embodiment, in addition to voltage Vr1 described with reference to FIG. 12, variable voltage Vh can be applied to dual-purpose electrode 341. One end of dual-purpose electrode 341 in the extension direction is connected to voltage Vr1, and the other end is connected to variable voltage Vh. The voltage applied from variable voltage Vh is determined by power supply circuit 123 under the control of control circuit 122.

[0104] During sensing, the control circuit 122 causes the dual-purpose electrode 341 to function in the same manner as the above-described common electrode 322. Specifically, during sensing, the control circuit 122 sets the variable voltage Vh to the same voltage as the voltage Vr1. As a result, the voltage Vr1 and the variable voltage Vh are in a parallel relationship, and the potential of the voltage Vr1 is applied to the common electrode 322.

[0105] When dual-purpose electrode 341 is caused to function in the same manner as seat heater 310, control circuit 122 sets variable voltage Vh to voltage Vr2, which is different from voltage Vr1. As a result, a current corresponding to the potential difference between voltage Vr1 and variable voltage Vh flows through dual-purpose electrode 341. Dual-purpose electrode 341 generates heat due to the current and functions in the same manner as seat heater 310. In the third embodiment, variable voltage Vh when dual-purpose electrode 341 is caused to function in the same manner as seat heater 310 is set to a voltage 1 V higher than voltage Vr1 (e.g., 3 V) or a voltage 1 V lower than voltage Vr1 (e.g., 1 V). However, variable voltage Vh when dual-purpose electrode 341 is caused to function in the same manner as seat heater 310 is not limited to this and can be changed as appropriate depending on various conditions, such as the required heat generation performance.

[0106] 19 is a time chart showing a case where a period in which the dual-purpose electrode 341 functions in the same manner as the seat heater 310 and a period in which the dual-purpose electrode 341 functions in the same manner as the common electrode 322 alternate with each other. In FIG. 19, the voltage Vr2 is set to a voltage (for example, 1 V) that is 1 V lower than the voltage Vr1.

[0107] 19, during a period in which voltage Vr2 is different from voltage Vr1, dual-purpose electrode 341 functions in the same manner as the above-described seat heater 310, heating photodiode PD. In the time chart shown in FIG. 19, during a period in which voltage Vr2 is equal to voltage Vr1, dual-purpose electrode 341 functions in the same manner as the above-described circuit board 320, applying a reverse bias to photodiode PD.

[0108] FIG. 20 is a flowchart showing the flow of main operation control of the detection device 302B in Embodiment 3. First, temperature conditions are set by the control circuit 122 (step S21). The process of step S21 is the same as the process of step S1 described above. Also, a temperature range is set by the control circuit 122 (step S22). The process of step S22 is the same as the process of step S11 described above.

[0109] Next, the control circuit 122 measures the temperature of the photodiode PD (step S23). The process of step S23 is the same as the process of step S2 described above. The control circuit 122 determines whether Tm<Ts holds (step S24). If Tm<Ts holds (step S24; Yes), the control circuit 122 makes the shared electrode 341 function in the same manner as the sheet heater 310 (step S25).

[0110] After the process of step S25, the control circuit 122 measures the temperature of the photodiode PD (step S26). After the process of step S26, the control circuit 122 determines whether Ts−td<Tm<Ts+td holds (step S27). In the process of step S27, Ts is the Ts of the temperature condition (Ts ° C.) set in the process of step S21. Also, in the process of step S27, td is the td of the temperature range (±td ° C.) set in the process of step S22. Also, in the process of step S27, Tm is the Tm of the temperature of the photodiode PD (Tm ° C.) acquired in the latest process of step S26. If Ts−td<Tm<Ts+td holds (step S27; Yes), the control circuit 122 stops making the shared electrode 341 function in the same manner as the sheet heater 310 (step S28), and makes the shared electrode 341 function in the same manner as the common electrode 322 to perform sensing (step S29). On the other hand, if Ts−td<Tm<Ts+td does not hold (step S27; No), the process returns to step S26 again.

[0111] Incidentally, the elapsed time from the completion of the process in step S25 until the process in step S26 is performed and the elapsed time until the process in step S26 is repeated again when Ts - td < Tm < Ts + Td does not hold in the process of step S27 (step S27; No) are arbitrary, but it is desirable that they be times determined with validity in advance based on prior measurements or the like. For example, it is desirable that the elapsed time be a time (for example, within the range from 2 seconds to 3 seconds) such that the temperature rise of the photodiode PD significantly occurs due to the photodiode PD being heated by the shared electrode 341 because the shared electrode 341 functions in the same manner as the sheet heater 310.

