Detection device

Abstract

The invention provides a detection device capable of improving detection precision. The detection device includes: a substrate; the photodiode is arranged on the substrate; the lens is overlapped with the photodiode; the light shielding layer is arranged between the photodiode and the lens, and an opening is formed in the area, overlapped with the photodiode, of the light shielding layer; and a light-transmitting resin layer and a buffer layer laminated between the light-shielding layer and the lens, the lens being provided on the buffer layer so as to be in direct contact with each other. The buffer layer is formed of a resin material containing a material different from that of the light-transmitting resin layer.

Description

Technical Field

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

[0002] Patent Document 1 describes a detection device including a plurality of photodiodes, a light-transmitting resin layer covering the plurality of photodiodes, and a plurality of lenses provided so as to overlap the plurality of photodiodes, respectively. The plurality of lenses are provided directly on the light-transmitting resin layer.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2022-84273

[0004] In such a detection device, if the shape of the lens varies, the state of light transmitted through the lens and focused on the photodiode will vary, and detection accuracy may be reduced. Therefore, it is required to suppress the shape of the lens in the detection device. Summary of the invention

[0005] An object of the present invention is to provide a detection device capable of improving detection accuracy.

[0006] The detection device of one aspect of the present invention comprises: a substrate; a photodiode, which is arranged on the substrate; a lens, which is arranged overlapping with the photodiode; a shading layer, which is arranged between the photodiode and the lens and has an opening in the area overlapping with the photodiode; and a translucent resin layer and a buffer layer, which are stacked between the shading layer and the lens, and the lens is arranged on the buffer layer in a directly connected manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1A It is a cross-sectional view showing a schematic cross-sectional structure of a detection device according to an embodiment.

[0008] Figure 1B This is a cross-sectional view schematically showing a cross-sectional structure of a detection device according to Modification 1.

[0009] Figure 1C This is a cross-sectional view schematically showing a cross-sectional structure of a detection device according to Modification Example 2.

[0010] Figure 1D This is a cross-sectional view showing a schematic cross-sectional structure of a detection device according to Modification 3.

[0011] Figure 2 It is a top view showing the detection device involved in the embodiment.

[0012] Figure 3 It is a block diagram showing a configuration example of a detection device according to an embodiment.

[0013] Figure 4is a circuit diagram showing a detection element.

[0014] Figure 5 It is a top view showing the optical filter involved in the embodiment.

[0015] Figure 6 yes Figure 5 VI-VI' cross-sectional view.

[0016] Figure 7 It is an explanatory diagram schematically showing the cross-sectional structure of a lens according to an embodiment.

[0017] Figure 8 It is an explanatory diagram schematically showing a cross-sectional structure of a lens according to a comparative example.

[0018] Fig. 9 This is a table showing the measurement results of the lens according to the example and the lens structure according to the comparative example.

[0019] Fig.10 It is a top view schematically showing a photodiode of the detection device according to the embodiment.

[0020] Fig.11 yes Fig.10 XI-XI' cross-sectional view.

[0021] Description of Reference Numerals

[0022] 1. 200, detection device; 2. array substrate; 7. 207, optical filter; 21. substrate; 30. photodiode; 71. first light-shielding layer; 72. second light-shielding layer; 73. filter layer; 74. blocking layer; 75. first light-transmitting resin layer; 76. second light-transmitting resin layer; 77. buffer layer; 78. 278, lens. DETAILED DESCRIPTION

[0023] The method (implementation method) for implementing the present invention is described in detail with reference to the accompanying drawings. The present disclosure is not limited to the contents described in the following implementation methods. In addition, the constituent elements described below include elements that can be easily thought of by a person skilled in the art and substantially the same elements. Furthermore, the constituent elements described below can be appropriately combined. It should be noted that the disclosure is only an example, and appropriate changes that can be easily thought of by a person skilled in the art to maintain the main purpose of the present disclosure are of course also included in the scope of the present disclosure. In addition, in order to make the description clearer, the width, thickness, shape, etc. of each part in the drawings are sometimes schematically represented compared to the actual aspects. In the final analysis, it is just an example and does not limit the interpretation of the present disclosure. In addition, in the present disclosure and the drawings, the same figure marks are marked for the same elements as those described in the drawings that have appeared, and the detailed description is sometimes appropriately omitted.

[0024] In the present specification and claims, when expressing the aspect of configuring other structures above a certain structure, when simply expressed as "on", unless otherwise specified, it includes both the case where other structures are configured directly above the certain structure in a manner connected to the certain structure and the case where other structures are configured above the certain structure further separated by another structure.

[0025] (Implementation Method)

[0026] Figure 1A It is a cross-sectional view showing a schematic cross-sectional structure of a detection device according to an embodiment. Figure 1B This is a cross-sectional view schematically showing a cross-sectional structure of a detection device according to Modification 1. Figure 1C This is a cross-sectional view schematically showing a cross-sectional structure of a detection device according to Modification Example 2. Figure 1D This is a cross-sectional view showing a schematic cross-sectional structure of a detection device according to Modification 3.

[0027] like Figure 1A As shown, there is a detection device 1, an array substrate 2 (photodiode 30), an optical filter 7, an adhesive layer 125, and an illuminating device 121 (cover component 122). That is, in a direction perpendicular to the surface of the array substrate 2, the array substrate 2 (photodiode 30), the optical filter 7, the adhesive layer 125, and the cover component 122 are stacked in sequence. It should be noted that the cover component 122 can also be replaced by the illuminating device 121 as described later. The adhesive layer 125 only needs to bond the optical filter 7 to the cover component 122, and it can also be a structure without the adhesive layer 125 in the area corresponding to the detection area AA. In the case where there is no adhesive layer 125 in the detection area AA, the adhesive layer 125 becomes a structure that bonds the cover component 122 to the optical filter 7 in the area corresponding to the peripheral area GA outside the detection area AA. In addition, the adhesive layer 125 provided in the detection area AA can also be simply referred to as a protective layer of the optical filter 7.

