JP2020088684A - Compound-eye imaging apparatus - Google Patents

Abstract

To provide a compound-eye imaging apparatus capable of acquiring a color image without color blur without performing a correction process for eliminating color blur when using an image sensor manufactured for a monocular imaging apparatus in the compound-eye imaging apparatus.SOLUTION: A compound-eye imaging apparatus 100 includes a lens array 31 including a plurality of lenses 31a, and an image sensor 2 that is provided such that the imaging surface 2a faces the lens array 31 in the optical axis direction, and forms an image for each of the lenses 31a of the lens array 31. Further, a first lens 51 for a color image including a plurality of colors from among the lenses 31a of the lens array 31 is provided at the center of the image sensor 2 so as to face the optical axis direction.SELECTED DRAWING: Figure 5

Description

The present invention relates to a compound eye imaging device.

BACKGROUND ART Conventionally, a compound eye imaging device including a lens array and an image sensor that forms an image for each lens of the lens array is known (for example, Patent Document 1).

Patent Document 1 discloses an image input device (compound eye imaging device) including a microlens array and a solid-state imaging device that forms an image for each lens of the microlens array.

Japanese Patent No. 3821614

Although it is not specified in Patent Document 1, an off-the-shelf image sensor (solid-state image sensor) is generally provided with a microlens array for light collection on the light-receiving element array in order to improve sensitivity. There are many. Further, in order to obtain a color image with a single image sensor, a color filter array is provided on the light receiving element array. In this case, a microlens array is provided on the color filter array.

Since off-the-shelf image sensors are often manufactured for monocular imaging devices, microlens arrays of image sensors are also often manufactured for monocular imaging devices. A microlens array of an image sensor manufactured for a monocular image pickup device is provided such that the center of the microlens is opposed to the center of the light receiving element in the optical axis direction at the center of the image sensor. At the end, the center of the microlens may be provided so as to be closer to the center of the image sensor with respect to the center of the light receiving element. The reason for this is as follows. That is, in the monocular imaging device, the light flux that forms an image on the light receiving element is incident substantially perpendicularly to the light receiving element in the central portion of the image sensor, but the image forming light flux is incident on the light receiving element at the end portion of the image sensor. This is because the light is incident at an angle with respect to, and the light collection efficiency can be increased by shifting the microlens in the tilt direction of the incident light beam. Of course, even in a monocular imaging device, when a lens is provided in the vicinity of the image sensor and the optical design is performed so that the image forming optical path is vertically incident on the light receiving element over the entire area of the image sensor, the lens is a peripheral microlens. Since the effect equivalent to the shift effect is taken, the above-mentioned shift of the microlens is unnecessary.

When using an off-the-shelf image sensor, an image sensor manufactured for such a monocular image pickup device (with a microlens staggered) may have to be used for the compound eye image pickup device. As a result of diligent study by the inventor of the present application, when an image sensor manufactured for a monocular imaging device is used in a compound eye imaging device, a color blur occurs in the color image when a color image is acquired at an end of the image sensor. I have newly discovered that points occur.

The present invention has been made to solve the above problems, and an object of the present invention is to prevent color bleeding when an image sensor manufactured for a monocular imaging device is used in a compound eye imaging device. It is an object of the present invention to provide a compound-eye imaging device capable of acquiring a color image without color blur without performing a correction process for eliminating it.

In order to solve the problems newly discovered by the inventor of the present application and to achieve the above object, a compound-eye imaging device according to an aspect of the present invention is a lens array including a plurality of lenses, an imaging surface having a lens array and an optical element. An image sensor that is provided so as to face each other in the axial direction and that forms an image for each lens of the lens array, and the image sensor includes a light receiving element array, a color filter array provided on the light receiving element array, and a color filter. The image sensor includes a microlens array provided on the filter array, and the center of the image sensor is such that the center of the microlens of the microlens array faces the center of the light receiving element of the light receiving element array in the optical axis direction. And the center of the microlens of the microlens array is located closer to the center of the image sensor with respect to the center of the light receiving element of the light receiving element array at the end of the image sensor. The first lens for a color image including a plurality of colors among the lenses of the array is provided in the central portion of the image sensor so as to face the optical axis direction.

