Light detection device, optical element, and electronic device

Abstract

A light detection device according to an embodiment of the present disclosure comprises: a first layer that has a first light receiving element and a second light receiving element; a second layer that has a first filter and is provided above the first layer; and a first narrow band filter that is provided between the first layer and the second layer for the first light receiving element and the second light receiving element.

Description

Optical Detection Device, Optical Element, and Electronic Device

[0001] The present disclosure relates to an optical detection device, an optical element, and an electronic device.

[0002] An image sensor having a plurality of unit filters corresponding one-to-one to a plurality of pixels has been proposed (Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2022-167858

[0004] In a device for detecting light, it is desirable to improve optical characteristics.

[0005] It is desired to provide an optical detection device capable of improving optical characteristics.

[0006] The optical detection device according to an embodiment of the present disclosure includes a first layer having a first light-receiving element and a second light-receiving element, a second layer having a first filter and provided above the first layer, and a first narrow-band filter provided for the first light-receiving element and the second light-receiving element between the first layer and the second layer. The optical element according to an embodiment of the present disclosure includes a substrate, a narrow-band filter provided above the substrate, and a first filter and a second filter provided adjacent to each other above the narrow-band filter. The electronic device according to an embodiment of the present disclosure includes an optical system and an optical detection device that receives light transmitted through the optical system. The optical detection device has a first layer having a first light-receiving element and a second light-receiving element, a second layer having a first filter and provided above the first layer, and a first narrow-band filter provided for the first light-receiving element and the second light-receiving element between the first layer and the second layer.

[0007] Figure 1 is a block diagram showing an example of the schematic configuration of an imaging device, which is an example of a photodetector according to the first embodiment of this disclosure. Figure 2 is a diagram showing an example of the pixel section of an imaging device according to the first embodiment of this disclosure. Figure 3 is a diagram showing an example of the circuit configuration of a pixel in an imaging device according to the first embodiment of this disclosure. Figure 4 is a diagram for explaining an example of the configuration of an imaging device according to the first embodiment of this disclosure. Figure 5 is a diagram for explaining an example of the configuration of an imaging device according to the first embodiment of this disclosure. Figure 6A is a diagram for explaining an example of the transmittance of a filter in an imaging device according to the first embodiment of this disclosure. Figure 6B is a diagram for explaining an example of the transmittance of a filter in an imaging device according to the first embodiment of this disclosure. Figure 6C is a diagram for explaining an example of the transmittance of a filter in an imaging device according to the first embodiment of this disclosure. Figure 7A is a diagram for explaining an example of the planar configuration of an imaging device according to the first embodiment of this disclosure. Figure 7B is a diagram for explaining an example of the planar configuration of an imaging device according to the first embodiment of this disclosure. Figure 8 is a diagram for explaining an example of the configuration of an imaging device according to the first embodiment of this disclosure. Figure 9A is a diagram illustrating an example configuration of an imaging device according to the first embodiment of this disclosure. Figure 9B is a diagram illustrating an example configuration of an imaging device according to the first embodiment of this disclosure. Figure 10 is a diagram illustrating an example configuration of an imaging device according to the first embodiment of this disclosure. Figure 11 is a diagram illustrating an example configuration of an imaging device according to the first embodiment of this disclosure. Figure 12 is a diagram illustrating an example configuration of an imaging device according to the first embodiment of this disclosure. Figure 13 is a diagram illustrating another example configuration of an imaging device according to the first embodiment of this disclosure. Figure 14 is a diagram illustrating another example configuration of an imaging device according to the first embodiment of this disclosure. Figure 15 is a diagram illustrating another example configuration of an imaging device according to the first embodiment of this disclosure. Figure 16 is a diagram illustrating another example configuration of an imaging device according to the first embodiment of this disclosure. Figure 17 is a diagram illustrating an example configuration of an imaging device according to the first embodiment of this disclosure. Figure 18 is a diagram illustrating an example configuration of an imaging device according to the first embodiment of this disclosure. Figure 19 is a diagram illustrating an example configuration of an imaging device according to the first embodiment of this disclosure.Figure 20 is a diagram illustrating an example configuration of an imaging device according to the first embodiment of this disclosure. Figure 21 is a diagram illustrating an example configuration of an imaging device according to Modification 1 of this disclosure. Figure 22 is a diagram illustrating an example configuration of an imaging device according to Modification 1 of this disclosure. Figure 23 is a diagram illustrating an example configuration of an imaging device according to Modification 1 of this disclosure. Figure 24 is a diagram illustrating another example configuration of an imaging device according to Modification 1 of this disclosure. Figure 25 is a diagram illustrating another example configuration of an imaging device according to Modification 1 of this disclosure. Figure 26 is a diagram illustrating another example configuration of an imaging device according to Modification 1 of this disclosure. Figure 27 is a diagram illustrating another example configuration of an imaging device according to Modification 1 of this disclosure. Figure 28 is a diagram illustrating another example configuration of an imaging device according to Modification 1 of this disclosure. Figure 29 is a diagram illustrating an example configuration of an imaging device according to Modification 2 of this disclosure. Figure 30 is a diagram illustrating an example configuration of an imaging device according to Modification 2 of this disclosure. Figure 31 is a diagram illustrating another example configuration of an imaging device according to Modification 2 of this disclosure. Figure 32 is a diagram illustrating another configuration example of an imaging device according to Modification 2 of the present disclosure. Figure 33 is a diagram illustrating another configuration example of an imaging device according to Modification 2 of the present disclosure. Figure 34 is a diagram illustrating another configuration example of an imaging device according to Modification 2 of the present disclosure. Figure 35 is a diagram illustrating another configuration example of an imaging device according to Modification 2 of the present disclosure. Figure 36 is a diagram illustrating an example configuration example of an imaging device according to Modification 3 of the present disclosure. Figure 37 is a diagram illustrating an example configuration example of an imaging device according to Modification 3 of the present disclosure. Figure 38 is a diagram illustrating an example configuration example of an imaging device according to Modification 4 of the present disclosure. Figure 39 is a diagram illustrating an example configuration example of an imaging device according to Modification 4 of the present disclosure. Figure 40 is a diagram illustrating an example configuration example of an optical element according to the second embodiment of the present disclosure. Figure 41 is a block diagram showing an example configuration of an electronic device having an imaging device. Figure 42 is a block diagram showing an example of a schematic configuration of a vehicle control system. Figure 43 is an explanatory diagram showing an example of the installation position of an external information detection unit and an imaging unit. Figure 44 is a diagram showing an example of a schematic configuration of an endoscopic surgery system. Figure 45 is a block diagram showing an example of the functional configuration of the camera head and CCU.

[0008] The embodiments of this disclosure will be described in detail below with reference to the drawings. The description will be in the following order: 1. First Embodiment 2. Second Embodiment 3. Application Example 4. Application Example

[0009] <1. Embodiments> Figure 1 is a block diagram showing an example of the schematic configuration of an imaging device, which is an example of a light detection device according to the first embodiment of the present disclosure. Figure 2 is a diagram showing an example of the pixel section of an imaging device according to the first embodiment. A light detection device is a device capable of detecting incident light. An imaging device 1, which is an example of a light detection device, has a plurality of pixels P including light-receiving elements and is configured to receive incident light and generate a signal.

[0010] The imaging device 1, for example, generates a signal by receiving light transmitted through an optical system (not shown). The imaging device 1 is constructed using, for example, a substrate on which the light-receiving elements of each pixel P are provided (for example, a semiconductor substrate such as a Si (silicon) substrate or an SOI (Silicon On Insulator) substrate). The imaging device 1 may also have a structure (layered structure) composed of multiple semiconductor layers stacked on top of each other.

[0011] The light-receiving element (light-receiving part) of each pixel P is, for example, a photodiode (PD) and is configured to convert light into photoelectric energy. The light-receiving element of each pixel P can also be called a photoelectric conversion element (photoelectric conversion part) or a photoelectric conversion region. The imaging device 1 has a region (pixel section 100) where a plurality of pixels P are provided, as shown in the example in Figure 1 or Figure 2. The imaging device 1 has, for example, a pixel section 100 in which a plurality of pixels P are arranged in a matrix in two dimensions as an imaging area.

[0012] The imaging device 1 captures incident light (image light) from the subject to be measured through an optical system that includes, for example, an optical lens and an aperture (diaphragm). The imaging device 1 captures an image of the subject formed by the optical lens. The imaging device 1 can generate a pixel signal by photoelectric conversion of the received light (for example, visible light, infrared light, or ultraviolet light). The imaging device 1, which is a light detection device, is a device that can receive light and generate a signal, and can also be called a light receiving device.

[0013] The imaging device 1 (light detection device) can be used as an image sensor, distance measuring sensor, etc. The imaging device 1 is, for example, a CMOS (Complementary Metal Oxide Semiconductor) image sensor, a CCD (Charge Coupled Device) image sensor, etc. The imaging device 1 can be used in various electronic devices such as digital still cameras, video cameras, and mobile phones.

[0014] The imaging device 1 is configured to detect light (multispectral) in multiple wavelength ranges (for example, four or more wavelength ranges). The imaging device 1 has, for example, a filter that can selectively transmit light in multiple wavelength ranges. The imaging device 1 is configured as a multispectral sensor and can generate image data containing, for example, four or more wavelength components.

[0015] As shown in Figure 2, the direction of incidence of light from the subject being measured is defined as the Z-axis direction, the left-right direction perpendicular to the Z-axis direction is defined as the X-axis direction, and the up-down direction perpendicular to both the Z-axis and X-axis directions is defined as the Y-axis direction. In subsequent figures, directions may also be indicated based on the direction of the arrows in Figure 2.

[0016] [Outline Configuration of the Imaging Device] The imaging device 1, as an example, includes a pixel unit 100, a pixel control unit 111, a signal processing unit 112, and a control unit 113, as shown in Figure 1. The imaging device 1 is also provided with, for example, a plurality of control lines L1 and a plurality of signal lines L2. The pixel unit 100 is a pixel array in which a plurality of pixels P are arranged. The number and arrangement of pixels P provided in the pixel unit 100 (i.e., the pixel array) can be changed as appropriate.

[0017] Control line L1 is a signal line capable of transmitting signals to control pixels P, and is connected to the pixel control unit 111 and the pixels P of the pixel unit 100. In the example shown in Figure 1, multiple control lines L1 are wired to each pixel row of the pixel unit 100, which is composed of multiple pixels P arranged horizontally (in the row direction). Control line L1 is configured to transmit control signals for reading signals from pixels P. Control line L1 can also be called a drive line (or pixel drive line) that transmits signals to drive pixels P.

[0018] The signal line L2 is a signal line capable of transmitting signals from the pixel P, and is connected to the pixel P of the pixel unit 100 and the signal processing unit 112. In the pixel unit 100, for example, one or more signal lines L2 are wired to each pixel row, which is composed of multiple pixels P arranged vertically (in the column direction). The signal line L2 is electrically connected to the pixel P and is configured to transmit signals output from the pixel P. Note that the number and arrangement of control lines L1 and signal lines L2 are not limited to the illustrated example and can be changed as appropriate.

[0019] The pixel control unit 111 is configured to control each pixel P of the pixel unit 100. The pixel control unit 111 is a control circuit (pixel control circuit) and is composed of multiple circuits, such as a buffer, a shift register, and an address decoder. The pixel control unit 111 generates a signal for controlling the pixels P and outputs it to each pixel P of the pixel unit 100 via the control line L1. The pixel control unit 111 is controlled by the control unit 113 and controls the pixels P of the pixel unit 100.

[0020] The pixel control unit 111 generates signals to control pixels P, such as signals to control the readout circuit for pixels P, and supplies them to each pixel P via the control line L1. The pixel control unit 111 can control the reading of pixel signals from each pixel P. The pixel control unit 111 can also be described as a pixel drive unit (pixel drive circuit) configured to drive each pixel P.

[0021] The control unit 113 is configured to control each part of the imaging device 1. The control unit 113 receives data such as a clock and operating mode commands from an external source, and can output data such as internal information of the imaging device 1. The control unit 113 is a control circuit and, for example, has a timing generator configured to generate various timing signals.