[0028] like Figure 1A As shown, the lighting device 121 may be, for example, a so-called side-light type headlamp, using the cover member 122 as a light guide plate provided at a position corresponding to the detection area AA of the detection device 1, and having a plurality of light sources 123 arranged at one end or both ends of the cover member 122. That is, the cover member 122 has a light irradiation surface 121a for irradiating light, and becomes a component of the lighting device 121. According to the lighting device 121, light L1 is irradiated from the light irradiation surface 121a of the cover member 122 toward the finger Fg as the detection object. As the light source 123, for example, a light emitting diode (LED: Light Emitting Diode) that emits light of a predetermined color is used.

[0029] In addition, if Figure 1B As shown, the lighting device 121 may include a light source (eg, LED) provided just below the detection area AA of the detection device 1 , and the lighting device 121 including the light source may also function as the cover member 122 .

[0030] In addition, the lighting device 121 is not limited to Figure 1B Examples include Figure 1C As shown, the light L1 may be provided on the side or above the cover member 122 , and the light L1 may be irradiated toward the finger Fg from the side or above the finger Fg.

[0031] Furthermore, if Figure 1D As shown, the lighting device 121 may be a so-called direct-type backlight having a light source (eg, LED) provided in the detection area AA of the detection device 1 .

[0032] The light L1 emitted from the lighting device 121 is reflected as light L2 by the finger Fg as the detection object. The detection device 1 detects the unevenness of the surface of the finger Fg (for example, a fingerprint) by detecting the light L2 reflected by the finger Fg. Furthermore, in addition to detecting fingerprints, the detection device 1 can also detect information related to a living body by detecting the light L2 reflected inside the finger Fg. Information related to a living body includes, for example, a blood vessel image such as a vein, a pulse, a pulse wave, and the like. The color of the light L1 from the lighting device 121 may also be different depending on the detection object.

[0033] The cover member 122 is a member for protecting the array substrate 2 and the optical filter 7, and covers the array substrate 2 and the optical filter 7. As described above, the lighting device 121 may also be a structure that also serves as the cover member 122. Figure 1C as well as Figure 1D In the structure shown in which the cover component 122 is separated from the lighting device 121, the cover component 122 is, for example, a glass substrate. It should be noted that the cover component 122 is not limited to a glass substrate, and may also be a resin substrate or the like. In addition, the cover component 122 may not be provided. In this case, a protective layer such as an insulating film is provided on the surface of the array substrate 2 and the optical filter 7, and the finger Fg is in contact with the protective layer of the detection device 1.

[0034] In addition, Figure 1BIn the embodiment, a display panel may be provided to replace the lighting device 121. The display panel may be, for example, an organic EL display panel (OLED: Organic Light Emitting Diode), an inorganic EL display (micro LED, mini LED (sub-millimeter LED)). Alternatively, the display panel may be a liquid crystal display panel (LCD: Liquid Crystal Display) using a liquid crystal element as a display element, or an electrophoretic display panel (EPD: Electrophoretic Display) using an electrophoretic element as a display element. Even in this case, the fingerprint of the finger Fg and information related to the biological body can be detected based on the light L2 after the display light (light L1) irradiated from the display panel is reflected by the finger Fg.

[0035] Figure 2 is a top view showing a detection device according to an embodiment. It should be noted that Figure 2 The first direction Dx shown below 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 orthogonal to the first direction Dx. It should be noted that the second direction Dy may also intersect the first direction Dx non-orthogonally. The third direction Dz is a direction orthogonal to the first direction Dx and the second direction Dy, and is the normal direction of the substrate 21. In addition, "viewed from above" refers to the positional relationship when viewed from the third direction Dz.

[0036] like Figure 2 As shown, the detection device 1 includes an array substrate 2 (substrate 21 ), a sensor unit 10 , a scanning line driving circuit 15 , a signal line selecting circuit 16 , a detection circuit 48 , a control circuit 102 , and a power supply circuit 103 .

[0037] The control substrate 101 is electrically connected to the substrate 21 via the wiring substrate 110. The wiring substrate 110 is, for example, a flexible printed substrate or a rigid substrate. The wiring substrate 110 is provided with a detection circuit 48. The control substrate 101 is provided with a control circuit 102 and a power supply circuit 103. The control circuit 102 is, for example, an FPGA (Field Programmable Gate Array). The control circuit 102 supplies control signals to the sensor unit 10, the scan line driving circuit 15, and the signal line selecting circuit 16 to control the operation of the sensor unit 10. The power supply circuit 103 generates a power supply potential VDD and a reference potential VCOM (reference potential VCOM). Figure 4) and other voltage signals are supplied to the sensor unit 10, the scanning line driving circuit 15, and the signal line selection circuit 16. It should be noted that in this embodiment, the detection circuit 48 is illustrated as being arranged on the wiring substrate 110, but it is not limited thereto. The detection circuit 48 may also be arranged on the substrate 21.

[0038] The substrate 21 has a detection area AA and a peripheral area GA. The detection area AA and the peripheral area GA extend in a surface direction parallel to the substrate 21. Each element (detection element 3) of the sensor unit 10 is provided in the detection area AA. The peripheral area GA is an area outside the detection area AA, and is an area where each element (detection element 3) is not provided. That is, the peripheral area GA is an area between the periphery of the detection area AA and the end of the substrate 21. A scan line drive circuit 15 and a signal line selection circuit 16 are provided in the peripheral area GA. The scan line drive circuit 15 is provided in an area extending along the second direction Dy in the peripheral area GA. The signal line selection circuit 16 is provided in an area extending along the first direction Dx in the peripheral area GA, and is provided between the sensor unit 10 and the detection circuit 48.

[0039] The plurality of detection elements 3 of the sensor unit 10 are light sensors each having a photodiode 30 as a sensor element. The photodiode 30 is a photoelectric conversion element that outputs an electrical signal corresponding to the light irradiated thereto. More specifically, the photodiode 30 is a PIN (Positive Intrinsic Negative) photodiode. In addition, the photodiode 30 may also be an OPD (Organic Photo Diode). The detection elements 3 are arranged in a matrix in the detection area AA. The photodiodes 30 of the plurality of detection elements 3 perform detection according to a gate drive signal (e.g., a reset control signal RST, a readout control signal RD) supplied from the scanning line drive circuit 15. The plurality of photodiodes 30 outputs an electrical signal corresponding to the light irradiated thereto to the signal line selection circuit 16 as a detection signal Vdet. The detection device 1 detects information related to the biological body based on the detection signal Vdet from the plurality of photodiodes 30.

