Multilayer film filter, imaging element, and camera module

Abstract

The present disclosure pertains to: a multilayer film filter with which it is possible to provide a highly-reliable filter; an imaging element; and a camera module. The multilayer film filter comprises: a first electrode provided to a light-entering surface side; a second electrode forming a pair with the first electrode; and, between the first electrode and the second electrode, an electrooptical layer formed from an electrooptical material of which the refractive index changes due to voltage, and a first insulating layer provided between the first electrode and the electrooptical layer and / or a second insulating layer provided between the second electrode and the electrooptical layer. The present technology can be applied to, for example, a Fabry-Perot type spectroscope.

Description

Multilayer filters, image sensors, and camera modules

[0001] The present disclosure relates to a multilayer filter, an imaging element, and a camera module, and more particularly to a multilayer filter, an imaging element, and a camera module that are capable of suppressing the occurrence of a transmission wavelength shift, for example.

[0002] Conventionally, imaging devices use imaging elements such as CMOS (Complementary Metal Oxide Semiconductor) image sensors and CCD (Charge Coupled Device) image sensors. Image sensors have a device structure in which color filters that transmit light in the red, green, and blue wavelength ranges are stacked on the light-receiving surface, and an image is captured by detecting light in each wavelength range.

[0003] In recent years, the applications of image sensors have expanded. For example, they are being considered for detecting and capturing images of light in the infrared wavelength range, or for capturing images by decomposing and detecting light into multiple wavelengths (multispectral) beyond red, green, and blue, and filters suitable for these applications are also being considered.

[0004] Various filters have been studied, including color filters using inorganic materials and photonic crystals (see, for example, Patent Documents 1 and 2). Color filters called wire grids and metal optical filters have also appeared (see, for example, Patent Document 3).

[0005] International Publication No. 2006 / 028128 International Publication No. 2005 / 013369 Japanese Patent Application Laid-Open No. 2018-98341

[0006] This is a filter that can selectively extract light of a specific wavelength, and there is a demand for a highly reliable filter with a low risk of breakage.

[0007] The present technology has been made in view of such circumstances, and makes it possible to provide a highly reliable filter.

[0008] A multilayer filter according to one aspect of the present technology is a multilayer filter including: a first electrode provided on a light incident surface side; a second electrode paired with the first electrode; an electro-optical layer between the first electrode and the second electrode, the electro-optical layer being made of an electro-optical material whose refractive index changes with voltage; a first insulating layer provided between the first electrode and the electro-optical layer; and at least one or both of a second insulating layer provided between the second electrode and the electro-optical layer.

[0009] An imaging element according to one aspect of the present technology includes a pixel array section in which a plurality of pixels are provided, each including a photoelectric conversion section that photoelectrically converts incident light, and a multilayer filter that transmits light of a predetermined wavelength on the light incident surface side of the pixel array section, wherein the multilayer filter includes: a first electrode provided on the light incident surface side; a second electrode that forms a pair with the first electrode; an electro-optical layer made of an electro-optical material whose refractive index changes depending on voltage, between the first electrode and the second electrode; and at least one or both of a first insulating layer provided between the first electrode and the electro-optical layer and a second insulating layer provided between the second electrode and the electro-optical layer.

[0010] According to one aspect of the present technology, there is provided a camera module including: a pixel array section in which a plurality of pixels are provided; a multilayer filter that transmits light of a predetermined wavelength toward a light incident surface side of the pixel array section; and an optical section that guides light from outside to the pixels, wherein the multilayer filter includes: a first electrode provided toward the light incident surface side; a second electrode that forms a pair with the first electrode; an electro-optical layer between the first electrode and the second electrode, the electro-optical layer being made of an electro-optical material whose refractive index changes depending on a voltage; and at least one or both of a first insulating layer provided between the first electrode and the electro-optical layer; and a second insulating layer provided between the second electrode and the electro-optical layer.

[0011] A multilayer filter according to one aspect of the present technology includes a first electrode provided on the light incident surface side, a second electrode paired with the first electrode, an electro-optical layer between the first electrode and the second electrode made of an electro-optical material whose refractive index changes with voltage, and at least one or both of a first insulating layer provided between the first electrode and the electro-optical layer, and a second insulating layer provided between the second electrode and the electro-optical layer.

[0012] An imaging element according to one aspect of the present technology includes a pixel array section in which a plurality of pixels including a photoelectric conversion section that photoelectrically converts incident light are provided, and the multilayer filter on the light incident surface side of the pixel array section.

[0013] A camera module according to one aspect of the present technology includes a pixel array unit in which a plurality of pixels are provided, the multilayer filter on the light incident surface side of the pixel array unit, and an optical unit that guides external light to the pixels.

[0014] 1 is a diagram illustrating a configuration of an embodiment of a camera module to which the present technology is applied. FIG. 1 is a cross-sectional view illustrating a configuration example of an imaging element. FIG. 2 is a diagram illustrating a configuration example of a multilayer filter in a first embodiment. FIG. 3 is a diagram for explaining a Fabry-Perot filter. FIG. 4 is a diagram for explaining an energy band of a multilayer filter in a first embodiment. FIG. 5 is a diagram for explaining an image height. FIG. 6 is a diagram for explaining an angle of incidence of light at an image height. FIG. 7 is a diagram illustrating a configuration example of a multilayer filter in a second embodiment. FIG. 8 is a diagram illustrating a circuit configuration example of a multilayer filter in a third embodiment. FIG. 9 is a diagram illustrating a configuration example of a multilayer filter in a 4-1 embodiment. FIG. 10 is a diagram illustrating a configuration example of a multilayer filter in a 4-2 embodiment. FIG. 11 is a diagram illustrating a configuration example of a multilayer filter in a fifth embodiment. FIG. 12 is a diagram illustrating a configuration example of a multilayer filter in a sixth embodiment. FIG. 13 is a diagram illustrating a configuration example of a multilayer filter in a seventh embodiment. FIG. 14 is a diagram illustrating another configuration example of a multilayer filter in the seventh embodiment. FIG. 15 is a diagram illustrating a configuration example of an electronic device. FIG. 16 is a diagram illustrating an example of a schematic configuration of an endoscopic surgery system. FIG. 17 is a block diagram illustrating an example of the functional configuration of a camera head and a CCU. FIG. 18 is a block diagram illustrating an example of a schematic configuration of a vehicle control system. FIG. 19 is an explanatory diagram illustrating an example of installation positions of an outside vehicle information detection unit and an imaging unit.

[0015] Hereinafter, modes for carrying out the present technology (hereinafter referred to as embodiments) will be described.

[0016] <Configuration Example of Camera Module> Fig. 1 is a diagram showing a cross-sectional configuration example of a camera module according to an embodiment to which the present technology is applied. The camera module 11 in Fig. 1 is mainly composed of an imaging block 21 having a mechanism for capturing an image, centered around an imaging element 31, and an optical block 22 that forms an image on the imaging surface of the imaging element 31 based on incident light incident on the imaging block 21.

[0017] The imaging block 21 has a plate 42 made of a hard metal or the like at the bottom in the figure for fixing the imaging element 31, and the imaging element 31 is adhered onto the plate 42 with adhesive 35. A circuit board 33 made of a substrate material such as ceramic or glass epoxy is provided on the plate 42, and the imaging element 31 and the circuit board 33 are electrically connected via metal wires 32.

[0018] The imaging element 31 is made up of a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor, has a pixel array section in which a plurality of pixels are arranged in an array, and generates an image signal by photoelectrically converting incident light from a subject, from which infrared light components have been removed by an IRCF (IR Cut Filter) 37, on a pixel-by-pixel basis. Note that when receiving infrared light components, the IRCF 37 is not provided.

[0019] On the circuit board 33, there are provided a connector 39 that outputs image data captured by the image sensor 31 to an external device and receives control signals input from the external device to the image sensor 31, an LSI (Large Scale Integration) 40 that outputs a PWM (Pulse Width Modulation) signal to control an actuator that drives the lens 36 in the optical block 22 and has functions such as autofocus, a driver, and a controller, and a memory unit 41 that stores correction values ​​for correcting variations in each pixel of the image sensor 31.

[0020] On the circuit board 33, a spacer 34 is provided which fixes a holder 38 that stores a lens 36 and is integrated with an actuator that drives the lens 36 that constitutes the optical block 22.

[0021] The optical block 22 adjusts the focal length by driving the stored lens 36 in the optical axis direction (up and down in the figure) using an actuator integrated with the holder 38, and adjusts the incident light to form an image on the imaging surface of the image sensor 31. An IRCF 37 that removes infrared light is provided between the lens 36 and the image sensor 31. The IRCF 37 removes the infrared light component contained in the incident light and transmits it to the image sensor 31.

