Photodetector, electronic apparatus, and optical element

Abstract

To provide a photodetector having good detection performance.SOLUTION: A photodetector according to an embodiment of the present disclosure comprises: a light guide unit that has a structure including a first portion having a size equal to or less than the wavelength of incident light and a second portion provided under the first portion, a first medium provided adjacent to the first portion and having a refractive index different from the refractive index of the structure, and a second medium provided adjacent to the second portion and having a refractive index different from the refractive index of the structure; and a photoelectric conversion unit that photoelectrically converts light incident through the light guide unit. The first portion is in contact with the second portion.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to light detection devices, electronic devices, and optical elements. [Background technology]

[0002] A meta-optical element including a plurality of nanostructures and a surrounding substance having a refractive index different from that of the nanostructures has been proposed (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2021-140152 A Summary of the Invention

[0004] In devices that detect light, it is desirable to improve detection performance.

[0005] It is desirable to provide a light detection device that has good detection performance.

[0006] A photodetector according to an embodiment of the present disclosure includes a structure including a first portion having a size equal to or smaller than the wavelength of incident light and a second portion provided below the first portion, a light guide including a first medium provided adjacent to the first portion and having a refractive index different from that of the structure, and a second medium provided adjacent to the second portion and having a refractive index different from that of the structure, and a first photoelectric conversion portion that performs photoelectric conversion on light incident via the light guide. The first portion is in contact with the second portion. An electronic device according to an embodiment of the present disclosure includes an optical system and a photodetector that receives light transmitted through the optical system. The photodetector includes a structure including a first portion having a size equal to or smaller than the wavelength of incident light and a second portion provided below the first portion, a light guide having a first medium provided next to the first portion and having a refractive index different from that of the structure, and a second medium provided next to the second portion and having a refractive index different from that of the structure, and a photoelectric conversion unit that photoelectrically converts light incident through the light guide. The first portion is in contact with the second portion. An optical element according to an embodiment of the present disclosure includes a structure including a first portion having a size equal to or smaller than the wavelength of incident light and a second portion provided below the first portion, a first medium provided adjacent to the first portion and having a refractive index different from that of the structure, and a second medium provided adjacent to the second portion and having a refractive index different from that of the structure. The first portion is in contact with the second portion. [Brief description of the drawings]

[0007] [Figure 1] 1 is a block diagram showing an example of a schematic configuration of an imaging device which is an example of a light detection device according to an embodiment of the present disclosure. [Diagram 2] 1 is a diagram illustrating an example of a pixel arrangement of an imaging device according to an embodiment of the present disclosure. [Diagram 3] 1 is a diagram illustrating an example of a cross-sectional configuration of an imaging device according to an embodiment of the present disclosure. [Figure 4A] FIG. 1 is a diagram illustrating an example of a planar configuration of an imaging device according to an embodiment of the present disclosure. [Figure 4B] FIG. 1 is a diagram illustrating an example of a planar configuration of an imaging device according to an embodiment of the present disclosure. [Figure 4C] FIG. 1 is a diagram illustrating an example of a planar configuration of an imaging device according to an embodiment of the present disclosure. [Diagram 5] 1 is a diagram illustrating an example of a cross-sectional configuration of an imaging device according to an embodiment of the present disclosure. [Figure 6] FIG. 1 is a diagram illustrating an example of a planar configuration of an imaging device according to an embodiment of the present disclosure. [Figure 7A]10A to 10C are diagrams illustrating an example of a method for manufacturing a light guiding section of an imaging device according to an embodiment of the present disclosure. [Figure 7B] 10A to 10C are diagrams illustrating an example of a method for manufacturing a light guiding section of an imaging device according to an embodiment of the present disclosure. [Figure 7C] 10A to 10C are diagrams illustrating an example of a method for manufacturing a light guiding section of an imaging device according to an embodiment of the present disclosure. [Figure 7D] 10A to 10C are diagrams illustrating an example of a method for manufacturing a light guiding section of an imaging device according to an embodiment of the present disclosure. [Figure 7E] 10A to 10C are diagrams illustrating an example of a method for manufacturing a light guiding section of an imaging device according to an embodiment of the present disclosure. [Figure 7F] 10A to 10C are diagrams illustrating an example of a method for manufacturing a light guiding section of an imaging device according to an embodiment of the present disclosure. [Figure 7G] 10A to 10C are diagrams illustrating an example of a method for manufacturing a light guiding section of an imaging device according to an embodiment of the present disclosure. [Figure 7H] 10A to 10C are diagrams illustrating an example of a method for manufacturing a light guiding section of an imaging device according to an embodiment of the present disclosure. [Figure 7I] 10A to 10C are diagrams illustrating an example of a method for manufacturing a light guiding section of an imaging device according to an embodiment of the present disclosure. [Figure 8] 11 is a diagram illustrating an example of a cross-sectional configuration of a light guiding section of an imaging device according to a first modified example of the present disclosure. FIG. [Figure 9] 11 is a diagram illustrating an example of a cross-sectional configuration of a light guiding section of an imaging device according to a first modified example of the present disclosure. FIG. [Figure 10] 10 is a diagram for explaining an example of a planar configuration of a light guiding section of an imaging device according to Modification 1 of the present disclosure. FIG. [Figure 11A] 13 is a diagram illustrating another example of a cross-sectional configuration of a light guiding section of an imaging device according to Modification 1 of the present disclosure. FIG. [Figure 11B] 13 is a diagram illustrating another example of a cross-sectional configuration of a light guiding section of an imaging device according to Modification 1 of the present disclosure. FIG. [Figure 12A] 13 is a diagram illustrating another example of a cross-sectional configuration of a light guiding section of an imaging device according to Modification 1 of the present disclosure. FIG. [Figure 12B] 13 is a diagram illustrating another example of a cross-sectional configuration of a light guiding section of an imaging device according to Modification 1 of the present disclosure. FIG. [Figure 13A]11 is a diagram illustrating an example of a cross-sectional configuration of a light guiding section of an imaging device according to a second modified example of the present disclosure. FIG. [Figure 13B] 13 is a diagram illustrating another example of a cross-sectional configuration of a light guiding section of an imaging device according to Modification 2 of the present disclosure. FIG. [Figure 14] 13 is a diagram illustrating another example of a cross-sectional configuration of a light guiding section of an imaging device according to Modification 2 of the present disclosure. FIG. [Figure 15] 13 is a diagram illustrating an example of a cross-sectional configuration of a light guiding section of an imaging device according to a third modified example of the present disclosure. FIG. [Figure 16] 13 is a diagram illustrating another example of a cross-sectional configuration of a light guiding section of an imaging device according to Modification 3 of the present disclosure. FIG. [Figure 17] 13 is a diagram for explaining an example of a planar configuration of a light guiding section of an imaging device according to a third modified example of the present disclosure. FIG. [Figure 18] 13 is a diagram illustrating an example of a cross-sectional configuration of an imaging device according to a fourth modified example of the present disclosure. FIG. [Figure 19] FIG. 1 is a block diagram illustrating an example of the configuration of an electronic device having an imaging device. [Figure 20] 1 is a block diagram showing an example of a schematic configuration of a vehicle control system; [Figure 21] 4 is an explanatory diagram showing an example of the installation positions of an outside-vehicle information detection unit and an imaging unit; FIG. [Figure 22] 1 is a diagram illustrating an example of a schematic configuration of an endoscopic surgery system. [Diagram 23] 2 is a block diagram showing an example of a functional configuration of a camera head and a CCU. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be made in the following order. 1. Embodiment 2. Variations 3. Application Examples 4. Application Examples

[0009] <1. Preferred embodiment> 1 is a block diagram showing an example of a schematic configuration of an imaging device which is an example of a photodetection device according to an embodiment of the present disclosure. The photodetection device is a device capable of detecting incident light. The imaging device 1 which is a photodetection device can receive light transmitted through an optical system and generate a signal. The imaging device 1 (photodetection device) has a plurality of pixels P each having a photoelectric conversion unit, and is configured to perform photoelectric conversion of the incident light to generate a signal.

[0010] The photoelectric conversion unit of each pixel P of the imaging device 1 is, for example, a photodiode, and is configured to be capable of photoelectrically converting light. The imaging device 1 has an area (pixel unit 100) in which a plurality of pixels P are two-dimensionally arranged in a matrix as an imaging area. The pixel unit 100 is a pixel array in which a plurality of pixels P are arranged, and can also be called a light receiving area.