[0022] The control unit 113 controls the operation of the pixel control unit 111 and the signal processing unit 112, etc., based on various timing signals (pulse signals, clock signals, etc.) generated by the timing generator. The control unit 113 may include circuits such as a PLL (Phase Locked Loop) and a DAC (Digital to Analog Converter).

[0023] The signal processing unit 112 is configured to acquire the signal from each pixel P and perform signal processing. The signal processing unit 112 is a signal processing circuit and is composed of circuits that perform various signal processing on the input pixel signals. The signal processing unit 112 includes an arithmetic circuit, a memory circuit, etc. The signal processing unit 112 is configured to include, for example, an AD (Analog Digital) conversion circuit.

[0024] The signals output from each pixel P selected and scanned by the pixel control unit 111 are input to the signal processing unit 112 via the signal line L2. The signal processing unit 112 (signal processing circuit) can perform various signal processing operations, such as AD conversion, noise reduction, and interpolation of the pixel P signals.

[0025] The signal processing unit 112 can perform signal processing on the pixel signal and output the processed pixel signal. The signal processing unit 112 may include a processor and memory. Note that some or all of the pixel control unit 111, signal processing unit 112, and control unit 113 may be configured as a single unit.

[0026] The pixel unit 100, pixel control unit 111, signal processing unit 112, control unit 113, etc., described above may be provided on a single substrate or divided and provided on multiple substrates. The pixel control unit 111, signal processing unit 112, control unit 113, etc., may be provided, for example, as peripheral circuits in the peripheral region of the pixel unit 100. The imaging device 1 may have a stacked structure formed by stacking multiple substrates.

[0027] [Pixel Configuration] Figure 3 shows an example of the circuit configuration of a pixel in an imaging device according to the first embodiment. A pixel P includes, for example, a light-receiving element 11 and a readout circuit 15. The readout circuit 15 is provided, for example, for each light-receiving element 11 or for each of a group of light-receiving elements 11. The light-receiving element 11 is configured to receive light and generate a signal. The readout circuit 15 is configured to output a signal based on the photoelectrically converted charge.

[0028] The light-receiving element 11 is configured to generate electric charge through photoelectric conversion. The light-receiving element 11 can also be described as a photoelectric conversion element (photoelectric conversion unit) configured to convert light into electric charge. In the example shown in Figure 3, the light-receiving element 11 is a photodiode (PD) that converts incident light into electric charge. The light-receiving element 11 can generate an electric charge corresponding to the amount of light received by performing photoelectric conversion.

[0029] The readout circuit 15 includes, as an example, a transistor TRG, a floating diffusion FD, a transistor AMP, a transistor SEL, and a transistor RST. The readout circuit 15 can read out pixel signals based on the charge photoelectrically converted by the photodetector 11.

[0030] The transistor TRG is configured to transfer the charge converted by the photodetector 11 to the floating diffusion FD. The transistor TRG is controlled by the signal STRG to electrically connect or disconnect the photodetector 11 and the floating diffusion FD. The transistor TRG is a transfer transistor. The transistor TRG can transfer the charge converted and stored by the photodetector 11 to the floating diffusion FD.

[0031] The floating diffusion FD is a storage unit and is configured to store the transferred charge. The floating diffusion FD can store the charge photoelectrically converted by the photodetector 11. The floating diffusion FD stores the transferred charge and converts it into a voltage corresponding to the capacitance of the floating diffusion FD. The floating diffusion FD can also be described as a storage unit capable of holding charge.

[0032] The transistor AMP is configured to generate and output a signal based on the charge stored in the floating diffusion FD. The transistor AMP is an amplifying transistor. The transistor AMP can generate and output a signal based on the charge converted by the photodetector 11 (i.e., the photoelectric conversion element).

[0033] The gate of the transistor AMP is electrically connected to the floating diffusion diode (FD), and the voltage converted by the floating diffusion diode is input to it. The drain of the transistor AMP is connected to a power line that supplies, for example, the power supply voltage (the power supply voltage VDD in the example shown in Figure 3).

[0034] The source of the transistor AMP is connected to signal line L2, for example, via transistor SEL. The transistor AMP is configured to generate a signal based on the charge stored in the floating diffusion FD, i.e., a signal based on the voltage of the floating diffusion FD, and output it to signal line L2.

[0035] The transistor SEL is configured to control the output of the pixel signal. The transistor SEL is electrically connected in series with the transistor AMP, for example, as shown in Figure 3. The transistor SEL is controlled by the signal SSEL and is configured to output the signal from the transistor AMP to the signal line L2. The transistor SEL is a selection transistor. The transistor SEL can control the timing of the pixel signal output.

[0036] The transistor SEL is configured to output a signal based on the charge converted by the photodetector 11. The transistor SEL can output the pixel signal of pixel P to the signal line L2. The transistor SEL may also be electrically connected in series between the power line to which the power supply voltage (power supply voltage VDD in the example shown in Figure 3) is supplied and the transistor AMP. The transistor SEL may be omitted if necessary.

[0037] The transistor RST is configured to reset the voltage of the floating diffusion FD. In the example shown in Figure 3, the transistor RST is electrically connected to a power line to which the power supply voltage VDD is supplied and is configured to perform a reset of the charge of pixel P. The transistor RST is a reset transistor.

[0038] The transistor RST is controlled by the signal SRST and can reset the charge accumulated in the floating diffusion FD and reset the voltage of the floating diffusion FD. The transistor RST electrically connects the power line and the floating diffusion FD and discharges the charge accumulated in the floating diffusion FD. In addition, the transistor RST can reset the charge accumulated in the photodetector 11 via the transistor TRG.

[0039] The transistors TRG (transfer transistor), AMP (amplifier transistor), SEL (selection transistor), and RST (reset transistor) mentioned above are, for example, MOS transistors (MOSFETs) having gate, source, and drain terminals.

[0040] In the example shown in Figure 3, transistors TRG, AMP, SEL, and RST are each composed of NMOS transistors. The transistor for pixel P may be composed of a PMOS transistor if necessary.

[0041] The pixel control unit 111 (see Figure 1) of the imaging device 1 supplies control signals to the gates of transistors TRG, SEL, RST, etc. of each pixel P via the control line L1 described above, and sets the transistors to an ON state (conducting state) or an OFF state (non-conducting state).

[0042] The multiple control lines L1 for each pixel row of the imaging device 1 include, as an example, wiring that transmits the signal STRG which controls the transistor TRG, wiring that transmits the signal SSEL which controls the transistor SEL, wiring that transmits the signal SRST which controls the transistor RST, and so on.

[0043] Transistors TRG, SEL, RST, etc. are turned on and off by the pixel control unit 111. The pixel control unit 111 controls the readout circuit 15 of each pixel P to output a pixel signal from each pixel P to the signal line L2. The pixel control unit 111 can perform control to read out the pixel signal of each pixel P to the signal line L2.

[0044] Note that the imaging device 1 may have a configuration in which a plurality of pixels P share one readout circuit 15. The readout circuit 15 is provided for, for example, a plurality of pixels P. In the imaging device 1, a readout circuit 15 may be arranged for each of the plurality of pixels P, and one readout circuit 15 may be shared by the plurality of pixels P. As an example, a 2×2 pixel formed by four adjacent pixels P may share one readout circuit 15.

[0045] [Configuration of Imaging Device] FIG. 4 is a diagram for explaining a configuration example of an imaging device according to the first embodiment. FIG. 4 schematically shows an example of a cross-sectional configuration of the imaging device 1. The imaging device 1 has, for example, a layer 120 provided with a filter and a layer 110 provided with a light-receiving element. The layer 120 includes an optical layer 102 having a filter 80 and an optical layer 101 having a filter 50. The filters 80 and 50 are configured to transmit light in specific wavelength ranges, as will be described later. The layer 110 includes a semiconductor layer 10 having a light-receiving element 11.

[0046] In the example shown in FIG. 4, the imaging device 1 has a configuration in which the optical layer 102, the optical layer 101, and the semiconductor layer 10 are stacked in the Z-axis direction. From the side where light is incident, the optical layer 102, the optical layer 101, and the semiconductor layer 10 are provided. The semiconductor layer 10 is formed of, for example, a semiconductor substrate such as a Si substrate or a SOI substrate. The semiconductor layer 10 has opposing surfaces 11S1 and 11S2. The surface 11S2 is the surface on the opposite side of the surface 11S1.

[0047] Surface 11S1 of the semiconductor layer 10 is, for example, a light-receiving surface (light incident surface). Surface 11S2 of the semiconductor layer 10 is, for example, an element-forming surface on which elements such as transistors and capacitive elements are formed. A gate electrode, a gate insulating film (for example, a gate oxide film), etc., are provided on surface 11S2 of the semiconductor layer 10. The element-forming surface of the semiconductor layer 10, i.e., surface 11S2, is a surface on which various circuit elements are provided, and can also be called a circuit surface.

[0048] An optical layer 101, etc., is provided on the surface 11S1 side of the semiconductor layer 10. On the surface 11S2 side of the semiconductor layer 10, for example, a wiring layer 90 is provided, as shown in the example in Figure 5. An optical layer 102 is provided on the side into which light from the optical system is incident, and a wiring layer 90 is provided on the side opposite to the side into which light is incident. Light from an object to be measured is incident on the optical layer 102, for example, through an optical system (imaging lens, aperture, etc.).

[0049] Optical layer 102 and optical layer 101 are stacked on the semiconductor layer 10 in a thickness direction perpendicular to the surface 11S1 of the semiconductor layer 10. The semiconductor layer 10 may be a SiGe (silicon germanium) substrate or a SiC (silicon carbide) substrate, etc. The semiconductor layer 10 may be composed of other semiconductor materials, such as III-V group compound semiconductor materials. The semiconductor layer 10 may be formed using other materials.

[0050] For example, the semiconductor layer 10 is provided with a light-receiving element 11 for each pixel P. The light-receiving element 11 (i.e., photoelectric conversion element) is provided between surfaces 11S1 and 11S2 of the semiconductor layer 10. Multiple light-receiving elements 11 are provided in the semiconductor layer 10 so as to be aligned with surfaces 11S1 and 11S2 of the semiconductor layer 10. For example, multiple light-receiving elements 11 are embedded in the semiconductor layer 10. The light-receiving element 11 can also be called a photoelectric conversion region or photoelectric conversion layer.

[0051] The wiring layer 90 is provided laminated on the semiconductor layer 10. The wiring layer 90 includes, for example, a conductive film and an insulating film, and has a plurality of wirings and a plurality of vias (also called contacts). The wiring layer 90 has a configuration in which a plurality of wirings are laminated with an insulating film acting as an interlayer insulating film (interlayer insulating layer). The wiring layer 90 is composed of, for example, two or more or three or more layers of wiring, and is provided as a multilayer wiring layer.

[0052] The wiring of the wiring layer 90 is formed using metallic materials such as aluminum (Al), copper (Cu), cobalt (Co), or ruthenium (Ru). The wiring of the wiring layer 90 may also be made of tungsten (W), polysilicon (Poly-Si), or other conductive materials. The interlayer insulating film may be formed using silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiON), or other insulating materials.

[0053] For example, the above-described readout circuit 15 (see Figure 3) is provided in the semiconductor layer 10 and the wiring layer 90 for each pixel P or for each of multiple pixels P. Furthermore, the above-described pixel control unit 111, signal processing unit 112, control unit 113 (see Figure 1), etc., may be provided in the semiconductor layer 10 and the wiring layer 90, or they may be provided on a substrate separate from the semiconductor layer 10.

[0054] In the imaging device 1, the pixel section 100 is provided with multiple types of pixels P (pixels P1, P2, P3, and P4 in Figure 4), each having a light-receiving element 11. Pixels P1 to P4 have filters 80 and 50 and are configured to generate electric charge by photoelectric conversion of light in different wavelength ranges. Pixels P1 to P4 are positioned adjacent to each other, for example, in the X-axis or Y-axis direction. In the pixel section 100, for example, multiple pixels P1 to multiple pixels P4 are repeatedly arranged.

[0055] The pixel section 100 (i.e., pixel array) of the imaging device 1 may be provided with multiple types of pixels P, for example, pixels P1 to P4, arranged in the X-axis direction (or Y-axis direction). Alternatively, pixels P1 to P4 may be arranged in both the X-axis direction and the Y-axis direction. For example, in the pixel section 100, a 2x2 pixel arrangement, consisting of pixels P1, P2, P3, and P4, may be repeatedly provided.