In the compound-eye image pickup device according to one aspect of the present invention, by configuring as described above, the first lens for a color image including a plurality of colors is provided in the central portion of the image sensor so as to face each other in the optical axis direction. Since a color image can be acquired while appropriately concentrating light by a microlens in the central part of the image sensor, unlike a case where a color image is acquired at the end part of the image sensor, there is no color blur. Images can be acquired. Further, since a color image without color fringing can be obtained, it is not necessary to perform a correction process for eliminating color fringing in the color image in order to obtain a color image without color fringing. As a result, when using an image sensor manufactured for a monocular imaging device in a compound-eye imaging device, a compound-eye imaging device capable of obtaining a color image without color bleeding without performing correction processing for eliminating color bleeding is provided. Can be provided.

In the compound-eye imaging device according to the above aspect, preferably, the second lens configured as an image lens other than a color image including a plurality of colors of the lenses of the lens array is combined with a wavelength selection filter. , Is provided so as to oppose the portion other than the central portion of the image sensor in the optical axis direction. According to this structure, it is possible to acquire a color image having no color blur in the central portion of the image sensor and acquire an image other than the color image in which the color blur is not noticeable in the portion other than the central portion of the image sensor. it can. As a result, a color image and an image other than the color image can be effectively acquired. In addition, it is possible to simultaneously acquire images whose wavelengths are selected by individual eyes other than those for color image acquisition.

In this case, preferably, the second lens is a lens for infrared image formed by combination with a filter for wavelength selection in the infrared region, and a monochromatic image formed by combination with a filter for wavelength selection in the wavelength region of a specific color. At least one of the imaging lenses is included. According to this structure, it is possible to obtain an infrared image or a monochromatic image in which color bleeding is not noticeable even if color bleeding occurs in portions other than the central portion of the image sensor.

In the configuration in which the second lens is provided so as to face the portion other than the central portion of the image sensor in the optical axis direction, preferably, the second lens includes a plurality of second lenses and a plurality of second lenses. The second lens is provided so as to surround the first lens. According to this structure, the first lens is provided so as to face the central portion of the image sensor in the optical axis direction, and the second lens is provided so as to face the portion other than the central portion of the image sensor in the optical axis direction. The lens can be easily provided.

In the compound-eye imaging device according to the above aspect, the color filter array of the image sensor is preferably a Bayer array color filter array. Here, if the configuration according to the above aspect is adopted, even when using a Bayer array color filter array in which complicated color blurring is likely to occur in a color image, the color processing is performed without performing the correction processing for eliminating the color blurring. It is possible to obtain a color image without blurring.

According to the present invention, as described above, when an image sensor manufactured for a monocular imaging device is used in a compound-eye imaging device, a color image without color bleeding can be obtained without performing correction processing to eliminate color bleeding. It is possible to provide a compound-eye imaging device that can be acquired.

FIG. 1A is a perspective view showing a compound eye imaging apparatus according to an embodiment of the present invention, and FIG. 1B is an exploded perspective view showing a compound eye imaging apparatus according to an embodiment of the present invention. FIG. 3 is an exploded perspective view showing an image sensor of the compound-eye imaging device according to the embodiment of the present invention. It is a figure for demonstrating a Bayer arrangement|sequence. FIG. 3 is a schematic view of the image sensor of the compound-eye imaging device according to the embodiment of the present invention as viewed from the side. FIG. 3 is a schematic diagram for explaining the position of a lens with respect to the image sensor of the compound-eye imaging device according to the embodiment of the present invention. FIG. 14 is a schematic diagram for explaining the position of a lens with respect to the image sensor of the compound-eye imaging device according to the first modification of the embodiment of the present invention. FIG. 14 is a schematic diagram for explaining the position of a lens with respect to the image sensor of the compound-eye imaging device according to the second modified example of the embodiment of the present invention.

Hereinafter, embodiments embodying the present invention will be described with reference to the drawings.