[0011] The imaging device 1 captures incident light (image light) from a subject through an optical system (not shown) including an optical lens. The imaging device 1 captures an image of the subject formed by the optical lens. The imaging device 1 can perform photoelectric conversion on the received light to generate a pixel signal. The imaging device 1 is, for example, a CMOS (Complementary Metal Oxide Semiconductor) image sensor. The imaging device 1 can be used in electronic devices such as digital still cameras, video cameras, and mobile phones.

[0012] 1, the imaging device 1 includes, for example, a pixel driving unit 111, a signal processing unit 112, a control unit 113, and a processing unit 114 in a peripheral region of a pixel unit 100 (pixel array). The imaging device 1 also includes a plurality of control lines L1 and a plurality of signal lines L2.

[0013] The imaging device 1 is provided with a control line L1, which is a signal line capable of transmitting a signal for controlling the pixel P. In the pixel section 100, for example, a plurality of control lines L1 are wired for each pixel row composed of a plurality of pixels P arranged in the horizontal direction (row direction). The control line L1 is configured to transmit a control signal for reading out a signal from the pixel P. The control line L1 can also be said to be a pixel drive line that transmits a signal for driving the pixel P.

[0014] The imaging device 1 is also provided with a signal line L2 capable of transmitting a signal from the pixel P. In the pixel section 100, for example, the signal line L2 is wired for each pixel column made up of a plurality of pixels P aligned in the vertical direction (column direction). The signal line L2 is a vertical signal line and is configured to transmit a signal output from the pixel P.

[0015] The pixel driving unit 111 is composed of a shift register, an address decoder, etc. The pixel driving unit 111 is configured to be able to drive each pixel P of the pixel unit 100. The pixel driving unit 111 generates a signal for controlling the pixel P, and outputs the signal to each pixel P of the pixel unit 100 via a control line L1.

[0016] The pixel driving unit 111 generates, for example, a signal for controlling a transfer transistor of the pixel P, a signal for controlling a reset transistor, etc., and supplies the signals to each pixel P via a control line L1. The pixel driving unit 111 can control reading out pixel signals from each pixel P. The pixel driving unit 111 can also be said to be a pixel control unit configured to be able to control each pixel P.

[0017] The signal processing unit 112 is configured to be able to execute signal processing of input pixel signals. The signal processing unit 112 has, for example, a load circuit unit, an AD (Analog Digital) conversion unit, a horizontal selection switch, and the like. A signal output from each pixel P selected and scanned by the pixel driving unit 111 is input to the signal processing unit 112 via a signal line L2. The signal processing unit 112 performs signal processing such as AD conversion of the pixel P signal and CDS (Correlated Double Sampling). The signal of each pixel P transmitted through each signal line L2 is subjected to signal processing by the signal processing unit 112 and output to the processing unit 114.

[0018] The processing unit 114 is configured to be able to execute signal processing on the input signal. The processing unit 114 is configured, for example, by a circuit that performs various types of signal processing on pixel signals. The processing unit 114 may include a processor and a memory. The processing unit 114 performs signal processing on pixel signals input from the signal processing unit 112, and outputs the processed pixel signals. The processing unit 114 can perform various types of signal processing, for example, noise reduction processing, tone correction processing, etc.

[0019] The control unit 113 is configured to be able to control each unit of the imaging device 1. The control unit 113 receives an externally provided clock, data instructing an operation mode, and the like, and can also output data such as internal information of the imaging device 1. The control unit 113 has a timing generator configured to be able to generate various timing signals. The control unit 113 controls the driving of peripheral circuits such as the pixel driving unit 111 and the signal processing unit 112 based on various timing signals (pulse signals, clock signals, and the like) generated by the timing generator. Note that the control unit 113 and the processing unit 114 may be configured integrally.

[0020] The pixel driving unit 111, the signal processing unit 112, the control unit 113, the processing unit 114, etc. may be provided on one semiconductor substrate, or may be provided separately on multiple semiconductor substrates. The imaging device 1 may have a structure (a stacked structure) formed by stacking multiple substrates.

[0021] 2 is a diagram showing an example of pixel arrangement of an imaging device according to an embodiment. A pixel P of the imaging device 1 has a color filter 25. The pixel P also has a light guide section 50 configured using a structure 30, which will be described later. As shown in FIG. 2, the incident direction of light from a subject is the Z-axis direction, the left-right direction on the paper perpendicular to the Z-axis direction is the X-axis direction, and the up-down direction on the paper perpendicular to the Z-axis and X-axis is the Y-axis direction. In the following figures, directions may be indicated based on the directions of the arrows in FIG. 2.

[0022] The color filter 25 is configured to selectively transmit light of a specific wavelength range among the incident light. The pixels P provided in the pixel section 100 of the imaging device 1 include a plurality of pixels Pr provided with a color filter 25 that transmits red (R) light, a plurality of pixels Pg provided with a color filter 25 that transmits green (G) light, and a plurality of pixels Pb provided with a color filter 25 that transmits blue (B) light.

[0023] In the pixel unit 100, a plurality of pixels Pr, a plurality of pixels Pg, and a plurality of pixels Pb are repeatedly arranged as shown in the example of Fig. 2. The pixels Pr, Pg, and Pb are arranged according to a Bayer array. The pixels Pr, Pg, and Pb generate pixel signals of R components, pixel signals of G components, and pixel signals of B components, respectively. The imaging device 1 can obtain pixel signals of RGB.

[0024] The color filter 25 provided in the pixel P of the pixel section 100 is not limited to a primary color (RGB) color filter, and may be a complementary color filter such as Cy (cyan), Mg (magenta), or Ye (yellow). The pixel P that receives white (W) light and performs photoelectric conversion may not have a color filter 25. A color filter corresponding to W (white), that is, a filter that transmits light of all wavelengths of incident light, may be disposed. The color filter 25 may be omitted as necessary. For example, depending on the characteristics of the light guide section 50, the color filter 25 may not be provided in some or all of the pixels P of the imaging device 1.

[0025] Fig. 3 is a diagram showing an example of a cross-sectional configuration of an imaging device according to an embodiment. Figs. 4A to 4C are diagrams showing an example of a planar configuration of an imaging device according to an embodiment. As shown in Fig. 3, the imaging device 1 has a configuration in which, for example, a light guide section 50, a transparent layer 20 (transparent layers 20a and 20b in Fig. 3), a color filter 25, a light receiving section 10, and a multilayer wiring layer 90 are stacked in the Z-axis direction. A pixel P has a photoelectric conversion section 12 as in the example shown in Fig. 3.

[0026] The light receiving unit 10 shown in FIG. 3 has a semiconductor substrate 11 having a first surface 11S1 and a second surface 11S2 facing each other. The semiconductor substrate 11 is made of, for example, a silicon substrate. A color filter 25, a light guiding unit 50, etc. are provided on the first surface 11S1 side of the semiconductor substrate 11. A multilayer wiring layer 90 is provided on the second surface 11S2 side of the semiconductor substrate 11. The light guiding unit 50 and the color filter 25, etc. are provided on the side where light from the optical system is incident, and the multilayer wiring layer 90 is provided on the side opposite to the side where the light is incident. The imaging device 1 is a so-called back-illuminated imaging device.

[0027] In the light receiving section 10, a plurality of photoelectric conversion sections 12 are provided along the first surface 11S1 and the second surface 11S2 of the semiconductor substrate 11. For example, the plurality of photoelectric conversion sections 12 are formed by being embedded in the semiconductor substrate 11. The photoelectric conversion sections 12 are configured to be capable of generating charges by photoelectric conversion. The photoelectric conversion sections 12 are photodiodes (PD) and convert incident light into charges. The photoelectric conversion sections 12 perform photoelectric conversion to generate charges according to the amount of received light.

[0028] The multi-layer wiring layer 90 has a configuration in which, for example, a plurality of wirings are stacked with interlayer insulating layers (interlayer insulating films) between them. The wiring layers of the multi-layer wiring layer 90 are formed using, for example, aluminum (Al), copper (Cu), or the like. The wiring layers may be formed using polysilicon (Poly-Si). The interlayer insulating layers are formed, for example, using silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), or the like.

[0029] The semiconductor substrate 11 and the multi-layer wiring layer 90 are provided with a readout circuit (not shown) configured to be able to output a pixel signal based on the charge generated in the photoelectric conversion unit 12. The pixel driving unit 111, the signal processing unit 112, the control unit 113, the processing unit 114, and the like described above may be formed on a substrate separate from the semiconductor substrate 11, or on the semiconductor substrate 11 and the multi-layer wiring layer 90.