[0022] <Example of Cross-Sectional Configuration of Image Sensor> FIG. 2 is a cross-sectional view showing an example of the configuration of the image sensor 31. As shown in FIG.

[0023] The image sensor 31 is arranged in an array in the pixel array section. In the image sensor 31, PDs (photodiodes) 119 constituting pixels 110 receive incident light 101 incident from the back surface (top surface in the drawing) of a semiconductor substrate 118. A planarization film 113, a multilayer filter 112, and an on-chip lens 111 are provided above the PD 119, and the PD 119 receives the incident light 101, which has passed through each section in sequence, on a light-receiving surface 117 and performs photoelectric conversion.

[0024] For example, in the PD 119, an n-type semiconductor region 120 is formed as a charge accumulation region that accumulates electric charges (electrons). In the PD 119, the n-type semiconductor region 120 is provided inside p-type semiconductor regions 116, 141 of a semiconductor substrate 118. A p-type semiconductor region 141 having a higher impurity concentration than the back surface (upper surface) side of the n-type semiconductor region 120 is provided on the front surface (lower surface) side of the semiconductor substrate 118. In other words, the PD 119 has a HAD (Hole-Accumulation Diode) structure, and the p-type semiconductor regions 116, 141 are formed so as to suppress the generation of dark current at each interface between the upper surface side and the lower surface side of the n-type semiconductor region 120.

[0025] A pixel separation section 130 that electrically separates the plurality of pixels 110 is provided inside the semiconductor substrate 118, and the PD 119 is provided in an area partitioned by this pixel separation section 130. When the image sensor is viewed from the top side in the figure, the pixel separation section 130 is formed, for example, in a lattice shape so as to be interposed between the plurality of pixels 110, and the PD 119 is formed within the area partitioned by this pixel separation section 130.

[0026] The anode of each PD 119 is grounded, and the signal charge (e.g., electrons) accumulated by the PD 119 in the image sensor is read out via a transfer Tr (MOS FET) (not shown) or the like, and output as an electrical signal to a VSL (vertical signal line) (not shown).

[0027] The wiring layer 150 is provided on the surface (lower surface) of the semiconductor substrate 118 opposite to the back surface (upper surface) on which the light-shielding film 114, the multilayer filter 112, the on-chip lens 111, and other components are provided.

[0028] The wiring layer 150 includes wiring 151 and an insulating layer 152, and the wiring 151 is formed in the insulating layer 152 so as to be electrically connected to each element. The wiring layer 150 is a so-called multi-layer wiring layer, and is formed by alternately stacking interlayer insulating films constituting the insulating layer 152 and wiring 151 multiple times. Here, the wiring 151 includes wiring to a Tr for reading out charges from the PD 119, such as a transfer Tr, and wiring such as a VSL, which are stacked via the insulating layer 152.

[0029] A support substrate 161 is provided on the surface of the wiring layer 150 opposite to the side where the PD 119 is provided. For example, a substrate made of a silicon semiconductor and having a thickness of several hundred μm is provided as the support substrate 161.

[0030] The light-shielding film 114 is provided on the back surface (top surface in the drawing) of the semiconductor substrate 118 .

[0031] The light-shielding film 114 is configured to block a part of the incident light 101 traveling from above the semiconductor substrate 118 toward below the semiconductor substrate 118 .

[0032] The light-shielding film 114 is provided above a pixel separation portion 130 provided inside the semiconductor substrate 118. Here, the light-shielding film 114 is provided so as to protrude in a convex shape on the rear surface (upper surface) of the semiconductor substrate 118 via an insulating film 115 such as a silicon oxide film. In contrast, above the PD 119 provided inside the semiconductor substrate 118, the light-shielding film 114 is not provided, and an opening is formed so that incident light 101 can be incident on the PD 119.

[0033] That is, when the image sensor is viewed from above in the figure, the planar shape of the light-shielding film 114 is a lattice shape, and openings are formed through which the incident light 101 passes to the light-receiving surface 117 .

[0034] The light-shielding film 114 is formed of a light-shielding material that blocks light. For example, the light-shielding film 114 is formed by sequentially stacking a titanium (Ti) film and a tungsten (W) film. Alternatively, the light-shielding film 114 can be formed by sequentially stacking a titanium nitride (TiN) film and a tungsten (W) film. The light-shielding film 114 may also be coated with nitride (N) or the like.

[0035] The light-shielding film 114 is covered with a planarizing film 113. The planarizing film 113 is made of an insulating material that transmits light.

[0036] The pixel separating section 130 includes a groove section 131 , a fixed charge film 132 , and an insulating film 133 .

[0037] The fixed charge film 132 is formed on the rear surface (upper surface) side of the semiconductor substrate 118 so as to cover the grooves 131 that separate the plurality of pixels 110 .

[0038] Specifically, the fixed charge film 132 is provided to a certain thickness so as to cover the inner surface of a groove 131 formed on the back surface (upper surface) of the semiconductor substrate 118. An insulating film 133 is provided (filled) so as to embed the inside of the groove 131 covered with the fixed charge film 132.

[0039] Here, the fixed charge film 132 is formed using a high dielectric constant material having a negative fixed charge so that a positive charge (hole) accumulation region is formed at the interface with the semiconductor substrate 118, thereby suppressing the generation of dark current. Since the fixed charge film 132 is formed to have a negative fixed charge, an electric field is applied to the interface with the semiconductor substrate 118 by the negative fixed charge, and a positive charge (hole) accumulation region is formed.

[0040] The fixed charge film 132 can be formed of, for example, a hafnium oxide film (HfO film). The fixed charge film 132 can also be formed to contain at least one of oxides of other elements, such as hafnium, zirconium, aluminum, tantalum, titanium, magnesium, yttrium, and lanthanoid elements.

[0041] The technology according to the present disclosure can be applied to the image sensor described above.

[0042] <First Embodiment> Fig. 3 is a diagram showing an example of the configuration of the multilayer filter 112 according to the first embodiment. The multilayer filter 112a shown in Fig. 3 has a configuration in which, in order from the light incident surface side (the upper side in the figure), a mirror electrode 201-1, an insulating layer 202-1, an electro-optical layer 203, an insulating layer 202-2, and a mirror electrode 201-2 are stacked. Hereinafter, when there is no need to distinguish between the mirror electrode 201-1 and the mirror electrode 201-2, they will simply be referred to as the mirror electrode 201. Other parts will be described in the same manner.

[0043] The multilayer filter 112a constitutes a Fabry-Perot filter (spectroscope). A typical Fabry-Perot spectrometer will be described with reference to FIG. 4. A Fabry-Perot spectrometer can be used as a filter that transmits light of a specific wavelength. As shown in FIG. 4, a Fabry-Perot spectrometer is an optical device that is composed of two mirrors, 221-1 and 221-2, and is arranged so that the two mirrors 221-1 and 221-2 face each other and are parallel to each other. The mirrors 221-1 and 221-2 are designed to have appropriate reflectance and transmittance.

[0044] Light entering one side of the Fabry-Perot spectrometer (the upper side in the figure) is reflected back and forth between the two reflecting surfaces many times, causing interference, and the wavelength that strongly resonates depending on the film thickness between the two reflecting surfaces has a high transmittance. Therefore, when used as a spectrometer, extremely high wavelength resolution can be achieved.

[0045] That is, from the incident light, a wavelength to be analyzed by the Fabry-Perot spectrometer can be selected, and the selected light can be received by the PD 119 (FIG. 2).

[0046] The Fabry-Perot spectrometer is configured so that light of a predetermined wavelength is transmitted by interference caused by light being reflected back and forth between mirror 221-1 and mirror 221-2. The wavelength of the transmitted light can be set by the distance between mirror 221-1 and mirror 221-2. In other words, by changing the distance between mirror 221-1 and mirror 221-2, light of a desired wavelength can be transmitted.

[0047] For example, a voltage can be applied to mirror 221-1 and mirror 221-2, and the distance between mirror 221-1 and mirror 221-2 can be adjusted by electrostatic attraction. Such a Fabry-Perot spectrometer that can change the wavelength band of light to be transmitted is called a MEMS (Micro Electro Mechanical Systems) Fabry-Perot spectrometer, etc.

[0048] The multilayer filter 112a shown in Fig. 3 is a Fabry-Perot spectrometer that can variably set the wavelength band of light to be transmitted to a desired wavelength band, but has a mechanism different from that of a MEMS Fabry-Perot spectrometer. The multilayer filter 112a shown in Fig. 3 has an electro-optic layer 203 between the mirror electrodes 201-1 and 201-2, and is configured so that the wavelength band of light to be transmitted can be set by applying a predetermined voltage to the electro-optic layer 203.