[0040] Figure 3 is a block diagram showing an example of the structure of a detection device according to an embodiment of the present invention. Figure 3 As shown, the detection device 1 further includes a detection control circuit 11 and a detection unit 40. A part or all of the functions of the detection control circuit 11 are included in the control circuit 102. In addition, a part or all of the functions of the detection unit 40 other than the detection circuit 48 are included in the control circuit 102.

[0041] The detection control circuit 11 is a circuit that supplies control signals to the scan line driving circuit 15, the signal line selection circuit 16, and the detection unit 40 to control their operations. The detection control circuit 11 supplies various control signals such as a start signal STV and a clock signal CK to the scan line driving circuit 15. In addition, the detection control circuit 11 supplies various control signals such as a selection signal ASW to the signal line selection circuit 16.

[0042] The scanning line driving circuit 15 drives a plurality of scanning lines (the readout control scanning line GLrd, the reset control scanning line GLrst (refer to Figure 4 The scanning line driving circuit 15 selects a plurality of scanning lines sequentially or simultaneously, and supplies a gate driving signal (for example, a reset control signal RST, a readout control signal RD) to the selected scanning lines. Thus, the scanning line driving circuit 15 selects a plurality of photodiodes 30 connected to the scanning lines.

[0043] The signal line selection circuit 16 selects a plurality of output signal lines SL in sequence or simultaneously (see Figure 4 ) is a switch circuit. The signal line selection circuit 16 is, for example, a multiplexer. The signal line selection circuit 16 connects the selected output signal line SL and the detection circuit 48 based on the selection signal ASW supplied from the detection control circuit 11. Thus, the signal line selection circuit 16 outputs the detection signal Vdet of the photodiode 30 to the detection unit 40.

[0044] The detection unit 40 includes a detection circuit 48, a signal processing circuit 44, a coordinate extraction circuit 45, a storage circuit 46, and a detection timing control circuit 47. The detection timing control circuit 47 controls the detection circuit 48, the signal processing circuit 44, and the coordinate extraction circuit 45 based on a control signal supplied from the detection control circuit 11 so that the detection circuit 48, the signal processing circuit 44, and the coordinate extraction circuit 45 operate synchronously.

[0045] The detection circuit 48 is, for example, an analog front end circuit (AFE). The detection circuit 48 is a signal processing circuit having at least the functions of the detection signal amplifier circuit 42 and the A / D converter circuit 43. The detection signal amplifier circuit 42 is a circuit that amplifies the detection signal Vdet, and is, for example, an integration circuit. The A / D converter circuit 43 converts the analog signal output from the detection signal amplifier circuit 42 into a digital signal.

[0046] The signal processing circuit 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 contacts or approaches the detection surface, the signal processing circuit 44 can detect the concavity and convexity of the surface of the finger Fg or the palm based on the signal from the detection circuit 48. In addition, the signal processing circuit 44 can also detect information related to the living body based on the signal from the detection circuit 48. The information related to the living body is, for example, the blood vessel image of the finger Fg or the palm, the pulse wave, the pulse, the blood oxygen saturation, etc.

[0047] The storage circuit 46 temporarily stores the signal calculated by the signal processing circuit 44. The storage circuit 46 may be, for example, a RAM (Random Access Memory) or a register circuit.

[0048] The coordinate extraction circuit 45 is a logic circuit that obtains the detection coordinates of the concavo-convex surface of the finger Fg, etc. when the contact or approach of the finger Fg is detected in the signal processing circuit 44. In addition, the coordinate extraction circuit 45 is a logic circuit that obtains the detection coordinates of the blood vessels of the finger Fg and the palm. The coordinate extraction circuit 45 combines the detection signals Vdet output from each detection element 3 of the sensor unit 10 to generate two-dimensional information representing the shape of the concavo-convex surface of the finger Fg, etc. It should be noted that the coordinate extraction circuit 45 may output the detection signal Vdet as the sensor output Vo without calculating the detection coordinates.

[0049] Next, a circuit configuration example of the detection device 1 will be described. Figure 4 is a circuit diagram showing the detection element. Figure 4 As shown, the detection element 3 has a photodiode 30, a reset transistor Mrst, a read transistor Mrd, and a source follower transistor Msf. The reset transistor Mrst, the read transistor Mrd, and the source follower transistor Msf are provided corresponding to one photodiode 30. The reset transistor Mrst, the read transistor Mrd, and the source follower transistor Msf are each composed of an n-type TFT (Thin Film Transistor). However, this is not limited to this, and each transistor may also be composed of a p-type TFT.

[0050] A reference potential VCOM is applied to the anode of the photodiode 30. The cathode of the photodiode 30 is connected to the node N1. The node N1 is connected to the capacitor Cs, one of the source and drain of the reset transistor Mrst, and the gate of the source follower transistor Msf. Furthermore, a parasitic capacitor Cp exists at the node N1. When light is incident on the photodiode 30, a signal (charge) output from the photodiode 30 is accumulated in the capacitor Cs. Here, the capacitor Cs is, for example, a portion of the upper electrode 34 and the lower electrode 35 (see FIG. 1 ) connected to the photodiode 30. Fig.11 The parasitic capacitance Cp is a capacitance added to the capacitance element Cs, and is a capacitance formed between various wirings and electrodes provided on the array substrate 2.

[0051] The gate of the reset transistor Mrst is connected to the reset control scanning line GLrst. The reset potential Vrst is supplied to the other of the source and the drain of the reset transistor Mrst. When the reset transistor Mrst is turned on (conducting state) in response to the reset control signal RST, the potential of the node N1 is reset to the reset potential Vrst. The reference potential VCOM has a potential lower than the reset potential Vrst, and the photodiode 30 is reverse biased and driven.

[0052] The source follower transistor Msf is connected between a terminal supplied with a power supply potential VDD and the read transistor Mrd (node ​​N2). The gate of the source follower transistor Msf is connected to the node N1. The gate of the source follower transistor Msf is supplied with a signal (charge) generated by the photodiode 30. Thus, the source follower transistor Msf outputs a voltage signal corresponding to the signal (charge) generated by the photodiode 30 to the read transistor Mrd.