(Configuration of compound eye imaging device)
The configuration of the compound-eye imaging device 100 according to the embodiment of the present invention will be described with reference to FIGS. 1 to 5. In the following description, the Z direction is the optical axis direction. Further, in the plane orthogonal to the optical axis direction, two directions orthogonal to each other are referred to as an X direction and a Y direction, respectively. The optical axis direction is a direction in which the optical axis A of the lens 31a described below extends and is a direction perpendicular to the imaging surface 2a of the image sensor 2 described below.

As shown in FIGS. 1A and 1B, the compound-eye imaging apparatus 100 includes a single image sensor 2 and a plurality of images (a plurality of individual eyes) formed by a plurality of lenses 31 a (a plurality of individual eyes). It is a device that forms an image at a time. Thereby, the compound-eye imaging device 100 is configured to be able to form a plurality of images by each of the plurality of lenses 31a at once by the single image sensor 2. Further, the compound-eye imaging device 100 is configured to be able to form a plurality of images having the same viewpoint at the same time. For example, the compound-eye imaging device 100 can form a plurality of images at the same viewpoint from each other having different spectral characteristics at one time. As a result, it is possible to acquire various kinds of information regarding the spectral characteristics of the subject by a single image pickup.

The compound eye imaging apparatus 100 includes a compound eye optical system 1 and an image sensor 2. The compound eye optical system 1 includes a filter section 10, a diaphragm section 20, a lens section 30, and a partition section 40. The filter section 10, the diaphragm section 20, the lens section 30, the partition section 40, and the image sensor 2 are arranged from one side (Z1 direction side) of the optical axis direction (Z direction) to the other side (Z2 direction side). They are arranged in this order. It should be noted that the diaphragm unit 20 is not necessarily disposed between the filter unit 10 and the lens unit 30, and may be disposed at a position suitable for optical performance. For example, the diaphragm unit 20 may be arranged on the Z1 direction side of the filter unit 10. In addition, the filter unit 10 is arranged on the object side (subject side, Z1 direction side) opposite to the image sensor 2 side with respect to the lens unit 30, from the viewpoint of not changing the optical path length and replacement. From the viewpoint of ease of use, it is preferable. The filter unit 10 is provided to selectively transmit light having a predetermined property. The diaphragm unit 20 is provided to improve image forming performance such as adjustment of the amount of light that has passed through the filter unit 10, aberration correction, and focus depth adjustment. The lens unit 30 is provided to form an image of light that has passed through the diaphragm unit 20. The partition wall portion 40 is provided to guide the light passing through the lens portion 30 to the image sensor 2 and to prevent adjacent unit images from interfering with each other on the image sensor 2. The image sensor 2 is provided to form an image by the light that has passed through the partition wall portion 40.

The filter unit 10 includes a filter array 11 and a filter holding unit 12. The filter array 11 includes a plurality (five) of filters 11a so as to correspond to a plurality (five) of lenses 31a of a lens array 31 of the lens unit 30 described later. The filter 11a is an optical filter such as a polarization filter, a spectral filter (band-pass filter, high-pass filter, low-pass filter), and a dimming filter (ND (Neutral Density) filter). The type of the filter 11a is appropriately determined according to the application of the compound-eye imaging device 100.

The filter holding unit 12 (filter frame) is provided so as to hold the filter array 11. The filter holding part 12 is provided in a substantially rectangular parallelepiped shape. The filter holding portion 12 has a substantially rectangular shape when viewed from the optical axis direction (Z direction). Further, the filter holding unit 12 includes a plurality (five) of filter placed portions 12a corresponding to the plurality (five) of filters 11a of the filter array 11. The filter arranged portion 12a is formed of a through hole that penetrates the filter holding portion 12 in the optical axis direction. Each of the plurality of filters 11a is provided in the corresponding filter placement portion 12a. Further, the filter holding unit 12 has a structure in which a plurality (a few sheets) of thin plates 12b are stacked in the optical axis direction. The thin plate 12b is made of metal (stainless steel, aluminum alloy, etc.). A plurality of through holes are formed in each of the plurality of thin plates 12b by etching so as to correspond to the plurality of filter arranged portions 12a.

