Detection device

Abstract

To provide a detection device capable of improving a utilization efficiency of a light.SOLUTION: A detection device includes: a substrate; a plurality of photodiodes provided to the substrate; a plurality of transistors provided so as to be corresponded to each of the plurality of photodiodes; a plurality of gate lines extended to a first direction; a plurality of signal lines extended to a second direction crossed to the first direction; a plurality of bottom electrodes that is provided between each transistor and each photodiode to a direction vertical to the substrate, and is provided so as to be corresponded to each of the plurality of photodiodes; an upper electrode provided over the plurality of photodiodes; and a reflective layer provided between the substrate and each photodiodes to the direction vertical to the substrate. The bottom electrode includes an area smaller than that of an area parted by a plurality of gate lines and a plurality of signal lines, and the reflective layer is provided between the adjacent bottom electrodes in a plan view.SELECTED DRAWING: Figure 6

Description

[Technical Field]

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

[0002] Optical sensors capable of detecting fingerprint patterns and vein patterns are known (for example, see Patent Document 1). Such optical sensors have multiple photodiodes that use organic semiconductor materials as active layers. The photodiodes are disposed between a lower electrode and an upper electrode. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-32005 Summary of the Invention [Problem to be solved by the invention]

[0004] By thinning the active layer of the photodiode, it is possible to increase the sensor capacitance formed between the lower electrode and the upper electrode. The charge generated when the photodiode is irradiated with light is stored in the sensor capacitance. On the other hand, if the active layer of the photodiode is thinned, the amount of light that can be absorbed by the photodiode when light is irradiated onto it decreases, which may result in a decrease in light utilization efficiency.

[0005] An object of the present invention is to provide a detection device that can improve the light utilization efficiency. [Means for solving the problem]

[0006] A detection device according to one embodiment of the present invention includes a substrate, a plurality of photodiodes provided on the substrate, a plurality of transistors provided corresponding to each of the photodiodes, a plurality of gate lines extending in a first direction, a plurality of signal lines extending in a second direction intersecting the first direction, a plurality of lower electrodes provided between the transistors and the photodiodes in a direction perpendicular to the substrate and corresponding to each of the photodiodes, an upper electrode provided across the photodiodes, and a reflective layer provided between the substrate and the photodiodes in a direction perpendicular to the substrate, wherein the lower electrode has an area smaller than an area defined by the gate lines and the signal lines, and the reflective layer is provided between adjacent lower electrodes in a planar view. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a plan view showing a detection device according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing a schematic cross-sectional configuration of the detection device according to the first embodiment. [Figure 3] FIG. 3 is a block diagram showing an example of the configuration of the detection device according to the first embodiment. [Figure 4] FIG. 4 is a circuit diagram showing the detection device. [Figure 5] FIG. 5 is a circuit diagram showing a plurality of detection elements. [Figure 6] FIG. 6 is a plan view schematically showing the detection device according to the first embodiment. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII' in FIG. [Figure 8] FIG. 8 is a cross-sectional view schematically showing a cross section of the detection device according to the second embodiment. [Figure 9] FIG. 9 is a cross-sectional view schematically showing a cross section of a detection device according to a modified example of the second embodiment. [Figure 10] FIG. 10 is a plan view schematically showing a detection device according to the third embodiment. [Figure 11]FIG. 11 is a cross-sectional view taken along the line XI-XI' in FIG. [Figure 12] FIG. 12 is a plan view schematically showing a detection device according to a fourth embodiment. [Figure 13] FIG. 13 is a cross-sectional view taken along the line XIII-XIII' in FIG. [Figure 14] FIG. 14 is a cross-sectional view schematically showing a cross section of a detection device according to a fifth embodiment. [Figure 15] FIG. 15 is a cross-sectional view showing a schematic cross-sectional configuration of a detection device according to a sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

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

[0009] In this specification and claims, when expressing an aspect of placing another structure on top of a certain structure, the term "on top" is used, unless otherwise specified, to include both a case in which another structure is placed directly on top of a certain structure so as to be in contact with the certain structure, and a case in which another structure is placed above a certain structure via yet another structure.

[0010] (First embodiment) Fig. 1 is a plan view showing a detection device according to a first embodiment. As shown in Fig. 1, the detection device 1 includes a substrate 21, a sensor unit 10, a gate line driving circuit 15, a signal line selection circuit 16, a detection circuit 48, a control circuit 122, a power supply circuit 123, a first light source substrate 51, a second light source substrate 52, a first light source 53, and a second light source 54. The first light source substrate 51 is provided with a plurality of first light sources 53. The second light source substrate 52 is provided with a plurality of second light sources 54.

[0011] A control board 121 is electrically connected to the substrate 21 via a wiring board 71. The wiring board 71 is, for example, a flexible printed circuit board or a rigid board. The detection circuit 48 is provided on the wiring board 71. 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 53 and the second light source 54 to control the lighting or non-lighting of the first light source 53 and the second light source 54. The power supply circuit 123 supplies voltage signals such as a sensor power supply signal VDDSNS (see FIG. 5) 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 53 and the second light source 54.

[0012] The substrate 21 has a detection area AA and a peripheral area GA. The detection area AA is an area where a plurality of photodiodes PD (see FIG. 5) of the sensor unit 10 are provided. The peripheral area GA is an area between the periphery of the detection area AA and the outer edge of the substrate 21, where a plurality of photodiodes PD are not provided.

[0013] 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.