[0053] The read transistor Mrd is connected between the source (node ​​N2) of the source follower transistor Msf and the output signal line SL (node ​​N3). The gate of the read transistor Mrd is connected to the read control scanning line GLrd. When the read transistor Mrd is turned on in response to the read control signal RD, the signal output from the source follower transistor Msf, that is, the voltage signal corresponding to the signal (charge) generated by the photodiode 30, is output to the output signal line SL as the detection signal Vdet.

[0054] It should be noted that in Figure 4In the example shown, the reset transistor Mrst and the read transistor Mrd are respectively two transistors connected in series to form a so-called dual-gate structure. However, it is not limited to this, and the reset transistor Mrst and the read transistor Mrd can also be a single-gate structure, or a multi-gate structure obtained by connecting more than three transistors in series. In addition, the circuit of a detection element 3 is not limited to having a configuration of three transistors including a reset transistor Mrst, a source follower transistor Msf, and a read transistor Mrd. The detection element 3 can also have two or more than four transistors.

[0055] Next, the detailed configuration of the detection element 3 and the optical filter 7 will be described. Figure 5 It is a top view showing the optical filter involved in the embodiment. Figure 6 yes Figure 5 VI-VI' section view. It should be noted that Figure 6 FIG. 2 shows a simplified structure of the array substrate 2, schematically showing the insulating films 26, 28, the protective film 29 and the photodiode 30. Fig.11 A detailed configuration example of the array substrate 2 is described in FIG.

[0056] like Figure 5 as well as Figure 6 As shown, the optical filter 7 is provided to cover the plurality of detection elements 3 (photodiodes 30) arranged in a matrix. The optical filter 7 is an optical element that allows the component of the light L2 reflected by the detected body such as the finger Fg to travel in the third direction Dz to pass toward the photodiode 30 and blocks the component traveling in the oblique direction. The optical filter 7 is also called a collimating aperture or a collimator.

[0057] The optical filter 7 has a plurality of lenses 78 provided for each of the plurality of detection elements 3. The plurality of lenses 78 are arranged in a region overlapping with one detection element 3 (photodiode 30). Figure 5 In the example shown, seven lenses 78 are provided for one detection element 3. The plurality of lenses 78 are arranged in a triangular lattice. More specifically, for one detection element 3, six lenses 78 are arranged in a regular hexagonal shape so as to surround one lens 78 located at the geometric center.

[0058] However, the number of the plurality of lenses 78 arranged for one detection element 3 may be six or less, or eight or more. The arrangement of the plurality of lenses 78 is not limited to the triangular lattice, and may be other arrangements such as a matrix.

[0059] like Figure 6As shown, the optical filter 7 includes a first light shielding layer 71, a second light shielding layer 72, a filter layer 73, a blocking layer 74, a first light-transmitting resin layer 75, a second light-transmitting resin layer 76, a buffer layer 77, and a lens 78. In the present embodiment, the first light shielding layer 71, the filter layer 73, the blocking layer 74, the first light-transmitting resin layer 75, the second light-shielding layer 72, the second light-transmitting resin layer 76, the buffer layer 77, and the lens 78 are sequentially stacked on the protective film 29 covering the photodiode 30.

[0060] The lens 78 is provided on the buffer layer 77 in direct contact. The lens 78 is a convex lens. The optical axis CL of the lens 78 is provided in a direction parallel to the third direction Dz and intersects with the photodiode 30. Figure 6 In the illustrated example, a plurality of lenses 78 are provided in a region overlapping one photodiode 30 , and the optical axes CL of the plurality of lenses 78 intersect with the photodiode 30 , respectively.

[0061] The first light shielding layer 71 is directly disposed on the protective film 29 of the array substrate 2. In other words, the first light shielding layer 71 is disposed between the photodiode 30 and the lens 78 in the third direction Dz. In addition, the first light shielding layer 71 is provided with a first opening OP1 in a region overlapping with the photodiode 30. The first opening OP1 is formed in a region overlapping with the optical axis CL of the lens 78. The first light shielding layer 71 is formed of a metal material such as molybdenum (Mo), for example.

[0062] The first light shielding layer 71 can reflect components of the light L2 traveling in the oblique direction other than the light L2 passing through the first opening OP1. In addition, since the first light shielding layer 71 is formed of a metal material, the diameter W1 (the width in the first direction Dx) of the first opening OP1 can be formed with high precision. Therefore, even when the arrangement pitch and area (diameter W3) of the lens 78 are small, the first opening OP1 can be provided corresponding to the lens 78.

[0063] The first light shielding layer 71 is implemented by forming the first opening OP1 in the metal material deposited on the protective film 29 of the array substrate 2 by sputtering, etc., which is different from bonding the so-called external optical filter to the protective film 29 of the array substrate 2. When bonding the external optical filter to the array substrate 2, it is difficult to align the small opening of the light shielding layer corresponding to the first opening OP1 of the first light shielding layer 71 of this embodiment with the photodiode 30. On the other hand, since the optical filter 7 of this embodiment is directly formed on the protective film 29 of the array substrate 2, the first opening OP1 can be set on the photodiode 30 with higher accuracy compared with bonding the external optical filter.

[0064] Furthermore, since the first light shielding layer 71 is formed of a metal material, unlike the second light shielding layer 72 formed of a resin material described later, it can be formed thinner than the second light shielding layer 72, and the first opening OP1 smaller than the second opening OP2 formed in the second light shielding layer 72 can be formed. The thickness of the first light shielding layer 71 is less than one tenth of the thickness of the second light shielding layer 72. As an example, the thickness of the first light shielding layer 71 is 0.055 μm or more, for example, 0.065 μm, and the thickness of the second light shielding layer is, for example, 1 μm. The first light shielding layer 71 is formed to be extremely thin compared with the thickness of the second light shielding layer 72.

[0065] The filter layer 73 is directly connected to the first light shielding layer 71, and is provided to cover the first light shielding layer 71 and the first opening OP1. The filter layer 73 is provided between the first light shielding layer 71 and the first light-transmitting resin layer 75 in the third direction Dz. The filter layer 73 is a filter that shields light of a specified wavelength band. The filter layer 73 is formed of a resin material colored green, for example, and is an IR cutoff filter that shields infrared rays. Thus, the optical filter 7 can allow the components of the wavelength band required for fingerprint detection in the light L2 to be incident on the photodiode 30, thereby improving the detection sensitivity.