The narrowed portion 20 is provided in a plate shape. The diaphragm 20 has a substantially rectangular shape when viewed from the optical axis direction (Z direction). Further, the diaphragm section 20 includes a plurality (five) of diaphragm openings 20a so as to correspond to a plurality (five) of lenses 31a of the lens array 31 of the lens section 30. The diaphragm opening 20a is formed of a through hole that penetrates the diaphragm 20 in the optical axis direction. The diaphragm opening 20a has a substantially circular shape when viewed from the optical axis direction. The aperture area of the aperture opening 20a is sufficiently smaller than the aperture area of the filter placement portion 12a of the filter holding portion 12 of the filter portion 10. As a result, the aperture opening 20a is provided so as to adjust the amount of light that enters the lens 31a of the lens array 31 of the lens unit 30.

The lens unit 30 includes a lens array 31 and a lens holding unit 32. The lens array 31 includes a plurality of (five) lenses 31a that are odd numbers. The plurality of lenses 31a are arranged in a substantially H shape. Each of the plurality of lenses 31a is provided so as to individually form an image of light on the image sensor 2. Each of the plurality of lenses 31a functions as an individual eye, which is an eye forming each compound eye. The lens holding portion 32 (lens slot) is provided so as to hold the lens array 31. The lens holding portion 32 is provided in a substantially rectangular parallelepiped shape. The lens holding portion 32 has a substantially rectangular shape when viewed from the optical axis direction (Z direction). Further, the lens holding unit 32 includes a plurality (five) of lens arranged portions 32a corresponding to the plurality (five) of lenses 31a of the lens array 31. The lens disposed portion 32a is formed of a through hole that penetrates the lens holding portion 32 in the optical axis direction. Each of the plurality of lenses 31a is provided in the corresponding lens placement portion 32a. In addition, the lens holding unit 32 has a structure in which a plurality of (several to several tens) thin plates 32b are stacked in the optical axis direction. The thin plate 32b is made of metal (stainless steel, aluminum alloy, etc.). A plurality of through holes are formed in each of the plurality of thin plates 32b by etching so as to correspond to the plurality of lens disposed portions 32a.

The partition wall portion 40 is provided so as to partition the optical path of the light for each lens 31a of the lens array 31 so that the light for each lens 31a of the lens array 31 emitted toward the image sensor 2 does not interfere with each other. .. As a result, it is possible to prevent light from the lenses 31a of the lens array 31 from interfering with each other, and thus it is possible to accurately obtain an image of each of the lenses 31a of the lens array 31. The partition wall portion 40 is provided in a substantially rectangular parallelepiped shape. The partition wall portion 40 has a substantially rectangular shape when viewed from the optical axis direction (Z direction). In addition, the partition wall portion 40 includes a plurality (five) of partition portions 40a so as to correspond to the plurality (five) of lenses 31a of the lens array 31. The partition 40a is formed by a through hole that penetrates the partition 40 in the optical axis direction. The partition 40a is provided so as to guide the light passing through the lens 31a to the image sensor 2 while blocking the light from the other partition 40a by the side wall that is a partition wall. The partition 40a is provided so as to extend along the optical axis direction from the vicinity of the lens 31a of the lens array 31 to the vicinity of the image sensor 2. The light of each lens 31a of the lens array 31 passes through the corresponding partition 40a and reaches the image sensor 2. Further, the partition wall portion 40 has a structure in which a plurality of (several to several dozen or so) thin plates 40b are stacked in the optical axis direction. The thin plate 40b is made of metal (stainless steel, aluminum alloy, etc.). A plurality of through holes are formed in each of the plurality of thin plates 40b by etching so as to correspond to the plurality of partition portions 40a.