[0112] When Tm < Ts does not hold in the process of step S24 (step S24; No), the control circuit 122 performs sensing (step S29). Except for the matters noted above, the detection device 302B of Embodiment 3 is the same as the detection device 302A of Embodiment 2.

[0113] (Embodiment 4) FIG. 21 is a side view showing the laminated structure of the detection device 302C according to Embodiment 4. The detection device 302C has a laminated structure in which these components are laminated in the order of the collimator 303, the sheet heater 310, and the sensor unit 10C from one surface side to the other surface side. The sensor unit 10C has a laminated structure in which these components are laminated in the order of the circuit board 320, the photodiode PD2, and the common electrode 322 from one surface side to the other surface side. The photodiode PD2 in the sensor unit 10C is the same as the photodiode PD except that the positional relationship between the individual electrodes 321 of the anode and the cathode and the common electrode 322 is opposite to that of the photodiode PD described above. The sensor unit 10C is the same as the sensor unit 10 except that the photodiode PD is replaced with the photodiode PD2 between the circuit board 320 and the common electrode 322.

[0114] Fig. 22 is a circuit diagram showing multiple partial detection areas PAA in embodiment 4. Fig. 23 is a schematic diagram showing the mechanism of detection by the sensor unit 10C in embodiment 4. As shown in Figs. 22 and 23, in embodiment 4, contrary to embodiment 1, the cathode of the photodiode PD2 is connected to the individual electrode 321. The anode of the photodiode PD2 is connected to the common electrode 322. Therefore, the individual electrode 321 and the electron transport layer 34 are in contact, and the common electrode 322 and the hole transport layer 35 are in contact.

[0115] Furthermore, in the fourth embodiment, unlike the first embodiment, the relative voltage level relationship between the individual electrode 321 and the common electrode 322 for applying the voltage Vr1 due to the sensor power supply signal VDDSNS to the photodiode PD is reversed from that in the first embodiment. Specifically, the voltage Vr1 applies a relatively high voltage to the individual electrode 321 and a relatively low voltage to the common electrode 322. As a result, in the fourth embodiment as well, the voltage Vr1 acts as a reverse bias on the photodiode PD2.

[0116] 21, the collimator 303 in the fourth embodiment is located on the circuit board 320 side. Therefore, as shown in Fig. 23, light (for example, light L61 and light L62) detected by the photodiode PD in the fourth embodiment enters from the individual electrode 321 side. Therefore, the individual electrode 321 is preferably made of a conductive material that is translucent, such as ITO or IZO.

[0117] Furthermore, in the fourth embodiment, similar to the second embodiment described above, the seat heater 310 is located on the path of light that enters the photodiode PD2 from the collimator 303 side. Therefore, the seat heater 310 of the fourth embodiment is translucent, similar to the second embodiment. Such a seat heater 310 can be realized by using a conductive material that exhibits translucency, such as the above-described ITO or IZO, as its material.

[0118] Furthermore, in the fourth embodiment, the collimator 303 is located on one side of the photodiode PD2, and the substrate 301 is located on one side of the collimator 303. Therefore, the substrate 301 in the fourth embodiment is preferably light-transmitting. Specifically, the substrate 301 in the fourth embodiment is, for example, a glass substrate or a light-transmitting flexible substrate. As described above, except for the points noted above, the detection device 302C in the fourth embodiment is similar to the detection device 302 in the first embodiment.

[0119] (Embodiment 5) 24 is a side view showing the layered structure of a detection device 302D according to embodiment 5. The detection device 302D has a layered structure in which a collimator 303, a sensor unit 10C, and a seat heater 310 are layered in this order from one side to the other side.

[0120] The seat heater 310 of the fifth embodiment is not located on the path of light that reaches the photodiode PD2 from the collimator 303 side. Therefore, the seat heater 310 of the fifth embodiment does not necessarily need to be made of a light-transmitting material. Of course, the seat heater 310 of the fifth embodiment may be made of a light-transmitting material. As described above, except for the points noted above, the detection device 302D of the fifth embodiment is the same as the detection device 302C of the fourth embodiment.