[0030] The readout circuit of the pixel P includes, for example, a transfer transistor, a floating diffusion (FD), a reset transistor, an amplification transistor, etc. The readout circuit is configured to be capable of reading out a pixel signal based on the charge converted by the photoelectric conversion unit 12 to the signal line L2, which is the above-mentioned vertical signal line.

[0031] The pixel driving unit 111 (see FIG. 1) controls a readout circuit of each pixel P to output a pixel signal from each pixel P to a signal line L2. The pixel driving unit 111 can control reading out the pixel signal of each pixel P to the signal line L2. The pixel driving unit 111 and the control unit 113 can be collectively referred to as a pixel control unit.

[0032] The transparent layer 20 (transparent layer 20a, transparent layer 20b in FIG. 3) is a transparent layer that transmits light, and is made of a material with a low refractive index, such as silicon oxide (SiOx), silicon nitride (SiNx), etc. The transparent layer 20a and the transparent layer 20b may each be made of another transparent material that transmits light.

[0033] The light guide unit 50 has a structure 30 and is configured to guide the incident light to the light receiving unit 10. Light from a subject to be measured is incident on the light guide unit 50. The structure 30 is a fine (micro) structure, and has a first portion 31 and a second portion 32 provided below the first portion 31, as shown in FIG. 3. The first portion 31 is in contact with the second portion 32. In this disclosure, "in contact" includes a direct contact and a contact via a natural oxide film or the like. "The first portion 31 and the second portion 32 are in contact" includes a case where a natural oxide film is present, and includes a case where the first portion 31 is in contact with the second portion 32 via a thin natural oxide film. As shown in the example in FIG. 3, the first portion 31 and the second portion 32 are provided to be in contact with each other.

[0034] 3, the first portion 31 and the second portion 32 are provided continuously. The structure 30 also has a medium (a first member 41) provided next to the first portion 31 and a medium (a second member 42) provided next to the second portion 32. The light guiding section 50 has a layered structure in which the first member 41 and the second member 42 are layered.

[0035] The first portion 31 and the second portion 32 of the structure 30 are microstructures having a size equal to or smaller than a predetermined wavelength of incident light, for example, a size equal to or smaller than the wavelength of visible light. Note that the first portion 31 and the second portion 32 may each have a size equal to or smaller than the wavelength of infrared light.

[0036] The light guiding unit 50 is an optical element (optical member) that guides (propagates) light. The light guiding unit 50 (light guiding member) utilizes the structure 30, which is a microstructure, to propagate light to the photoelectric conversion unit 12. As will be described later, the light guiding unit 50 according to this embodiment is also a spectroscopic unit (spectroscopic element) and is configured to disperse incident light. The light guiding unit 50 is provided for each pixel P or for each set of multiple pixels P.

[0037] The structures 30 are, for example, pillar-shaped structures as shown in Fig. 3. As shown typically in Fig. 3, the multiple structures 30 are arranged side by side in the left-right direction (X-axis direction) of the page. In each pixel P of the imaging device 1, the multiple structures 30 can be arranged at intervals equal to or less than a predetermined wavelength of incident light, for example, equal to or less than the wavelength of visible light.

[0038] The first portions 31 of the multiple structures 30 are arranged side by side in the left-right direction (X-axis direction) with the first member 41 between them. It can also be said that the first portions 31 are provided within the first member 41 and are arranged to replace a part of the first member 41. The second portions 32 of the multiple structures 30 are arranged side by side in the left-right direction (X-axis direction) with the second member 42 between them. It can also be said that the second portions 32 are provided within the second member 42 and are arranged to replace a part of the second member 42.

[0039] The structure 30 has a refractive index different from the refractive index of the surrounding medium. In the example shown in Fig. 3, the structure 30 has a refractive index different from the refractive index of a first member 41 and a second member 42, which are media around the structure 30. The first portion 31 of the structure 30 has a refractive index different from the refractive index of the first member 41. In addition, the second portion 32 of the structure 30 has a refractive index different from the refractive index of the second member 42.

[0040] For example, the first portion 31 of the structure 30 may have a refractive index higher than the refractive index of the first member 41. The second portion 32 of the structure 30 may have a refractive index higher than the refractive index of the second member 42. The structure 30 may be made of a material having a refractive index higher than the refractive index of the first member 41 and the refractive index of the second member 42.

[0041] Furthermore, for example, the first portion 31 may have a refractive index lower than the refractive index of the first member 41. The second portion 32 may have a refractive index lower than the refractive index of the second member 42. The structure 30 may be made of a material having a refractive index lower than the refractive index of the first member 41 and the refractive index of the second member 42.

[0042] As an example, the structure 30 is formed using silicon, a silicon compound (silicon nitride, silicon carbide, silicon oxynitride, etc.), etc. The structure 30 may also be configured using amorphous silicon (a-Si), polysilicon, germanium (Ge), etc.

[0043] The structure 30 may be made of a simple substance, an oxide, a nitride, an oxynitride, or a composite of titanium, hafnium, zirconium, tantalum, aluminum, niobium, indium, or the like. The structure 30 may also be made of an organic substance such as siloxane. For example, the structure 30 may be made of a siloxane-based resin, a styrene-based resin, an acrylic-based resin, or the like.

[0044] The first member 41 and the second member 42 may each be made of an element, oxide, nitride, oxynitride, or compound of silicon, titanium, hafnium, zirconium, tantalum, aluminum, niobium, indium, or the like. The first member 41 and the second member 42 may each be made of an organic material, such as siloxane.

[0045] For example, the first member 41 and the second member 42 may be made of a siloxane resin, a styrene resin, an acrylic resin, or the like. The first member 41 and the second member 42 may be made of different materials or the same type of material. Note that a portion of the structure 30, the first member 41, and the second member 42 may be made of air (voids).

[0046] The light guiding section 50 can affect the wavefront by causing a phase delay in the incident light due to the difference between the refractive index of the structure 30 and the refractive index of the surrounding medium. The light guiding section 50 can adjust the propagation direction of the light by imparting different amounts of phase delay according to the wavelength of the light, and can separate the incident light into light of each wavelength range.

[0047] The size, shape, refractive index, etc. of each structure 30 are determined so that light of each wavelength range contained in the incident light travels in a desired direction. In the example shown in Fig. 3, the size, shape, refractive index, etc. of each of the first portion 31 and the second portion 32 of the structure 30 can be adjusted.

[0048] The light guide unit 50 (spectroscope unit) is a spectroscopic element capable of dispersing light using metamaterial (metasurface) technology, and can also be called a splitter (color splitter). The imaging device 1 can also be said to have a color splitter structure.

[0049] The propagation direction of light of each wavelength through the light guiding section 50 can be adjusted by the materials (optical constants) of the structure 30, the first member 41, the second member 42, etc., the shape, height, arrangement interval (gap), etc. of the structure 30. The light guiding section 50 can also be said to be a region (spectral region) where the structure 30 separates incident light.

[0050] The light guiding unit 50 is a spectroscopic unit configured to be able to separate incident light. The light guiding unit 50 imparts different phase delays to light in a plurality of wavelength ranges, for example, light in a first wavelength range to a third wavelength range. This allows the imaging device 1 to separate the light incident on the light guiding unit 50 into light in the first wavelength range (for example, light in the red wavelength range), light in the second wavelength range (for example, light in the green wavelength range), and light in the third wavelength range (for example, light in the blue wavelength range).

[0051] The light guiding section 50 of the pixel Pg is configured to be able to propagate, of the incident light, green (G) light to the color filter 25 and photoelectric conversion section 12 of the pixel Pg, and red (R) light to the color filter 25 and photoelectric conversion section 12 of the pixel Pr. The light guiding section 50 of the pixel Pg splits the incident light, and guides light in the red wavelength range of the incident light toward the pixel Pr.

[0052] Furthermore, the light guiding unit 50 of the pixel Pg is configured to propagate blue (B) light, of the incident light, to the color filter 25 and the photoelectric conversion unit 12 of the pixel Pb. The light guiding unit 50 of the pixel Pg splits the incident light, and guides light in the blue wavelength range, of the incident light, toward the pixel Pb.

[0053] The light guiding section 50 of the pixel Pr is configured to be able to propagate, of the incident light, red (R) light to the color filter 25 and photoelectric conversion section 12 of the pixel Pr, and green (G) light to the color filter 25 and photoelectric conversion section 12 of the pixel Pg. The light guiding section 50 of the pixel Pr splits the incident light, and guides, of the incident light, light in the green wavelength range toward the pixel Pg.