[0056] The optical layer 102 has a filter 80 and is configured to selectively transmit incident light to the optical layer 101. The optical layer 102 includes, for example, a plurality of filters 80 (in Figure 4, filters 80a, 80b, 80c, and 80d) and is provided stacked on the optical layer 101 which has a plurality of filters 50 (in Figure 4, filters 50a and 50b). The filters 80 are provided on the light incident side of the filters 50. The filters 80 are positioned in the optical layer 102 above the filters 50.

[0057] The filter 80 is configured to selectively transmit light in a specific wavelength range from the incident light. As a broadband filter, the filter 80 is configured to have a transmission wavelength range wider than, for example, the transmission wavelength range of the filter 50. For example, the filter 80 has a transmission wavelength range wider than one of the multiple transmission wavelength ranges of the filter 50.

[0058] In the imaging device 1, for example, one filter 80 is placed for one pixel P. Alternatively, one filter 80 may be placed for multiple pixels P. The filter 80 is provided for each pixel P or for multiple pixels P (i.e., for a predetermined number of pixels P). In the optical layer 102, for example, multiple filters 80 are arranged in a matrix in a two-dimensional manner.

[0059] In the example shown in Figure 4, filter 80a is provided for pixel P1, filter 80b is provided for pixel P2, filter 80c is provided for pixel P3, and filter 80d is provided for pixel P4. The optical layer 102 is, for example, a layer (region) containing a plurality of filters 80 which are broadband filters, and is provided as a broadband filter array.

[0060] Multiple types of filters 80, for example filters 80a to 80d, are configured to transmit light in different wavelength ranges. For example, the center wavelength of the transmission wavelength range of filter 80a, filter 80b, filter 80c, and filter 80d are all different from each other. Each of filters 80a to 80d has a broad transmission wavelength range with a predetermined wavelength as its center wavelength.

[0061] For example, filter 80a is configured to transmit light in a wavelength range that includes wavelength λ1 as the central wavelength. Filter 80b is configured to transmit light in a wavelength range that includes wavelength λ2 as the central wavelength. Filter 80c is configured to transmit light in a wavelength range that includes wavelength λ3 as the central wavelength. Filter 80d is configured to transmit light in a wavelength range that includes wavelength λ4 as the central wavelength. Note that the transmission wavelength ranges of filters 80a to 80d may be set so that their wavelength ranges partially overlap.

[0062] Each filter 80 (filters 80a to 80d) of pixels P1 to P4 may be configured to selectively transmit light of different wavelengths (and central wavelengths) in the visible light region. Alternatively, each filter 80 of pixels P1 to P4 may be configured to selectively transmit light of different wavelengths in the infrared light region.

[0063] The optical layer 101 is provided between the optical layer 102 and the semiconductor layer 10. The optical layer 101 has a filter 50 and is configured to selectively transmit incident light to the light-receiving element 11. The optical layer 101 includes, for example, a plurality of filters 50 (filter 50a, filter 50b in Figure 4) and is provided to be stacked on the semiconductor layer 10 having the light-receiving element 11. The filters 50 are positioned in the optical layer 101 above the light-receiving element 11.

[0064] Filter 50 is configured to selectively transmit light in a specific wavelength range from the incident light. As a narrowband filter, filter 50 is configured to transmit light in at least one specific wavelength range. Filter 50 has, for example, a transmission wavelength range narrower than the transmission wavelength range of filter 80, which is a broadband filter. Filter 50 has, for example, a plurality of narrow transmission bands.

[0065] In the imaging device 1, for example, one filter 50 is provided for multiple pixels P. A filter 50 is provided for each of the multiple pixels P (i.e., for each predetermined number of pixels P). In the optical layer 101, for example, multiple filters 50 are arranged in a matrix in two dimensions. A filter 50 may be provided for each of multiple adjacent pixels P (or multiple photodetectors 11). The optical layer 101 is a layer (region) containing multiple filters 50, which are narrowband filters, and is provided as a narrowband filter array.

[0066] In the imaging device 1, for example, a filter 50 is provided for each of several pixels P, and several pixels P share one filter 50. The filter 50 is provided in common for several adjacent pixels P in the X-axis direction (or Y-axis direction) and is shared by several pixels P. The imaging device 1 may have a configuration in which two pixels P share one filter 50, or a configuration in which three or more pixels P share one filter 50.

[0067] In the example shown in Figure 4, the filter 50a is provided for pixels P1 and P2. The filter 50a is positioned across adjacent pixels P1 and P2. For example, the filter 50a is provided between the optical layer 102 and the semiconductor layer 10 so as to cover the light-receiving element 11 of pixel P1 and the light-receiving element 11 of pixel P2. The filter 50a is shared by pixels P1 and P2, or by a plurality of pixels P including pixels P1 and P2.

[0068] The filter 50b is provided for pixels P3 and P4. The filter 50b is positioned across adjacent pixels P3 and P4. For example, the filter 50b is provided between the optical layer 102 and the semiconductor layer 10 so as to cover the light-receiving element 11 of pixel P3 and the light-receiving element 11 of pixel P4. The filter 50b is shared by pixels P3 and P4, or by a plurality of pixels P including pixels P3 and P4.

[0069] Multiple types of filters 50, such as filter 50a and filter 50b, are configured to transmit light in different wavelength ranges. For example, the center wavelength of the transmission wavelength range of filter 50a and the center wavelength of the transmission wavelength range of filter 50b are different from each other. Filter 50a and filter 50b each have a narrow transmission wavelength range with a specific wavelength as its center wavelength.

[0070] For example, filter 50a is configured to transmit light in a wavelength range that includes wavelength λ1 as the central wavelength. Filter 50b is configured to transmit light in a wavelength range that includes wavelength λ2 as the central wavelength. Filters 50a and 50b each have one or more transmission wavelength ranges. The transmission wavelength ranges of filters 50a and 50b may be set so that their wavelength ranges partially overlap.

[0071] Each filter 50 (filter 50a, filter 50b) of pixels P1 to P4 may be configured to selectively transmit light of different wavelengths (and center wavelengths) in the visible light region, for example. Alternatively, each filter 50 of pixels P1 to P4 may be configured to selectively transmit light of different wavelengths in the infrared light region, for example.

[0072] In the imaging device 1, for example, pixel P1 receives light in a first wavelength range with the photodetector 11 and performs photoelectric conversion. Pixel P2 receives light in a second wavelength range with the photodetector 11 and performs photoelectric conversion. Pixel P3 receives light in a third wavelength range with the photodetector 11 and performs photoelectric conversion. Pixel P4 receives light in a fourth wavelength range with the photodetector 11 and performs photoelectric conversion.

[0073] Pixel P1 generates a pixel signal for the first wavelength component, pixel P2 generates a pixel signal for the second wavelength component, pixel P3 generates a pixel signal for the third wavelength component, and pixel P4 generates a pixel signal for the fourth wavelength component. The imaging device 1 receives each spectrum in the wavelength range of visible light or infrared light, and can obtain pixel signals of multiple types of wavelength components. By using the pixel signals of each pixel P, image data containing, for example, four or more wavelength components can be generated.

[0074] Figures 6A to 6C illustrate an example of the transmittance of filters in an imaging device according to the first embodiment. Figure 6A shows an example of the transmittance of filter 80, which is a broadband filter, and Figure 6B shows an example of the transmittance of filter 50, which is a narrowband filter. Figure 6C also shows an example of the transmittance of light passing through filter 80 and filter 50. In Figures 6A to 6C, the vertical axis represents transmittance and the horizontal axis represents wavelength.

[0075] The filter 80c of one of several types of pixels P, for example, pixel P3 shown in Figure 4, has a transmission wavelength range R2 that includes wavelength λ3 as its central wavelength, as shown in Figure 6A. The filter 80c (i.e., broadband filter) selectively transmits light in the transmission wavelength range R2 from the incident light from the subject being measured.

[0076] As shown in Figure 6B, the filter 50b (i.e., narrowband filter) of pixel P3 has a transmission wavelength range R1a that includes wavelength λ1 as the central wavelength, a transmission wavelength range R1b that includes wavelength λ2 as the central wavelength, a transmission wavelength range R1c that includes wavelength λ3 as the central wavelength, and a transmission wavelength range R1d that includes wavelength λ4 as the central wavelength.

[0077] Filter 50b selectively transmits light in the transmission wavelength range R1c from the light in the transmission wavelength range R2 incident through filter 80c. The photodetector 11 of pixel P3 receives light in the transmission wavelength range R1c incident through filter 80c and filter 50b. In this way, the incident light from the subject is spectrally separated into light in each band (for example, light in the transmission wavelength range R1a to light in the transmission wavelength range R1d), and each pixel P (for example, pixels P1 to P4) performs photoelectric conversion, thereby realizing multi-spectroscopy.

[0078] The arrangement and type of filters 80 and 50 in the pixel section 100 can be arbitrarily set. The pixel section 100 may be provided with five or more types of pixels P that receive light of different wavelengths and perform photoelectric conversion. For example, eight types of pixels P may be repeatedly arranged in the pixel section 100, or sixteen types of pixels P may be repeatedly arranged. A multispectral image containing eight wavelength components or sixteen wavelength components can be obtained.

[0079] Figures 7A and 7B are diagrams illustrating an example of the planar configuration of an imaging device according to the first embodiment. Figure 7A schematically shows an example of the planar configuration of the optical layer 102, which includes a filter 80 provided on the side where light is incident. Figure 7B schematically shows an example of the planar configuration of the optical layer 101, which includes a filter 50. Note that in Figures 7A and 7B, only a portion of the pixel area 100, specifically the 4x4 pixels, are shown.

[0080] The imaging device 1 may have four types of filters 80 (filters 80a to 80d), as shown in the example in Figure 7A. A filter 80 is provided, for example, for each pixel P (i.e., for each light-receiving element 11). In the pixel section 100, as an example, filters 80a, 80b, 80c, and 80d are arranged repeatedly.

[0081] Furthermore, the imaging device 1 has four types of filters 50 (filters 50a to 50d), as shown in the example in Figure 7B. In the imaging device 1, for example, a filter 50 is provided for every four pixels P (i.e., four light-receiving elements 11), and one filter 50 is shared by four adjacent pixels P. In the pixel section 100, as an example, filters 50a, 50b, 50c, and 50d are arranged repeatedly.

[0082] Figures 8, 9A, and 9B are diagrams illustrating an example of the configuration of an imaging device according to the first embodiment. Figure 8 shows an example of the cross-sectional configuration of the imaging device 1. Figures 9A and 9B show an example of the planar configuration of the imaging device 1. The optical layer 101 includes, for example, a reflective layer 35, an intermediate layer 30, and a reflective layer 36, as shown in Figure 8.

[0083] Each filter 50 (filters 50a, 50b in Figure 8) of the optical layer 101 includes, for example, a reflective layer 35, an intermediate layer 30, and a reflective layer 36, and is configured as a Fabry-Perot filter. The filter 50 has a configuration in which the reflective layer 35, the intermediate layer 30, and the reflective layer 36 are stacked in the Z-axis direction. The reflective layer 35, the intermediate layer 30, and the reflective layer 36 are provided from the side of the optical layer 101 into which light is incident.

[0084] The reflective layers 35 and 36 are provided relative to the intermediate layer 30. The reflective layers 35 and 36 are provided facing each other with the intermediate layer 30 in between. For example, each of the reflective layers 35 and 36 is a reflective member (reflective film) and is configured to have a predetermined reflectance with respect to incident light.

[0085] The reflective layers 35 and 36 are arranged apart from each other in the thickness direction of the intermediate layer 30, i.e., in the stacking direction (Z-axis direction in Figure 8). The reflective layer 35 is provided on one side of the intermediate layer 30, and the reflective layer 36 is provided on the other side of the intermediate layer 30. In the example shown in Figure 8, the reflective layer 35 is the upper reflective layer of the intermediate layer 30, and the reflective layer 36 is the lower reflective layer of the intermediate layer 30.

[0086] The intermediate layer 30 is provided between the reflective layer 35 and the reflective layer 36. The intermediate layer 30 is an intermediate member between the reflective layer 35 and the reflective layer 36, and is also called a resonant layer or resonator layer. The filter 50, for example, includes the intermediate layer 30 as a resonator (Fabry-Perot resonator) and is provided as a Fabry-Perot type filter. The filter 50 can be configured as an optical filter that utilizes Fabry-Perot resonance.