[0014] In the following description, the first direction Dx is a direction in a plane parallel to the substrate 21. The second direction Dy is a direction in a plane parallel to the 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. Furthermore, "plan view" refers to the positional relationship when viewed from a direction perpendicular to the substrate 21.

[0015] The plurality of first light sources 53 are provided on the first light source substrate 51 and arranged along the second direction Dy. The plurality of second light sources 54 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.

[0016] The plurality of first light sources 53 and the plurality of second light sources 54 may be, for example, inorganic light emitting diodes (LEDs) or organic light emitting diodes (OLEDs). The plurality of first light sources 53 and the plurality of second light sources 54 emit first light and second light of different wavelengths, respectively.

[0017] The first light emitted from the first light source 53 is mainly reflected by the surface of the detection object Fg, such as a finger, and enters the sensor unit 10. As a result, the sensor unit 10 can detect a fingerprint by detecting the uneven shape of the surface of the finger or the like. The second light emitted from the second light source 54 is mainly reflected by the inside of the finger or the like or passes through the finger or the like and enters the sensor unit 10. As a result, the sensor unit 10 can detect information about the living body inside the finger or the like. The information about the living body includes, for example, the pulse wave, pulse rate, blood vessel image, etc. of the finger or palm. In other words, the detection device 1 may be configured as a fingerprint detection device that detects fingerprints, or a vein detection device that detects blood vessel patterns such as veins.

[0018] The first light may have a wavelength of 500 nm or more and 600 nm or less, for example, approximately 550 nm, and the second light may have a wavelength of 780 nm or more and 950 nm or less, for example, approximately 850 nm. In this case, the first light is blue or green visible light, 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 53. The second light emitted from the second light source 54 is reflected from the inside of the detection object Fg, such as a finger, or transmitted through or absorbed by the finger, etc., and then enters the sensor unit 10. This allows the sensor unit 10 to detect a pulse wave or a blood vessel image (blood vessel pattern) as information about the living body inside the finger, etc.

[0019] Alternatively, the first light may have a wavelength of 600 nm or more and 700 nm or less, for example, about 660 nm, and the second light may have a 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 53 and the second light emitted from the second light source 54, the sensor unit 10 can detect information about the living body, such as pulse wave, pulse rate, and blood vessel image, as well as blood oxygen saturation. In this way, the detection device 1 has the first light source 53 and multiple second light sources 54, and therefore can detect various pieces of information about the living body by performing detection based on the first light and detection based on the second light.

[0020] The arrangement of the first light source 53 and the second light source 54 shown in FIG. 1 is merely an example and can be changed as appropriate. The detection device 1 is provided with multiple types of light sources (first light source 53 and second light source 54). However, this is not limited to this, and the light source may be of one type. For example, multiple first light sources 53 and multiple second light sources 54 may be arranged on each of the first light source substrate 51 and the second light source substrate 52. Furthermore, the number of light source substrates on which the first light source 53 and the second light source 54 are arranged may be one or three or more. Alternatively, it is sufficient that at least one or more light sources are arranged.

[0021] FIG. 2 is a cross-sectional view showing a schematic cross-sectional configuration of the detection device according to the first embodiment. As shown in FIG. 2, a plurality of detection elements PAA including photodiodes PD are arranged on a substrate 21. The photodiodes PD are OPDs (organic photodiodes) using organic semiconductors. A light source LS is provided above the substrate 21 and the plurality of photodiodes PD, sandwiching a detection object Fg such as a finger. Light L1 emitted from the light source LS passes through the detection object Fg and is irradiated onto the plurality of photodiodes PD. The plurality of photodiodes PD can detect information about the detection object Fg using the light L1 irradiated from the light source LS.

[0022] The detection device 1 shown in Fig. 2 is a transmission type detection device that detects light L1 transmitted through the detection object Fg. However, the detection device 1 is not limited to this, and may be a reflection type detection device. The light source LS shown in Fig. 2 is configured to include at least one of the first light source 53 and the second light source 54 described above. However, the number, arrangement, etc. of the light sources LS can be changed as appropriate.

[0023] Fig. 3 is a block diagram showing an example of the configuration of the detection device according to the first embodiment. As shown in Fig. 3, the detection device 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.

[0024] The sensor unit 10 has a plurality of photodiodes PD. The photodiodes PD of the sensor unit 10 output electrical signals corresponding to the incident light as detection signals Vdet to the signal line selection circuit 16. The sensor unit 10 also performs detection in accordance with the gate drive signals Vgcl supplied from the gate line drive circuit 15.

[0025] 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 53 and the second light source 54, and controls the lighting and non-lighting of each.

[0026] The gate line driving circuit 15 is a circuit that drives multiple gate lines GCL (see FIG. 4) 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.

[0027] The signal line selection circuit 16 is a switch circuit that sequentially or simultaneously selects a plurality of signal lines SGL (see FIG. 4). 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.

[0028] 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, an image processing unit 49, and an output processing unit 50. 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.

[0029] 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.

[0030] 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 a finger touches or approaches the detection surface, the signal processing unit 44 can detect unevenness on the surface of the finger 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, an image of the blood vessels of the finger or palm, a pulse wave, a pulse rate, and a blood oxygen concentration.

[0031] The signal processing unit 44 may also acquire detection signals Vdet (information about the living body) simultaneously detected by a plurality of 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 detection object Fg, such as a finger, and the sensor unit 10, thereby enabling stable detection.

[0032] 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.