[0049] The electro-optic layer 203 is a layer made of an electro-optic material whose refractive index changes when a voltage is applied. Examples of electro-optic materials that can be used include 4-dimethyl-aminoN-methyl-4-stilbazoliumtosylate (DAST) and polymer-based electro-optic materials. The HOMO (Highest Occupied Molecular Orbital) and LUMO (Lowest Unoccupied Molecular Orbital) change depending on the material.

[0050] The optical path difference that determines the wavelength of light that passes through the multilayer filter 112a depends on the refractive index n and the distance d between the mirrors. The refractive index n can be changed by providing an electro-optical layer 203 and applying a voltage to the electro-optical layer 203. By changing the strength of the voltage applied to the multilayer filter 112a, the multilayer filter 112a can function as a filter that can transmit light of a desired wavelength.

[0051] In order to apply a voltage to the electro-optical layer 203, a mirror electrode 201-1 and a mirror electrode 201-2 that forms a pair with the mirror electrode 201-1 are provided above and below the electro-optical layer 203, respectively. The mirror electrode 201 has a light-reflecting surface and functions as a mirror and also as an electrode. The mirror electrode 201 corresponds to the mirror 221 in the Fabry-Perot spectrometer shown in FIG. 4 and is designed to have appropriate reflectance and transmittance. The mirror electrode 201 also functions as an electrode that applies a voltage to the electro-optical layer 203. The mirror electrode 201 can be made of, for example, silver (Ag).

[0052] The multilayer filter 112a shown in Figure 3 is configured to include an insulating layer 202-1 between the mirror electrode 201-1 and the electro-optical layer 203, and an insulating layer 202-2 between the mirror electrode 201-2 and the electro-optical layer 203. When the multilayer filter 112a is used as a spectrometer, it may be configured without the insulating layer 202. However, if the multilayer filter 112a is configured without the insulating layer 202 and is composed of the mirror electrode 201 and the electro-optical layer 203, a leakage current will easily flow when a voltage is applied to the electro-optical layer 203. This will be explained with reference to Figure 5.

[0053] 5A and 5B show the energy bands of a multilayer filter 112a composed of a mirror electrode 201 and an electro-optical layer 203. While FIG. 5 shows an example in which a material with a large LUMO is used for the electro-optical layer, allowing electrons to flow easily through the LUMO, a similar effect can be achieved with a material with a small HOMO, allowing holes to flow easily through the HOMO. FIG. 5A shows a state in which no voltage is applied, in which electrons do not flow through the electro-optical layer 203. FIG. 5B shows a state in which a voltage is applied, in which electrons easily flow through the electro-optical layer 203. Therefore, when a voltage is applied to the electro-optical layer 203, a current flows, increasing power consumption. Furthermore, when a current flows through the electro-optical layer 203 and power consumption increases, in other words, a leakage current occurs, which may damage the electro-optical layer 203 and reduce the reliability of the filter.

[0054] In the multilayer filter 112a shown in Fig. 3, the insulating layer 202 is provided between the mirror electrode 201 and the electro-optical layer 203, thereby suppressing the occurrence of leakage current. Fig. 5C shows the energy band of the multilayer filter 112a shown in Fig. 3. As shown in Fig. 5C, by providing the insulating layers 202-1 and 202-2 on both ends of the electro-optical layer 203, the insulating layers act as a barrier to current injection from the electrodes even when a voltage is applied, thereby suppressing leakage current.

[0055] By providing the insulating layer 202, no current flows through the insulating layer 202 even when a voltage is applied, preventing current from flowing through the electro-optical layer 203 and reducing power consumption. This makes it possible to suppress the occurrence of leakage current, reduce the possibility of damage to the electro-optical layer 203, and improve the reliability of the filter.

[0056] The provision of the insulating layer 202 allows application of a high voltage, which increases the number of materials that can be used for the electro-optical layer 203, thereby improving the degree of freedom in selecting materials for the electro-optical layer 203. This allows application of a high voltage, and ensures reliability even when a high voltage is applied.

[0057] Materials such as silicon oxide and silicon nitride can be used for the insulating layer 202. Note that, although the explanation will be continued here using an example in which there are two layers, namely, insulating layer 202-1 and insulating layer 202-2, in order to function as the multilayer filter 112, it is also possible to use a configuration in which only one of insulating layer 202-1 and insulating layer 202-2 is provided.

[0058] 3 can change the refractive index n by applying a voltage, thereby changing the wavelength of light that passes through (hereinafter referred to as the transmission wavelength). Utilizing this, a multilayer filter 112 that maintains the same transmission wavelength regardless of the image height and allows desired light to be received will be described below.

[0059] 6 is a plan view of a pixel array section 51 having a plurality of pixels, as viewed from the surface of the semiconductor substrate 118 (FIG. 2) that constitutes the pixel array section 51, i.e., from a direction (hereinafter also referred to as the optical axis direction) perpendicular to the light receiving surface of the pixel array section 51. In the pixel array section 51, a plurality of image pickup elements 31 shown in FIG. 2 are arranged in an array.

[0060] 6, position P1 in the pixel array unit 51 is the center position of the light receiving surface of the pixel array unit 51, i.e., the position at the center of the image height. Position P2, which is to the right of position P1 in the figure, is a position on the image height end side (high image height side) away from the image height center, i.e., a position on the end side of the light receiving surface of the pixel array unit 51.

[0061] As shown in FIG. 7 , at position P1 at the center of the image height (center of the screen) in the pixel array section 51, light is incident in a substantially vertical direction (incident angle θ = 0 degrees). However, at a position away from the center of the image height in the pixel array section 51, i.e., position P2 at the edge of the screen, the incident angle θ of the light incident on the pixel becomes larger, which may result in a transmission wavelength shift.

[0062] The refractive index of the electro-optic layer 203 of the multilayer filter 112 is adjusted so that the transmission wavelengths at the center of the imaging surface of the image sensor and the edges of the imaging surface match. Optical interference depends on n × cos θ, where n is the refractive index and θ is the angle of incidence. Therefore, at the edges where the angle of incidence θ is large, the refractive index n is increased accordingly, thereby suppressing fluctuations in the transmission wavelength due to interference.

[0063] Therefore, the multilayer filter 112 can reduce the occurrence of a transmission wavelength shift by adjusting the voltage applied to the electro-optic layer 203 so that the refractive index is greater at the edges of the screen than at the center of the screen.

[0064] Fig. 8 is a diagram showing the configuration of the multilayer filter 112b in the second embodiment. The left diagram in Fig. 8 shows the configuration of the multilayer filter 112b at the center of the screen (position P1), the middle diagram in Fig. 8 shows the configuration of the multilayer filter 112b at the center between the center of the screen (position P1) and the edge of the screen (position P2) (referred to as "center-edge of the screen"), and the right diagram in Fig. 8 shows the configuration of the multilayer filter 112b at the edge of the screen (position P2).

[0065] In the multilayer filter 112b, parts that are the same as those in the multilayer filter 112a (FIG. 3) of the first embodiment are given the same reference numerals, and their description will be omitted where appropriate. Similarly, in the embodiments described below, parts that are the same as those in the multilayer filter 112a (FIG. 3) of the first embodiment are given the same reference numerals, and their description will be omitted where appropriate.

[0066] The multilayer filter 112b shown in Fig. 8 differs from the multilayer filter 112a (Fig. 3) in the first embodiment in that the insulating layer 202-2 disposed in the lower layer is replaced with an insulating layer 251. The multilayer filter 112b shown in Fig. 8 has a laminated structure in which, from the light incident surface side, a mirror electrode 201-1, an insulating layer 202-1, an electro-optical layer 203, an insulating layer 251, and a mirror electrode 201-2 are stacked.

[0067] The insulating layer 202-1 and the insulating layer 251 are provided as a pair of insulating layers. A conductive film 252 is provided below the electro-optical layer 203. In FIG. 5, the insulating layers to the left and right of the conductive film 252 are formed of the same material as the insulating layer 251, and the conductive film 252 is included within the insulating layer 251. This configuration is acceptable, or the layer containing the conductive film 252 may be configured as a separate layer made of a different material from the insulating layer 251. The conductive film 252 is made of a transparent material. This conductive film 252 is provided as a floating layer between the electro-optical layer 203 and the insulating layer 251. The conductive film 252 can be formed of, for example, ITO (indium tin oxide).

[0068] The insulating layer 251 is composed of an insulator 261 and an insulator 262. The capacitance of the insulating layer 251 is adjusted by adjusting the capacitance ratio between the insulators 261 and 262, thereby adjusting the magnitude of the voltage applied to the electro-optical layer 203.