[0087] The filter 50 resonates light in a specific wavelength range between the reflective layers 35 and 36, i.e., in the intermediate layer 30, and selectively transmits light in that specific wavelength range. Light incident on the intermediate layer 30 from above via the optical layer 102 and the reflective layer 35 is reflected and interfered with by the reflective layers 35 and 36, and the light in the resonant wavelength range is transmitted through the reflective layer 36 and output.

[0088] The filter 50 has, for example, multiple resonance modes and can transmit multiple narrowband light signals that resonate in the intermediate layer 30 to the photodetector 11. In the imaging device 1, the resonance wavelength can be controlled by adjusting the effective refractive index of the intermediate layer 30, the thickness of the intermediate layer 30, etc., so that, for example, different wavelength spectra can be obtained for each pixel.

[0089] The reflective layer 35 and the reflective layer 36 are each composed of a metallic material such as Ag (silver), Au (gold), copper (Cu), Al (aluminum), or Ti (titanium). Each of the reflective layer 35 and the reflective layer 36 may be formed using other metallic materials or other materials. The reflective layer 35 and the reflective layer 36 may be formed by laminating multiple dielectric films (dielectric films) having different refractive indices.

[0090] Each of the reflective layers 35 and 36 may be constructed as a dielectric multilayer film using SiO (silicon oxide), TiO (titanium oxide), SiN (silicon nitride), a-Si (amorphous silicon), Poly-Si (polysilicon), etc. As an example, each of the reflective layers 35 and 36 has multiple stacked films and is constructed as a Bragg reflective layer.

[0091] The intermediate layer 30 is, for example, silicon oxide (SiO ２ It is constructed using dielectric materials such as silicon oxynitride (SiON) and silicon nitride (SiN). The intermediate layer 30 may be formed using a semiconductor material, or it may be formed using other materials that transmit light in the wavelength range to be measured.

[0092] Each filter 50 of multiple types of pixels (for example, pixels P1 to P4) is configured such that the refractive index and thickness of the intermediate layer 30 differ so as to transmit light in a specific wavelength range to be detected. The intermediate layer 30 of each of pixels P1 to P4 may be made of the same material or of different materials. The intermediate layer 30 may be made up of multiple layers.

[0093] The filter 50 may have a structure 31, as shown in the examples in Figures 8 and 9A. The imaging device 1 has, for example, a structure 31 provided in the intermediate layer 30 of the optical layer 101 in some or all of the pixels P. The intermediate layer 30 includes, as an example, the structure 31 and a member 32 provided around the structure 31. The structure 31 and the member 32 are made of materials having different refractive indices.

[0094] The intermediate layer 30 (or optical layer 101) includes a structure 31 as a nanostructure and has a metasurface structure (or metamaterial structure). For example, one or more structures 31 and members 32 are formed in the intermediate layer 30 for each pixel P. The filter 50 is configured to propagate light in a specific wavelength range to the photodetector 11 side using the intermediate layer 30 having the structures 31.

[0095] Each pixel P has a filter 50 that includes a plurality of structures 31, as shown in the example in Figures 8 and 9A (or 9B). The filter 50 has a periodic structure and is configured as a narrowband filter. The filter 50 (i.e., narrowband filter) has a plurality of structures 31 arranged, for example, in the X-axis and Y-axis directions. A small structure 31 is arranged in the region of the intermediate layer 30 of each pixel P.

[0096] Furthermore, in the filter 50, structures 31 may also be provided at the boundaries of multiple adjacent pixels P. The filter 50 has a periodic structure formed to span multiple adjacent pixels P. In the examples shown in Figures 8 and 9A, some of the structures 31 are arranged to span two adjacent pixels P. For example, structures 31 may be provided at edges that form the boundary between two adjacent pixels P in the X-axis or Y-axis direction, or at intersections that form the boundaries between four pixels P.

[0097] In the filter 50 of each pixel P, for example, the effective refractive index of the structure 31 and member 32 is adjusted according to the occupancy rate (volume fraction) of the structure 31, and the wavelength band (and center wavelength) of light transmitted by the filter 50 is determined. By adjusting the size and number of structures 31 in each filter 50, the transmitted wavelength band in each filter 50 can be set.

[0098] Each filter 50 of pixels P1 to P4 may be configured to selectively transmit light of different wavelengths (and center wavelengths) in the visible light region, for example. Alternatively, each filter 50 of pixels P1 to P4 may be configured to selectively transmit light of different wavelengths in the infrared light region, for example.

[0099] As an example, the structure 31 has a cylindrical shape. As another example, the structure 31 has a prismatic shape. In plan view (i.e., when viewed in the XY plane), the structure 31 may be circular, elliptical, or quadrilateral. The shape of the structure 31 can be changed as appropriate, and it may be polygonal, cross-shaped, or other shapes.

[0100] The structure 31, in plan view (i.e., viewed in the XY plane), has a size that is, for example, less than or equal to a predetermined wavelength of incident light. When viewed in the XY plane, the structure 31 may have a size that is less than or equal to the wavelength range of the light to be measured. The size of the structure 31 when viewed in the XZ or YZ plane (for example, the height of the structure 31) may be less than or equal to the predetermined wavelength of incident light, or it may be greater than the wavelength of incident light.

[0101] In the intermediate layer 30, the multiple structures 31 are arranged two-dimensionally in the X-axis and Y-axis directions, for example, as shown in the example in Figure 9A. As an example, the multiple structures 31 of each filter 50 are arranged so as to be aligned with each other in the X-axis direction or the Y-axis direction, with a part of the member 32 in between. In the optical layer 101, the size (width, height, etc.), number of structures 31, spacing between structures, material of structures 31, etc. are determined so that light in the wavelength range to be detected at each pixel P is transmitted to the photodetector 11.

[0102] Member 32 is provided between a plurality of adjacent structures 31. Member 32 is a member located around the structure 31. Member 32 has a different refractive index than the structure 31 and can be called a material layer. Member 32 is provided, for example, to fill the space between a plurality of adjacent structures 31 and can be called a filling member. A part of member 32 may be provided above and below the structure 31. The structure 31 may be arranged to be embedded in member 32 (i.e., the material layer).

[0103] The structure 31 and the member 32 may be made of different materials. For example, the structure 31 may be made of a material having a relatively high refractive index. The structure 31 may be made of a material having a higher refractive index than the member 32, and thus have a higher refractive index than the member 32. The structure 31 may be made of a high refractive index material and can be called a high refractive index part. The member 32 may be made of a low refractive index material and can be called a low refractive index part.

[0104] Structure 31 is, for example, made of titanium oxide (TiO). Structure 31 may also be formed using silicon, polysilicon (Poly-Si), amorphous silicon (a-Si), germanium (Ge), etc. Structure 31 may be made of a metal compound or a silicon compound, or it may be formed using other materials.

[0105] Component 32 is, for example, silicon oxide (SiO ２ The member 32 is composed of silicon nitride (SiN), silicon oxynitride (SiON), or silicon carbide (SiC). The member 32 may be composed of other silicon compounds or formed using other materials.

[0106] Each pixel P's light-receiving element 11 receives incident light through the filter 50 of the optical layer 101 and generates a pixel signal. For example, pixels P1 to P4 can generate and output pixel signals of the first wavelength component to the fourth wavelength component. The imaging device 1 can use the pixel signals obtained from each pixel P to generate, for example, image data showing the subject image, image data relating to the distance to the measurement target (object) (distance image data), and the like.

[0107] The number and arrangement of structures 31 in each filter 50, the constituent materials of each structure 31 and member 32, etc., are selected according to the wavelength range of the light to be measured, the refractive index difference with the surrounding material, etc. In the imaging device 1, for example, as shown in the example in Figure 10, pixels having structures 31 (pixels P1, P4) and pixels without structures 31 (pixels P2, P3) may be arranged.

[0108] The reflective layer 35 and the reflective layer 36 may each have multiple stacked films, as shown in the example in Figure 11, and may be provided as a dielectric multilayer film. Each of the reflective layer 35 and the reflective layer 36 may be configured as a Bragg reflective layer. The reflective layer 35 and the reflective layer 36 may have a structure in which a dielectric with a high refractive index and a dielectric with a low refractive index are alternately stacked.

[0109] The reflective layer 35 and the reflective layer 36 can be constructed as dielectric multilayer films using, for example, SiO (silicon oxide), TiO (titanium oxide), SiN (silicon nitride), a-Si (amorphous silicon), Poly-Si (polysilicon), tantalum oxide (TaO), aluminum oxide (AlO), zirconium oxide (ZrO), etc.

[0110] The imaging device 1 may be configured such that, for example, the thickness of the intermediate layer 30 differs for each filter 50 or for each of the multiple filters 50. The optical layer 101 may have multiple intermediate layers 30 having different thicknesses from each other. For example, the thickness (height) of the intermediate layer 30 in the Z-axis direction may differ for each of the multiple pixels P.

[0111] In the example shown in Figure 12, the thickness of the intermediate layer 30 (referred to as intermediate layer 30a) in the filter 50a for pixels P1 and P2 is different from the thickness of the intermediate layer 30 (referred to as intermediate layer 30b) in the filter 50b for pixels P3 and P4. For example, intermediate layer 30b has a greater thickness than intermediate layer 30a.

[0112] By adjusting the thickness of the intermediate layers 30a and 30b, the transmission wavelength range of filter 50a and filter 50b can be adjusted, respectively. The intermediate layers 30a and 30b may be made of the same material or different materials. Using intermediate layers 30a and 30b with different thicknesses expands the range over which the transmission wavelength range (and center wavelength) can be adjusted.

[0113] As shown in the example in Figure 12, the structure 31 may be provided in the intermediate layers 30a and 30b. Alternatively, only one of the intermediate layers 30a or 30b may have the structure 31. In the imaging device 1, for example, the thickness of the intermediate layers 30a and 30b, the volume ratio of the structure 31 in each filter 50, etc., are determined so that the resonant wavelength in each filter 50 becomes a desired wavelength.

[0114] Furthermore, the structure 31 may be constructed using a material having a relatively low refractive index. For example, the structure 31 may be constructed of a material having a lower refractive index than that of member 32, and thus having a lower refractive index than member 32. In this case, the structure 31 is constructed of a low refractive index material and can be called a low refractive index portion. Member 32 is constructed of a high refractive index material and can be called a high refractive index portion.

[0115] Figures 13 and 14 are diagrams illustrating another configuration example of the imaging device according to the first embodiment. Figure 13 shows an example of the cross-sectional configuration of the imaging device 1. Figure 14 shows an example of the planar configuration of the imaging device 1. The filter 50 may be configured as a GMR (Guided Mode Resonance) filter. The optical layer 101 includes, for example, a grating layer 40 and a waveguide layer 43.

[0116] Each filter 50 of the optical layer 101 includes, for example, a grating layer 40 and a waveguide layer 43, and is configured as an optical filter utilizing waveguide mode resonance, i.e., a GMR filter. The filter 50 has a configuration in which the grating layer 40 and the waveguide layer 43 are stacked in the Z-axis direction. The grating layer 40 and the waveguide layer 43 (waveguide layer) are provided from the side of the optical layer 101 into which light is incident.

[0117] The filter 50 has a plurality of structures 41, as shown in the examples in Figures 13 and 14. For example, a plurality of structures 41 are formed in the grating layer 40 for each pixel P. The filter 50 has a diffraction grating 42 constructed using the plurality of structures 41. The diffraction grating 42 has, for example, periodically formed structures 41 (i.e., convex portions). The filter 50 has a periodic structure and is configured as a narrowband filter. The grating layer 40 can also be called a diffraction grating layer.

[0118] In the lattice layer 40, the multiple structures 41 are arranged two-dimensionally, for example, in the X-axis and Y-axis directions. The filter 50 has multiple structures 41 arranged, for example, in the X-axis and Y-axis directions. A structure 41 as a nanostructure is arranged in each region of the lattice layer 40 of each pixel P.