[0033] The coordinate extraction unit 45 is a logic circuit that calculates the detection 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 detection coordinates of the blood vessels of the finger or 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 or the like and two-dimensional information indicating the shape of the blood vessels of the finger or palm. The coordinate extraction unit 45 may output the detection signal Vdet as the sensor output voltage 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.

[0034] The output processing unit 50 functions as a processing unit that performs processing based on outputs from the multiple photodiodes PD. The output processing unit 50 may include the detected coordinates determined by the coordinate extraction unit 45, the two-dimensional information generated by the image processing unit 49, etc. in the sensor output voltage Vo. Furthermore, the function of the output processing unit 50 may be integrated into another configuration (for example, the image processing unit 49, etc.).

[0035] Next, an example of the circuit configuration of the detection device 1 will be described. Fig. 4 is a circuit diagram showing the detection device. As shown in Fig. 4, the sensor unit 10 has a plurality of detection elements PAA arranged in a matrix. Each of the plurality of detection elements PAA is provided with a photodiode PD.

[0036] The gate line GCL extends in a first direction Dx and is connected to a plurality of detection elements 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 there is no need to distinguish between the plurality of gate lines GCL(1), GCL(2), ..., GCL(8), they will be simply referred to as gate lines GCL. Furthermore, for ease of understanding, eight gate lines GCL are shown in FIG. 4, but this is merely an example, and M gate lines GCL (M is 8 or more, for example, M=256) may be arranged.

[0037] The signal line SGL extends in the second direction Dy and is connected to the photodiodes PD of the plurality of detection elements 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.

[0038] 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. The resolution of the sensor is, for example, 508 dpi (dots per inch), and the number of cells is 252×256. In FIG. 4, the sensor unit 10 is provided between the signal line selection circuit 16 and the reset circuit 17. However, this is not limiting, and the signal line selection circuit 16 and the reset circuit 17 may be connected to ends of the signal lines SGL in the same direction.

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

[0040] 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.

[0041] 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.

[0042] The control circuit 122 (see FIG. 1) sequentially supplies the selection signal ASW to the selection signal line Lsel. As a result, the signal line selection circuit 16 sequentially selects the signal lines SGL in one signal line block in a time-division manner through the operation of the third switching element TrS. The signal line selection circuit 16 also selects one signal line SGL from each of the multiple signal line blocks. With this configuration, the detection device 1 can reduce the number of ICs (Integrated Circuits) including the detection circuit 48 or the number of IC terminals. The signal line selection circuit 16 may also bundle multiple signal lines SGL and connect them to the detection circuit 48.

[0043] 4, 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.

[0044] 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. 5) included in the multiple detection elements PAA.

[0045] Fig. 5 is a circuit diagram showing a plurality of detection elements. Fig. 5 also shows the circuit configuration of a detection circuit 48. As shown in Fig. 5, the detection element PAA includes a photodiode PD, a capacitance element Ca, and a first switching element Tr. The capacitance element Ca is a capacitance (sensor capacitance) formed in the photodiode PD, and is equivalently connected in parallel with the photodiode PD.

[0046] 5 shows two gate lines GCL(m) and GCL(m+1) aligned in the second direction Dy among the multiple gate lines GCL. Also shown are two signal lines SGL(n) and SGL(n+1) aligned in the first direction Dx among the multiple signal lines SGL. The detection element PAA is an area surrounded by the gate lines GCL and the signal lines SGL.

[0047] The first switching element Tr is provided corresponding to the photodiode PD. The first switching element Tr is configured by a thin film transistor, and in this example, is configured by an n-channel MOS (Metal Oxide Semiconductor) TFT (Thin Film Transistor).

[0048] The gates of the first switching elements Tr belonging to the plurality of detection elements PAA arranged in the first direction Dx are connected to the gate line GCL, the sources of the first switching elements Tr belonging to the plurality of detection elements PAA arranged 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.

[0049] A sensor power supply signal VDDSNS is supplied to the anode of the photodiode PD from the power supply circuit 123. In addition, a reference signal COM, which becomes the initial potential of the signal line SGL and the capacitance element Ca, is supplied from the power supply circuit 123 to the signal line SGL and the capacitance element Ca.

[0050] When light is irradiated onto the detection element 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 detection device 1 to detect a signal corresponding to the amount of light irradiated onto the photodiode PD for each detection element PAA or for each block unit PAG.

[0051] During the readout period, the switch SSW of the detection circuit 48 is turned on and connected to the signal line SGL. The detection signal amplifier 42 of the detection circuit 48 converts fluctuations in the current supplied from the signal line SGL into fluctuations in voltage and amplifies the voltage. A reference potential (Vref) having a fixed potential is input to the non-inverting input terminal (+) of the detection signal amplifier 42, and the signal line SGL is connected to the inverting input terminal (-). In this embodiment, a signal identical to the reference signal COM is input as the reference potential (Vref) voltage. The signal processor 44 (see FIG. 3) calculates the difference between the detection signal Vdet when light is irradiated and the detection signal Vdet when light is not irradiated as the sensor output voltage Vo. The detection signal amplifier 42 also has a capacitance element Cb and a reset switch RSW. During the reset period, the reset switch RSW is turned on and the charge of the capacitance element Cb is reset.

[0052] Next, the configuration of the photodiode PD will be described. Fig. 6 is a plan view schematically showing the detection device according to the first embodiment. In Fig. 6, the reflective layer 25 is shown with diagonal lines.