[0121] (Modification of the fifth embodiment) A modification of the fifth embodiment will now be described with reference to Fig. 25 and Fig. 26. In the modification of the fifth embodiment, a strip-shaped electrode 3101 shown in Fig. 25 or a strip-shaped electrode 3102 shown in Fig. 26 may be provided instead of the seat heater 310.

[0122] Fig. 25 is a schematic diagram showing an example of the configuration of a strip-shaped electrode 3101. As shown in Fig. 25, a configuration in which a plurality of strip-shaped electrodes 3101 are arranged in parallel may be provided instead of the seat heater 310. Furthermore, the configuration shown in Fig. 25 may be formed by providing a plurality of slits 3101a in the seat heater 310.

[0123] Fig. 26 is a schematic diagram showing a configuration example of a strip electrode 3102. As shown in Fig. 26, a strip electrode 3102 having multiple bent portions from one end to the other may be provided instead of the seat heater 310. Note that the bent portions in Fig. 26 may be curved. The configuration shown in Fig. 26 can also be achieved by forming slits 3102a in the seat heater 310 in an alternating pattern so as not to completely divide the seat heater 310.

[0124] The strip-shaped electrode 3101 and the band-shaped electrode 3102 have a heat generating portion similar to that of the seat heater 310. In other words, the sheet-like form of the seat heater 310 may be replaced with the form shown in Figs. 25 and 26.

[0125] 25 and 26 is a voltage (e.g., 1 V) applied to the strip electrodes 3101 and the strip electrodes 3102 to cause them to function as a component for heating the photodiode PD2 (or photodiode PD) in the same manner as the above-described seat heater 310. Also, the switch Sw shown in FIGS. 25 and 26 is a schematic diagram showing that the heating function of the photodiode PD2 (or photodiode PD) by the strip electrodes 3101 and the strip electrodes 3102 can be turned on and off. The opening and closing of the switch Sw is controlled by the control circuit 122.

[0126] The above describes a modified example of embodiment 5 with reference to Figures 25 and 26, but the strip-shaped electrode 3101 and the strip-shaped electrode 3102 described with reference to Figures 25 and 26 may be adopted as a configuration replacing the seat heater 310 in embodiment 1.

[0127] (Embodiment 6) FIG. 27 is a side view showing the layered structure of a detection device 302E according to the sixth embodiment. The detection device 302E has a layered structure in which a collimator 303 and a sensor unit 10E are layered in this order from one side to the other. The sensor unit 10E has a layered structure in which a circuit board 320, a photodiode PD, and a dual-purpose electrode 341 are layered in this order from one side to the other. The dual-purpose electrode 341 in the sixth embodiment has a similar configuration to the dual-purpose electrode 341 in the third embodiment. However, just as the relationship between the level of the voltage Vr1 and the individual electrodes 321 and the common electrode 322 is reversed between the first embodiment and the fourth embodiment, the relationship between the level of the voltage Vr1 and the variable voltage Vh and the individual electrodes 321 and the dual-purpose electrode 341 is reversed between the third embodiment and the sixth embodiment. That is, in the sixth embodiment, a relatively high voltage of the voltage Vr1 and the variable voltage Vh is applied to the individual electrode 321, and a relatively low voltage is applied to the dual-purpose electrode 341. In other words, the detection device 302E of the sixth embodiment has a configuration in which the common electrode 322 and the seat heater 310 in the detection device 302D of the fifth embodiment are replaced with a dual-purpose electrode 341. Note that the electrical resistance of the current path from the individual electrode 321 to the dual-purpose electrode 341 via the photodiode PD is significantly higher than the electrical resistance of the current path between one end and the other end in the extension direction of the dual-purpose electrode 341, so that even with this connection, a current can be passed through the dual-purpose electrode 341. As an example, if the sheet resistance of the dual-purpose electrode 341 is about 40 Ω / sq, heat generation of about 0.1 W can be expected when a current of 50 mA flows.

[0128] Unlike the fifth embodiment, the modified examples of the fifth embodiment cannot be applied to the sixth embodiment. This is because the dual-purpose electrode 341 of the sixth embodiment also functions as the common electrode 322 for the individual electrodes 321. As described above, except for the points noted above, the detection device 302E of the sixth embodiment is the same as the detection device 302D of the fifth embodiment.