[0066] The blocking layer 74 is provided to cover the filter layer 73. The first light-transmitting resin layer 75 is provided on the blocking layer 74. The blocking layer 74 is provided between the first light-shielding layer 71 and the filter layer 73 and the first light-transmitting resin layer 75 in the third direction Dz.

[0067] In the present embodiment, since the barrier layer 74 is provided on the first light shielding layer 71, even when a metal material that is easily ionized, such as molybdenum (Mo), is used as the first light shielding layer 71, the diffusion of the reactant (for example, Mo-based ions) generated from the first light shielding layer 71 can be suppressed by the barrier layer 74. More specifically, when the reactant (for example, Mo-based ions) from the first light shielding layer 71 diffuses and reaches the first light-transmitting resin layer 75 and the second light-transmitting resin layer 76, it is possible that the reactant (for example, Mo-based ions) reacts with the first light-transmitting resin layer 75 and the second light-transmitting resin layer 76 to form a metal complex, causing discoloration. In the present embodiment, since the barrier layer 74 is provided, the discoloration of the first light-transmitting resin layer 75 and the second light-transmitting resin layer 76 caused by the diffusion of the Mo-based ions can be prevented, and the reduction in the light transmittance of the first light-transmitting resin layer 75 and the second light-transmitting resin layer 76 can be suppressed.

[0068] The barrier layer 74 is a light-transmitting resin material, for example, formed of an acrylic resin material. The barrier layer 74 can be made of any material that can inhibit the penetration of the reactants, for example, a hard coating film formed of the same material as the insulating film 26 or the protective film 29 used in the array substrate 2, that is, an organic material. The film thickness of the barrier layer 74 is, for example, about 2.0 μm or more and 3.0 μm or less. The film thickness of the barrier layer 74 is greater than the film thickness of the first light-shielding layer 71 and the filter layer 73, and less than the film thickness of the first light-transmitting resin layer 75.

[0069] The first light-transmitting resin layer 75 is provided directly on the barrier layer 74. In addition, the first light-transmitting resin layer 75 is provided between the first light-shielding layer 71 and the second light-shielding layer 72 in the third direction Dz. The first light-transmitting resin layer 75 and the second light-transmitting resin layer 76 are formed of, for example, a light-transmitting acrylic resin.

[0070] The second light shielding layer 72 is provided on the first light-transmitting resin layer 75 in a directly contacting manner. The second light shielding layer 72 is provided between the first light shielding layer 71 and the lens 78 in the third direction Dz. In addition, the second light shielding layer 72 is provided with a second opening OP2 in a region overlapping with the photodiode 30 and the first opening OP1. The second opening OP2 is formed in a region overlapping with the optical axis CL of the lens 78. It is more preferable that the center of the second opening OP2 and the center of the first opening OP1 overlap with the optical axis CL.

[0071] The second light shielding layer 72 is formed of, for example, a resin material colored in black. Thus, the second light shielding layer 72 functions as a light absorption layer, absorbing the components of the light L2 traveling in the oblique direction other than the light L2 passing through the second opening OP2. In addition, the second light shielding layer 72 absorbs the light reflected by the first light shielding layer 71. Thus, compared with a configuration in which the second light shielding layer 72 is formed of a metal material, it is possible to suppress the light reflected by the first light shielding layer 71 from being repeatedly reflected multiple times and traveling as stray light in the first light-transmitting resin layer 75 and incident on other photodiodes 30. In addition, the second light shielding layer 72 can absorb external light incident from between adjacent lenses 78. Thus, compared with a configuration in which the second light shielding layer 72 is formed of a metal material, it is possible to suppress the reflected light at the second light shielding layer 72. However, the second light shielding layer 72 is not limited to the example of being formed of a resin material colored in black, and may also be formed of a metal material with a surface treated to be black.

[0072] The second light-transmitting resin layer 76 is provided on the second light-shielding layer 72 in direct contact therewith. The second light-transmitting resin layer 76 is provided between the second light-shielding layer 72 and the buffer layer 77 and the lens 78.

[0073] The second light-transmitting resin layer 76 is made of the same material as the first light-transmitting resin layer 75, and the refractive index of the second light-transmitting resin layer 76 is substantially equal to the refractive index of the first light-transmitting resin layer 75. Thus, it is possible to suppress the reflection of the light L2 at the interface between the first light-transmitting resin layer 75 and the second light-transmitting resin layer 76 at the second opening OP2. However, the present invention is not limited thereto, and the first light-transmitting resin layer 75 and the second light-transmitting resin layer 76 may also be made of different materials, and the refractive index of the first light-transmitting resin layer 75 and the refractive index of the second light-transmitting resin layer 76 may also be different.

[0074] In the present embodiment, the diameter W3 (width in the first direction Dx) of the lens 78, the diameter W2 (width in the first direction Dx) of the second opening OP2, and the diameter W1 (width in the first direction Dx) of the first opening OP1 are sequentially reduced. In addition, the diameter W3 of the lens 78, the diameter W2 of the second opening OP2, and the diameter W1 of the first opening OP1 are respectively smaller than the width of the photodiode 30. The diameter W2 of the second opening OP2 and the diameter W1 of the first opening OP1 are appropriately set according to the shape of the lens 78 (diameter W3, curvature, etc.) and the distance between the lens 78 and the photodiode 30.

[0075] The thickness of the first light-transmitting resin layer 75 and the thickness of the second light-transmitting resin layer 76 are respectively about 10 μm or more and 30 μm or less. Figure 6 In the example shown, the film thickness of the first light-transmitting resin layer 75 is formed to be thinner than the film thickness of the second light-transmitting resin layer 76. However, the present invention is not limited thereto, and the film thickness of the first light-transmitting resin layer 75 may be equal to the film thickness of the second light-transmitting resin layer 76. Alternatively, the film thickness of the first light-transmitting resin layer 75 may be formed to be thicker than the film thickness of the second light-transmitting resin layer 76.

[0076] The buffer layer 77 is directly disposed on the second light-transmitting resin layer 76. The lens 78 is directly disposed on the buffer layer 77. In other words, the second light-transmitting resin layer 76 and the buffer layer 77 are stacked between the second light-shielding layer 72 and the lens 78. The film thickness of the buffer layer 77 is, for example, about 1.0 μm or more and 2.0 μm or less. The film thickness of the buffer layer 77 is thinner than the film thickness of the first light-transmitting resin layer 75 and the second light-transmitting resin layer 76.