[0054] Furthermore, the light guiding section 50 of the pixel Pr is configured to propagate blue (B) light, of the incident light, to the color filter 25 and the photoelectric conversion section 12 of the pixel Pb. The light guiding section 50 of the pixel Pr splits the incident light, and guides light in the blue wavelength range, of the incident light, toward the pixel Pb.

[0055] The light guiding section 50 of the pixel Pb is configured to be able to propagate, of the incident light, blue (B) light to the color filter 25 and photoelectric conversion section 12 of the pixel Pb, and green (G) light to the color filter 25 and photoelectric conversion section 12 of the pixel Pg. The light guiding section 50 of the pixel Pr splits the incident light, and guides, of the incident light, light in the green wavelength range toward the pixel Pg.

[0056] Furthermore, the light guiding unit 50 of the pixel Pb is configured to propagate red (R) light, of the incident light, to the color filter 25 and the photoelectric conversion unit 12 of the pixel Pr. The light guiding unit 50 of the pixel Pb splits the incident light, and guides light in the red wavelength range, of the incident light, toward the pixel Pr.

[0057] In this way, as shown by the arrows in Fig. 4A, the pixels surrounding the pixel Pr guide the red wavelength light of the incident light toward the pixel Pr. The red wavelength light incident on the pixel Pr and the red wavelength light incident on each of the pixels surrounding the pixel Pr can be collected on the color filter 25 and the photoelectric conversion unit 12 of the pixel Pr. The photoelectric conversion unit 12 of the pixel Pr can efficiently receive light in the red wavelength range and perform photoelectric conversion, thereby generating electric charges according to the amount of received light.

[0058] As shown by arrows in Fig. 4B, the pixels surrounding the pixel Pg guide the green wavelength light of the incident light toward the pixel Pg. The green wavelength light incident on the pixel Pg and the green wavelength light incident on each of the pixels surrounding the pixel Pg can be collected on the color filter 25 and the photoelectric conversion unit 12 of the pixel Pg. The photoelectric conversion unit 12 of the pixel Pg can efficiently receive the light in the green wavelength range and perform photoelectric conversion, thereby generating electric charges according to the amount of received light.

[0059] As shown by arrows in Fig. 4C, the pixels surrounding pixel Pb guide blue wavelength light of the incident light toward pixel Pb. The blue wavelength light incident on pixel Pb and the blue wavelength light incident on each of the pixels surrounding pixel Pb can be collected on color filter 25 and photoelectric conversion unit 12 of pixel Pb. Photoelectric conversion unit 12 of pixel Pb can efficiently receive light in the blue wavelength range and perform photoelectric conversion, thereby generating electric charges according to the amount of received light.

[0060] In this way, in the imaging device 1, more light can be effectively taken into the pixel P, and the quantum efficiency (QE) can be improved. Note that the structures 30 of the light guide sections 50 of the pixels Pr, Pg, and Pb described above can be formed to have different sizes, shapes, etc.

[0061] In the imaging device 1 according to the present embodiment, as described above, the light guide section 50 is formed using a layer in which the first portion 31 and the first member 41 are provided, and a layer in which the second portion 32 and the second member 42 are provided. By forming the light guide section 50 as a laminated structure, it becomes possible to finely control the shape of the structure 30. This makes it possible to reduce the height of the imaging device 1 and effectively suppress deterioration of the spectral characteristics in the case of obliquely incident light. It also becomes possible to form the light guide section 50 in a topology (3D) shape.

[0062] When manufacturing the imaging device 1, the first member 41 and the second member 42 serve as etching stopper films, which can improve processing controllability of the structure 30. This makes it possible to process the structure 30 into a shape without a taper (inclined portion). It becomes possible to process the cross-sectional structure as designed.

[0063] Fig. 5 shows an example of a cross-sectional configuration of a light guiding section in a region where the image height is high, i.e., the distance from the center of the pixel section 100 (pixel array) of the imaging device 1. Fig. 6 (A) and (B) show examples of planar configurations of a first portion 31 of the light guiding section 50 and a second portion 32 of the light guiding section 50, respectively, in a region where the image height is high.

[0064] Light from the optical lens is incident almost perpendicularly on the central portion of the pixel unit 100 of the imaging device 1. On the other hand, light is incident obliquely on the peripheral portion located outside the central portion, i.e., on the region away from the center of the pixel unit 100, as shown by the outlined arrow in Fig. 5. Therefore, in the imaging device 1, as shown in Figs. 5 and 6, the positions of the first portion 31 and the second portion 32 of the light guide unit 50, the color filter 25, the photoelectric conversion unit 12, etc. in each pixel P are configured to differ depending on the distance from the center of the pixel unit 100, i.e., the image height.

[0065] 5 and 6(A) and (B), the first portion 31 of the light guide section 50 of the pixel P is disposed to be shifted toward the center of the pixel unit 100 with respect to the second portion 32 of the light guide section 50 of the pixel P. It can also be said that the second portion 32 of the light guide section 50 of the pixel P is disposed to be shifted toward the edge of the pixel unit 100 with respect to the first portion 31 of the light guide section 50 of the pixel P.

[0066] 5, first portion 31 of light guiding portion 50 is shifted leftward in the plane of the drawing relative to second portion 32 of light guiding portion 50. In other words, second portion 32 of light guiding portion 50 is shifted rightward in the plane of the drawing relative to first portion 31 of light guiding portion 50.

[0067] In the central region of the pixel section 100 (pixel array), the pixel P is configured, for example, as shown in Fig. 2 and Fig. 3. In the central pixel P of the pixel section 100, the respective central positions of the first portion 31 and the second portion 32 of the light guide section 50 are approximately aligned, as in the example shown in Fig. 3. In addition, the respective central positions of the color filter 25 and the photoelectric conversion section 12 are approximately aligned.

[0068] In this way, in the imaging device 1, the positions of the first portion 31, the second portion 32, etc. of the light guiding unit 50 are adjusted according to the image height, and pupil correction can be appropriately performed. It is possible to suppress a decrease in the amount of light incident on the photoelectric conversion unit 12 and prevent a decrease in sensitivity to the incident light. Even when light is incident obliquely, it is possible to appropriately propagate the incident light to the photoelectric conversion unit 12.

[0069] 7A to 7I are diagrams showing an example of a method for manufacturing a light guiding section of an imaging device according to an embodiment. First, as shown in FIG. 7A, a resist film 61 is formed on the second member 42 by lithography and etching. Furthermore, as shown in FIG. 7B, a part of the second member 42 is removed by dry etching. Then, as shown in FIG. 7C, a titanium oxide film (TiO film) is formed as the second portion 32 of the structure 30.

[0070] Next, as shown in Fig. 7D, an excess titanium oxide film is removed by CMP processing. Furthermore, as shown in Fig. 7E, a first member 41 is formed on the second member 42. Then, as shown in Fig. 7F, a resist film 62 is formed by lithography and etching.

[0071] Next, as shown in FIG. 7G, a part of the first member 41 is removed by dry etching. Furthermore, as shown in FIG. 7H, a titanium oxide film (TiO film) is formed on the second member 42 as the first portion 31 of the structure 30. Then, as shown in FIG. 7I, excess titanium oxide film is removed by CMP processing. By the above-mentioned manufacturing method, the light guide section 50 shown in FIG. 3 etc. can be manufactured. Note that the above-mentioned manufacturing method is merely one example, and other manufacturing methods may be adopted.

[0072] [Actions and Effects] The light detection device according to this embodiment includes a structure (structure 30) including a first portion (first portion 31) having a size equal to or smaller than the wavelength of incident light and a second portion (second portion 32) provided below the first portion, a light guide (light guide 50) including a first medium (first member 41) provided next to the first portion and having a refractive index different from that of the structure, and a second medium (second member 42) provided next to the second portion and having a refractive index different from that of the structure, and a first photoelectric conversion unit (photoelectric conversion unit 12) that photoelectrically converts light incident via the light guide. The first portion is in contact with the second portion.

[0073] The light detection device (imaging device 1) according to this embodiment is provided with a structure 30 including a first portion 31 and a second portion 32, and a light guiding section 50 having a first member 41 and a second member 42. By forming the light guiding section 50 into a laminated structure, it becomes possible to control the shape of the structure 30 and suppress a decrease in sensitivity to obliquely incident light. It becomes possible to realize a light detection device with good detection performance.

[0074] In this embodiment, the first and second parts of the structure 30 are provided so as to be in contact with each other. This allows for improved light controllability. In addition, compared to a case in which the first and second parts are provided separately, the number of steps in the manufacturing process can be reduced, making it possible to prevent an increase in the manufacturing cost of the imaging device 1.