[0053] 6, the photodiode PD, the lower electrode 23, the reflective layer 25, and the first switching element Tr are provided in an area surrounded by the gate line GCL and the signal line SGL. The lower electrode 23 is a cathode electrode of the photodiode PD, and a plurality of the photodiodes PD and a plurality of the lower electrodes 23 are arranged in a matrix on the substrate 21.

[0054] 6, the lower electrode 23 is formed with an area smaller than the region defined by the gate line GCL and the signal line SGL, and is provided so as to overlap at least a portion of the first switching element Tr. The lower electrode 23 has a rectangular shape including a first side 23s1 extending in the second direction Dy and a second side 23s2 extending in the first direction Dx. The first side 23s1 of the lower electrode 23 and the signal line SGL are provided so as to be spaced apart in the first direction Dx. The second side 23s2 of the lower electrode 23 and the gate line GCL are provided so as to be spaced apart in the second direction Dy.

[0055] The reflective layer 25 is provided between adjacent lower electrodes 23 in plan view. More specifically, the reflective layer 25 is formed continuously and integrally with the source electrode 62 of the first switching element Tr. The reflective layer 25 is provided between the first side 23s1 of the lower electrode 23 and the signal line SGL, and between the second side 23s2 of the lower electrode 23 and the gate line GCL, in plan view. The reflective layer 25 is provided so as to overlap with at least one of the gate lines GCL adjacent to each other in the second direction Dy. In the example shown in FIG. 6, the outer edge of the reflective layer 25 is provided so as to overlap with the gate line GCL located near the first switching element Tr. The reflective layer 25 is also provided so as to be spaced apart from the signal line SGL.

[0056] As shown in FIG. 6, the first switching element Tr has a semiconductor layer 61, a source electrode 62, a drain electrode 63, and a gate electrode 64. The semiconductor layer 61 extends along the gate line GCL and is arranged to intersect with the gate electrode 64 in a plan view. The gate electrode 64 is connected to the gate line GCL and extends in a direction perpendicular to the gate line GCL. The two gate electrodes 64 are arranged side by side in the first direction Dx. The first switching element Tr of this embodiment has a double-gate structure in which the two gate electrodes 64 are arranged to overlap the semiconductor layer 61.

[0057] One end of the semiconductor layer 61 is connected to the source electrode 62 via the second contact hole CH2. The lower electrode 23 is electrically connected to the source electrode 62 of the first switching element Tr via the first contact hole CH1. This electrically connects the first switching element Tr to the photodiode PD. The other end of the semiconductor layer 61 is connected to the drain electrode 63 via the third contact hole CH3. The drain electrode 63 is connected to the signal line SGL.

[0058] The configuration and arrangement of the first switching element Tr shown in FIG. 6 are merely an example and can be changed as appropriate.

[0059] Fig. 7 is a cross-sectional view taken along line VII-VII' in Fig. 6. As shown in Fig. 7, the detection device 1 includes a substrate 21, a first switching element Tr, an organic insulating film 94, a lower electrode 23, a photodiode PD, an upper electrode 24, and a reflective layer 25. Although not shown in Fig. 7, a sealing film covering the photodiode PD and the upper electrode 24 is provided as necessary.

[0060] The substrate 21 is an insulating base material, and is made of, for example, glass or a resin material. The substrate 21 is not limited to a flat plate shape and may have a curved surface. In this case, the substrate 21 may be a film-like resin.

[0061] In this specification, the direction perpendicular to the surface of the substrate 21 from the substrate 21 to the photodiode PD is referred to as the "upper side" or simply "upper." The direction from the photodiode PD to the substrate 21 is referred to as the "lower side" or simply "lower."

[0062] The undercoat films 91a and 91b are provided on the substrate 21. The undercoat films 91a and 91b are formed of an inorganic insulating film such as a silicon nitride film or a silicon oxide film. The configuration of the undercoat films 91a and 91b is not limited to a laminated film in which two inorganic insulating films are stacked, but may be a three-layer or more layer film, or a single-layer film. A light-shielding film may be provided between the substrate 21 and the semiconductor layer 61.

[0063] A plurality of first switching elements Tr (transistors) are provided on a substrate 21. The plurality of first switching elements Tr are formed by stacking a semiconductor layer 61, a gate electrode 64, a source electrode 62, and a drain electrode 63 on the substrate 21 in this order. More specifically, the semiconductor layer 61 is provided on an undercoat film 91b. The semiconductor layer 61 is made of, for example, polysilicon. However, the semiconductor layer 61 is not limited to this and may be made of a microcrystalline oxide semiconductor, an amorphous oxide semiconductor, low-temperature polysilicon, or the like. Although only n-type TFTs are shown as the first switching elements Tr, p-type TFTs may also be formed at the same time.

[0064] The gate insulating film 92 covers the semiconductor layer 61 and is provided on the undercoat film 91b. The gate insulating film 92 is an inorganic insulating film such as a silicon oxide film. The gate electrode 64 is provided on the gate insulating film 92. In the example shown in FIG. 7, the first switching element Tr has a top-gate structure. However, without being limited to this, the first switching element Tr may have a bottom-gate structure or a dual-gate structure in which the gate electrodes 64 are provided on both the upper and lower sides of the semiconductor layer 61.

[0065] The interlayer insulating film 93 is provided on the gate insulating film 92, covering the gate electrode 64. The interlayer insulating film 93 has, for example, a stacked structure of a silicon nitride film and a silicon oxide film. The source electrode 62 and the drain electrode 63 are provided on the interlayer insulating film 93. The source electrode 62 is connected to the source region of the semiconductor layer 61 via a second contact hole CH2 provided in the gate insulating film 92 and the interlayer insulating film 93. The drain electrode 63 is connected to the drain region of the semiconductor layer 61 via a third contact hole CH3 provided in the gate insulating film 92 and the interlayer insulating film 93.