[0119] Furthermore, in the filter 50, structures 41 may also be provided at the boundaries of multiple adjacent pixels P. The filter 50 has a periodic structure formed to span multiple adjacent pixels P. In the examples shown in Figures 13 and 14, some of the structures 41 are arranged to span two adjacent pixels P. For example, structures 41 may also be provided at edges that form the boundary between two adjacent pixels P in the X-axis or Y-axis direction, or at intersections that form the boundary between four pixels P.

[0120] The structure 41 may have, for example, a cylindrical or prismatic shape. In plan view (i.e., viewed in the XY plane), the structure 41 may be circular, elliptical, or quadrilateral. The shape of the structure 41 is not limited to the illustrated example and can be changed as appropriate. The filter 50 is configured to propagate light in a specific wavelength range to the photodetector 11 side using the lattice layer 40 having the structure 41.

[0121] In each pixel P filter 50, the wavelength band (and center wavelength) of light transmitted by the filter 50 is determined according to the number of structures 41, the spacing between them, the size of the structures 41 (width, height (thickness), etc.), and the material of the structures 41. By adjusting the number, spacing, size, etc. of the structures 41 in each filter 50, the transmission wavelength band of each filter 50 can be set.

[0122] The lattice layer 40 structure 41 and the waveguide layer 43 are constructed using, for example, silicon oxide (SiO), titanium oxide (TiO), silicon nitride (SiN), amorphous silicon (a-Si), polysilicon (Poly-Si), tantalum oxide (TaO), aluminum oxide (AlO), zirconium oxide (ZrO), etc. The structure 41 and the waveguide layer 43 may be constructed using different materials or the same type of material.

[0123] Figures 15 and 16 are diagrams illustrating another configuration example of the imaging device according to the first embodiment. Figure 15 shows an example of the cross-sectional configuration of the imaging device 1. Figure 16 shows an example of the planar configuration of the imaging device 1. The filter 50 may be configured as a plasmon filter. The optical layer 101 includes, for example, a member 46 having a structure 45 and a member 47. The structure 45 is provided on member 46 and is configured as an opening (groove).

[0124] Each filter 50 of the optical layer 101 includes, for example, a member 46 provided with a plurality of structures 45, and is configured as an optical filter utilizing surface plasmons, i.e., a plasmon filter. The member 46 is made of a metallic material, for example, aluminum (Al), and is configured as a metallic film (metal member). The member 46 may also be formed using other metallic materials such as silver (Ag), gold (Au), copper (Cu), or titanium (Ti).

[0125] The filter 50 has a plurality of structures 45, as shown in the examples in Figures 15 and 16. A plurality of structures 45 are formed on the member 46, for example, for each pixel P. In the example shown in Figure 15, the structures 45 are configured as holes (pores) that penetrate the member 46 (i.e., the metal film) and are provided periodically. The member 46 has, for example, periodically formed structures 45, i.e., hole structures. The filter 50 has a periodic structure and is configured as a narrowband filter.

[0126] In member 46, for example, multiple structures 45 are arranged two-dimensionally in the X-axis and Y-axis directions. The filter 50 has, for example, multiple structures 45 arranged to be aligned in the X-axis and Y-axis directions. A structure 45 as a nanostructure is arranged in the region of member 46 of each pixel P. The filter 50 can also be said to have a periodic hole array. Note that the structures 45 may be configured as non-through holes.

[0127] Furthermore, in the filter 50, structures 45 may also be provided at the boundaries of multiple adjacent pixels P. The filter 50 may have a periodic structure formed to span multiple adjacent pixels P. In the examples shown in Figures 15 and 16, some of the structures 45 are arranged to span two adjacent pixels P. For example, structures 45 may also be provided at edges that form the boundary between two adjacent pixels P in the X-axis or Y-axis direction, or at intersections that form the boundary between four pixels P.

[0128] Member 47 is provided around member 46 having structure 45. Member 47 may also be provided to fill the inside of structure 45 (hole structure), and can be called a filling member. Member 47 may be made of silicon oxide (SiO2) as a dielectric film, for example. ２ The component 47 is constructed using the following materials. The component 47 may be constructed using other insulating materials such as silicon nitride (SiN) or aluminum oxide (AlO), or it may be formed using other materials.

[0129] The structure 45 has, for example, a cylindrical or prismatic shape. In plan view (i.e., viewed in the XY plane), the structure 45 may be circular, elliptical, or quadrilateral. The shape of the structure 45 is not limited to the illustrated example and can be changed as appropriate. The filter 50 is configured to propagate light in a specific wavelength range to the photodetector 11 side by utilizing surface plasmon resonance caused by incident light.

[0130] In the filter 50 of each pixel P, the wavelength band (and center wavelength) of light transmitted by the filter 50 is determined according to the number of structures 45, the spacing between them, and the size of the structures 45 (e.g., width (diameter), length (depth)). By adjusting the number, spacing, and size of the structures 45 in each filter 50, the transmission wavelength band of each filter 50 can be set.

[0131] As described above, the imaging device 1 according to this embodiment includes a filter 80 and a filter 50 provided between the filter 80 and the light-receiving element 11. The filter 50 is provided for multiple pixels P. Therefore, the optical characteristics of the filter can be improved. This makes it possible to realize a light detection device (imaging device) capable of improving optical characteristics.

[0132] In the imaging device 1, the filter 50 can be configured to have a structure (for example, the structure 31, structure 41, or structure 45 described above) that spans multiple pixels P, thereby improving the performance of the filter 50 (i.e., the narrowband filter). Compared to the case where one narrowband filter is provided in one pixel P, it is possible to suppress the limitation of spectral characteristics due to the size of the pixel P.

[0133] According to the technology disclosed herein, structures (structure 31, structure 41, or structure 45) can be placed between pixels P, and even when there are constraints on the size of the structures or the spacing between them, the packing density (volume fraction) of the structures can be increased. Therefore, when a filter 50 is configured as a Fabry-Perot filter or the like using multiple structures (nanostructures), the range in which the transmission wavelength range (and center wavelength) of the filter 50 can be adjusted can be expanded. This makes it possible to improve the spectral characteristics.

[0134] In this embodiment, the number of periods in the periodic structure of the filter 50 can be increased (i.e., the number of structures 31, 41, or 45 can be increased). Therefore, for example, when the filter 50 is configured as a GMR filter or a plasmon filter, the resonance in the filter 50 can be strengthened, and the transmission wavelength range can be made narrower. This makes it possible to realize a multispectral sensor with high wavelength resolution.

[0135] Furthermore, in the imaging device 1, by providing filters 50 for the regions of multiple pixels P, it is possible to suppress the deterioration of the filter characteristics caused by interference between filters 50 (i.e., between resonators) compared to the case where one narrowband filter is provided in one pixel P. For example, it is possible to suppress deterioration of the transmittance and spectral characteristics of the filter 50.

[0136] Furthermore, as described above, the filter 50 is provided between the semiconductor layer 10 having the light-receiving element 11 and the optical layer 102 having the filter 80. Therefore, for example, the filter 50 can be formed on the semiconductor layer 10 which has high flatness, thereby improving the optical characteristics of the filter 50. This makes it possible to realize an imaging device 1 that is advantageous for high performance.

[0137] Figures 17 to 20 are diagrams illustrating an example configuration of an imaging device according to the first embodiment. Figures 17 to 20 show an example configuration of the filter 80 of the imaging device 1. As schematically shown in Figure 17, the filter 80 may be configured as an RGB color filter. The filter 80 is formed using, for example, a resin material. As an example, a pixel P is provided with a filter 80 that transmits red (R) light, a filter 80 that transmits green (G) light, or a filter 80 that transmits blue (B) light.

[0138] The filter 80 may be formed using a dielectric multilayer film and can be configured as a dielectric multilayer film filter. For example, as shown in the example in Figure 18, the filter 80 has a structure in which a dielectric 81 having a high refractive index and a dielectric 82 having a low refractive index are alternately stacked, and is configured as a dielectric multilayer film in which multiple dielectrics are stacked. The filter 80 is configured as a broadband filter to selectively transmit light in a specific wavelength range.

[0139] Furthermore, the filter 80 may be configured as a Fabry-Perot filter, having a reflective layer 85 and a reflective layer 86 and an intermediate layer 87, as schematically shown in Figure 19. Alternatively, as shown in the example in Figure 20, the filter 80 may be configured as a plasmon filter, having a member 89 with multiple structures 88 (i.e., holes). Also, for example, the filter 80 may be configured as a GMR (Guided Mode Resonance) filter.

[0140] [Function and Effects] The light detection device according to this embodiment comprises a first layer (e.g., semiconductor layer 10) having a first light-receiving element (e.g., light-receiving element 11 of pixel P1) and a second light-receiving element (e.g., light-receiving element 11 of pixel P2), a second layer (e.g., optical layer 102) having a first filter (filter 80) and provided above the first layer, and a first narrow-band filter (filter 50) provided between the first layer and the second layer for the first and second light-receiving elements.

[0141] The photodetector (imaging device 1) according to this embodiment includes a semiconductor layer 10 having a light-receiving element 11, an optical layer 102 having a filter 80, and a filter 50. The filter 50 is provided between the semiconductor layer 10 and the optical layer 102 for a plurality of light-receiving elements 11. This makes it possible to realize a photodetector capable of improving optical characteristics.

[0142] Next, modified examples of the present disclosure will be described. In the following, components similar to those in the above embodiments will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate.

[0143] (Modification 1) Figures 21 and 22 are diagrams illustrating an example of the configuration of an imaging device according to Modification 1 of the present disclosure. Figure 21 is a diagram illustrating an example of the planar configuration of the imaging device. Figure 22 shows an example of the cross-sectional configuration in the direction of the line A-A' shown in Figure 21. Figure 23 also shows an example of the transmittance of a filter 50, which is a narrowband filter. The filter 50 may be provided for two, three, or four pixels P, as in the example shown in Figure 21.

[0144] In the imaging device 1, for example, a filter 50 is provided for every two or three pixels P (i.e., two or three photodetectors 11), and one filter 50 is shared by two or three adjacent pixels P. The filter 50 may be configured to have multiple transmission wavelength ranges (in the example shown in Figure 23, three transmission wavelength ranges R1a to R1c) corresponding to the number of pixels P that share the filter 50.

[0145] Figures 24 and 25 illustrate another configuration example of the imaging device according to Modification 1. Figure 24 illustrates an example of the planar configuration of the imaging device. Figure 25 shows an example of the cross-sectional configuration in the direction of line A-A' shown in Figure 24. Figure 26 also shows an example of the transmittance of the filter 50. The filter 50 may be provided for five pixels P, as in the example shown in Figure 24.

[0146] In the pixel section 100 of the imaging device 1, for example, a filter 50 is provided for every five pixels P (i.e., five light-receiving elements 11), and one filter 50 is shared by five adjacent pixels P. The filter 50 may be configured to have five transmission wavelength ranges R1a to R1e, as shown in the example in Figure 26.

[0147] Figures 27 and 28 illustrate another configuration example of the imaging device according to Modification 1. Figure 27 is a diagram illustrating an example of the planar configuration of the imaging device. Figure 28 shows an example of the cross-sectional configuration in the direction of the line A-A' shown in Figure 27. The filter 50 may be provided for nine pixels P in a 3x3 arrangement, as in the example shown in Figure 27.

[0148] Furthermore, as shown in the example in Figure 27, nine types of filters 80 (filters 80a, 80b, 80c, 80d, 80e, 80f, 80g, 80h, 80i) may be arranged for nine 3x3 pixels P. In the pixel section 100, for example, a filter 50 is provided for each of the nine pixels P, and one filter 50 is shared by nine adjacent pixels P. Each filter 50 (filters 50a to 50d) may be configured to have nine transmission wavelength ranges.

[0149] (Modification 2) Figures 29 and 30 are diagrams illustrating an example of the configuration of an imaging device according to Modification 2. Figure 30 shows an example of a cross-sectional configuration in the direction of the line A-A' shown in Figure 29. The imaging device 1 may be configured to have one type of filter 50 (for example, filter 50a). Filter 50a is configured to have, for example, a number of transmission wavelength ranges corresponding to the number of pixels P that share filter 50a.

[0150] Figures 31 and 32 are diagrams illustrating another configuration example of the imaging device according to Modification 2. Figure 32 shows an example of a cross-sectional configuration in the direction of line A-A' shown in Figure 31. The imaging device 1 may be configured to have three types of filters 50 (for example, filter 50a, filter 50b, and filter 50c).