In the present embodiment, as described above, the filter holding portion 12 of the filter portion 10, the lens holding portion 32 of the lens portion 30, and the partition wall portion 40 are laminated by thin plates (12b, 32b, 40b) formed by etching. It is configured to have a different structure. As a result, the filter holding portion 12 of the filter portion 10 is configured as compared with the case where the filter holding portion 12 of the filter portion 10, the lens holding portion 32 of the lens portion 30, and the partition wall portion 40 are configured by a structure obtained by cutting a thick plate. The lens holding portion 32 of the lens portion 30 and the partition wall portion 40 can be accurately manufactured. As a result, it is possible to prevent the performance of the compound-eye imaging device 100 from being deteriorated due to the processing accuracy. This effect is particularly effective when manufacturing a small-sized compound-eye imaging device 100 that is easily affected by processing accuracy.

The image sensor 2 is a semiconductor image sensor such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge Coupled Device) image sensor. The image sensor 2 is provided so that the imaging surface 2a faces the lens array 31 in the optical axis direction (Z direction). The image sensor 2 is configured to form an image for each lens 31 a of the lens array 31 by the light transmitted through the lens array 31. The image sensor 2 has a substantially rectangular shape when viewed from the optical axis direction.

Further, as shown in FIGS. 2 to 4, the image sensor 2 includes a light receiving element array 121, a color filter array 122, and a microlens array 123. The light receiving element array 121 is provided to convert the received light into an electric signal. The light receiving element array 121 has a plurality of light receiving elements 121a for converting the received light into an electric signal and transmitting the electric signal. The plurality of light receiving elements 121a are arranged in a matrix so as to have a predetermined resolution. Each of the plurality of light receiving elements 121a is provided so as to form each pixel of the image.

The color filter array 122 is provided to acquire a color image including a plurality of colors (so-called RGB image or the like). The color filter array 122 is provided on the light receiving element array 121. The color filter array 122 has a plurality of color filters 122a so as to correspond to the plurality of light receiving elements 121a of the light receiving element array 121. The color filter 122a is a primary color filter, and includes a red (R) color filter, a green (G) color filter, and a blue (B) color filter. The color filter array 122 having the color filter 122a which is a primary color filter is a Bayer array color filter array (see FIG. 3). The color filter array 122 is provided such that the green (G) color filters 122a are in a checkered pattern, and the red (R) color filters 122a and the blue (B) color filters 122a are line-sequential. There is. Note that FIG. 3 illustrates only a part of the color filter array 122.

The microlens array 123 is provided to collect light on the light receiving element 121a of the light receiving element array 121. The microlens array 123 is provided on the color filter array 122. The microlens array 123 has a plurality of microlenses 123a so as to correspond to the plurality of light receiving elements 121a of the light receiving element array 121.

As shown in FIG. 4, in the image sensor 2, in the central portion of the image sensor 2, the center 123b of the microlens 123a of the microlens array 123 (optical axis center, indicated by a black circle) and the light receiving element 121a of the light receiving element array 121 ( The center 121b (indicated by a black circle) is provided so as to face the optical axis direction. On the other hand, in the image sensor 2, at the end portion of the image sensor 2, the center 123b (center of the optical axis) of the microlens 123a of the microlens array 123 is positioned with respect to the center 121b of the light receiving element 121a of the light receiving element array 121. It is provided so as to approach the center side. As described above, the image sensor 2 is manufactured for a monocular imaging device.

Here, when the image sensor 2 manufactured for a monocular image pickup device is used for the compound eye image pickup device 100, the monocular image pickup device and the compound eye image pickup device 100 are connected to the microlens 123a of the microlens array 123 at the ends of the image sensor 2. The way light is incident differs. Specifically, in the monocular imaging device, the incident angle of light to the microlens 123a at the end of the image sensor 2 is relatively large, while in the compound-eye imaging device 100, the microlens 123a at the end of the image sensor 2 is incident. The incident angle of light becomes smaller than that of the monocular imaging device. Due to this, the inventor of the present application cannot properly collect light by the microlenses 123a at the end of the image sensor 2 and obtains a color image at the end of the image sensor 2. In addition, it was newly discovered that color bleeding occurs in color images.