[0066] The overlapping portion 62s is formed continuously with the source electrode 62 and is provided in a region overlapping with the gate electrode 64 in the same layer as the source electrode 62. In other words, the portion of the source electrode 62 that overlaps with the gate electrode 64 can be expressed as the overlapping portion 62s. The overlapping portion 62s can prevent the semiconductor layer 61 from being irradiated with light L1.

[0067] The reflective layer 25 is formed continuously with the source electrode 62 and is provided in the same layer as the source electrode 62, that is, between the interlayer insulating film 93 and the organic insulating film 94. In other words, the portion of the source electrode 62 that does not overlap with the lower electrode 23 can be expressed as the reflective layer 25.

[0068] The organic insulating film 94 covers the source electrode 62 and the drain electrode 63 of the first switching element Tr and is provided on the interlayer insulating film 93. The organic insulating film 94 is an organic planarizing film, and is superior in coverage of wiring steps and surface flatness compared to inorganic insulating materials formed by CVD or the like.

[0069] The photodiodes PD are provided on the organic insulating film 94. The lower electrodes 23 are provided in a direction perpendicular to the surface of the substrate 21, between the substrate 21 and the organic insulating film 94 and the photodiodes PD.

[0070] More specifically, the lower electrode 23 is provided on the organic insulating film 94 and covers the bottom and inner side surfaces of a first contact hole CH1 formed in the organic insulating film 94. The lower electrode 23 is connected to the source electrode 62 of the first switching element Tr at the bottom surface of the first contact hole CH1. The lower electrode 23 is a cathode electrode of the photodiode PD and is formed of a metal material such as silver (Ag). This allows the lower electrode 23 to function as a reflective electrode. The multiple lower electrodes 23 are arranged spaced apart for each detection element PAA (photodiode PD). Furthermore, the photodiode PD has a larger area than the lower electrode 23 in a plan view and covers the upper surface and outer edge portion of the lower electrode 23.

[0071] The photodiode PD is provided to cover the plurality of lower electrodes 23 and the organic insulating film 94. Although not shown in FIG. 7, the photodiode PD has a configuration in which, for example, an electron transport layer (first carrier transport layer), an active layer, and a hole transport layer (second carrier transport layer) are stacked between the lower electrode 23 and the upper electrode 24.

[0072] The electron transport layer is formed by coating a material such as zinc acetate, ethoxylated polyethyleneimine (PEIE), or polyethyleneimine (PEI).

[0073] The active layer is made of a mixture of a p-type organic semiconductor and an n-type organic semiconductor. An example of a p-type organic semiconductor is PMDPP3T (poly((2,5-bis(2-hexyldecyl)-2,3,5,6-tetrahydro-3,6-dioxopyrrolo(3,4-c)pyrrole-1,4-diyl)-alt-(3',3"-dimethyl-2,2':5',2"-terthiophene)-5,5"-diyl)). An example of an n-type organic semiconductor is PC61BM ([6,6]-phenyl C61-butyric acid methyl ester). Alternatively, the active layer may be made of materials such as P3HT:PC61BM or PTB7:PC71BM.

[0074] The hole transport layer is, for example, a metal oxide layer such as tungsten oxide (WO3) or molybdenum oxide (MoOx). The hole transport layer is formed by vapor deposition or sputtering. Alternatively, the hole transport layer may be formed by coating a material such as PEDOT:PSS.

[0075] The electron transport layer, active layer, and hole transport layer that form the photodiode PD are provided continuously to cover the plurality of lower electrodes 23. In other words, the photodiode PD includes a portion that is provided overlapping with the lower electrode 23 and a portion that is provided on the organic insulating film 94 in a region that does not overlap with the lower electrode 23.

[0076] The upper electrode 24 is provided over the multiple photodiodes PD. The upper electrode 24 is an anode electrode of the photodiodes PD, and is formed continuously over the multiple detection elements PAA (photodiodes PD). The upper electrode 24 is made of a light-transmitting conductive material such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide).

[0077] As described above, the detection device 1 of this embodiment includes the substrate 21, a plurality of photodiodes PD provided on the substrate 21, a plurality of first switching elements Tr (transistors) provided corresponding to each of the plurality of photodiodes PD, a plurality of gate lines GCL extending in a first direction Dx, a plurality of signal lines SGL extending in a second direction Dy intersecting the first direction Dx, a plurality of lower electrodes 23 provided between the transistors and the photodiodes PD in a direction perpendicular to the substrate 21 and corresponding to each of the plurality of photodiodes PD, an upper electrode 24 provided across the plurality of photodiodes PD, and a reflective layer 25 provided between the substrate 21 and the photodiodes PD in a direction perpendicular to the substrate 21. The lower electrode 23 has an area smaller than the region defined by the plurality of gate lines GCL and the plurality of signal lines SGL, and the reflective layer 25 is provided between adjacent lower electrodes 23 in a plan view.

[0078] In the detection device 1 of this embodiment, the first switching element Tr (transistor) includes a semiconductor layer 61, a gate electrode 64, and a source electrode 62, which are stacked in this order in a direction perpendicular to the substrate 21. The reflective layer 25 is provided in the same layer as the source electrode 62.