[0151] Figures 33 and 34 are diagrams illustrating another configuration example of the imaging device according to Modification 2. Figure 34 shows an example of a cross-sectional configuration in the direction of line A-A' shown in Figure 33. Figure 35 also shows an example of the transmittance of the filter 50. The imaging device 1 may be configured to have five or more types of filters 50, for example, filters 50a to 50e.

[0152] Filters 50a to 50e are configured to transmit light in different wavelength ranges. For example, filters 50a to 50e are configured to have different spectral characteristics. For example, as shown in Figure 35, filter 50a has the transmittance shown by line A1, filter 50b has the transmittance shown by line A2, filter 50c has the transmittance shown by line A3, filter 50d has the transmittance shown by line A4, and filter 50e has the transmittance shown by line A5.

[0153] Filters 50a to 50e may be configured such that the peak transmittance positions of filter 50a, filter 50b, filter 50c, filter 50d, and filter 50e are different, as shown in the example in Figure 35. In the example shown in Figure 35, filter 50a has spectral characteristics with transmittance peaks at four wavelengths, including wavelength λa, as shown by line A1.

[0154] Furthermore, filter 50b has spectral characteristics with transmittance peaks at four wavelengths, including wavelength λb, as shown by line A2. Filter 50c has spectral characteristics with transmittance peaks at four wavelengths, including wavelength λc, as shown by line A3. Filter 50d has spectral characteristics with transmittance peaks at four wavelengths, including wavelength λd, as shown by line A4. Furthermore, filter 50e has spectral characteristics with transmittance peaks at four wavelengths, including wavelength λe, as shown by line A5.

[0155] (Modification 3) Figures 36 and 37 are diagrams illustrating an example of the configuration of an imaging device according to Modification 3. Figure 37 shows an example of a cross-sectional configuration in the direction of line A-A' shown in Figure 36. The filter 80 may be provided for multiple pixels P. The filter 80 may be arranged for, for example, two, three, or four or more adjacent pixels P.

[0156] In the pixel section 100 of the imaging device 1, for example, filters 80 are provided for two or four pixels P, and one filter 80 is shared by two or four adjacent pixels P. In the examples shown in Figures 36 and 37, some of the filters 80b are provided for two adjacent pixels P in the X-axis direction. Also, in the example shown in Figure 36, filter 80d is provided for four adjacent pixels P in the X-axis and Y-axis directions.

[0157] (Modification 4) Figures 38 and 39 are diagrams illustrating an example of the configuration of an imaging device according to Modification 4. Figure 39 shows an example of a cross-sectional configuration in the direction of line A-A' shown in Figure 38. In the optical layer 102 of the imaging device 1, multiple filters 80 may be stacked. As an example, as shown in Figure 39, filter 80c is stacked on top of filter 80a or filter 80b.

[0158] Each pixel P of the imaging device 1 is provided with a broadband filter, which is constructed by stacking two types of filters 80, as shown in the examples in Figures 38 and 39. By configuring the imaging device 1 in this way, it is possible to realize an imaging device that can handle multiple transmission wavelength ranges while keeping the number of types of filters 80 to be arranged to a minimum. Note that the arrangement of the filters 80 in the imaging device 1 is not limited to the illustrated examples and can be changed as appropriate.

[0159] <2. Second Embodiment> Next, a second embodiment of the present disclosure will be described. The technology relating to the present disclosure is applicable to various electronic devices, optical devices, etc. The filters 50 and 80 described above are applicable to various optical elements (optical components). In the following, components similar to those in the above-described embodiment will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate.

[0160] Figure 40 is a diagram illustrating an example of the configuration of an optical element according to a second embodiment of the present disclosure. The optical element 300 includes, for example, a substrate 130 and a layer 120 including optical layers 102 and 101. The optical element 300 is configured as an optical filter capable of selectively transmitting light in multiple wavelength ranges. The optical element 300 may be configured as a multispectral filter. The optical element 300 may be configured, for example, as part of the optical system of various devices.

[0161] The substrate 130 is a light-transmitting substrate (transparent substrate), and is made of, for example, a glass substrate. The substrate 130 (base material) may be made of quartz glass, borosilicate glass, etc., or it may be made of a resin substrate. The substrate 130 may be made of other materials that transmit the light to be measured. As shown in Figure 40, the substrate 130 has opposing surfaces 13S1 and 13S2. Surface 13S2 is the surface opposite to surface 13S1.

[0162] The layer 120, which includes optical layers 102 and 101, is provided, for example, on the side of the substrate 130 where light is incident. In the example shown in Figure 40, an optical layer 101 containing a plurality of filters 50 (filters 50a and 50b in Figure 40) is formed on the surface 13S1 of the substrate 130. An optical layer 102 containing a plurality of filters 80 (filters 80a to 80d in Figure 40) is provided on the optical layer 101. The filters 50 have a periodic structure and are configured as narrowband filters.

[0163] The layer 120 may be provided on the side of the substrate 130 opposite to the side where light is incident (i.e., the side where light is emitted). The layer 120 may be laminated on the substrate 130 via an insulating layer on either the light incident side or the light emission side of the substrate 130. The shape of the substrate 130 is not particularly limited and may be circular, rectangular, or any other shape. Furthermore, the configurations of the filters 50 and 80 can be modified as appropriate, as in the first embodiment.

[0164] The optical element 300 according to this embodiment includes a filter 50 and a plurality of filters 80 arranged adjacent to each other above the filter 50. The filter 50, which acts as a narrowband filter, is provided between the filter 80, which acts as a wideband filter, and the substrate 130. By configuring it in this way, the optical characteristics of the filter can be improved. This makes it possible to realize an optical element capable of improving optical characteristics.

[0165] [Function and Effects] The optical element according to this embodiment comprises a substrate (substrate 130), a narrowband filter (for example, filter 50a) provided above the substrate, and a first filter and a second filter (for example, filters 80a, 80b) provided adjacent to each other above the narrowband filter.

[0166] The optical element (optical element 300) according to this embodiment comprises a filter 50a provided above the substrate 130 and a plurality of filters 80 provided adjacent to each other above the filter 50. This makes it possible to realize an optical element capable of improving optical characteristics.

[0167] <3. Examples of Application> The above-described imaging device 1 can be applied to any type of electronic device equipped with an imaging function, such as camera systems like digital still cameras and video cameras, or mobile phones with imaging capabilities. Figure 41 shows a schematic configuration of the electronic device 1000.

[0168] The electronic device 1000 includes, for example, a lens group 1001, an imaging device 1, a DSP (Digital Signal Processor) circuit 1002, a frame memory 1003, a display unit 1004, a recording unit 1005, an operation unit 1006, and a power supply unit 1007, all of which are interconnected via a bus line 1008.

[0169] The lens group 1001 captures incident light (image light) from the subject and forms an image on the imaging surface of the imaging device 1. The imaging device 1 converts the amount of incident light formed on the imaging surface by the lens group 1001 into an electrical signal on a pixel-by-pixel basis and supplies it as a pixel signal to the DSP circuit 1002.

[0170] The DSP circuit 1002 is a signal processing circuit that processes signals supplied from the imaging device 1. The DSP circuit 1002 outputs image data obtained by processing the signals from the imaging device 1. The frame memory 1003 temporarily holds the image data processed by the DSP circuit 1002 in frame units.

[0171] The display unit 1004 consists of, for example, a panel-type display device such as a liquid crystal panel or an organic EL (Electro Luminescence) panel, and records the video or still image data captured by the imaging device 1 onto a recording medium such as a semiconductor memory or a hard disk.

[0172] The operation unit 1006 outputs operation signals for various functions possessed by the electronic device 1000 in accordance with user operations. The power supply unit 1007 appropriately supplies various power sources to the DSP circuit 1002, frame memory 1003, display unit 1004, recording unit 1005, and operation unit 1006.

[0173] <4. Application Examples> (Application Examples to Mobile Devices) The technology relating to this disclosure (this technology) can be applied to various products. For example, the technology relating to this disclosure may be implemented as a device mounted on any type of mobile device such as automobiles, electric vehicles, hybrid electric vehicles, motorcycles, bicycles, personal mobility devices, airplanes, drones, ships, and robots.

[0174] Figure 42 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a mobile control system to which the technology described herein may be applied.

[0175] The vehicle control system 12000 comprises a plurality of electronic control units connected via a communication network 12001. In the example shown in Figure 42, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an external information detection unit 12030, an internal information detection unit 12040, and an integrated control unit 12050. The functional configuration of the integrated control unit 12050 is shown in the figure, which includes a microcomputer 12051, an audio / image output unit 12052, and an in-vehicle network interface 12053.

[0176] The drivetrain control unit 12010 controls the operation of devices related to the vehicle's drivetrain according to various programs. For example, the drivetrain control unit 12010 functions as a control device for a drivetrain generating device that generates driving force for the vehicle, such as an internal combustion engine or a drive motor; a drivetrain transmission mechanism that transmits driving force to the wheels; a steering mechanism that adjusts the steering angle of the vehicle; and a braking device that generates braking force for the vehicle.

[0177] The body system control unit 12020 controls the operation of various devices mounted on the vehicle body according to various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window system, or various lamps such as headlights, reverse lights, brake lights, turn signals, or fog lights. In this case, the body system control unit 12020 may receive radio waves transmitted from a portable device that replaces a key or signals from various switches. The body system control unit 12020 receives these radio waves or signals and controls the vehicle's door lock system, power window system, lamps, etc.

[0178] The external information detection unit 12030 detects information from outside the vehicle equipped with the vehicle control system 12000. For example, an imaging unit 12031 is connected to the external information detection unit 12030. The external information detection unit 12030 causes the imaging unit 12031 to capture images of the outside of the vehicle and receives the captured images. Based on the received images, the external information detection unit 12030 may perform object detection processing such as detecting people, cars, obstacles, signs, or characters on the road surface, or distance detection processing.

[0179] The imaging unit 12031 is a light sensor that receives light and outputs an electrical signal corresponding to the amount of light received. The imaging unit 12031 can output the electrical signal as an image or as distance measurement information. The light received by the imaging unit 12031 may be visible light or invisible light such as infrared light.

[0180] The in-vehicle information detection unit 12040 detects information inside the vehicle. The in-vehicle information detection unit 12040 is connected to, for example, a driver status detection unit 12041 that detects the driver's state. The driver status detection unit 12041 includes, for example, a camera that captures images of the driver, and the in-vehicle information detection unit 12040 may calculate the driver's level of fatigue or concentration, or determine whether the driver is drowsy, based on the detection information input from the driver status detection unit 12041.

[0181] The microcomputer 12051 can calculate control target values ​​for the drive force generator, steering mechanism, or braking device based on information inside and outside the vehicle acquired by the external information detection unit 12030 or the internal information detection unit 12040, and output control commands to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing ADAS (Advanced Driver Assistance System) functions, including collision avoidance or impact mitigation, following driving based on distance between vehicles, maintaining vehicle speed, vehicle collision warning, or vehicle lane departure warning.

[0182] Furthermore, the microcomputer 12051 can perform cooperative control for purposes such as autonomous driving, where the vehicle drives autonomously without driver intervention, by controlling the drive force generating device, steering mechanism, or braking device, etc., based on information about the vehicle's surroundings acquired by the external information detection unit 12030 or the internal information detection unit 12040.

[0183] Furthermore, the microcomputer 12051 can output control commands to the body system control unit 12020 based on external information acquired by the external information detection unit 12030. For example, the microcomputer 12051 can control the headlights according to the position of a preceding or oncoming vehicle detected by the external information detection unit 12030, and perform coordinated control aimed at reducing glare, such as switching from high beams to low beams.

[0184] The audio-image output unit 12052 transmits at least one of audio and image output signals to an output device capable of visually or audibly notifying information to the vehicle's occupants or to those outside the vehicle. In the example shown in Figure 42, the output devices include an audio speaker 12061, a display unit 12062, and an instrument panel 12063. The display unit 12062 may include, for example, at least one of an onboard display and a head-up display.

[0185] Figure 43 shows an example of the installation position of the imaging unit 12031.

[0186] In Figure 43, the imaging unit 12031 includes imaging units 12101, 12102, 12103, 12104, and 12105.