[0129] (Embodiment 7) 28 is a side view showing the layered structure of a detecting device 302F according to the seventh embodiment. The detecting device 302F has a layered structure in which a temperature detection light source 390, a seat heater 310, a sensor unit 10, and a collimator 303 are layered in this order from one side to the other side. That is, the detecting device 302F according to the seventh embodiment is configured by further providing a temperature detection light source 390 on one side of the detecting device 302 according to the first embodiment.

[0130] The temperature detection light source 390 has a light source that irradiates the photodiode PD with light of a constant intensity. The light source is, for example, an LED, but is not limited to this, and may be any light source that can irradiate the photodiode PD with light of a constant intensity in response to power supply.

[0131] 28, the seat heater 310 is interposed between the temperature detection light source 390 and the photodiode PD. Therefore, the seat heater 310 of the seventh embodiment is translucent, similar to the second embodiment. The temperature detection light source 390 irradiates the photodiode PD with light from the circuit board 320 side. Therefore, the individual electrodes 321 of the sixth embodiment are desirably translucent, similar to the fourth embodiment.

[0132] 29 is a graph showing the relationship between the output of the photodiode PD receiving light from the temperature detection light source 390 and the temperature of the photodiode PD. As described above, the output of the photodiode PD exhibits temperature dependency. Therefore, the level of the output of the photodiode PD receiving light of a constant intensity from the temperature detection light source 390 corresponds to the temperature of the photodiode PD. In other words, the temperature of the photodiode PD can be determined from the output of the photodiode PD under the condition of receiving light of a constant intensity from the temperature detection light source 390. This is because the higher the temperature of the photodiode PD, the higher the output of the photodiode PD under the condition of receiving light of a constant intensity from the temperature detection light source 390.

[0133] The light source 390 for temperature detection is connected to the control circuit 122 via an interface provided on the control board 121 corresponding to the light source 390 for temperature detection, like the terminal part 332 corresponding to the temperature detection part 331. It operates by receiving power supply from the power supply circuit 123 under the control of the control circuit 122. In Embodiment 7 including the light source 390 for temperature detection, the temperature detection part 331 and the terminal part 332 can be omitted. That is, data showing the relationship between the output of the photodiode PD and the temperature of the photodiode PD under the condition of receiving light of a certain intensity from the light source 390 for temperature detection is held in advance in the control circuit 122 or in an external storage circuit (not shown) readable from the control circuit 122. Then, by including the lighting period of lighting the light source 390 for temperature detection without lighting the first light source 61 and the second light source 62 in the operation period of the detection device 302F, the temperature of the photodiode PD can be measured.

[0134] FIG. 30 is a flowchart showing the main operation control flow of the detection device 302F in Embodiment 7. First, the control circuit 122 sets the temperature condition (step S31). The process of step S31 is the same as the process of step S1 described above. Also, the control circuit 122 sets the temperature range (step S32). The process of step S32 is the same as the process of step S11 described above.

[0135] The control circuit 122 lights the light source 390 for temperature detection (step S33). The control circuit 122 measures the temperature of the photodiode PD based on the output of the photodiode PD during the lighting period of the light source 390 for temperature detection (step S34). The control circuit 122 determines whether Tm < Ts holds (step S35). When Tm < Ts holds (step S35; Yes), the control circuit 122 operates the sheet heater 310 (step S36).

[0136] After the process of step S36, the control circuit 122 measures the temperature of the photodiode PD (step S37). Note that the process of step S37 is due to the continuous irradiation of light with a certain intensity from the temperature detection light source 390 that was lit in the process of step S33.

[0137] The control circuit 122 determines whether Ts - td < Tm < Ts + Td holds (step S38). In the process of step S38, Ts is the Ts of the temperature condition (Ts °C) set in the process of step S31. Also, in the process of step S38, td is the td of the temperature range (±td °C) set in the process of step S32. Further, in the process of step S38, Tm is the Tm of the temperature (Tm °C) of the photodiode PD obtained in the latest process of step S37. When Ts - td < Tm < Ts + Td holds (step S38; Yes), the control circuit 122 terminates the operation of the seat heater 310 (step S39), turns off the temperature detection light source 390 (step S40), and performs sensing (step S41). On the other hand, when Ts - td < Tm < Ts + Td does not hold (step S38; No), the process returns to step S37 again.