[0075] Next, a modified example of the present disclosure will be described. In the following, the same components as those in the above embodiment are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0076] <2. Modifications> (2-1. Variation 1) Fig. 8 is a diagram showing an example of a cross-sectional configuration of a light guiding section of an imaging device according to Modification 1 of the present disclosure. Light guiding section 50 may be configured using a plurality of first portions 31 and second portions 32, and a plurality of first members 41 and second members 42. For example, as in the example shown in Fig. 8, light guiding section 50 may have a structure in which a layer in which first portion 31a and first member 41a are provided, a layer in which second portion 32 and second member 42 are provided, and a layer in which first portion 31b and first member 41b are provided are stacked.

[0077] Fig. 9 shows an example of a cross-sectional configuration of light guiding section 50 of pixel P in a region where the image height is high. Also, (A), (B), and (C) of Fig. 10 show examples of planar configurations of first portion 31a of light guiding section 50, second portion 32 of light guiding section 50, and first portion 31b of light guiding section 50 in a region where the image height is high, respectively.

[0078] 9 and 10, the first portion 31a, the second portion 32, and the first portion 31b may be arranged with a shift according to the image height. The center position of the first portion 31a, the center position of the second portion 32, and the center position of the first portion 31b are different according to the incident direction of light from the subject. In this modification, the three-layer light guiding section 50 can appropriately guide obliquely incident light.

[0079] As shown in Fig. 11A, the light guide section 50 may be configured using the first portions 31a-31d, the second portions 32a-32c, the first members 41a-41d, and the second members 42a-42c. As shown in Fig. 11B, in a region away from the center of the pixel section 100, the first portions 31a-31d and the second portions 32a-32c may be arranged to be shifted from each other in accordance with the direction of incidence of light. The first portions 31a-31d and the second portions 32a-32c of the structure 30 may have a tapered shape as shown in Fig. 12A or 12B.

[0080] (2-2. Variation 2) The multiple portions constituting the structure 30, for example the first portion 31 and the second portion 32, may have sizes (height (thickness), width, etc.) different from each other. In addition, the medium surrounding the structure 30, for example the first member 41 and the second member 42, may have sizes (thickness, width, etc.) different from each other.

[0081] 13A and 13B are diagrams showing an example of a cross-sectional configuration of a light guiding section of an imaging device according to Modification 2. As shown in FIG. 13A or 13B, the first portion 31 and the second portion 32 may have different sizes. In the example shown in FIG. 13A, the size of the second portion 32 is smaller than the size of the first portion 31a. Also, in the example shown in FIG. 13B, the size of the second portion 32 is smaller than the size of each of the first portion 31a and the first portion 31b.

[0082] FIG. 14 is a diagram showing another example of a cross-sectional configuration of a light guide section of an imaging device according to Modification 2. As shown in FIG. 14, light guide section 50 may have third section 33 provided below second section 32 in contact with it, and third member 43 provided next to third section 33. Second section 32 and third section 33 are in contact with each other. Here, "second section 32 and third section 33 are in contact with each other" includes a case where a natural oxide film is interposed, and includes a case where second section 32 is in contact with third section 33 via a thin natural oxide film. As in the example shown in FIG. 14, second section 32 and third section 33 are provided so as to be in contact with each other.

[0083] The first portion 31, the second portion 32, and the third portion 33 may have different sizes (thickness, width, etc.) from each other. The first portion 31, the second portion 32, and the third portion 33 may be arranged to be shifted depending on the image height. The first member 41, the second member 42, and the third member 43 may be made of, for example, different materials.

[0084] (2-3. Variation 3) Fig. 15 is a diagram showing an example of a cross-sectional configuration of a light guide section of an imaging device according to Modification 3. As in the examples shown in Fig. 15 or 16, the first portion 31 and the second portion 32 may have different widths. The first portion 31 and the second portion 32 may be formed to have different sizes, shapes, etc., from each other. In this case, it is possible to effectively suppress the degradation of the spectral characteristics in the case of obliquely incident light.

[0085] The first portions 31a, 31b and the second portion 32 may each have a cross shape, a square shape, or the like, as in the example shown in Fig. 17. The shape of the structure 30 can be changed as appropriate, and may be, for example, a square shape in a plan view. The shape of the structure 30 may be a polygon, an ellipse, a cross, or another shape.

[0086] (2-4. Variation 4) FIG. 18 is a diagram showing an example of a cross-sectional configuration of an imaging device according to Modification 4. As shown in FIG. 18, imaging device 1 may have lens unit 26. Lens unit 26 guides light incident from above to light guide unit 50. Lens unit 26 is an optical member also called an on-chip lens. Lens unit 26 is provided above light guide unit 50 for each pixel P or for each set of multiple pixels P, for example. Light from a subject is incident on lens unit 26 via an optical system such as an imaging lens. Photoelectric conversion unit 12 can perform photoelectric conversion on light incident via lens unit 26, light guide unit 50, and color filter 25.

[0087] Note that, instead of or in addition to the color filter 25, a light guide section configured using a structure may be provided above the photoelectric conversion section 12. This structure is, for example, a columnar microstructure similar to the structure 30 of the light guide section 50. Note that the shape of the structure can be appropriately changed and may be a polygon or other shape.

[0088] <3. Application Examples> The imaging device 1 and the like can be applied to any type of electronic device equipped with an imaging function, such as a camera system such as a digital still camera or a video camera, or a mobile phone with an imaging function. Fig. 19 shows a schematic configuration of an electronic device 1000.

[0089] 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, which are interconnected via a bus line 1008.

[0090] The lens group 1001 captures incident light (image light) from a 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 the signal to the DSP circuit 1002 as a pixel signal.

[0091] The DSP circuit 1002 is a signal processing circuit that processes a signal supplied from the imaging device 1. The DSP circuit 1002 outputs image data obtained by processing the signal from the imaging device 1. The frame memory 1003 temporarily holds the image data processed by the DSP circuit 1002 on a frame-by-frame basis.

[0092] The display unit 1004 is, for example, a panel-type display device such as a liquid crystal panel or an organic EL (Electro Luminescence) panel, and records image data of moving images or still images captured by the imaging device 1 in a recording medium such as a semiconductor memory or a hard disk.

[0093] The operation unit 1006 outputs operation signals for various functions of the electronic device 1000 in accordance with operations by a user. The power supply unit 1007 appropriately supplies various types of power to the DSP circuit 1002, the frame memory 1003, the display unit 1004, the recording unit 1005, and the operation unit 1006 as operating power sources to these power sources.

[0094] <4. Application Examples> (Example of application to moving objects) The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure may be realized as a device mounted on any type of moving body such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, a personal mobility device, an airplane, a drone, a ship, a robot, etc.

[0095] FIG. 20 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a moving object control system to which the technology according to the present disclosure can be applied.

[0096] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 20, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an outside-vehicle information detection unit 12030, an inside-vehicle information detection unit 12040, and an integrated control unit 12050. Also, as functional configurations of the integrated control unit 12050, a microcomputer 12051, an audio / video output unit 12052, and an in-vehicle network I / F (interface) 12053 are illustrated.

[0097] The drivetrain control unit 12010 controls the operation of devices related to the drivetrain of the vehicle in accordance with various programs. For example, the drivetrain control unit 12010 functions as a control device for a drive force generating device for generating a drive force of the vehicle, such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, and a braking device for generating a braking force of the vehicle.

[0098] 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 device, or various lamps such as head lamps, back lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves or signals of various switches transmitted from a portable device that replaces a key may be input to the body system control unit 12020. The body system control unit 12020 receives the input of these radio waves or signals and controls the door lock device, power window device, lamps, and the like of the vehicle.

[0099] The outside-vehicle information detection unit 12030 detects information outside the vehicle equipped with the vehicle control system 12000. For example, an imaging unit 12031 is connected to the outside-vehicle information detection unit 12030. The outside-vehicle information detection unit 12030 causes the imaging unit 12031 to capture an image outside the vehicle and receives the captured image. The outside-vehicle information detection unit 12030 may perform object detection processing or distance detection processing for a person, a car, an obstacle, a sign, or characters on a road surface, based on the received image.

[0100] The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal according 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.

[0101] The in-vehicle information detection unit 12040 detects information inside the vehicle. For example, a driver state detection unit 12041 that detects the state of the driver is connected to the in-vehicle information detection unit 12040. The driver state detection unit 12041 includes, for example, a camera that captures an image of the driver, and the in-vehicle information detection unit 12040 may calculate the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 12041, or may determine whether the driver is dozing.