[0069] The insulating layer 251 of the multilayer filter 112b arranged at the center of the screen shown in the left diagram of Fig. 8 is made up of an insulator 261 and does not include an insulator 262. The insulating layer 251 of the multilayer filter 112b arranged at the edge of the screen shown in the middle diagram of Fig. 8 is configured so that the insulator 262-1 is included in the insulator 261 at a predetermined capacitance ratio. The insulating layer 251 of the multilayer filter 112b arranged at the edge of the screen shown in the right diagram of Fig. 8 is configured so that the insulator 262-2 is included in the insulator 261 at a predetermined capacitance ratio.

[0070] The insulators 262 are formed in the shape of, for example, a cylinder or a prism inside the insulator 261. The insulators 262-2 at the screen edge are formed larger than the insulators 262-1 at the screen center-edge. The insulators 262 are formed to gradually increase in size in the direction moving from the screen center toward the edge of the field of view, and are configured so that the proportion of the insulators 262 in the insulating layer 251 gradually increases.

[0071] Here, reference is made to Fig. 9. Fig. 9A is a circuit diagram showing the configuration of the multilayer filter 112b (left diagram in Fig. 8) arranged at the center of the screen, and Fig. 9B is a circuit diagram showing the configuration of the multilayer filter 112b (right diagram in Fig. 8) arranged at the edge of the screen.

[0072] 9A, the multilayer filter 112b located at the center of the screen has a configuration in which capacitors C1 and C2 are connected in series. Capacitor C1 is a capacitor formed by the electro-optical layer 203 and the upper insulating layer (insulating layer 202-1), and capacitor C2 is a capacitor formed by the lower insulating layer (insulating layer 251).

[0073] Referring to the circuit diagram of the multilayer filter 112b arranged at the edge of the screen shown in FIG. 9B, the configuration shows that capacitors C11 and C12 are connected in series. Capacitor C11 is a capacitor formed by the electro-optical layer 203 and the upper insulating layer (insulating layer 202-1). Capacitor C12 is a capacitor formed by the lower insulating layer (insulating layer 251). However, since insulating layer 251 includes insulators 261 and 262-2, the configuration shows that a capacitor formed by insulator 261 (referred to as capacitor C21) and a capacitor formed by insulator 262-2 (referred to as capacitor C22) are connected in parallel.

[0074] The same voltage is applied to the multilayer filter 112b at the center of the screen and the multilayer filter 112b at the edge of the screen. The voltage applied to the electro-optical layer 203 of the multilayer filter 112b at the center of the screen, in other words, the voltage applied to capacitor C1, is determined by the capacitance ratio between capacitors C1 and C2. Similarly, the voltage applied to the electro-optical layer 203 of the multilayer filter 112b at the edge of the screen, in other words, the voltage applied to capacitor C11, is determined by the capacitance ratio between capacitors C11 and C12.

[0075] For these reasons, the magnitude of the voltage applied to the electro-optical layer 203 of the multilayer filter 112b at the center of the screen is different from the magnitude of the voltage applied to the electro-optical layer 203 of the multilayer filter 112b at the edge of the screen, and therefore the refractive index n1 of the electro-optical layer 203 of the multilayer filter 112b at the center of the screen is different from the refractive index n2 of the electro-optical layer 203 of the multilayer filter 112b at the edge of the screen.

[0076] For these reasons, by adjusting the capacitance of capacitor C12, it is possible to adjust the magnitude of the voltage applied to the electro-optical layer 203, thereby adjusting the refractive index of the electro-optical layer 203, and as a result, adjusting the transmission wavelength. Even if the incident angle θ of light incident on the pixel increases, it is possible to prevent the occurrence of a transmission wavelength shift by appropriately adjusting the refractive index of the electro-optical layer 203.

[0077] The capacitance of the capacitor C12 can be set by adjusting the proportion of the insulator 262 in the insulating layer 251. Referring again to FIG. 8 , the insulating layer 251 is configured so that the ratio of the insulator 261 to the insulator 262 varies depending on the position within the pixel array section 51. The insulators 261 and 262 are formed of insulating materials with different relative dielectric constants. The insulator 261 is formed using, for example, SiN (silicon nitride), and the insulator 262 is formed using HfO2 (hafnium oxide). Using materials with similar refractive indices for the insulators 261 and 262 can prevent interference in the insulating layer 251.

[0078] It is possible to adjust the voltage applied to the electro-optical layer 203 according to the mixing ratio of the insulators 261 and 262 in the insulating layer 251, in other words, the volume ratio of the insulators 261 and 262. Therefore, as shown in Fig. 8, the volume ratio of the insulators 261 and 262 is set depending on the position of the multilayer filter 112b in the pixel array section 51 so as to obtain a desired refractive index at that position.

[0079] The volume ratio of the insulator 262 is gradually increased in the direction from the center of the screen toward the edge of the angle of view, and the proportion of the insulator 262 in the insulating layer 251 is gradually increased. As shown in the right diagram of Fig. 8 , the insulating layer 251 arranged at the center of the screen is formed only with the insulator 261 and does not include the insulator 262.

[0080] As shown in the middle diagram of Fig. 8, the insulating layer 251 arranged between the center and the edge of the screen is configured to include, for example, a cylindrical insulator 262-1. As shown in the left diagram of Fig. 8, the insulating layer 251 arranged at the edge of the screen is configured to include, for example, a cylindrical insulator 262-2. The insulator 262-2 arranged at the edge of the field of view is configured to have a larger volume than the insulator 262-1 arranged between the center and the edge of the field of view.

[0081] Note that, here, it has been explained that the volume ratio of the insulator 262 is formed to gradually increase in the direction from the center of the screen toward the edge of the angle of view. However, since optical interference depends on n × cosθ using the refractive index n and the angle of incidence θ, even if the volume ratio gradually increases, it does not increase at a constant rate, but by increasing at a rate determined depending on cosθ, a more appropriate refractive index can be obtained, resulting in a multilayer filter 112 that can transmit light of the desired wavelength with high precision regardless of the position of the pixel array section 51.

[0082] Here, as shown in Figure 8, an example is described in which the shape of the insulator 262, for example, a cylindrical shape, remains the same but the size (volume) of the insulator 262 increases. However, the shape and size of the insulator 262 are not limited to the example given here, as long as the volume ratio is configured to be different. For example, as in the insulator 262-1 shown in the middle diagram of Figure 8, a configuration may be used in which thin, circular insulators 262 are arranged so that their density varies depending on their position in the pixel array section 51. In this case, the density per unit volume at which the insulators 262 are arranged gradually increases in the direction from the center of the screen toward the edge of the angle of view, so that the proportion of the insulator 262 in the insulating layer 251 gradually increases.

[0083] In this way, the insulating layer 251 is configured to include insulators 261 and 262 having different dielectric constants, and the volume ratio of the insulators 261 and 262 is adjusted depending on the position of the pixel array section 51 so that the refractive index of the electro-optical layer 203 becomes the desired refractive index that suppresses the transmission wavelength shift, thereby making it possible to configure a multilayer filter 112 that transmits light of the same wavelength regardless of the incident angle of the light.

[0084] In Figure 8, an example is given in which insulating layer 251 including insulators 261 and 262 having different dielectric constants is used as the lower insulating layer, but it is also possible to provide insulating layer 251 at the position of the upper insulating layer, i.e., insulating layer 202-1, and to provide insulating layer 202-2 (Figure 3) as the lower insulating layer.

[0085] 10 is a diagram showing an example of the configuration of a multilayer filter 112c according to a third embodiment. In the following description, a multilayer filter 112 arranged at the center of the screen and a multilayer filter 112 arranged at an edge of the screen are taken as examples.

[0086] The multilayer filter 112c shown in FIG. 10 has a structure in which a mirror electrode 201-1, an insulating layer 202-1, an electro-optical layer 203, a mirror conductive film 301, an insulating layer 251, and a transparent electrode 302 are stacked in this order from the light incident surface side.

[0087] Comparing the multilayer filter 112c shown in Figure 10 with the multilayer filter 112b shown in Figure 8, the difference is that the conductive film 252 and mirror electrode 201-2 included in the multilayer filter 112b shown in Figure 8 are replaced with a mirror conductive film 301 having a mirror function (light reflecting surface) and a transparent electrode 302 having no mirror function, respectively, but the other points are the same.

[0088] In the multilayer filter 112c shown in FIG. 10, the electrode that applies a voltage to the electro-optical layer 203 and that forms a pair with the electrode function of the mirror electrode 201-1 arranged in the upper layer is a transparent electrode 302, and the mirror that forms a pair with the mirror function is a mirror conductive film 301. The mirror conductive film 301 is provided between the electro-optical layer 203 and the insulating layer 251. The mirror conductive film 301 can be made of silver (Ag). The mirror electrode 201-1 and the mirror conductive film 301 may be made of the same material or different materials.