[0138] Note that the elapsed time from after the process of step S36 until the process of step S37 is performed and the elapsed time until the process of step S37 is repeated again when Ts - td < Tm < Ts + Td does not hold (step S38; No) in the process of step S38 are arbitrary, but it is desirable that they are times determined with validity in advance based on prior measurements or the like. For example, it is desirable that the elapsed time is a time (e.g., 10 seconds) such that a significant temperature rise of the photodiode PD due to heating of the photodiode PD by the seat heater 310 when the seat heater 310 operates is considered to occur.

[0139] If Tm<Ts does not hold in the process of step S35 (step S35; No), the control circuit 122 performs sensing (step S41) after the process of step S40. Except for the matters noted above, the detection device 302F of Embodiment 7 is the same as the detection device 302 of Embodiment 1.

[0140] Note that the temperature detection light source 390 of Embodiment 7 can also be provided in Embodiments 2 to 6. When the temperature detection light source 390 is provided in Embodiments 2 to 6, the temperature detection light source 390 may be further laminated so that the temperature detection light source 390 and the collimator 303 are in a positional relationship facing each other with the photodiode PD (or photodiode PD2) interposed therebetween.

[0141] As described above, the detection devices (detection devices 302, 302A, 302B, 302C, 302D, 302E, 302F) according to the present disclosure include a photoelectric conversion unit (photoelectric conversion unit AA) in which a plurality of photodiodes (photodiode PD or photodiode PD2) are arranged in a planar shape, a light source (first light source 61, second light source 62) that irradiates light to the photodiodes, and a heating electrode (sheet heater 310 or shared electrode 341) that is provided so as to face the photoelectric conversion unit and generates heat to conduct the heat to the photoelectric conversion unit.

[0142] According to the present disclosure, the heating electrode (sheet heater 310 or shared electrode 341) that generates heat and conducts the heat to the photoelectric conversion unit (photoelectric conversion unit AA) can heat the plurality of photodiodes (photodiode PD or photodiode PD2) arranged in the photoelectric conversion unit. That is, according to the present disclosure, the temperature of the photodiode can be increased. Therefore, according to the present disclosure, it is possible to suppress a decrease in the output responsiveness of the photodiode that may occur when the temperature is too low. Thus, according to the present disclosure, it is possible to provide a detection device (detection devices 302, 302A, 302B, 302C, 302D, 302E, 302F) that can more easily ensure output responsiveness.

[0143] The detection device (detection devices 302, 302A, 302B, 302C, 302D, 302E, and 302F) also includes a circuit board (circuit board 320) having a plurality of electrodes (individual electrodes 321) to which the anodes or cathodes of the plurality of photodiodes (photodiodes PD and PD2) are individually connected. The detection device (e.g., detection device 302) is stacked from one side to the other side in the order of the heating electrode (seat heater 310), the circuit board, and the photoelectric conversion unit (photoelectric conversion unit AA), with the heating electrode and the photoelectric conversion unit sandwiched between them. The light sources (first light source 61 and second light source 62) are located on the other side of the photoelectric conversion unit (see FIGS. 12 and 18). This allows light (light L61 and L62) from the light sources (first light source 61 and second light source 62) to more efficiently reach the photoelectric conversion unit.

[0144] Furthermore, the detection device (e.g., detection devices 302, 302A, 302B) may have the anodes of the multiple photodiodes (photodiodes PD) individually connected to multiple electrodes (individual electrodes 321), and the detection device (e.g., detection devices 302C, 302D, 302E) may have the cathodes of the multiple photodiodes (photodiode PD2) individually connected to multiple electrodes (individual electrodes 321).

[0145] In addition, the detection device (e.g., detection devices 302A, 302B) may be configured such that the circuit board (circuit board 320) and the heating electrode (seat heater 310 or dual-purpose electrode 341) sandwich the photoelectric conversion unit (photoelectric conversion unit AA) in that order from one side to the other, and the light source (first light source 61, second light source 62) is positioned on the other side of the heating electrode.

[0146] In addition, the heating electrode (dual-purpose electrode 341) is connected to one of the anodes or cathodes of the multiple photodiodes (photodiode PD or photodiode PD2) that is not connected to the multiple electrodes (individual electrodes 321), and is configured to be switchable between a voltage for operating the multiple photodiodes and a voltage for generating heat (see, for example, Figure 18).