[0187] The imaging units 12101, 12102, 12103, 12104, and 12105 are installed, for example, on the front nose, side mirrors, rear bumper, back door, and the upper part of the windshield inside the vehicle 12100. The imaging unit 12101 installed on the front nose and the imaging unit 12105 installed on the upper part of the windshield inside the vehicle mainly acquire images of the front of the vehicle 12100. The imaging units 12102 and 12103 installed on the side mirrors mainly acquire images of the sides of the vehicle 12100. The imaging unit 12104 installed on the rear bumper or back door mainly acquires images of the rear of the vehicle 12100. The imaging unit 12105 installed on the upper part of the windshield inside the vehicle is mainly used for detecting preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, or lanes.

[0188] Figure 43 shows an example of the imaging range of imaging units 12101 to 12104. Imaging range 12111 indicates the imaging range of imaging unit 12101 located on the front nose, imaging ranges 12112 and 12113 indicate the imaging ranges of imaging units 12102 and 12103 located on the side mirrors, respectively, and imaging range 12114 indicates the imaging range of imaging unit 12104 located on the rear bumper or back door. For example, by superimposing the image data captured by imaging units 12101 to 12104, an overhead view image of the vehicle 12100 can be obtained.

[0189] At least one of the imaging units 12101 to 12104 may have a function for acquiring distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera consisting of multiple image sensors, or an image sensor having pixels for phase difference detection.

[0190] For example, the microcomputer 12051, based on distance information obtained from the imaging units 12101 to 12104, can determine the distance to each object within the imaging range 12111 to 12114 and the temporal change of this distance (relative speed to the vehicle 12100). In particular, it can extract the closest object on the vehicle 12100's path that is traveling in approximately the same direction as the vehicle 12100 at a predetermined speed (e.g., 0 km / h or more) as the preceding vehicle. Furthermore, the microcomputer 12051 can set a predetermined distance to be maintained before the preceding vehicle and perform automatic braking control (including follow-and-stop control) and automatic acceleration control (including follow-and-start control), etc. In this way, cooperative control aimed at autonomous driving, where the vehicle drives autonomously without driver intervention, can be performed.

[0191] For example, the microcomputer 12051 can use distance information obtained from imaging units 12101 to 12104 to classify and extract three-dimensional object data related to three-dimensional objects, such as motorcycles, passenger cars, large vehicles, pedestrians, utility poles, and other three-dimensional objects, and use this data for automatic obstacle avoidance. For example, the microcomputer 12051 identifies obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. The microcomputer 12051 then determines the collision risk, which indicates the degree of risk of collision with each obstacle. If the collision risk is above a set value and there is a possibility of collision, the microcomputer 12051 can provide driving assistance to avoid collisions by outputting a warning to the driver via the audio speaker 12061 or the display unit 12062, or by performing forced deceleration or evasive steering via the drive system control unit 12010.

[0192] At least one of the imaging units 12101 to 12104 may be an infrared camera that detects infrared light. For example, the microcomputer 12051 can recognize pedestrians by determining whether or not pedestrians are present in the images captured by the imaging units 12101 to 12104. Such pedestrian recognition is performed, for example, by a procedure to extract feature points from the images captured by the imaging units 12101 to 12104 as infrared cameras, and a procedure to perform pattern matching on a series of feature points that indicate the contour of an object to determine whether or not it is a pedestrian. When the microcomputer 12051 determines that a pedestrian is present in the images captured by the imaging units 12101 to 12104 and recognizes a pedestrian, the audio-image output unit 12052 controls the display unit 12062 to superimpose a rectangular contour line for emphasis on the recognized pedestrian. The audio-image output unit 12052 may also control the display unit 12062 to display an icon indicating a pedestrian at a desired position.

[0193] The above describes an example of a mobile control system to which the technology described herein can be applied. The technology described herein can be applied to, for example, the imaging unit 12031 of the configuration described above. Specifically, for example, the imaging device 1 can be applied to the imaging unit 12031. By applying the technology described herein to the imaging unit 12031, it becomes possible to obtain high-definition captured images. This makes it possible to perform high-precision control using captured images in the mobile control system.

[0194] (Examples of application to endoscopic surgical systems) The technology disclosed herein (this technology) can be applied to various products. For example, the technology disclosed herein may be applied to endoscopic surgical systems.

[0195] Figure 44 is a diagram showing an example of a schematic configuration of an endoscopic surgical system to which the technology described herein (the technology) may be applied.

[0196] Figure 44 illustrates a surgeon (physician) 11131 performing surgery on a patient 11132 on a patient bed 11133 using an endoscopic surgical system 11000. As shown in the figure, the endoscopic surgical system 11000 consists of an endoscope 11100, other surgical instruments 11110 such as a pneumoperitoneum tube 11111 and an energy treatment device 11112, a support arm device 11120 for supporting the endoscope 11100, and a cart 11200 equipped with various devices for endoscopic surgery.

[0197] The endoscope 11100 consists of a barrel 11101, the tip of which is inserted into the body cavity of the patient 11132 for a predetermined length, and a camera head 11102 connected to the base end of the barrel 11101. In the illustrated example, the endoscope 11100 is shown as a so-called rigid endoscope having a rigid barrel 11101, but the endoscope 11100 may also be configured as a so-called flexible endoscope having a flexible barrel.

[0198] An opening into which an objective lens is fitted is provided at the tip of the microscope tube 11101. A light source device 11203 is connected to the endoscope 11100, and the light generated by the light source device 11203 is guided to the tip of the microscope tube by a light guide extending inside the microscope tube 11101, and is irradiated through the objective lens towards the object to be observed inside the body cavity of the patient 11132. The endoscope 11100 may be a straight-viewing endoscope, an oblique-viewing endoscope, or a side-viewing endoscope.

[0199] The camera head 11102 contains an optical system and an image sensor. Reflected light from the object being observed (observation light) is focused onto the image sensor by the optical system. The image sensor converts the observation light into electrical signals, generating an electrical signal corresponding to the observation light, i.e., an image signal corresponding to the observed image. This image signal is transmitted as RAW data to the camera control unit (CCU) 11201.

[0200] The CCU 11201 is composed of a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), and other components, and comprehensively controls the operation of the endoscope 11100 and the display device 11202. Furthermore, the CCU 11201 receives an image signal from the camera head 11102 and performs various image processing operations on that image signal, such as development processing (demosaic processing), to display the image based on that image signal.

[0201] The display device 11202 displays an image based on an image signal that has been processed by the CCU 11201, under control from the CCU 11201.

[0202] The light source device 11203 consists of a light source such as an LED (Light Emitting Diode) and supplies illumination light to the endoscope 11100 when photographing the surgical area, etc.

[0203] The input device 11204 is an input interface for the endoscopic surgical system 11000. The user can input various types of information and instructions to the endoscopic surgical system 11000 via the input device 11204. For example, the user can input instructions to change the imaging conditions (type of light, magnification, focal length, etc.) of the endoscope 11100.

[0204] The treatment instrument control device 11205 controls the drive of the energy treatment instrument 11112 for purposes such as tissue cauterization, incision, or blood vessel sealing. The insufflation device 11206 injects gas into the body cavity of the patient 11132 via the insufflation tube 11111 to inflate the body cavity for the purpose of securing a field of view by the endoscope 11100 and securing the operator's workspace. The recorder 11207 is a device capable of recording various information related to the surgery. The printer 11208 is a device capable of printing various information related to the surgery in various formats such as text, images, or graphs.

[0205] The light source device 11203 that supplies illumination light to the endoscope 11100 when photographing the surgical area can be configured as a white light source consisting of, for example, an LED, a laser light source, or a combination thereof. When the white light source is configured as a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high precision, so the white balance of the captured image can be adjusted in the light source device 11203. In this case, it is also possible to capture images corresponding to each of the RGB colors in time-division by irradiating the observation target with laser light from each of the RGB laser light sources in time-division and controlling the drive of the image sensor of the camera head 11102 in synchronization with the irradiation timing. According to this method, a color image can be obtained without providing a color filter on the image sensor.

[0206] Furthermore, the light source device 11203 may be controlled to change the intensity of the light it outputs at predetermined time intervals. By controlling the drive of the image sensor of the camera head 11102 in synchronization with the timing of the change in light intensity, images can be acquired in time-division order, and these images can be combined to generate high dynamic range images without so-called black crushing and white clipping.

[0207] Furthermore, the light source device 11203 may be configured to supply light in a predetermined wavelength band corresponding to special light observation. In special light observation, for example, by utilizing the wavelength dependence of light absorption in body tissue and irradiating with narrow-band light compared to the irradiation light used in normal observation (i.e., white light), so-called narrow-band imaging is performed to image predetermined tissues such as blood vessels on the surface of mucosa with high contrast. Alternatively, in special light observation, fluorescence observation may be performed to obtain an image from fluorescence generated by irradiation with excitation light. In fluorescence observation, excitation light is irradiated onto body tissue and fluorescence from the body tissue is observed (autofluorescence observation), or a reagent such as indocyanine green (ICG) is injected into body tissue and excitation light corresponding to the fluorescence wavelength of the reagent is irradiated onto the body tissue to obtain a fluorescence image. The light source device 11203 may be configured to supply narrow-band light and / or excitation light corresponding to such special light observation.

[0208] Figure 45 is a block diagram showing an example of the functional configuration of the camera head 11102 and CCU 11201 shown in Figure 44.

[0209] The camera head 11102 includes a lens unit 11401, an imaging unit 11402, a drive unit 11403, a communication unit 11404, and a camera head control unit 11405. The CCU 11201 includes a communication unit 11411, an image processing unit 11412, and a control unit 11413. The camera head 11102 and the CCU 11201 are connected to each other via a transmission cable 11400 so that they can communicate with each other.

[0210] The lens unit 11401 is an optical system provided at the connection point with the lens barrel 11101. Observation light taken in from the tip of the lens barrel 11101 is guided to the camera head 11102 and then incident on the lens unit 11401. The lens unit 11401 is composed of a combination of multiple lenses, including a zoom lens and a focus lens.

[0211] The imaging unit 11402 is composed of image sensors. The imaging unit 11402 may consist of one image sensor (a so-called single-chip type) or multiple image sensors (a so-called multi-chip type). If the imaging unit 11402 is composed of multiple chips, for example, each image sensor may generate image signals corresponding to RGB, and these may be combined to obtain a color image. Alternatively, the imaging unit 11402 may be configured to have a pair of image sensors for acquiring image signals for the right eye and left eye, respectively, corresponding to 3D (Dimensional) display. By performing 3D display, the surgeon 11131 can more accurately grasp the depth of the biological tissue in the surgical area. In addition, if the imaging unit 11402 is composed of multiple chips, multiple lens units 11401 may also be provided corresponding to each image sensor.

[0212] Furthermore, the imaging unit 11402 does not necessarily have to be located on the camera head 11102. For example, the imaging unit 11402 may be located inside the lens barrel 11101, directly behind the objective lens.

[0213] The drive unit 11403 is composed of actuators and, under control from the camera head control unit 11405, moves the zoom lens and focus lens of the lens unit 11401 along the optical axis by a predetermined distance. This allows the magnification and focus of the image captured by the imaging unit 11402 to be adjusted as appropriate.

[0214] The communication unit 11404 is composed of communication devices for sending and receiving various types of information with the CCU 11201. The communication unit 11404 transmits the image signal obtained from the imaging unit 11402 as RAW data to the CCU 11201 via the transmission cable 11400.

[0215] Furthermore, the communication unit 11404 receives a control signal from the CCU 11201 to control the drive of the camera head 11102 and supplies it to the camera head control unit 11405. The control signal includes information about imaging conditions, such as information to specify the frame rate of the captured image, information to specify the exposure value at the time of imaging, and / or information to specify the magnification and focus of the captured image.

[0216] The imaging conditions such as frame rate, exposure value, magnification, and focus may be specified by the user as appropriate, or they may be automatically set by the control unit 11413 of the CCU 11201 based on the acquired image signal. In the latter case, the endoscope 11100 will be equipped with so-called AE (Auto Exposure), AF (Auto Focus), and AWB (Auto White Balance) functions.

[0217] The camera head control unit 11405 controls the drive of the camera head 11102 based on the control signal received from the CCU 11201 via the communication unit 11404.