Therefore, in the present embodiment, as shown in FIG. 5, the first lens 51 for a color image including a plurality of colors among the lenses 31a of the lens array 31 is provided in the central portion of the image sensor 2 in the optical axis direction (Z Direction). Specifically, the first lens 51 is provided such that the center of the optical axis faces the center of imaging of the image sensor 2 in the optical axis direction. On the other hand, the first lens 51 is provided at the end of the image sensor 2 so as not to face the optical axis direction (Z direction). Note that, in FIG. 5, for easy understanding, the image sensor 2 is represented by a square with a chain double-dashed line, each of the plurality of lenses 31a is represented by a circle with a solid line, and the individual image of each of the plurality of lenses 31a is represented by a square with a solid line. , Each of which is shown schematically.

The first lens 51 for a color image means the lens 31a that forms a single-eye image for forming a color image including a plurality of colors on the image sensor 2. The first lens 51 for the color image is provided so as to face the filter 11a for the color image among the plurality of filters 11a of the filter unit 10 in the optical axis direction. The color image filter 11a is a filter 11a capable of selectively transmitting visible light (light having a wavelength component in a wavelength band of approximately 360 nm to 830 nm). The color image filter 11a is, for example, an IR cut filter that transmits visible light and blocks infrared light.

Further, in the present embodiment, the lenses 31a of the lens array 31 are configured as a plurality (four) of second lenses 52 for images other than color images including a plurality of colors by combination with the wavelength selection filter 11a. Is included. The plurality of second lenses 52 are provided so as to face a portion of the image sensor 2 other than the central portion. The plurality of second lenses 52 are provided so as to surround the first lens 51. Specifically, the plurality of second lenses 52 are provided so as to surround the first lens 51 from one side and the other side. On one side of the first lens 51, two second lenses 52 that are half lenses of the plurality of second lenses 52 are provided, and on the other side of the first lens 51, a plurality of second lenses 52 are provided. Two second lenses 52, which are the other half of the second lenses 52, are provided. In addition, the plurality of second lenses 52 are provided in a point-symmetrical manner with the first lens 51 as the center. Further, the plurality of second lenses 52 are provided so as to correspond to the four corners of the substantially rectangular image sensor 2. The first lens 51 and the plurality of second lenses 52 are arranged in a substantially H shape centered on the first lens 51.

The second lens 52 for an image other than the color image means the lens 31a for forming an individual image for forming an image other than the color image on the image sensor 2. The second lens 52 for images other than the color image is provided so as to face the filters 11a for images other than the color image among the plurality of filters 11a of the filter unit 10 in the optical axis direction. The image filter 11a other than the color image is, for example, a filter 11a that is a bandpass filter that can selectively transmit light of a specific color of visible light, a filter 11a that can selectively transmit infrared light, and the like. ..

For example, in the example shown in FIG. 5, the second lens 52 includes an infrared image lens 31a in combination with a filter 11a for wavelength selection in the infrared region, and a wavelength selection lens in the wavelength region of a specific color. It includes a lens 31a for a single color image in combination with the filter 11a. Specifically, the upper left and lower left second lenses 52 are lenses 31a for infrared images. The upper left and lower left second lenses 52 are provided so as to form a single-eye image for forming an infrared image on the image sensor 2. The upper left and lower left second lenses 52 are provided so as to face the filter 11a, which is a filter for infrared images, of the plurality of filters 11a of the filter unit 10 and which can selectively transmit infrared rays, in the optical axis direction. Has been. When a plurality of second lenses 52 for infrared images are provided as in the example shown in FIG. 5, the plurality of second lenses 52 are lenses 31 a for infrared images of different wavelength bands. It may be.

Further, the upper right and lower right second lenses 52 are lenses 31a for monochromatic images. The upper right and lower right second lenses 52 are provided so as to form an individual image for forming a monochromatic image on the image sensor 2. The upper right and lower right second lenses 52 oppose in the optical axis direction the filters 11a of the plurality of filters 11a of the filter unit 10 that are capable of selectively transmitting light of a specific color that is a filter for a monochromatic image. Is provided. Specifically, the second lens 52 on the upper right is provided so as to face the filter 11a capable of selectively transmitting blue light in the optical axis direction. As a result, a blue image is obtained as a monochrome image. Further, the lower right second lens 52 is provided so as to face the filter 11a capable of selectively transmitting red light in the optical axis direction. As a result, a red image is obtained as a monochrome image. The monochromatic image may be a monochromatic image (green image or the like) other than the blue image and the red image. Further, what kind of image to obtain as an image other than the color image may be appropriately determined according to the application of the compound-eye imaging device 100.