[0089] By providing the mirror conductive film 301, the electrode provided in the lower layer, which is used to apply a voltage to the electro-optical layer 203, can be an electrode that does not function as a mirror, and can be a transparent electrode 302 made of a transparent material, such as ITO.

[0090] The insulating layer 251 is provided as an insulating layer paired with the insulating layer 202-1, and like the insulating layer 251 of the multilayer filter 112b in the second embodiment (Figure 8), is composed of insulators 261 and 262, and is configured so that by adjusting the volume ratio of the insulators 261 and 262, the magnitude of the voltage applied to the electro-optical layer 203 is adjusted and the occurrence of a transmission wavelength shift is suppressed.

[0091] In the multilayer filter 112c, the portion constituting the Fabry-Perot type spectrometer is a portion in which a mirror electrode 201-1, an insulating layer 202-1, an electro-optical layer 203, and a mirror conductive film 301 are stacked, and the structure sandwiched between the mirror layers is a simple structure in which the electro-optical layer 203 and the insulating layer 202-1 formed of a single insulator are sandwiched between the mirror layers, and this structure makes it easier to consider the optical effects of the materials in the Fabry-Perot resonant layer.

[0092] 10 illustrates an example in which the insulating layer 251 including the insulators 261 and 262 having different dielectric constants is used as the lower insulating layer, but the insulating layer 251 may be provided at the position of the upper insulating layer, i.e., the insulating layer 202-1, and the insulating layer 202-2 (FIG. 3) may be provided as the lower insulating layer. Furthermore, when the insulating layer 251 including the insulators 261 and 262 having different dielectric constants is provided as the upper layer, the mirror conductive film 301 is also provided as the upper layer.

[0093] <Embodiment 4-1> FIG. 11 is a diagram showing an example of the configuration of a multilayer filter 112d according to embodiment 4-1.

[0094] The multilayer filter 112d shown in FIG. 11 has a structure in which a mirror electrode 201-1, an insulating layer 202-1, an electro-optical layer 203, a mirror conductive film 301, an insulating layer 202-2, and an electrode 321 are stacked in this order from the light incident surface side.

[0095] Comparing the multilayer filter 112d shown in Figure 11 with the multilayer filter 112c shown in Figure 10, the difference is that the insulating layer 251 included in the multilayer filter 112c shown in Figure 10 is replaced by an insulating layer 202-2 made of the same material, and the lower transparent electrode 302 is replaced by an electrode 321 that is partially interrupted in cross section, but the other points are the same.

[0096] The multilayer filter 112d shown in Figure 11 has a structure in which the refractive index is adjusted by adjusting the area of ​​the electrode 321 to adjust the voltage applied to the electro-optic layer 203. The electrode 321 located at the center of the screen is formed, for example, in a grid pattern on the lower surface of the insulating layer 202-2. For example, by forming it in a grid pattern, an area where the electrode 321 is not formed (an area within the grid) is provided on the surface of the insulating layer 202-2 of the multilayer filter 112d on the side where the electrode 321 is located. At the center of the screen, the area of ​​the area where the electrode 321 is formed per unit area of ​​the insulating layer 202-2 is small, for example, formed to a ratio of about 50%.

[0097] The electrodes 321 disposed at the screen edges are formed, for example, as a solid coating on the underside of the insulating layer 202-2, so that the area of ​​the region where the electrodes 321 are formed per unit area of ​​the insulating layer 202-2 at the screen edges is 100%.

[0098] The electrodes 321 are formed so that the ratio (occupancy) of the area per unit area where they are formed gradually increases in the direction from the center of the screen toward the edge of the angle of view. When the area where the electrodes 321 are formed is small, the voltage applied to the electro-optical layer is small, and when the area where the electrodes 321 are formed is large, the voltage applied to the electro-optical layer is large. By utilizing this, the voltage applied to the electro-optical layer 203 is adjusted depending on the position in the pixel array unit 51 where the multilayer filter 112d is arranged, and the refractive index of the electro-optical layer 203 is adjusted.

[0099] In the second and third embodiments, when the voltage applied to the center of the screen is used as a reference, the voltage applied to the edges of the field of view is adjusted to be greater than that to the center of the screen, whereas in the fourth embodiment, when the voltage applied to the edges of the screen is used as a reference, the voltage applied to the center of the field of view is adjusted to be smaller than that to the edges of the screen.

[0100] In the second to fourth embodiments, the voltage applied to the edge of the angle of view is adjusted to be relatively larger than that applied to the center of the screen.

[0101] 11, the electrode 321 disposed in the lower layer may be formed as a transparent electrode, and may be formed using, for example, ITO. Also, the insulating layers 202-1 and 202-2 are a pair of insulating layers, similar to the multilayer filter 112a shown in FIG. 3, and may be formed of the same material or different materials.

[0102] Like the multilayer filter 112c shown in FIG. 10, the multilayer filter 112d shown in FIG. 11 has a Fabry-Perot type spectrometer in which a mirror electrode 201-1, an insulating layer 202-1, an electro-optical layer 203, and a mirror conductive film 301 are laminated. The structure sandwiched between the mirror layers is a simple structure in which the electro-optical layer 203 and the insulating layer 202-1 are formed solely from an insulator, and this structure makes it easier to consider the optical effects of the materials in the Fabry-Perot resonant layer.

[0103] <Embodiment 4-2> FIG. 12 is a diagram showing an example of the configuration of a multilayer filter 112d according to embodiment 4-2.

[0104] The multilayer filter 112d shown in Figure 11 has been described as an example of a configuration in which the capacitance of the capacitor formed in the lower layer of the electro-optical layer 203 is adjusted by adjusting the area of ​​the electrode 321 in the lower layer. However, as shown in Figure 12, an electrode 321 may be provided at the position of the mirror electrode 201-1 in the upper layer, and the mirror electrode 201-1 may be provided as the electrode in the lower layer.

[0105] The multilayer filter 112d shown in FIG. 12 has a structure in which a transparent electrode 321, an insulating layer 202-1, a mirror conductive film 301, an electro-optical layer 203, an insulating layer 202-2, and a mirror electrode 201-2 are stacked in this order from the light incident surface side.

[0106] In the multilayer filter 112d shown in Fig. 12, a transparent electrode 321 is provided on the light incident surface side. The transparent electrode 321 is formed using, for example, ITO. As in the case shown in Fig. 11, the transparent electrode 321 is formed so that the proportion (occupancy) of the area where the electrode 321 is formed per unit area gradually increases in the direction from the center of the screen toward the edge of the angle of view.

[0107] When the electrode 321 is provided in the upper layer, the mirror conductive film 301 is also provided on the insulating layer 202-1 side provided in the upper layer.

[0108] Fifth Embodiment FIG. 13 is a diagram showing an example of the configuration of a multilayer filter 112f according to a fifth embodiment.

[0109] The multilayer filter 112f of the fifth embodiment shown in Fig. 13 is different from the multilayer filters 112 of the second to fifth embodiments in that the electro-optical layer 203e is not formed continuously but is configured as a separate layer for each pixel, but is otherwise similar. The multilayer filter 112f shown in Fig. 13 shows a configuration in which the fifth embodiment is applied to the multilayer filter 112d of the fourth embodiment shown in Fig. 11, but the fifth embodiment can also be applied in combination with any one or more of the first to fourth embodiments.

[0110] 13, an insulating layer 202 is formed between the electro-optical layers 203e disposed between adjacent pixels, separating the electro-optical layers 203e from each other. By separating the electro-optical layers 203e in this manner, optical color mixing and electrical crosstalk in the electro-optical layers 203e can be suppressed.

[0111] The electro-optical layer 203e may be separated for every predetermined number of pixels, for example, every four pixels of 2 × 2. The separation unit is not limited to one pixel unit, and may be a unit of several pixels.

[0112] Sixth Embodiment FIG. 14 is a diagram showing an example of the configuration of a multilayer filter 112g according to a sixth embodiment.

[0113] The multilayer filter 112g of the sixth embodiment shown in Figure 14 differs from the multilayer filter 112a of the second embodiment (Figure 8) in that it does not have a conductive film 252, but is basically the same in other respects.

[0114] 8, the multilayer filter 112g disposed at the pixel edge has an insulating layer 251 composed of insulators 261 and 262 having different dielectric constants. The insulators 262 contained in the insulating layer 251 of the multilayer filter 112g disposed at the pixel edge are formed in a fine pattern. The fine pattern means that each of the insulators 262 is formed finely, for example, in the shape of a thin cylinder.