[0079] According to this, in the detection device 1, light L1 that has passed through the object to be detected Fg (see FIG. 2) is irradiated onto the photodiode PD. In the region that overlaps with the lower electrode 23, the component of the light L1 that is not absorbed by the photodiode PD is reflected by the lower electrode 23. Then, a portion of the reflected light L1a reflected by the lower electrode 23 is absorbed by the photodiode PD.

[0080] In the region not overlapping with the lower electrode 23 (the region between adjacent lower electrodes 23), light L1 transmitted through the photodiode PD, i.e., the component of light L1 not absorbed by the photodiode PD, is reflected by the reflective layer 25. The reflected light L1b reflected by the reflective layer 25 travels upward (toward the photodiode PD), and a portion of the reflected light L1b is absorbed by the photodiode PD. In this way, by providing the reflective layer 25, the detection device 1 of this embodiment can improve the utilization efficiency of light L1 in the region between adjacent lower electrodes 23.

[0081] Furthermore, since the outer edge of the reflective layer 25 is provided so as to overlap the gate line GCL, the gap between the reflective layer 25 and the gate line GCL can be reduced in plan view. The reflective layer 25 can effectively reflect light L1 in the area surrounded by the gate line GCL and the signal line SGL, thereby improving the utilization efficiency of light L1. The reflective layer 25 also functions as a light-shielding layer that blocks external light from entering the photodiode PD from the substrate 21 side. The detection device 1 can suppress noise components caused by external light irradiated from between adjacent lower electrodes 23.

[0082] (Second embodiment) 8 is a cross-sectional view schematically showing a cross section of a detection device according to the second embodiment. In the following description, the same components as those described in the above-mentioned embodiments are denoted by the same reference numerals, and redundant description will be omitted.

[0083] In the first embodiment described above, a configuration was described in which the reflective layer 25 is provided in the same layer as the source electrode 62, but this is not limited to this, and the reflective layer 25 may be provided in a layer different from the source electrode 62, i.e., in any layer between the substrate 21 and the photodiode PD.

[0084] 8, in the detection device 1A according to the second embodiment, the reflective layer 25a is provided in a layer between the substrate 21 and the semiconductor layer 61 of the first switching element Tr in a direction perpendicular to the substrate 21. More specifically, the reflective layer 25a is provided on an undercoat film 91a. The undercoat film 91b is provided on the undercoat film 91a, covering the reflective layer 25a.

[0085] 8, the reflective layer 25a is provided in an area that does not overlap with the lower electrode 23, and is provided individually for each detection element PAA (photodiode PD). Although not shown, the reflective layer 25a is provided between adjacent lower electrodes 23 in plan view, similar to FIG. 6. However, since the reflective layer 25a is provided in a layer different from the source electrode 62 (signal line SGL) and the gate electrode 64 (gate line GCL), there are fewer restrictions on the arrangement due to these electrodes, wiring, etc. In other words, the reflective layer 25a may be provided so as to overlap with at least a portion of the signal line SGL and the gate line GCL in plan view (see FIGS. 6 and 10), or may be provided so as to be spaced apart from the signal line SGL and the gate line GCL.

[0086] (Modification of the second embodiment) 9 is a cross-sectional view schematically illustrating a cross section of a detection device according to a modification of the second embodiment. As shown in FIG. 9, in a detection device 1B according to the modification of the second embodiment, the reflective layer 25b is provided extending from a region that does not overlap with the lower electrode 23 to a region that overlaps with the first switching element Tr and the lower electrode 23. In the region that overlaps with the first switching element Tr, the reflective layer 25b is provided in a direction perpendicular to the substrate 21 below the semiconductor layer 61, i.e., between the substrate 21 and the semiconductor layer 61.

[0087] The reflective layer 25b is formed in a region overlapping the entire semiconductor layer 61 and the lower electrode 23, and also in a region overlapping at least a part of the signal line SGL. In this modification, the reflective layer 25b also functions as a light-shielding layer that suppresses light entering the semiconductor layer 61 from the substrate 21 side.

[0088] The reflective layer 25b may be provided so as to overlap at least a portion of the signal lines SGL and the gate lines GCL in a plan view (see FIGS. 6 and 10), or may be provided so as to be spaced apart from the signal lines SGL and the gate lines GCL. The reflective layer 25b may also be formed continuously across a plurality of detection elements PAA (photodiodes PD).

[0089] (Third embodiment) Fig. 10 is a plan view schematically showing a detection device according to a third embodiment. Fig. 11 is a cross-sectional view taken along line XI-XI' in Fig. 10. As shown in Figs. 10 and 11, in a detection device 1C according to the third embodiment, a reflective layer 25c and a gate electrode 64 are provided in the same layer.

[0090] 10, the reflective layer 25c is formed integrally and continuously with the gate electrode 64 and the gate line GCL. The reflective layer 25c is connected to one of the gate lines GCL located close to the first switching element Tr and is spaced apart from the other of the gate lines GCL located farther from the first switching element Tr. The reflective layer 25c is also arranged to overlap at least one of the signal lines SGL adjacent to each other in the first direction Dx in plan view. More specifically, the outer edge of the reflective layer 25c is arranged to overlap one of the signal lines SGL adjacent to the first side 23s1 of the lower electrode 23.

[0091] In other words, the reflective layer 25c is provided to cover most of the area defined by the gate line GCL and the signal line SGL, and openings are formed in the areas that overlap with the semiconductor layer 61, source electrode 62, and drain electrode 63 of the first switching element Tr.