[0077] The buffer layer 77 is formed of a translucent resin material, and is formed of a resin material containing a material different from that of the second translucent resin layer 76. In more detail, the buffer layer 77 is formed to contain a translucent acrylic resin and a surfactant of the same system as the material used for the lens 78. The buffer layer 77 contains, for example, a fluorine-based surfactant or an Si-based surfactant. As a result, when the resin material forming the lens 78 is applied in the manufacturing process of the detection device 1, the wettability of the resin material of the lens 78 and the buffer layer 77 is improved compared to the case where the buffer layer 77 is not provided and is directly applied on the second translucent resin layer 76. As a result, the shape of the lens 78 formed on the buffer layer 77 is stable, and the radius of curvature of the lens 78 is formed to be constant. That is, in a lens 78, when the arc in the cross-sectional structure is divided into multiple parts, the deviation of the radius of curvature of each divided arc can be suppressed.

[0078] With such a configuration, the light L2 traveling in the third direction Dz among the light L2 reflected by the detected body such as the finger Fg is focused by the lens 78 as designed, and passes through the second opening OP2 and the first opening OP1 well to be incident on the photodiode 30. In addition, the light L2 inclined at a predetermined angle with respect to the third direction Dz is shielded by the first light shielding layer 71 and the second light shielding layer 72. Thus, the detection device 1 of this embodiment can improve the detection accuracy compared with the case where the lens 78 is formed on the second light-transmitting resin layer 76 without the buffer layer 77.

[0079] As described above, the optical filter 7 is formed by directly forming a film on the array substrate 2 and performing patterning and other processes. That is, the first light shielding layer 71 of the optical filter 7 is directly disposed on the protective film 29, and no adhesive layer or other components are disposed between the first light shielding layer 71 and the protective film 29. However, this is not limited to this, and the optical filter 7 may also be a so-called external optical filter attached to the protective film 29 of the array substrate 2 via an adhesive layer.

[0080] In addition, the optical filter 7 is not limited to the configuration having the first light shielding layer 71 and the second light shielding layer 72, and may be formed of a single light shielding layer. Figure 6The second light-shielding layer 72 and the second light-transmitting resin layer 76 are omitted, and a buffer layer 77 and a lens 78 are provided on the first light-transmitting resin layer 75. In addition, the filter layer 73 is provided between the first light-shielding layer 71 and the first light-transmitting resin layer 75, but the position of the filter layer 73 is not limited thereto. The position of the filter layer 73 can be appropriately changed according to the characteristics and manufacturing process required by the optical filter 7. In addition, the optical filter 7 is not limited to the structure of stacked light-shielding layers and light-transmitting resin layers. For example, the optical filter 7 may also be a light-guiding column type structure. That is, the optical filter 7 may also be a structure having a non-light-transmitting component formed of a black resin material and a plurality of light-transmitting areas (light-guiding columns) formed in a columnar shape and penetrating the upper and lower surfaces of the non-light-transmitting component.

[0081] (Example)

[0082] Figure 7 It is an explanatory diagram schematically showing the cross-sectional structure of a lens according to an embodiment. Figure 8 It is an explanatory diagram schematically showing a cross-sectional structure of a lens according to a comparative example. Fig. 9 is a table showing the measurement results of the lens structure involved in the embodiment and the lens structure involved in the comparative example. Figure 8 In FIG. 1 , for easy understanding, the lens 78 involved in the embodiment is indicated by a two-dot chain line.

[0083] exist Figure 7 In the embodiment shown, a buffer layer 77 is provided on the second light-transmitting resin layer 76, and a lens 78 is formed on the buffer layer 77. Figure 8 In the detection device 200 and the optical filter 207 of the comparative example shown, the buffer layer 77 is not provided, and the lens 278 is formed on the second light-transmitting resin layer 76 .

[0084] like Fig. 9 As shown, the height H, Ha, diameter W3, W3a, radius of curvature, deviation of radius of curvature, and presence or absence of lens peeling were measured for the lens 78 of the embodiment and the lens 278 of the comparative example. The radius of curvature was measured for each region of the lenses 78 and 278. Specifically, the radius of curvature of the arc in the range from the top to 1 / 4 of the height H, Ha, the radius of curvature of the arc in the range from the top of the lens 78 and 278 to 1 / 2 of the height H, Ha, and the radius of curvature of the arc in the range (the entire range) from the top of the lens 78 and 278 to 1 / 1 of the height H, Ha were calculated.

[0085] For the embodiment and the comparative example, when the maximum curvature radius of the three regions is set to Rmax and the minimum curvature radius is set to Rmin, the following formula (1) is used to calculate: Fig. 9Deviation in radius of curvature shown.

[0086] ((Rmax-Rmin) / (Rmax+Rmin))×100(%)...(1)

[0087] like Figures 7 to 9 As shown, the height H of the lens 78 of the embodiment is formed to be higher than the height Ha of the lens 278 of the comparative example, and the diameter W3 of the lens 78 of the embodiment is smaller than the diameter W3a of the lens 278 of the comparative example.

[0088] The curvature radius of the lens 78 of the example is formed to be substantially constant in each region of (1 / 4)×H, (1 / 2)×H, and H. In the lens 78 of the example, the curvature radius deviation calculated by equation (1) is suppressed to a small value of 2.61%.

[0089] Compared with lens 78 of the embodiment, lens 278 of the comparative example has a larger curvature radius in each region of (1 / 4)×H, (1 / 2)×H, and H. In addition, the curvature radius of lens 278 of the comparative example is formed to have a deviation in each region of (1 / 4)×H, (1 / 2)×H, and H. Specifically, the closer to the top (for example, the region to the height (1 / 4)×H) of lens 278 of the comparative example, the larger the curvature radius is, and the farther away from the top (for example, the region to the height H), the smaller the curvature radius is. In lens 278 of the comparative example, the curvature radius deviation calculated according to formula (1) is 10.51%.