[0115] If the insulator 262 is configured with a fine pattern, there is a possibility that non-uniformity will occur in the voltage applied to the electro-optical layer 203, as shown in the lower diagram of Fig. 14. In the lower diagram of Fig. 14, the wavy line shown next to the electro-optical layer 203 indicates the magnitude of the voltage applied to the electro-optical layer 203. As shown in the lower diagram of Fig. 14, a large voltage is applied in the region where the insulator 262 is formed, and a small voltage is applied between the insulators 262, i.e., in the region where the insulator 261 is formed.

[0116] It is possible to create an area where a voltage is applied and an area where no voltage is applied (a low voltage is applied), and the magnitude of the voltage applied to the electro-optical layer 203 can be adjusted by adjusting the ratio between the two areas.

[0117] The insulators 262 are arranged so that the density per unit area gradually increases in the direction from the center of the screen toward the edge of the viewing angle, thereby adjusting the magnitude of the voltage applied to the electro-optical layer 203.

[0118] 14, when viewed microscopically, the voltage applied to the electro-optic layer 203 may be non-uniform, which may lead to non-uniform modulation of the refractive index, i.e., an increase in the half-value width of the transmission wavelength. Whether or not to provide a conductive layer may be determined depending on the conductivity of the electro-optic layer 203 and the required half-value width of the transmission wavelength.

[0119] Seventh Embodiment FIG. 15 is a diagram showing an example of the configuration of a multilayer filter 112h according to a seventh embodiment.

[0120] The multilayer filter 112h of the seventh embodiment shown in Figure 15 differs from the multilayer filters 112 of the first to sixth embodiments in that the part having the mirror function is formed of a dielectric multilayer mirror 402, but can be configured in the same way in other respects.

[0121] The multilayer filter 112h shown in Fig. 15 has a configuration in which, from the light incident surface side, a transparent electrode 401-1, a dielectric multilayer mirror 402-1, an electro-optical layer 203, a transparent conductive film 403, a dielectric multilayer mirror 402-2, an insulating layer 251, and a transparent electrode 401-2 are stacked. The multilayer filter 112h shown in Fig. 15 shows a configuration in which the seventh embodiment is applied to the multilayer filter 112g in the sixth embodiment shown in Fig. 14, but the seventh embodiment can also be applied in combination with any one or more of the first to seventh embodiments.

[0122] The dielectric multilayer mirror 402 is configured by laminating, for example, silicon oxide layers and titanium nitride layers. For example, the mirror electrode 201 (FIG. 8) described above is a metal electrode that serves as both a mirror and an electrode, and therefore there is a possibility that a portion of the incident light is absorbed. However, such absorption can be suppressed by using the dielectric multilayer mirror 402.

[0123] The dielectric multilayer mirror 402 may be configured to be provided above the transparent electrode 401-1 and below the transparent electrode 401-2, as shown in Fig. 16. The multilayer filter 112h shown in Fig. 16 has a configuration in which, from the light incident surface side, a dielectric multilayer mirror 402-1, a transparent electrode 401-1, an electro-optical layer 203, a transparent conductive film 403, an insulating layer 251, a transparent electrode 401-2, and a dielectric multilayer mirror 402-2 are stacked.

[0124] 16, a configuration may be adopted in which the dielectric multilayer mirror 402-1 is provided above the transparent electrode 401-1, and the dielectric multilayer mirror 402-2 is provided below the transparent electrode 401-2. In other words, the dielectric multilayer mirror 402 may be disposed above or below the transparent electrode 401.

[0125] It is also possible to configure either the dielectric multilayer film mirror 402-1 or the dielectric multilayer film mirror 402-2 to be formed of the mirror electrode 201. Also, for example, it is possible to configure the multilayer film filter 112c (FIG. 10) in the third embodiment to have a dielectric multilayer film mirror 402 instead of the mirror conductive film 301.

[0126] According to the present technology, it is possible to provide a highly reliable Fabry-Perot spectrometer. The multilayer filter 112 can reduce power consumption. The multilayer filter 112 can transmit light of a desired transmission wavelength regardless of the image height of the pixel array.

[0127] The above-described multilayer filter 112 can be manufactured relatively easily without using fine lithography or the like, and therefore, it is possible to reduce the difficulty and cost of manufacturing.

[0128] <Application Examples to Electronic Devices> The present technology is applicable to general electronic devices that use an imaging element in an image capture unit (photoelectric conversion unit), such as imaging devices such as digital still cameras and video cameras, portable terminal devices with imaging functions, copiers that use an imaging element in an image reading unit, etc. The imaging element may be formed as a single chip, or may be in the form of a module having an imaging function in which the imaging unit and a signal processing unit or an optical system are packaged together.

[0129] Fig. 17 is a block diagram showing an example configuration of an imaging device as an electronic device to which the present technology is applied. The imaging device 1000 in Fig. 17 includes an optical unit 1001 including a lens group and the like, an imaging element (imaging device) 1002, and a DSP (Digital Signal Processor) circuit 1003 which is a camera signal processing circuit. The imaging device 1000 also includes a frame memory 1004, a display unit 1005, a recording unit 1006, an operation unit 1007, and a power supply unit 1008. The DSP circuit 1003, the frame memory 1004, the display unit 1005, the recording unit 1006, the operation unit 1007, and the power supply unit 1008 are connected to each other via a bus line 1009.

[0130] The optical unit 1001 takes in incident light (image light) from a subject and forms an image on the imaging surface of the image sensor 1002. The image sensor 1002 converts the amount of incident light formed on the imaging surface by the optical unit 1001 into an electrical signal on a pixel-by-pixel basis and outputs the signal as a pixel signal.

[0131] The display unit 1005 is configured with a thin display such as an LCD (Liquid Crystal Display) or an organic EL (Electro Luminescence) display, and displays moving images or still images captured by the imaging element 1002. The recording unit 1006 records the moving images or still images captured by the imaging element 1002 on a recording medium such as a hard disk or semiconductor memory.

[0132] An operation unit 1007, under user operation, issues operation commands for various functions of the imaging device 1000. A power supply unit 1008 appropriately supplies various types of power to the DSP circuit 1003, frame memory 1004, display unit 1005, recording unit 1006, and operation unit 1007 as operating power sources.

[0133] The above-described imaging element 31 and camera module 11 can be applied to a part of the imaging device shown in FIG.

[0134] <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.

[0135] FIG. 18 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.

[0136] 18 shows an operator (doctor) 11131 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.

[0137] 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 example shown, the endoscope 11100 is configured as a so-called rigid scope having a rigid lens barrel 11101, but the endoscope 11100 may also be configured as a so-called flexible scope having a flexible lens barrel.

[0138] 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 object to be observed inside 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.

[0139] An optical system and an image sensor are provided inside the camera head 11102, and light reflected from the object of observation (observation light) is collected onto 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 the observed image. The image signal is sent to a camera control unit (CCU) 11201 as RAW data.

[0140] The CCU 11201 is configured with a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), etc., and comprehensively controls 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), to display an image based on the image signal.

[0141] 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.

[0142] The light source device 11203 is composed of a light source such as an LED (light emitting diode), and supplies irradiation light to the endoscope 11100 when photographing the surgical area, etc.

[0143] 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 irradiation light, magnification, focal length, etc.) of the endoscope 11100.

[0144] 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 inflates the body cavity of the patient 11132 through the insufflation tube 11111 in order to ensure a clear field of view for the endoscope 11100 and a working space for the surgeon. The recorder 11207 is a device capable of recording various types of information related to the surgery. The printer 11208 is a device capable of printing various types of information related to the surgery in various formats such as text, images, or graphs.

[0145] The light source device 11203, which supplies illumination light to the endoscope 11100 when photographing the surgical site, can be configured from a white light source, such as an LED, a laser light source, or a combination of these. When the white light source is configured from a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high precision, allowing the light source device 11203 to adjust the white balance of the captured image. In this case, it is also possible to time-share images corresponding to each RGB by irradiating the object of observation with laser light from each RGB laser light source and controlling the drive of the image sensor of the camera head 11102 in synchronization with the irradiation timing. According to this method, color images can be obtained without providing a color filter to the image sensor.

[0146] Furthermore, the light source device 11203 may be controlled to change the intensity of light it outputs at predetermined time intervals. By controlling the driving of the image sensor of the camera head 11102 in synchronization with the timing of the change in light intensity to acquire images in a time-division manner and combining the images, it is possible to generate an image with a high dynamic range that is free from so-called blocked-up shadows and blown-out highlights.