[0102] The microcomputer 12051 can calculate control target values ​​for the driving force generating device, the steering mechanism, or the braking device based on the information inside and outside the vehicle acquired by the outside-of-vehicle information detection unit 12030 or the inside-vehicle information detection unit 12040, and output a control command to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing the functions of an ADAS (Advanced Driver Assistance System), including vehicle collision avoidance or impact mitigation, following driving based on the inter-vehicle distance, vehicle speed maintenance driving, vehicle collision warning, vehicle lane departure warning, etc.

[0103] In addition, the microcomputer 12051 can perform cooperative control for the purpose of autonomous driving, which allows the vehicle to travel autonomously without relying on the driver's operation, by controlling the driving force generating device, steering mechanism, braking device, etc. based on information about the surroundings of the vehicle acquired by the outside vehicle information detection unit 12030 or the inside vehicle information detection unit 12040.

[0104] Furthermore, the microcomputer 12051 can output a control command to the body system control unit 12020 based on the information outside the vehicle acquired by the outside-vehicle information detection unit 12030. For example, the microcomputer 12051 can control the headlamps according to the position of a preceding vehicle or an oncoming vehicle detected by the outside-vehicle information detection unit 12030, and perform cooperative control for the purpose of preventing glare, such as switching from high beams to low beams.

[0105] The audio / video output unit 12052 transmits at least one output signal of audio and image to an output device capable of visually or audibly notifying information to passengers in the vehicle or the outside of the vehicle. In the example of Fig. 20, an audio speaker 12061, a display unit 12062, and an instrument panel 12063 are exemplified as the output device. The display unit 12062 may include at least one of an on-board display and a head-up display, for example.

[0106] FIG. 21 is a diagram showing an example of the installation position of the imaging unit 12031.

[0107] In FIG. 21, a vehicle 12100 has imaging units 12101, 12102, 12103, 12104, and 12105 as an imaging unit 12031.

[0108] The imaging units 12101, 12102, 12103, 12104, and 12105 are provided at positions such as the front nose, side mirrors, rear bumper, back door, and the upper part of the windshield inside the vehicle cabin of the vehicle 12100. The imaging unit 12101 provided at the front nose and the imaging unit 12105 provided at the upper part of the windshield inside the vehicle cabin mainly acquire images of the front of the vehicle 12100. The imaging units 12102 and 12103 provided at the side mirrors mainly acquire images of the sides of the vehicle 12100. The imaging unit 12104 provided at the rear bumper or back door mainly acquires images of the rear of the vehicle 12100. The images of the front acquired by the imaging units 12101 and 12105 are mainly used to detect a preceding vehicle, a pedestrian, an obstacle, a traffic light, a traffic sign, a lane, or the like.

[0109] 21 shows an example of the imaging ranges of the imaging units 12101 to 12104. Imaging range 12111 indicates the imaging range of the imaging unit 12101 provided on the front nose, imaging ranges 12112 and 12113 indicate the imaging ranges of the imaging units 12102 and 12103 provided on the side mirrors, respectively, and imaging range 12114 indicates the imaging range of the imaging unit 12104 provided on the rear bumper or back door. For example, an overhead image of the vehicle 12100 viewed from above is obtained by superimposing the image data captured by the imaging units 12101 to 12104.

[0110] At least one of the imaging units 12101 to 12104 may have a function of acquiring distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera made up of a plurality of imaging elements, or may be an imaging element having pixels for detecting a phase difference.

[0111] For example, the microcomputer 12051 can extract, as a preceding vehicle, a three-dimensional object that is the closest three-dimensional object on the travel path of the vehicle 12100 and travels at a predetermined speed (for example, 0 km / h or more) in approximately the same direction as the vehicle 12100, by calculating the distance to each three-dimensional object in the imaging ranges 12111 to 12114 and the change over time of this distance (relative speed with respect to the vehicle 12100) based on the distance information obtained from the imaging units 12101 to 12104. Furthermore, the microcomputer 12051 can set a vehicle distance to be secured in advance in front of the preceding vehicle, and perform automatic brake control (including follow-up stop control) and automatic acceleration control (including follow-up start control). In this way, cooperative control can be performed for the purpose of automatic driving that travels autonomously without relying on the driver's operation.

[0112] For example, the microcomputer 12051 classifies and extracts three-dimensional object data on three-dimensional objects into two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects based on distance information obtained from the imaging units 12101 to 12104, and can use the data for automatic obstacle avoidance. For example, the microcomputer 12051 distinguishes obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. Then, the microcomputer 12051 determines a collision risk indicating the risk of collision with each obstacle, and when the collision risk is equal to or greater than a set value and a collision is possible, the microcomputer 12051 can provide driving assistance for collision avoidance by outputting an alarm to the driver via the audio speaker 12061 or the display unit 12062, or by performing forced deceleration or avoidance steering via the drive system control unit 12010.

[0113] At least one of the imaging units 12101 to 12104 may be an infrared camera that detects infrared rays. For example, the microcomputer 12051 can recognize a pedestrian by determining whether or not a pedestrian is present in the captured images of the imaging units 12101 to 12104. The recognition of such a pedestrian is performed, for example, by a procedure of extracting feature points in the captured images of the imaging units 12101 to 12104 as infrared cameras, and a procedure of performing pattern matching processing on a series of feature points that indicate the contour of an object to determine whether or not the object is a pedestrian. When the microcomputer 12051 determines that a pedestrian is present in the captured images of the imaging units 12101 to 12104 and recognizes the 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 or the like indicating a pedestrian at a desired position.

[0114] An example of a mobile object control system to which the technology according to the present disclosure can be applied has been described above. The technology according to the present disclosure can be applied to, for example, the imaging unit 12031 among the configurations described above. Specifically, for example, the imaging device 1 or the like can be applied to the imaging unit 12031. By applying the technology according to the present disclosure to the imaging unit 12031, a high-definition captured image can be obtained, and high-precision control using the captured image can be performed in the mobile object control system.

[0115] (Application example to endoscopic surgery system) The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure may be applied to an endoscopic surgery system.

[0116] FIG. 22 is a diagram showing an example of a schematic configuration of an endoscopic surgery system to which the technology according to the present disclosure (the present technology) can be applied.

[0117] 22 shows a state in which an operator (doctor) 11131 is performing surgery on a patient 11132 on a patient bed 11133 using an endoscopic surgery system 11000. As shown in the figure, the endoscopic surgery system 11000 is composed of an endoscope 11100, other surgical tools 11110 such as an insufflation tube 11111 and an energy treatment tool 11112, a support arm device 11120 that supports the endoscope 11100, and a cart 11200 on which various devices for endoscopic surgery are mounted.

[0118] The endoscope 11100 is composed of a lens barrel 11101, a region of a predetermined length from the tip of which is inserted into a body cavity of a patient 11132, and a camera head 11102 connected to the base end of the lens barrel 11101. In the illustrated example, the endoscope 11100 is configured as a so-called rigid scope having a rigid lens barrel 11101, but the endoscope 11100 may be configured as a so-called flexible scope having a flexible lens barrel.

[0119] An opening into which an objective lens is fitted is provided at the tip of the lens barrel 11101. A light source device 11203 is connected to the endoscope 11100, and light generated by the light source device 11203 is guided to the tip of the lens barrel by a light guide extending inside the lens barrel 11101, and is irradiated via the objective lens toward an observation target in the body cavity of the patient 11132. The endoscope 11100 may be a direct-viewing endoscope, an oblique-viewing endoscope, or a side-viewing endoscope.

[0120] An optical system and an image sensor are provided inside the camera head 11102, and reflected light (observation light) from an observation target is collected on the image sensor by the optical system. The observation light is photoelectrically converted by the image sensor to generate an electrical signal corresponding to the observation light, i.e., an image signal corresponding to an observation image. The image signal is transmitted to a camera control unit (CCU) 11201 as RAW data.

[0121] The CCU 11201 is configured with a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), etc., and performs overall control of the operations 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 types of image processing on the image signal, such as development processing (demosaic processing), for displaying an image based on the image signal.

[0122] Under the control of the CCU 11201, the display device 11202 displays an image based on an image signal that has been subjected to image processing by the CCU 11201.

[0123] The light source device 11203 is composed of a light source such as an LED (Light Emitting Diode), and supplies the endoscope 11100 with irradiation light when photographing an operation site or the like.

[0124] The input device 11204 is an input interface for the endoscopic surgery system 11000. A user can input various information and instructions to the endoscopic surgery system 11000 via the input device 11204. For example, the user inputs an instruction to change the imaging conditions (type of irradiated light, magnification, focal length, etc.) of the endoscope 11100.