[0147] As exemplified by the strip electrodes 3101 and 3102, the heating electrodes may have slits (for example, slits 3101a and 3102a).

[0148] Furthermore, like the detection device 302F, a temperature detection light source (temperature detection light source 390) may be provided at a position different from the light sources (first light source 61, second light source 62) and at a position where an external object does not enter the optical path to the photoelectric conversion unit (photoelectric conversion unit AA), and the light source and the temperature detection light source may be provided at positions facing each other with the photoelectric conversion unit in between (for example, see the relationship between the position of the temperature detection light source 390 in FIG. 28 and the positions of the first light source 61 and second light source 62 in FIG. 12). In this way, as described above, the temperature of the photoelectric conversion unit (photoelectric conversion unit AA) can be measured by turning on the temperature detection light source.

[0149] Furthermore, the light sources (first light source 61, second light source 62) and the temperature detection light source (temperature detection light source 390) are turned on at different times, and the heating electrode operates until the output of the photodiode (photodiode PD) in response to light of a certain intensity from the temperature detection light source becomes the output when the temperature of the photodiode exceeds a predetermined temperature. This makes it possible to suppress a decrease in the output responsiveness of the photodiode by setting the predetermined temperature to a temperature that can sufficiently ensure the output responsiveness of the photodiode.

[0150] Note that the terms "one side" and "other side" in the above-described embodiments and modifications may be formally reversed. That is, "one side" in the above-described embodiments and modifications may be read as "other side", and "other side" in the above-described embodiments and modifications may be read as "one side".

[0151] Furthermore, other effects and advantages brought about by the aspects described in the above-mentioned embodiments and variants that are clear from the description in this specification or that can be appropriately thought of by a person skilled in the art are naturally understood to be brought about by the present disclosure. [Explanation of symbols]

[0152] 34 Electron transport layer 35 Hole transport layer 61 1st light source 62 Second light source 302, 302A, 302B, 302C, 302D, 302E, 302F Detector 310 Seat heater 320 Circuit Board 321 Individual electrode 322 Common electrode 341 Dual purpose electrode 390 Temperature detection light source AA photoelectric conversion section PD photodiode

Claims

1. a photoelectric conversion unit in which a plurality of photodiodes are arranged in a plane; a light source that irradiates the photodiode with light; a heating electrode that is provided to face the photoelectric conversion unit and generates heat to conduct the heat to the photoelectric conversion unit; Equipped with A circuit board having a plurality of electrodes to which the anodes or cathodes of the plurality of photodiodes are individually connected and the heating electrode are stacked in this order from one surface side to the other surface side in a positional relationship in which the photoelectric conversion unit is sandwiched between the circuit board, the photoelectric conversion unit, and the heating electrode; The light source is located on the other side of the heating electrode. Detection device.

2. the anodes of the plurality of photodiodes are individually connected to the plurality of electrodes; The detection device according to claim 1 .

3. The heating electrode is connected to one of the anodes or cathodes of the plurality of photodiodes that is not connected to the plurality of electrodes, and is configured to be switchable between a voltage for operating the plurality of photodiodes and a voltage for generating the heat.

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

4. The heating electrode has a slit.

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

5. a temperature detection light source provided at a position different from the light source and at a position where an external object does not enter an optical path to the photoelectric conversion unit; the light source and the temperature detection light source are provided at positions facing each other with the photoelectric conversion unit therebetween; 4. A detection device according to any one of claims 1 to 3.

6. a photoelectric conversion unit in which a plurality of photodiodes are arranged in a plane; a light source that irradiates the photodiode with light; a heating electrode that is provided to face the photoelectric conversion unit and generates heat to conduct the heat to the photoelectric conversion unit; a temperature detection light source provided at a position different from the light source and at a position where an external object does not enter an optical path to the photoelectric conversion unit, the light source and the temperature detection light source are provided at positions facing each other with the photoelectric conversion unit therebetween; Detection device.

7. the light source and the temperature detection light source are turned on at different timings, The heating electrode operates until the output of the photodiode in response to light of a certain intensity from the temperature detection light source becomes the output when the temperature of the photodiode exceeds a predetermined temperature.

7. The detection device according to claim 5 or 6.

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