[0147] The light source device 11203 may also be configured to supply light in a predetermined wavelength band corresponding to special light observation. Special light observation, for example, utilizes the wavelength dependence of light absorption in body tissues to irradiate light with a narrower band than the light irradiated during normal observation (i.e., white light), thereby capturing high-contrast images of specific tissues, such as blood vessels on the surface of mucous membranes, known as narrow-band imaging. Alternatively, special light observation may involve fluorescence observation, in which images are obtained using fluorescence generated by irradiating excitation light. Fluorescence observation may involve irradiating excitation light onto body tissues and observing the fluorescence from the tissue (autofluorescence observation), or by locally injecting a reagent such as indocyanine green (ICG) into the body tissue and irradiating the 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.

[0148] FIG. 19 is a block diagram showing an example of the functional configuration of the camera head 11102 and the CCU 11201 shown in FIG.

[0149] 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 via a transmission cable 11400 so that they can communicate with each other.

[0150] 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 composed of a combination of multiple lenses including a zoom lens and a focus lens.

[0151] The imaging unit 11402 may include one imaging element (a so-called single-chip type) or multiple imaging elements (a so-called multi-chip type). When the imaging unit 11402 is configured as a multi-chip 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 these 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 a 3D (dimensional) display. The 3D display allows the surgeon 11131 to more accurately grasp the depth of the biological tissue at the surgical site. Note that when the imaging unit 11402 is configured as a multi-chip type, multiple lens units 11401 may be provided corresponding to each imaging element.

[0152] 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 after the objective lens.

[0153] 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 adjusted appropriately.

[0154] The communication unit 11404 is configured by a communication device for transmitting and receiving various types of 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.

[0155] 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 imaging, and / or information specifying the magnification and focus of the captured image.

[0156] The image capturing conditions such as the frame rate, exposure value, magnification, and focus may be appropriately specified by the user, or may be automatically set by the control unit 11413 of the CCU 11201 based on the acquired image signal. In the latter case, the endoscope 11100 is equipped with a so-called AE (Auto Exposure) function, AF (Auto Focus) function, and AWB (Auto White Balance) function.

[0157] 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 .

[0158] The communication unit 11411 is configured by 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.

[0159] 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.

[0160] The image processing unit 11412 performs various image processing operations on the image signal, which is RAW data transmitted from the camera head 11102 .

[0161] The control unit 11413 performs various controls related to the imaging of the surgical site, etc. by the endoscope 11100 and the 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.

[0162] Furthermore, the control unit 11413 displays the captured image showing the surgical site, etc., on the display device 11202 based on the image signal subjected to image processing by the image processing unit 11412. At this time, the control unit 11413 may recognize various objects in the captured image using various image recognition technologies. For example, the control unit 11413 can recognize surgical tools such as forceps, specific biological parts, bleeding, mist generated when using the energy treatment tool 11112, etc., by detecting the shape and color of the edges of objects included in the captured image. When displaying the captured image on the display device 11202, the control unit 11413 may use the recognition results to superimpose various surgical support information on the image of the surgical site. By superimposing the surgical support information and presenting it to the surgeon 11131, the burden on the surgeon 11131 can be reduced and the surgeon 11131 can proceed with the surgery reliably.

[0163] The transmission cable 11400 connecting the camera head 11102 and the CCU 11201 is an electrical signal cable for electrical signal communication, an optical fiber for optical communication, or a composite cable of these.

[0164] 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.

[0165] <Application to a Mobile Body> 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 mobile body, such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, personal mobility, an airplane, a drone, a ship, or a robot.

[0166] FIG. 20 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a mobile object control system to which the technology according to the present disclosure can be applied.

[0167] 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 shown as functional components of the integrated control unit 12050 are a microcomputer 12051, an audio / video output unit 12052, and an in-vehicle network I / F (Interface) 12053.

[0168] 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.

[0169] The body system control unit 12020 controls the operation of various devices equipped in 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 headlamps, backup lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves transmitted from a portable device that serves as a key or signals from various switches can be input to the body system control unit 12020. The body system control unit 12020 receives these radio waves or signals and controls the vehicle's door lock device, power window device, lamps, etc.

[0170] 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 images outside the vehicle and receives the captured images. The outside-vehicle information detection unit 12030 may perform object detection processing or distance detection processing for people, cars, obstacles, signs, characters on the road surface, etc. based on the received images.

[0171] The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal corresponding to the amount of light received. The imaging unit 12031 can output the electrical signal as an image or as distance measurement information. The light received by the imaging unit 12031 may be visible light or invisible light such as infrared light.

[0172] 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 off.

[0173] The microcomputer 12051 can calculate control target values ​​for the driving force generating device, steering mechanism, or braking device based on the information inside and outside the vehicle acquired by the outside-vehicle information detection unit 12030 or the inside-vehicle information detection unit 12040, and output control commands to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing the functions of an ADAS (Advanced Driver Assistance System), including vehicle collision avoidance or impact mitigation, following driving based on the distance between vehicles, maintaining vehicle speed, vehicle collision warning, vehicle lane departure warning, etc.

[0174] 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 driver operation, by controlling the driving force generating device, steering mechanism, braking device, etc. based on information about the surroundings of the vehicle obtained by the outside vehicle information detection unit 12030 or the inside vehicle information detection unit 12040.

[0175] 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 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 information detection unit 12030, and perform cooperative control aimed at preventing glare, such as switching from high beams to low beams.

[0176] The audio / video output unit 12052 transmits at least one of audio and video output signals to an output device capable of visually or audibly notifying the passengers of the vehicle or the outside of the vehicle of information. In the example of Fig. 20, the output devices are exemplified by an audio speaker 12061, a display unit 12062, and an instrument panel 12063. The display unit 12062 may include, for example, at least one of an on-board display and a head-up display.

[0177] FIG. 21 is a diagram showing an example of the installation position of the imaging unit 12031.

[0178] In FIG. 21, the imaging unit 12031 includes imaging units 12101, 12102, 12103, 12104, and 12105.

[0179] The imaging units 12101, 12102, 12103, 12104, and 12105 are provided, for example, at positions such as the front nose, side mirrors, rear bumper, back door, and the top of the windshield inside the vehicle cabin of the vehicle 12100. The imaging unit 12101 provided on the front nose and the imaging unit 12105 provided on the top of the windshield inside the vehicle cabin mainly acquire images of the front of the vehicle 12100. The imaging units 12102 and 12103 provided on the side mirrors mainly acquire images of the sides of the vehicle 12100. The imaging unit 12104 provided on the rear bumper or back door mainly acquires images of the rear of the vehicle 12100. The imaging unit 12105 provided on the top of the windshield inside the vehicle cabin is mainly used to detect preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, lanes, etc.

[0180] 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, by overlaying the image data captured by the imaging units 12101 to 12104, an overhead image of the vehicle 12100 viewed from above can be obtained.

[0181] At least one of the image capturing units 12101 to 12104 may have a function of acquiring distance information. For example, at least one of the image capturing units 12101 to 12104 may be a stereo camera made up of multiple image capturing elements, or may be an image capturing element having pixels for phase difference detection.

[0182] For example, based on the distance information obtained from the imaging units 12101 to 12104, the microcomputer 12051 can calculate the distance to each three-dimensional object within the imaging ranges 12111 to 12114 and the change in this distance over time (relative speed with respect to the vehicle 12100), thereby extracting as a preceding vehicle, in particular, the three-dimensional object that is the closest three-dimensional object on the path of the vehicle 12100 and traveling in approximately the same direction as the vehicle 12100 at a predetermined speed (e.g., 0 km / h or higher). Furthermore, the microcomputer 12051 can set a vehicle-to-vehicle distance to be maintained in advance in front of the preceding vehicle, and perform automatic braking control (including follow-up stop control), automatic acceleration control (including follow-up start control), etc. In this way, cooperative control can be performed for the purpose of autonomous driving, which allows the vehicle to travel autonomously without relying on driver operation.

[0183] For example, the microcomputer 12051 classifies and extracts three-dimensional object data regarding 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. The microcomputer 12051 then determines a collision risk that indicates 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.

[0184] At least one of the image capturing 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 a pedestrian is present in the images captured by the image capturing units 12101 to 12104. Such pedestrian recognition is performed, for example, by extracting feature points from the images captured by the image capturing units 12101 to 12104 as infrared cameras and performing pattern matching on a series of feature points that indicate the outline of an object to determine whether the object is a pedestrian. When the microcomputer 12051 determines that a pedestrian is present in the images captured by the image capturing units 12101 to 12104 and recognizes the pedestrian, the audio / image output unit 12052 controls the display unit 12062 to superimpose a rectangular outline on the recognized pedestrian for emphasis. The audio / image output unit 12052 may also control the display unit 12062 to display an icon or the like indicating the pedestrian at a desired position.