[0090] Fig. 9 The “lens peeling” shown in the figure indicates whether or not any of the plurality of lenses 78, 278 provided in the detection area AA has peeled off from the buffer layer 77 (the second light-transmitting resin layer 76 in the comparative example) and a portion not forming the lenses 78, 278 has fallen off. Fig. 9 As shown, in the example, no lens peeling occurred, and all lenses 78 were well formed. In contrast, in the comparative example, lens peeling occurred, and some lenses 278 were peeled off and not formed.

[0091] In summary, it is shown that the lens 78 involved in the embodiment has improved wettability between the lens 78 and the buffer layer 77 and improved curvature uniformity by providing the buffer layer 77 compared with the comparative example. That is, in the cross-sectional structure of the lens 78 involved in the embodiment, the deviation of the curvature radius of each part after being divided into a plurality of parts along the arc is suppressed. Furthermore, it is shown that the lens 78 involved in the embodiment also suppresses the occurrence of lens peeling.

[0092] Next, a configuration example of the photodiode 30 and the array substrate 2 will be described. Fig.10 It is a top view schematically showing a photodiode of the detection device according to the embodiment. Fig.11 yes Fig.10 XI-XI' section view. It should be noted that Fig.10 In order to facilitate viewing of the drawings, a plurality of lenses 78 overlapping the photodiode 30 are indicated by double-dashed lines. Fig.11 , the cross-sectional structure of the reset transistor Mrst among the three transistors included in the detection element 3 is shown, but the cross-sectional structures of the source follower transistor Msf and the read transistor Mrd are also the same as that of the reset transistor Mrst.

[0093] like Fig.10 As shown, a plurality of scanning lines GL extend in the first direction Dx and are arranged in the second direction Dy. A plurality of output signal lines SL extend in the second direction Dy and are arranged in the first direction Dx. A detection element 3 (photodiode 30) is formed in the area surrounded by two scanning lines GL and two output signal lines SL. It should be noted that Fig.10 The scan lines GL shown are the read control scan line GLrd and the reset control scan line GLrst (see Figure 4 ) in either party.

[0094] like Fig.11 As shown, the photodiode 30 is provided on the array substrate 2, that is, on the first main surface S1 side of the substrate 21. The substrate 21 is an insulating substrate. For example, a glass substrate such as quartz or alkali-free glass is used for the substrate 21. The substrate 21 has a first main surface S1 and a second main surface S2 on the opposite side of the first main surface S1. Various transistors including the reset transistor Mrst, various wirings (scanning lines and signal lines) and an insulating film are provided on the first main surface S1 of the substrate 21 to form the array substrate 2.

[0095] The undercoat film 22 is provided on the first main surface S1 of the substrate 21. The undercoat film 22, the insulating films 23, 24, 25, and the insulating films 27, 28 are inorganic insulating films, such as silicon oxide (SiO2), silicon nitride (SiN), and the like.

[0096] The semiconductor layer 61 is provided on the base coat film 22. For example, polysilicon is used for the semiconductor layer 61. However, the semiconductor layer 61 is not limited thereto, and may be microcrystalline oxide semiconductor, amorphous oxide semiconductor, low temperature polysilicon (LTPS: Low Temperature Polycrystalline Silicone), or the like.

[0097] The insulating film 23 is provided on the base coat film 22 in a manner covering the semiconductor layer 61. The gate electrode 64 is provided on the insulating film 23. It should be noted that the gate electrode 68 of the source follower transistor Msf is also provided on the insulating film 23 in the same layer as the gate electrode 64. In addition, the scanning line GL (the reset control scanning line GLrst and the readout control scanning line GLrd) is also provided in the same layer as the gate electrode 64. The insulating film 24 is provided on the insulating film 23 in a manner covering the gate electrode 64.

[0098] like Fig.11 As shown, the reset transistor Mrst is a top gate structure in which the gate electrode 64 is disposed on the upper side of the semiconductor layer 61. However, in the detection device 1, it can also be a bottom gate structure in which the gate electrode 64 is disposed on the lower side of the semiconductor layer 61, or it can be a double gate structure in which the gate electrode 64 is disposed on the upper side and the lower side of the semiconductor layer 61.

[0099] The insulating film 24 and the insulating film 25 are provided on the insulating film 23 so as to cover the gate electrode 64. The source electrode 62 and the drain electrode 63 are provided on the insulating film 25. The source electrode 62 is connected to the source region of the semiconductor layer 61 via the contact hole CH4 penetrating the insulating films 23, 24, and 25. The drain electrode 63 is connected to the drain region of the semiconductor layer 61 via the contact hole CH3 penetrating the insulating films 23, 24, and 25. The source electrode 62 and the drain electrode 63 are composed of, for example, a stacked structure of titanium and aluminum, that is, a stacked film of TiAlTi or TiAl.

[0100] The output signal line SL and the connection wiring SLcn are provided in the same layer as the source electrode 62 and the drain electrode 63. The connection wiring SLcn of the detection element 3 is connected to the gate electrode 68 of the source follower transistor Msf via a contact hole penetrating the insulating films 24 and 25.

[0101] In addition, a first electrode 81 and a second electrode 82 are provided in a region overlapping with the photodiode 30. A capacitor Cad is formed between the first electrode 81 and the second electrode 82. The capacitor Cad is a capacitor added to the photodiode 30 and is Figure 4 The capacitor element Cs shown is connected in parallel. The first electrode 81 and the second electrode 82 are provided using two layers of each layer constituting the transistor (e.g., the reset transistor Mrst). In this embodiment, the second electrode 82 is in the same layer as the semiconductor layer 61 and is formed of the same material as the semiconductor layer 61. The first electrode 81 is in the same layer as the gate electrode 64 and is formed of the same material as the gate electrode 64.

[0102] The insulating film 26 is provided on the insulating film 25 so as to cover a plurality of transistors such as the reset transistor Mrst. The insulating film 26 is made of an organic material such as photosensitive acrylic. The insulating film 26 is thicker than the insulating film 25. The insulating film 26 has better coverage of steps than inorganic insulating materials, and can flatten the steps formed by the various transistors and various wirings.

[0103] The photodiode 30 is provided on the insulating film 26. Specifically, the lower electrode 35 is provided on the insulating film 26 and is electrically connected to the connection wiring SLcn via the contact hole CH2. The photodiode 30 is connected to the lower electrode 35. The lower electrode 35 can adopt a stacked structure of titanium (Ti) and titanium nitride (TiN), for example. Since the lower electrode 35 is provided between the substrate 21 and the semiconductor layer of the photodiode 30, the lower electrode 35 functions as a light shielding layer, which can suppress light from entering the photodiode 30 from the second main surface S2 side of the substrate 21.