[0125] The treatment tool control device 11205 controls the driving of the energy treatment tool 11112 for cauterizing tissue, incising, sealing blood vessels, etc. The insufflation device 11206 sends gas into the body cavity of the patient 11132 via the insufflation tube 11111 to inflate the body cavity for the purpose of securing the field of view of the endoscope 11100 and securing the working space of the surgeon. 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, image, or graph.

[0126] The light source device 11203 that supplies irradiation light to the endoscope 11100 when photographing the surgical site can be composed of a white light source composed of, for example, an LED, a laser light source, or a combination of these. When the white light source is composed of 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 that 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 a time-division manner by irradiating the observation object with laser light from each of the RGB laser light sources in a time-division manner and controlling the driving 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 to the image sensor.

[0127] The light source device 11203 may be controlled to change the intensity of the light it outputs at predetermined time intervals. The driving of the image sensor of the camera head 11102 may be controlled in synchronization with the timing of the change in the light intensity to obtain images in a time-division manner, and the images may be synthesized to generate an image with a high dynamic range that is free of so-called blackout and whiteout.

[0128] The light source device 11203 may be configured to supply light of a predetermined wavelength band corresponding to the special light observation. In the special light observation, for example, by utilizing the wavelength dependency of light absorption in body tissue, a narrow band light is irradiated compared to the irradiated light (i.e., white light) during normal observation, and a predetermined tissue such as blood vessels on the mucous membrane surface is photographed with high contrast, so-called narrow band imaging is performed. Alternatively, in the special light observation, a fluorescent observation may be performed in which an image is obtained by fluorescence generated by irradiating an excitation light. In the fluorescent observation, it is possible to irradiate an excitation light to a body tissue and observe the fluorescence from the body tissue (autofluorescence observation), or to locally inject a reagent such as indocyanine green (ICG) into the body tissue and irradiate the body tissue with excitation light corresponding to the fluorescent wavelength of the reagent to obtain a fluorescent image. The light source device 11203 may be configured to supply narrow band light and / or excitation light corresponding to such special light observation.

[0129] FIG. 23 is a block diagram showing an example of the functional configuration of the camera head 11102 and the CCU 11201 shown in FIG.

[0130] The camera head 11102 has 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 has 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 by a transmission cable 11400 so as to be able to communicate with each other.

[0131] The lens unit 11401 is an optical system provided at the connection portion 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 enters the lens unit 11401. The lens unit 11401 is configured by combining a plurality of lenses including a zoom lens and a focus lens.

[0132] The imaging unit 11402 is composed of an imaging element. The imaging element constituting the imaging unit 11402 may be one (so-called single-plate type) or multiple (so-called multi-plate type). When the imaging unit 11402 is composed of a multi-plate type, for example, each imaging element may generate an image signal corresponding to each of RGB, and a color image may be obtained by combining the image signals. Alternatively, the imaging unit 11402 may be configured to have a pair of imaging elements for acquiring image signals for the right eye and the left eye 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 site. Note that when the imaging unit 11402 is composed of a multi-plate type, multiple lens units 11401 may be provided corresponding to each imaging element.

[0133] Furthermore, the imaging unit 11402 does not necessarily have to be provided in the camera head 11102. For example, the imaging unit 11402 may be provided inside the lens barrel 11101, immediately behind the objective lens.

[0134] The driving unit 11403 is configured by an actuator, and moves the zoom lens and focus lens of the lens unit 11401 by a predetermined distance along the optical axis under the control of the camera head control unit 11405. This allows the magnification and focus of the image captured by the imaging unit 11402 to be appropriately adjusted.

[0135] The communication unit 11404 is configured by a communication device for transmitting and receiving various information to and from the CCU 11201. The communication unit 11404 transmits the image signal obtained from the imaging unit 11402 to the CCU 11201 via the transmission cable 11400 as RAW data.

[0136] Furthermore, the communication unit 11404 receives a control signal for controlling the driving of the camera head 11102 from the CCU 11201, and supplies the control signal to the camera head control unit 11405. The control signal includes information on the imaging conditions, such as information specifying the frame rate of the captured image, information specifying the exposure value at the time of capturing the image, and / or information specifying the magnification and focus of the captured image.

[0137] The image capturing conditions such as the frame rate, exposure value, magnification, and focus may be appropriately specified by a user, or may be automatically set by the control unit 11413 of the CCU 11201 based on an acquired image signal. In the latter case, the endoscope 11100 is equipped with a so-called AE (Auto Exposure) function, AF (Auto Focus) function, and AWB (Auto White Balance) function.

[0138] The camera head control unit 11405 controls the driving of the camera head 11102 based on a control signal received from the CCU 11201 via the communication unit 11404.

[0139] The communication unit 11411 is configured with a communication device for transmitting and receiving various information to and from the camera head 11102. The communication unit 11411 receives an image signal transmitted from the camera head 11102 via the transmission cable 11400.

[0140] Furthermore, the communication unit 11411 transmits, to the camera head 11102, a control signal for controlling the driving of the camera head 11102. The image signal and the control signal can be transmitted by electrical communication, optical communication, or the like.

[0141] The image processing unit 11412 performs various types of image processing on the image signal, which is RAW data sent from the camera head 11102 .

[0142] The control unit 11413 performs various controls related to imaging of the surgical site etc. by the endoscope 11100 and display of the captured image obtained by imaging the surgical site etc. For example, the control unit 11413 generates a control signal for controlling the driving of the camera head 11102.

[0143] Further, the control unit 11413 causes the display device 11202 to display the captured image showing the surgical site, etc., based on the image signal that has been image-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 techniques. For example, the control unit 11413 can recognize surgical tools such as forceps, specific living body parts, bleeding, mist when the energy treatment tool 11112 is used, etc., by detecting the shape and color of the edge of an object included in the captured image. When the control unit 11413 causes the display device 11202 to display the captured image, it may use the recognition result to superimpose various types of surgery support information on the image of the surgical site. By superimposing and presenting the surgery support information to the surgeon 11131, the burden on the surgeon 11131 can be reduced and the surgeon 11131 can proceed with the surgery reliably.

[0144] The transmission cable 11400 connecting the camera head 11102 and the CCU 11201 is an electrical signal cable for communication of electrical signals, an optical fiber for optical communication, or a composite cable of these.

[0145] Here, in the illustrated example, communication is performed wired using a transmission cable 11400, but communication between the camera head 11102 and the CCU 11201 may also be performed wirelessly.

[0146] An example of an endoscopic surgery system to which the technology according to the present disclosure can be applied has been described above. Of the configurations described above, the technology according to the present disclosure can be suitably applied to, for example, the imaging unit 11402 provided in the camera head 11102 of the endoscope 11100. By applying the technology according to the present disclosure to the imaging unit 11402, the sensitivity of the imaging unit 11402 can be increased, and a high-definition endoscope 11100 can be provided.

[0147] Although the present disclosure has been described above by way of the embodiment, modifications, application examples, and application examples, the present technology is not limited to the above-described embodiment, etc., and various modifications are possible. For example, although the above-described modifications have been described as modifications of the above-described embodiment, the configurations of the modifications can be appropriately combined.

[0148] In the above-mentioned embodiment, an imaging device is described as an example, but the light detection device of the present disclosure may be, for example, a device that receives incident light and converts the light into an electric charge. The output signal may be a signal of image information or a signal of distance measurement information. The light detection device (imaging device) may be applied to an image sensor, a distance measurement sensor, etc.

[0149] The light detection device according to the present disclosure may also be applied as a distance measurement sensor capable of measuring distances using a time-of-flight (TOF) method. The light detection device (imaging device) may also be applied as a sensor capable of detecting an event, for example, an event-driven sensor (also called an event vision sensor (EVS), an event driven sensor (EDS), a dynamic vision sensor (DVS), or the like).

[0150] The light guide section 50, which is an optical element, may be configured as a lens section that focuses light, depending on the design of the structure 30. The light guide section 50 may also be configured as a filter section that selectively transmits light of a specific wavelength range among the incident light. The light detection device and optical element (light guide section 50) according to the present disclosure can be applied to various devices.

[0151] The photodetector according to an embodiment of the present disclosure includes a structure including a first portion having a size equal to or smaller than the wavelength of incident light and a second portion provided below the first portion, a light guide having a first medium provided next to the first portion and having a refractive index different from that of the structure, and a second medium provided next to the second portion and having a refractive index different from that of the structure, and a first photoelectric conversion portion that performs photoelectric conversion on light incident through the light guide. The first portion is in contact with the second portion. This makes it possible to control the shape of the structure and suppress a decrease in sensitivity to obliquely incident light. It is possible to realize a photodetector having good detection performance.