[0218] The communication unit 11411 is comprised of a communication device for sending and receiving various types of information with the camera head 11102. The communication unit 11411 receives image signals transmitted from the camera head 11102 via the transmission cable 11400.

[0219] Furthermore, the communication unit 11411 transmits control signals to the camera head 11102 to control the driving of the camera head 11102. Image signals and control signals can be transmitted by telecommunications, optical communications, etc.

[0220] The image processing unit 11412 performs various image processing operations on the image signal, which is RAW data transmitted from the camera head 11102.

[0221] The control unit 11413 performs various controls related to imaging the surgical area, etc., by the endoscope 11100, and the display of the images obtained from imaging the surgical area, etc. For example, the control unit 11413 generates a control signal to control the driving of the camera head 11102.

[0222] Furthermore, the control unit 11413 displays the captured image showing the surgical area, etc., on the display device 11202 based on the image signal processed by the image processing unit 11412. At this time, the control unit 11413 may recognize various objects in the captured image using various image recognition technologies. For example, the control unit 11413 can recognize surgical instruments such as forceps, specific biological sites, bleeding, mist when using the energy treatment device 11112, etc., by detecting the shape and color of the edges of objects included in the captured image. When the control unit 11413 displays the captured image on the display device 11202, it may use the recognition results to superimpose various surgical support information onto the image of the surgical area. By superimposing the surgical support information and presenting it to the surgeon 11131, the burden on the surgeon 11131 can be reduced, and the surgeon 11131 can proceed with the surgery reliably.

[0223] The transmission cable 11400 connecting the camera head 11102 and the CCU 11201 is an electrical signal cable compatible with electrical signal communication, an optical fiber compatible with optical communication, or a composite cable thereof.

[0224] In the illustrated example, communication was performed via a wired connection using a transmission cable 11400, but communication between the camera head 11102 and the CCU 11201 may be performed wirelessly.

[0225] The above describes an example of an endoscopic surgical system to which the technology described herein may be applied. The technology described herein can be suitably applied, for example, to the imaging unit 11402 provided on the camera head 11102 of the endoscope 11100. By applying the technology described herein to the imaging unit 11402, it becomes possible to provide a high-definition endoscope 11100.

[0226] Although the present disclosure has been described above with reference to embodiments, modifications, application examples, and application examples, the present technology is not limited to the above embodiments, and various modifications are possible. For example, although the above modifications were described as modifications of the above embodiments, the configurations of each modification can be combined as appropriate.

[0227] In the embodiments described above, an imaging device was used as an example; however, the light detection device of this disclosure may be any device that receives incident light and converts the light into an electric charge. The output signal may be an image information signal or a distance measurement information signal. The light detection device (imaging device) can be applied to an image sensor, a distance measurement sensor, etc. Furthermore, this disclosure is not limited to back-illuminated image sensors, but is also applicable to front-illuminated image sensors.

[0228] The light detection device according to this disclosure can also be used as a distance measuring sensor capable of measuring distance using the TOF (Time Of Flight) method. The light-receiving element (photoelectric conversion unit) of each pixel may be an APD (Avalanche Photo Diode). The light-receiving element may be composed of, for example, a SPAD (Single Photon Avalanche Diode). The light detection device (imaging device) can also be used as a sensor capable of detecting events, for example, an event-driven sensor (also called an EVS (Event Vision Sensor), EDS (Event Driven Sensor), DVS (Dynamic Vision Sensor), etc.).

[0229] An optical detection device according to one embodiment of the present disclosure comprises a first layer having a first photodetector and a second photodetector, a second layer having a first filter and provided above the first layer, and a first narrowband filter provided between the first layer and the second layer for the first and second photodetectors. This makes it possible to realize an optical detection device capable of improving optical characteristics.

[0230] An optical element according to one embodiment of the present disclosure comprises a substrate, a narrowband filter provided above the substrate, and a first filter and a second filter provided adjacent to each other above the narrowband filter. This makes it possible to realize an optical element capable of improving optical characteristics.

[0231] The effects described herein are merely illustrative and not limited to those described herein; other effects may also exist. Furthermore, this disclosure may also take the following configurations: (1) A photodetector comprising: a first layer having a first photodetector and a second photodetector; a second layer having a first filter and provided above the first layer; and a first narrowband filter provided between the first layer and the second layer for the first photodetector and the second photodetector. (2) The photodetector according to (1) wherein the first narrowband filter has a periodic structure. (3) The photodetector according to (1) or (2) wherein the first narrowband filter has a plurality of structures arranged in a direction perpendicular to the stacking direction of the first layer and the second layer. (4) The photodetector according to any one of (1) to (3) wherein the first narrowband filter is provided between the first layer and the second layer so as to cover the first photodetector and the second photodetector. (5) The photodetector according to any one of (1) to (4), comprising a first pixel including the first photodetector and a second pixel including the second photodetector, wherein the first narrowband filter has a plurality of structures, and at least a portion of the plurality of structures is provided at the boundary between the first pixel and the second pixel. (6) The photodetector according to any one of (1) to (5), wherein the first filter is a broadband filter, the first narrowband filter is capable of transmitting light in at least a first wavelength band, and the first photodetector receives light in the first wavelength band via the first filter and the first narrowband filter. (7) The photodetector according to any one of (1) to (6), wherein the first narrowband filter has a transmission wavelength band narrower than the transmission wavelength band of the first filter.(8) The photodetector according to any one of (1) to (7), wherein the second layer has a first filter that can transmit light in a band including a first wavelength band and a second filter that can transmit light in a band including a second wavelength band, the first narrowband filter is capable of transmitting light in the first wavelength band and light in the second wavelength band, the first photodetector receives light in the first wavelength band via the first filter and the first narrowband filter, and the second photodetector receives light in the second wavelength band via the second filter and the first narrowband filter. (9) The photodetector according to any one of (1) to (8), wherein the first layer has a third photodetector, and the first narrowband filter is provided between the first layer and the second layer for the first photodetector, the second photodetector, and the third photodetector. (10) The photodetector according to any one of (1) to (9), wherein the first layer has a third photodetector, and the first filter is provided for the second and third photodetectors. (11) The photodetector according to any one of (1) to (10), further comprising a third filter provided stacked with the first filter. (12) The photodetector according to any one of (1) to (11), wherein the first narrowband filter is a Fabry-Perot filter, a GMR (Guided Mode Resonance) filter, or a plasmon filter. (13) The photodetector according to any one of (1) to (12), wherein the first narrowband filter has a first reflective layer, a second reflective layer, and an intermediate layer provided between the first and second reflective layers, and the intermediate layer includes a structure and a member having a refractive index different from that of the structure. (14) The light detection device according to (13), comprising a first pixel including the first light-receiving element and a second pixel including the second light-receiving element, wherein the intermediate layer has a plurality of the structures, and at least a portion of the plurality of structures is provided in the intermediate layer at the boundary between the first pixel and the second pixel.(15) The photodetector according to (13) or (14), further comprising a first pixel including the first photodetector and a second pixel including the second photodetector, wherein the thickness of the intermediate layer in the first pixel is different from the thickness of the intermediate layer in the second pixel. (16) The photodetector according to any one of (1) to (15), further comprising a second narrowband filter, wherein the first layer has a third photodetector and a fourth photodetector, and the second narrowband filter is provided between the first layer and the second layer for the third photodetector and the fourth photodetector. (17) The photodetector according to any one of (1) to (16), wherein the first filter is a Fabry-Perot filter, a GMR (Guided Mode Resonance) filter, or a plasmon filter. (18) An optical element comprising a substrate, a narrowband filter provided above the substrate, and a first filter and a second filter provided adjacent to each other above the narrowband filter. (19) The optical element according to (18), wherein the narrowband filter has a periodic structure. (20) An electronic device comprising an optical system and a light detection device for receiving light transmitted through the optical system, wherein the light detection device comprises a first layer having a first light-receiving element and a second light-receiving element, a second layer having a first filter and provided above the first layer, and a first narrowband filter provided between the first layer and the second layer for the first light-receiving element and the second light-receiving element.

[0232] This application claims priority based on Japanese Patent Application No. 2024-212367, filed with the Japan Patent Office on December 5, 2024, and all contents of that application are incorporated herein by reference.

[0233] Those skilled in the art will understand that various modifications, combinations, subcombinations, and changes can be conceived depending on design requirements and other factors, and that these fall within the scope of the attached claims and their equivalents.

Claims

1. A photodetector comprising: a first layer having a first photodetector and a second photodetector; a second layer having a first filter and provided above the first layer; and a first narrowband filter provided between the first layer and the second layer for the first photodetector and the second photodetector.

2. The photodetector according to claim 1, wherein the first narrowband filter has a periodic structure.

3. The photodetector according to claim 1, wherein the first narrowband filter has a plurality of structures arranged in a direction perpendicular to the stacking direction of the first layer and the second layer.

4. The photodetector according to claim 1, wherein the first narrowband filter is provided between the first layer and the second layer so as to cover the first photodetector and the second photodetector.

5. The photodetector according to claim 1, comprising a first pixel including the first photodetector and a second pixel including the second photodetector, wherein the first narrowband filter has a plurality of structures, and at least a portion of the plurality of structures is provided at the boundary between the first pixel and the second pixel.

6. The photodetector according to claim 1, wherein the first filter is a broadband filter, the first narrowband filter is capable of transmitting light in at least a first wavelength band, and the first photodetector receives light in the first wavelength band via the first filter and the first narrowband filter.

7. The photodetector according to claim 1, wherein the first narrowband filter has a transmission wavelength band narrower than the transmission wavelength band of the first filter.

8. The photodetector according to claim 1, wherein the second layer has a first filter that can transmit light in a band including a first wavelength band and a second filter that can transmit light in a band including a second wavelength band, the first narrowband filter is capable of transmitting light in the first wavelength band and light in the second wavelength band, the first photodetector receives light in the first wavelength band via the first filter and the first narrowband filter, and the second photodetector receives light in the second wavelength band via the second filter and the first narrowband filter.

9. The photodetector according to claim 1, wherein the first layer has a third photodetector, and the first narrowband filter is provided between the first layer and the second layer with respect to the first photodetector, the second photodetector, and the third photodetector.

10. The photodetector according to claim 1, wherein the first layer has a third photodetector, and the first filter is provided for the second photodetector and the third photodetector.

11. The photodetector according to claim 1, further comprising a third filter provided in stacked with the first filter.

12. The photodetector according to claim 1, wherein the first narrowband filter is a Fabry-Perot filter, a GMR (Guided Mode Resonance) filter, or a plasmon filter.

13. The photodetector according to claim 1, wherein the first narrowband filter comprises a first reflective layer and a second reflective layer and an intermediate layer provided between the first reflective layer and the second reflective layer, and the intermediate layer comprises a structure and a member having a refractive index different from that of the structure.

14. The light detection device according to claim 13, comprising a first pixel including the first light-receiving element and a second pixel including the second light-receiving element, wherein the intermediate layer has a plurality of the structures, and at least a portion of the plurality of structures is provided in the intermediate layer at the boundary between the first pixel and the second pixel.

15. The light detection device according to claim 13, comprising a first pixel including the first light-receiving element and a second pixel including the second light-receiving element, wherein the thickness of the intermediate layer in the first pixel is different from the thickness of the intermediate layer in the second pixel.

16. The photodetector according to claim 1, further comprising a second narrowband filter, wherein the first layer has a third photodetector and a fourth photodetector, and the second narrowband filter is provided between the first layer and the second layer with respect to the third photodetector and the fourth photodetector.

17. The photodetector according to claim 1, wherein the first filter is a Fabry-Perot filter, a GMR (Guided Mode Resonance) filter, or a plasmon filter.

18. An optical element comprising a substrate, a narrowband filter provided above the substrate, and a first filter and a second filter provided adjacent to each other above the narrowband filter.

19. The optical element according to claim 18, wherein the narrowband filter has a periodic structure.

20. An electronic device comprising an optical system and a light detection device for receiving light transmitted through the optical system, wherein the light detection device comprises a first layer having a first light-receiving element and a second light-receiving element, a second layer having a first filter and provided above the first layer, and a first narrow-band filter provided between the first layer and the second layer for the first light-receiving element and the second light-receiving element.

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