[0104] The photodiode 30 includes a semiconductor layer having a photovoltaic effect. Specifically, the semiconductor layer of the photodiode 30 includes an i-type semiconductor layer 31, a p-type semiconductor layer 32, and an n-type semiconductor layer 33. The i-type semiconductor layer 31, the p-type semiconductor layer 32, and the n-type semiconductor layer 33 are, for example, amorphous silicon (a-Si). It should be noted that the material of the semiconductor layer is not limited thereto, and may also be polycrystalline silicon, microcrystalline silicon, etc.

[0105] The p-type semiconductor layer 32 is formed by doping impurities in a-Si to form a p+ region. The n-type semiconductor layer 33 is formed by doping impurities in a-Si to form an n+ region. The i-type semiconductor layer 31 is, for example, a non-doped intrinsic semiconductor and has lower conductivity than the p-type semiconductor layer 32 and the n-type semiconductor layer 33.

[0106] In the direction (third direction Dz) perpendicular to the surface of the substrate 21, the i-type semiconductor layer 31 is provided between the n-type semiconductor layer 33 and the p-type semiconductor layer 32. In the present embodiment, the n-type semiconductor layer 33, the i-type semiconductor layer 31, and the p-type semiconductor layer 32 are sequentially stacked on the lower electrode 35. In the present embodiment, the upper electrode 34 is the anode electrode of the photodiode 30, and the lower electrode 35 is the cathode electrode of the photodiode 30.

[0107] The lower electrode 35 is provided to extend outside the photodiode 30, that is, to a region not overlapping the n-type semiconductor layer 33, the i-type semiconductor layer 31, and the p-type semiconductor layer 32. The lower electrode 35 is electrically connected to the connection wiring SLcn, the reset transistor Mrst, and the source follower transistor Msf via the contact hole CH2 provided in the insulating film 26.

[0108] The upper electrode 34 is provided on the p-type semiconductor layer 32. The upper electrode 34 is, for example, a light-transmitting conductive material such as ITO (Indium Tin Oxide). The insulating film 27 is provided on the insulating film 26 so as to cover the photodiode 30 and the upper electrode 34. The insulating film 27 is provided with a contact hole CH1 (opening) in a region overlapping with the upper electrode 34.

[0109] The connection wiring 36 is provided on the insulating film 27 and is electrically connected to the upper electrode 34 via the contact hole CH1 (opening). The reference potential VCOM (see Figure 4 ).

[0110] The insulating film 28 is provided on the insulating film 27 so as to cover the upper electrode 34 and the connection wiring 36. The insulating film 28 is provided as a protective layer for suppressing the intrusion of moisture into the photodiode 30. Furthermore, a protective film 29 is provided on the insulating film 28. The protective film 29 is a hard coating film (organic protective film) formed of an organic material. The protective film 29 flattens the step on the surface of the insulating film 28 formed by the photodiode 30 and the connection wiring 36.

[0111] The optical filter 7 is provided on the protective film 29. The optical filter 7 is provided directly on the protective film 29 without an adhesive layer. The cover member 122 is provided on the optical filter 7. The cover member 122 is bonded to the optical filter 7 via an adhesive layer 125 (see FIG. 1 ). The adhesive layer 125 is, for example, a light-transmitting optical adhesive sheet (OCA: Optical Clear Adhesive: optically transparent adhesive).

[0112] It should be noted that Fig.10 as well as Fig.11 The structure of the photodiode 30 shown is only an example and can be modified as appropriate. For example, the stacking order of the photodiode 30 may be reversed, and the p-type semiconductor layer 32 , the i-type semiconductor layer 31 , and the n-type semiconductor layer 33 may be stacked in this order on the lower electrode 35 .

[0113] Above, suitable embodiments of the present invention have been described, but the present invention is not limited to such embodiments. The contents disclosed in the embodiments are only examples, and various changes can be made within the scope of the gist of the present invention. Appropriate changes made within the scope of the gist of the present invention certainly also belong to the technical scope of the present invention. Within the scope of the gist of the above-mentioned embodiments and the modifications, at least one of the various omissions, substitutions and changes of the constituent elements can be made.

Claims

1. A detection device, comprising: substrate; A photodiode, disposed on the substrate; A lens is arranged overlapping with the photodiode; a light shielding layer, disposed between the photodiode and the lens, and having an opening in a region overlapping with the photodiode; and A light-transmitting resin layer and a buffer layer are stacked between the light-shielding layer and the lens. The lens is directly disposed on the buffer layer.

2. The detection device according to claim 1, wherein: The buffer layer is formed of a resin material including a material different from that of the light-transmitting resin layer.

3. The detection device according to claim 1, wherein: The buffer layer is formed of a resin material containing a surfactant of the same system as that of the material used for the lens.

4. The detection device according to claim 1, wherein: The buffer layer has a film thickness thinner than that of the light-transmitting resin layer.

5. The detection device according to claim 1, wherein: The detection device includes a blocking layer provided between the light shielding layer and the light-transmitting resin layer and formed of an acrylic resin.

6. The detection device according to claim 5, wherein: The detection device includes a filter layer, which is provided to cover the light shielding layer and the opening and shield light of a predetermined wavelength band. The barrier layer is arranged to cover the filter layer, The light-transmitting resin layer is disposed on the barrier layer.

7. The detection device according to claim 1, wherein: The detection device has an organic protective film covering the photodiode, The light shielding layer comprises: A first light shielding layer is disposed on the organic protective film and has a first opening in a region overlapping with the photodiode; and A second light shielding layer is provided between the first light shielding layer and the lens, and has a second opening in a region overlapping the photodiode and the first opening. The light-transmitting resin layer has: A first light-transmitting resin layer is provided between the first light-shielding layer and the second light-shielding layer; and The second light-transmitting resin layer is disposed between the second light-shielding layer and the buffer layer.

8. The detection device according to claim 1, wherein: The detection device has a plurality of lenses. A plurality of the lenses are provided in a region overlapping with one of the photodiodes.

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