[0092] 11, the reflective layer 25c is provided between the gate insulating film 92 and the interlayer insulating film 93. That is, the reflective layer 25c and the gate electrode 64 are provided on the gate insulating film 92. The interlayer insulating film 93 is provided on the gate insulating film 92, covering the gate electrode 64.

[0093] With this configuration, in this embodiment, the reflective layer 25c is provided to cover most of the area that does not overlap with the lower electrode 23, and can effectively reflect the light L1 that has passed through the photodiode PD.

[0094] (Fourth embodiment) FIG. 12 is a plan view schematically showing a detection device according to the fourth embodiment. FIG. 13 is a cross-sectional view taken along line XIII-XIII′ of FIG. 12. Note that in FIG. 12, for ease of viewing, the source electrode 62 and the reflective layer 25 (see FIG. 6) formed integrally with the source electrode 62 are omitted. As shown in FIGS. 12 and 13, the detection device 1D according to the fourth embodiment further includes a bottom gate line GCLB and a bottom gate electrode 65. In the detection device 1D, the reflective layer 25d is provided in the same layer as the bottom gate line GCLB and the bottom gate electrode 65.

[0095] 12, the bottom gate line GCLB is provided below the gate line GCL and extends in the first direction Dx along the gate line GCL. The bottom gate electrode 65 is connected to the bottom gate line GCLB and extends in a direction perpendicular to the bottom gate line GCLB. The two bottom gate electrodes 65 are arranged side by side in the first direction Dx and overlap the semiconductor layer 61. The two bottom gate electrodes 65 are also provided below the gate electrode 64, respectively.

[0096] The reflective layer 25d is formed integrally and continuously with the bottom gate electrode 65 and the bottom gate line GCLB. The reflective layer 25d is connected to one of the bottom gate lines GCLB located close to the first switching element Tr and is spaced apart from the other of the bottom gate lines GCLB located away from the first switching element Tr. The reflective layer 25d is also provided so as to overlap at least one of the signal lines SGL adjacent to each other in the first direction Dx in plan view. More specifically, the outer edge of the reflective layer 25d is provided so as to overlap one of the signal lines SGL adjacent to the first side 23s1 of the lower electrode 23.

[0097] In other words, the reflective layer 25d is provided to cover most of the area defined by the gate line GCL and the signal line SGL, and openings are formed in the areas that overlap with the semiconductor layer 61, source electrode 62, and drain electrode 63 of the first switching element Tr.

[0098] 13, the first switching element Tr is formed by stacking a bottom gate electrode 65, a semiconductor layer 61, a gate electrode 64 (top gate electrode), a source electrode 62, and a drain electrode 63 in this order in a direction perpendicular to the substrate 21. That is, the first switching element Tr of this embodiment has a dual-gate structure.

[0099] As described above, in the detection device 1D, the reflective layer 25d is provided in the same layer as the bottom gate electrode 65. The bottom gate electrode 65 and the reflective layer 25d are provided on an undercoat film 91a. The undercoat film 91b is provided on the undercoat film 91a, covering the bottom gate electrode 65 and the reflective layer 25a. The bottom gate line GCLB is electrically connected to the gate line GCL at an arbitrary point, and a gate drive signal Vgcl having the same potential as the gate electrode 64 is supplied to the bottom gate electrode 65.

[0100] In a region not overlapping with the lower electrode 23, a reflective layer 25 is provided on the reflective layer 25d via an undercoat film 91b, a gate insulating film 92, and an interlayer insulating film 93. The configurations of the source electrode 62 and the reflective layer 25 are the same as those in the first embodiment described above, and a repeated description will be omitted. The detection device 1D of this embodiment has two reflective layers 25, 25d, and therefore can effectively reflect light L1 transmitted through the photodiode PD.

[0101] With this configuration, the reflective layer 25d is provided to cover most of the area that does not overlap with the lower electrode 23, and can effectively reflect the light L1 that has passed through the photodiode PD.

[0102] (Fifth embodiment) FIG. 14 is a cross-sectional view schematically illustrating a cross section of a detection device according to a fifth embodiment. As shown in FIG. 14, a detection device 1E according to the fifth embodiment has an inorganic insulating film 95 provided on an organic insulating film 94. The inorganic insulating film 95 is made of an inorganic insulating material such as a silicon nitride film or a silicon oxide film. The organic insulating film 94 and the inorganic insulating film 95 are provided to cover a plurality of first switching elements Tr. The inorganic insulating film 95 covers the inner side surface of a first contact hole CH1 formed in the organic insulating film 94, and has an opening in a region overlapping the bottom surface of the first contact hole CH1.

[0103] The lower electrode 23 and the photodiode PD are provided on the inorganic insulating film 95 and are electrically connected to the source electrode 62 of the first switching element Tr through the first contact hole CH1. That is, the inorganic insulating film 95 is provided between the organic insulating film 94 and the lower electrode 23.

[0104] In the present embodiment, the reflective layer 25e is provided between the organic insulating film 94 and the inorganic insulating film 95 in a region that does not overlap with the lower electrode 23. That is, in the region where the reflective layer 25e is provided, the organic insulating film 94, the reflective layer 25e, the inorganic insulating film 95, the photodiode PD, and the upper electrode 24 are stacked in this order in the direction perpendicular to the substrate 21. The reflective layer 25e may be provided so as to overlap with the gate line GCL or the signal line SGL, as in the above-described embodiments.