[0152] The optical element according to an embodiment of the present disclosure includes a structure including a first portion having a size equal to or smaller than the wavelength of incident light and a second portion provided below the first portion, a first medium provided next to the first portion and having a refractive index different from that of the structure, and a second medium provided next to the second portion and having a refractive index different from that of the structure. The first portion is in contact with the second portion. Note that "in contact" here includes a case where the first portion is in direct contact and a case where the second portion is in contact via a native oxide film. According to the optical element according to the present disclosure, it is possible to control the shape of the structure. In addition, it is possible to improve the characteristics with respect to obliquely incident light.

[0153] In addition, the effects described in this specification are merely examples and are not limited to the description, and other effects may be obtained. In addition, the present disclosure may have the following configurations. (1) a light guiding section including a structure including a first portion having a size equal to or smaller than the wavelength of incident light and a second portion provided below the first portion, a first medium provided adjacent to the first portion and having a refractive index different from that of the structure, and a second medium provided adjacent to the second portion and having a refractive index different from that of the structure; a first photoelectric conversion unit that performs photoelectric conversion on the light incident via the light guiding unit; Equipped with The first portion is in contact with the second portion. Light detection device. (2) The first medium is in contact with the second medium. The light detection device according to (1) above. (3) The first medium and the second medium are made of different materials. The optical detection device according to (1) or (2). (4) The first medium and the second medium have different thicknesses in a stacking direction of the first medium and the second medium. The optical detection device according to any one of (1) to (3). (5) The first portion and the second portion are provided continuously. The photodetector according to any one of (1) to (4). (6) The first portion and the second portion have different sizes. The optical detection device according to any one of (1) to (5). (7) a light receiving section provided with a plurality of the first photoelectric conversion sections; The distance between the center of the first portion and the center of the second portion varies depending on the distance from the center of the light receiving portion. The photodetector according to any one of (1) to (6). (8) the structure includes a third portion disposed below the second portion, The light guiding portion includes a third medium provided adjacent to the third portion and having a refractive index different from that of the third portion. The optical detection device according to any one of (1) to (7). (9) The second portion and the third portion have different sizes. The photodetector according to (8) above. (10) a light receiving section provided with a plurality of the first photoelectric conversion sections; The distance between the center of the second portion and the center of the third portion varies depending on the distance from the center of the light receiving portion. The optical detection device according to (8) or (9) above. (11) The light guide section is provided on the first photoelectric conversion section and divides incident light into light beams. The optical detection device according to any one of (1) to (10) above. (12) a second photoelectric conversion unit that is provided adjacent to the first photoelectric conversion unit and performs photoelectric conversion on light that is incident via the light guiding unit; The light guide guides, of the incident light, a light having a first wavelength to the first photoelectric conversion unit side and a light having a second wavelength to the second photoelectric conversion unit side. The photodetector according to any one of (1) to (11) above. (13) a third photoelectric conversion unit provided adjacent to the first photoelectric conversion unit and configured to perform photoelectric conversion on light incident via the light guiding unit; The light guide guides light having a third wavelength out of the incident light to the third photoelectric conversion unit. The light detection device according to (12) above. (14) The first portion and the second portion each have a size equal to or smaller than the wavelength of visible light. The photodetector according to any one of (1) to (13) above. (15) A lens is provided on the light guide portion, and the lens has light incident thereon; The first photoelectric conversion unit performs photoelectric conversion on the light transmitted through the lens and the light guiding unit. The photodetector according to any one of (1) to (14) above. (16) a color filter provided between the light guiding unit and the first photoelectric conversion unit; The first photoelectric conversion unit photoelectrically converts light transmitted through the color filter. The photodetector according to any one of (1) to (15) above. (17) An optical system; a light detection device that receives light transmitted through the optical system; Equipped with The light detection device includes: a light guiding section including a structure including a first portion having a size equal to or smaller than the wavelength of incident light and a second portion provided below the first portion, a first medium provided adjacent to the first portion and having a refractive index different from that of the structure, and a second medium provided adjacent to the second portion and having a refractive index different from that of the structure; a photoelectric conversion unit that photoelectrically converts light incident via the light guiding unit; having The first portion is in contact with the second portion. electronic equipment. (18) a structure including a first portion having a size equal to or smaller than the wavelength of incident light and a second portion provided below the first portion; a first medium provided adjacent to the first portion and having a refractive index different from a refractive index of the structure; a second medium provided adjacent to the second portion and having a refractive index different from that of the structure; Equipped with The first portion is in contact with the second portion. Optical elements. [Explanation of symbols]

[0154] 1...imaging device, 10...light receiving section, 12...photoelectric conversion section, 20...transparent layer, 25...color filter, 30...structural body, 31...first portion, 32...second portion, 41...first member, 42...second member, 50...light guiding section, 100...pixel section.

Claims

1. a light guide section including a structure including a first portion having a size equal to or smaller than the wavelength of incident light and a second portion provided below the first portion, a first medium provided adjacent to the first portion and having a refractive index different from that of the structure, and a second medium provided adjacent to the second portion and having a refractive index different from that of the structure; a first photoelectric conversion unit that performs photoelectric conversion on the light incident via the light guiding unit; Equipped with The first portion is in contact with the second portion. Light detection device.

2. The first medium is in contact with the second medium.

2. The optical detection device according to claim 1.

3. The first medium and the second medium are made of different materials.

2. The optical detection device according to claim 1.

4. The first medium and the second medium have different thicknesses in a stacking direction of the first medium and the second medium.

2. The optical detection device according to claim 1.

5. The first portion and the second portion are provided continuously.

2. The optical detection device according to claim 1.

6. The first portion and the second portion have different sizes.

2. The optical detection device according to claim 1.

7. a light receiving section provided with a plurality of the first photoelectric conversion sections; The distance between the center of the first portion and the center of the second portion varies depending on the distance from the center of the light receiving portion.

2. The optical detection device according to claim 1.

8. the structure includes a third portion disposed below the second portion; The light guide portion is provided adjacent to the third portion and includes a third medium having a refractive index different from that of the third portion.

2. The optical detection device according to claim 1.

9. The second portion and the third portion have different sizes.

9. The optical detection device according to claim 8.

10. a light receiving section provided with a plurality of the first photoelectric conversion sections; The distance between the center of the second portion and the center of the third portion varies depending on the distance from the center of the light receiving portion.

9. The optical detection device according to claim 8.

11. The light guide section is provided on the first photoelectric conversion section and divides incident light into light beams.

2. The optical detection device according to claim 1.

12. a second photoelectric conversion unit that is provided adjacent to the first photoelectric conversion unit and performs photoelectric conversion on light that is incident via the light guiding unit; The light guide guides, of the incident light, a light having a first wavelength to the first photoelectric conversion unit side and a light having a second wavelength to the second photoelectric conversion unit side.

2. The optical detection device according to claim 1.

13. a third photoelectric conversion unit provided adjacent to the first photoelectric conversion unit and configured to perform photoelectric conversion on light incident via the light guiding unit; The light guide guides light having a third wavelength out of the incident light to the third photoelectric conversion unit.

13. The optical detection device of claim 12.

14. The first portion and the second portion each have a size equal to or smaller than the wavelength of visible light.

2. The optical detection device according to claim 1.

15. A lens is provided on the light guide portion, and the lens has light incident thereon; The first photoelectric conversion unit performs photoelectric conversion on the light transmitted through the lens and the light guiding unit.

2. The optical detection device according to claim 1.

16. a color filter provided between the light guiding unit and the first photoelectric conversion unit; The first photoelectric conversion unit performs photoelectric conversion on the light transmitted through the color filter.

2. The optical detection device according to claim 1.

17. An optical system; a light detection device that receives light transmitted through the optical system; Equipped with The light detection device includes: a light guide section including a structure including a first portion having a size equal to or smaller than the wavelength of incident light and a second portion provided below the first portion, a first medium provided adjacent to the first portion and having a refractive index different from that of the structure, and a second medium provided adjacent to the second portion and having a refractive index different from that of the structure; a photoelectric conversion unit that photoelectrically converts light incident via the light guiding unit; having The first portion is in contact with the second portion. electronic equipment.

18. a structure including a first portion having a size equal to or smaller than the wavelength of incident light and a second portion provided below the first portion; a first medium disposed adjacent to the first portion and having a refractive index different from that of the structure; a second medium provided adjacent to the second portion and having a refractive index different from that of the structure; Equipped with The first portion is in contact with the second portion. Optical elements.

Images