[0185] In this specification, a system refers to an entire device made up of multiple devices.

[0186] The effects described in this specification are merely examples and are not limiting, and other effects may also be present.

[0187] It should be noted that the embodiments of the present technology are not limited to the above-described embodiments, and various modifications are possible within the scope of the present technology.

[0188] The present technology can also be configured as follows: (1) A multilayer filter including: a first electrode provided on a light incident surface side; a second electrode paired with the first electrode; an electro-optical layer between the first electrode and the second electrode, the electro-optical layer being made of an electro-optical material whose refractive index changes with voltage; and at least one or both of a first insulating layer provided between the first electrode and the electro-optical layer and a second insulating layer provided between the second electrode and the electro-optical layer. (2) The multilayer filter according to (1), in which the first electrode and the second electrode have reflective surfaces that reflect light. (3) The multilayer filter according to (1) or (2), in which the first insulating layer or the second insulating layer is composed of a first insulating material and a second insulating material having different relative dielectric constants. (4) The multilayer filter according to (3), in which a ratio of the first insulating material to the second insulating material varies depending on the angle of incidence of light. (5) The multilayer filter according to (4), wherein the proportion of the second insulating material increases as one moves from the center of the screen toward the edges of the screen on the light incident surface. (6) The multilayer filter according to any one of (1) to (5), further comprising a conductive film having a light reflecting surface between the first insulating layer or the second insulating layer and the electro-optical layer. (7) The multilayer filter according to any one of (1) to (6), wherein the area of ​​the region where the first electrode or the second electrode is formed varies depending on the angle of incidence of light. (8) The multilayer filter according to (7), wherein the area of ​​the region where the first electrode or the second electrode is formed increases as one moves from the center of the screen toward the edges of the screen on the light incident surface. (9) The multilayer filter according to any one of (1) to (8), wherein the electro-optical layer is provided in separate regions corresponding to pixels arranged on the surface opposite the light incident surface. (10) The multilayer filter according to any one of (3) to (9), wherein the second insulating material is formed in a fine pattern on the edge side of the light incident surface.(11) The multilayer filter according to any one of (1) to (10), further comprising: a first dielectric multilayer mirror having multiple layers of different dielectrics provided above or below the first electrode; and a second dielectric multilayer mirror that forms a pair with the first dielectric multilayer mirror. (12) An imaging element comprising: a pixel array section provided with a plurality of pixels including a photoelectric conversion section that photoelectrically converts incident light; and a multilayer filter that transmits light of a predetermined wavelength on the light incident surface side of the pixel array section, wherein the multilayer filter comprises: a first electrode provided on the light incident surface side; a second electrode that forms a pair with the first electrode; an electro-optic layer made of an electro-optic material whose refractive index changes depending on a voltage, and at least one of a first insulating layer provided between the first electrode and the electro-optic layer and a second insulating layer provided between the second electrode and the electro-optic layer. (13) The image sensor according to (12), wherein the first insulating layer or the second insulating layer is composed of a first insulating material and a second insulating material having different relative dielectric constants, and a ratio of the first insulating material to the second insulating material varies depending on a position in the pixel array unit. (14) A camera module comprising: a pixel array unit in which a plurality of pixels are provided, a multilayer filter that transmits light of a predetermined wavelength on a light incident surface side of the pixel array unit, and an optical unit that guides light from outside to the pixels, wherein the multilayer filter comprises: a first electrode provided on the light incident surface side, a second electrode that forms a pair with the first electrode, an electro-optical layer made of an electro-optical material whose refractive index changes depending on a voltage, and at least one of a first insulating layer provided between the first electrode and the electro-optical layer and a second insulating layer provided between the second electrode and the electro-optical layer. (15) The camera module according to (14), wherein the first insulating layer or the second insulating layer is made of a first insulating material and a second insulating material having different relative dielectric constants, and the ratio of the first insulating material to the second insulating material varies depending on the position within the pixel array section.

[0189] REFERENCE SIGNS LIST 11 camera module, 21 imaging block, 22 optical block, 31 imaging element, 32 metal wire, 33 circuit board, 34 spacer, 35 adhesive, 36 lens, 38 holder, 39 connector, 41 memory section, 42 plate, 51 pixel array section, 101 incident light, 110 pixel, 111 on-chip lens, 112 multilayer film filter, 113 planarization film, 114 light-shielding film, 115 insulating film, 116 n-type semiconductor region, 117 light-receiving surface, 118 semiconductor substrate, 120 n-type semiconductor region, 130 pixel separation section, 131 groove, 132 fixed charge film, 133 insulating film, 150 wiring layer, 151 wiring, 152 insulating layer 161 Support substrate, 201 Mirror electrode, 202 Insulating layer, 203 Electro-optical layer, 251 Insulating layer, 252 Conductive film, 261 Insulator, 262 Insulator, 301 Mirror conductive film, 302 Transparent electrode, 321 Transparent electrode, 323 Transparent conductive layer, 401 Transparent electrode, 402 Dielectric multilayer film mirror, 403 Transparent conductive film

Claims

1. A multilayer filter comprising: a first electrode provided on the light incident surface side; a second electrode paired with the first electrode; an electro-optical layer between the first electrode and the second electrode, made of an electro-optical material whose refractive index changes with voltage; and at least one or both of a first insulating layer provided between the first electrode and the electro-optical layer and a second insulating layer provided between the second electrode and the electro-optical layer.

2. The multilayer filter according to claim 1, wherein the first electrode and the second electrode have reflective surfaces that reflect light.

3. The multilayer filter according to claim 1, wherein the first insulating layer or the second insulating layer is made of a first insulating material and a second insulating material having different relative dielectric constants.

4. The multilayer filter according to claim 3, wherein the ratio of the first insulating material to the second insulating material varies depending on the angle of incidence of light.

5. A multilayer filter according to claim 4, wherein the ratio of the second insulating material increases from the center of the screen to the edges of the screen on the light incident surface.

6. The multilayer filter according to claim 1, further comprising a conductive film having a light-reflecting surface between the first insulating layer or the second insulating layer and the electro-optical layer.

7. The multilayer filter according to claim 1, wherein the area of ​​the region where the first electrode or the second electrode is formed varies depending on the angle of incidence of light.

8. A multilayer filter according to claim 7, wherein the area of ​​the region where the first electrode or the second electrode is formed increases from the center of the screen to the edge of the screen on the light incident surface.

9. The multilayer filter according to claim 1, wherein the electro-optical layer is provided separately for each region corresponding to a pixel arranged on the surface opposite to the light incident surface.

10. A multilayer filter according to claim 3, wherein the second insulating material is formed in a fine pattern on the screen edge side of the light incident surface.

11. The multilayer filter according to claim 1, further comprising: a first dielectric multilayer mirror having multiple layers of different dielectric materials provided above or below the first electrode; and a second dielectric multilayer mirror paired with the first dielectric multilayer mirror.

12. An imaging element comprising: a pixel array section in which a plurality of pixels are provided, each including a photoelectric conversion section that photoelectrically converts incident light; and a multilayer filter that transmits light of a predetermined wavelength on the light incident surface side of the pixel array section, wherein the multilayer filter comprises: a first electrode provided on the light incident surface side; a second electrode that forms a pair with the first electrode; an electro-optical layer made of an electro-optical material whose refractive index changes depending on voltage, between the first electrode and the second electrode; and at least one or both of a first insulating layer provided between the first electrode and the electro-optical layer and a second insulating layer provided between the second electrode and the electro-optical layer.

13. An imaging element as described in claim 12, wherein the first insulating layer or the second insulating layer is composed of a first insulating material and a second insulating material having different relative dielectric constants, and the ratio of the first insulating material to the second insulating material varies depending on the position within the pixel array section.

14. A camera module comprising: a pixel array section in which a plurality of pixels are provided; a multilayer filter that transmits light of a predetermined wavelength on the light incident surface side of the pixel array section; and an optical section that guides light from outside to the pixels, wherein the multilayer filter comprises: a first electrode provided on the light incident surface side; a second electrode that forms a pair with the first electrode; an electro-optical layer made of an electro-optical material whose refractive index changes depending on voltage between the first electrode and the second electrode; and at least one or both of a first insulating layer provided between at least the first electrode and the electro-optical layer and a second insulating layer provided between the second electrode and the electro-optical layer.

15. A camera module as described in claim 14, wherein the first insulating layer or the second insulating layer is composed of a first insulating material and a second insulating material having different relative dielectric constants, and the ratio of the first insulating material to the second insulating material varies depending on the position within the pixel array section.

Images