[0105] In the detection device 1E according to the fifth embodiment, the reflective layer 25e is provided at a position closer to the photodiode PD than in the first to fourth embodiments described above. That is, in the direction perpendicular to the substrate 21, the organic insulating film 94 is not provided between the photodiode PD and the reflective layer 25e, and the photodiode PD and the reflective layer 25e face each other via the inorganic insulating film 95, which is thinner than the organic insulating film 94.

[0106] As a result, the reflected light L1b reflected by the reflective layer 25e is efficiently returned to the photodiode PD side without generating stray light, etc. Therefore, the detection device 1E can improve the utilization efficiency of the light L1.

[0107] The reflective layer 25e of this embodiment can be combined with the reflective layers 25, 25a, 25b, 25c, and 25d of the first to fourth embodiments described above. As an example, a reflective layer 25 (see FIG. 7) provided in the same layer as the source electrode 62 may be provided below the reflective layer 25e. Alternatively, the inorganic insulating film 95 of this embodiment may be provided in any of the first to fourth embodiments described above.

[0108] In each of the above-described embodiments, the photodiode PD has the lower electrode 23 as the cathode electrode of the photodiode PD and the upper electrode 24 as the anode electrode of the photodiode PD. However, the present invention is not limited to this, and the lower electrode 23 may be the anode electrode of the photodiode PD and the upper electrode 24 may be the cathode electrode of the photodiode PD.

[0109] (Sixth embodiment) FIG. 15 is a cross-sectional view showing a schematic cross-sectional configuration of a detection device according to a sixth embodiment. While the first to fifth embodiments have described transmission-type detection devices 1, 1A-1E, the present invention is not limited to this. As shown in FIG. 15, a detection device 1F according to the sixth embodiment is a reflection-type detection device. Specifically, two light sources LS are provided on either side of a detection target Fg, such as a finger, and are arranged side by side in a first direction Dx, sandwiching the detection target Fg therebetween. Light L1 emitted from the light source LS travels in the first direction Dx and is reflected by the surface or interior of the detection target Fg. The light reflected by the detection target Fg is irradiated onto a photodiode PD. This allows the multiple photodiodes PD to detect information about the detection target Fg based on the light L1 irradiated from the light source LS.

[0110] The positions, number, etc. of the light sources LS shown in FIG. 15 are merely shown schematically, and can be changed as appropriate depending on the characteristics (detection sensitivity) required of the detection device 1F, the detection target, etc.

[0111] Although preferred embodiments of the present invention have been described above, the present invention is not limited to such embodiments. The contents disclosed in the embodiments are merely examples, and various modifications are possible without departing from the spirit of the present invention. Appropriate modifications made without departing from the spirit of the present invention naturally fall within the technical scope of the present invention. At least one of various omissions, substitutions, and modifications of components can be made without departing from the spirit of each of the above-described embodiments and modifications. [Explanation of symbols]

[0112] 1, 1A, 1B, 1C, 1D, 1E Detector 10 Sensor section 11 Detection control section 15 Gate line driving circuit 16 Signal line selection circuit 21 PCB 23 Lower electrode 24 Upper electrode 25, 25a, 25b, 25c, 25d, 25e reflective layer 40 Detector 48 Detection circuit 61 Semiconductor layer 62 Source electrode 63 Drain electrode 64 gate electrode 65 Bottom gate electrode 94 Organic insulating film 95 Inorganic insulating film CH1 1st contact hole PD photodiode AA detection area GA peripheral area GCL Gate line SGL signal line Tr First switching element

Claims

1. A substrate; a plurality of photodiodes provided on the substrate; a plurality of transistors provided corresponding to the plurality of photodiodes, respectively; a plurality of gate lines extending in a first direction; a plurality of signal lines extending in a second direction intersecting the first direction; a plurality of lower electrodes provided between the transistor and the photodiode in a direction perpendicular to the substrate, the lower electrodes corresponding to the plurality of photodiodes, respectively; an upper electrode provided across the plurality of photodiodes; a reflective layer provided between the substrate and the photodiode in a direction perpendicular to the substrate; the lower electrode has an area smaller than an area defined by the plurality of gate lines and the plurality of signal lines; the reflective layer is provided between the adjacent lower electrodes in a plan view, and has a shape in which a portion extending in the second direction between one of the signal lines adjacent in the first direction and a first side of the lower electrode and a portion extending in the first direction between one of the gate lines adjacent in the second direction and a second side of the lower electrode are continuous; The reflective layer is provided to overlap the other of the gate lines adjacent to each other in the second direction and to be spaced apart from one of the signal lines adjacent to each other in the first direction in a plan view. Detection device.

2. an organic insulating film covering the plurality of transistors; an inorganic insulating film provided between the organic insulating film and the lower electrode, The reflective layer is provided between the organic insulating film and the inorganic insulating film. The detection device according to claim 1 .

3. the transistor includes a semiconductor layer, a gate electrode, and a source electrode; The reflective layer is provided between the substrate and the semiconductor layer in a direction perpendicular to the substrate. The detection device according to claim 1 .

4. The reflective layer is provided so as to overlap the other of the signal lines adjacent to each other in the first direction in a plan view. The detection device according to any one of claims 1 to 3.

5. the transistor includes a semiconductor layer, a gate electrode, and a source electrode; the semiconductor layer, the gate electrode, and the source electrode are stacked in this order in a direction perpendicular to the substrate; The reflective layer is formed continuously with the source electrode and is provided in the same layer as the source electrode. The detection device according to claim 1 .

6. The source electrode is provided so as to overlap the gate electrode. The detection device according to claim 5 .

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