(Effect of this embodiment)
In this embodiment, the following effects can be obtained.

In the present embodiment, as described above, the first lens 51 for a color image including a plurality of colors of the lenses 31a of the lens array 31 is provided in the central portion of the image sensor 2 so as to face the optical axis direction. .. Accordingly, the first lens 51 can appropriately collect light by the microlens 123a in the central portion of the image sensor 2 and acquire a color image, so that the color image can be obtained at the end portion of the image sensor 2. Unlike the case of acquiring, it is possible to acquire a color image without color fringing. Further, since a color image without color fringing can be obtained, it is not necessary to perform a correction process for eliminating color fringing in the color image in order to obtain a color image without color fringing. As a result, when the image sensor 2 manufactured for a monocular imaging device is used in the compound-eye imaging device 100, a compound-eye imaging capable of obtaining a color image without color bleeding without performing a correction process for eliminating color bleeding. A device 100 can be provided.

In addition, in the present embodiment, as described above, the second lens 31a is configured as an image other than a color image including a plurality of colors of the lenses 31a of the lens array 31 by the combination with the wavelength selection filter 11a. The lens 52 is provided at a portion other than the central portion of the image sensor 2 so as to face the optical axis direction. As a result, it is possible to obtain a color image having no color blur in the central portion of the image sensor 2 and an image other than the color image in which the color blur is not noticeable in the portion other than the central portion of the image sensor 2. As a result, a color image and an image other than the color image can be effectively acquired. In addition, it is possible to simultaneously acquire images whose wavelengths are selected by individual eyes other than those for color image acquisition.

Further, in the present embodiment, as described above, the second lens 52 is combined with the filter 11a for wavelength selection in the infrared region to form the infrared image lens 31a and the wavelength in the wavelength region of the specific color. It is configured so as to include a lens 31a for a monochromatic image in combination with the selection filter 11a. This makes it possible to obtain an infrared image or a monochromatic image in which color bleeding is not noticeable even if color bleeding occurs in a portion other than the central portion of the image sensor 2.

In addition, in the present embodiment, as described above, the second lens 52 is configured to include the plurality of second lenses 52. Further, the plurality of second lenses 52 are provided so as to surround the first lens 51. Thereby, while the first lens 51 is provided so as to face the central portion of the image sensor 2 in the optical axis direction, the second lens is provided so as to face the portion other than the central portion of the image sensor 2 in the optical axis direction. The lens 52 can be easily provided.

Further, in the present embodiment, as described above, the color filter array 122 of the image sensor 2 is configured to be a Bayer array color filter array. This makes it possible to obtain a color image without color fringing without performing correction processing to eliminate color fringing when using a Bayer array color filter array in which complicated color fringing is likely to occur in a color image.

[First Modification of One Embodiment]
Next, with reference to FIG. 6, a first modification example of the embodiment will be described. In the first modification of this one embodiment, unlike the above-described embodiment in which the lens array includes five lenses, an example in which the lens array includes nine lenses will be described.

As shown in FIG. 6, the lens array 131 according to the first modified example of the embodiment of the present invention includes a plurality (9) of odd-numbered lenses 131a. The first lens 151 for a color image including a plurality of colors of the lenses 131a of the lens array 131 is provided at the center of the image sensor 102 so as to face the optical axis direction (Z direction). Specifically, the first lens 151 is provided so that the center of the optical axis faces the center of imaging of the image sensor 102 in the optical axis direction. On the other hand, the first lens 151 is provided at the end of the image sensor 102 so as not to face the optical axis direction (Z direction).

Further, the lens 131a of the lens array 131 includes a plurality (eight) of second lenses 152 for images other than color images including a plurality of colors. The plurality of second lenses 152 include, for example, an infrared image lens 131a and a monochromatic image lens 131a. In addition, the plurality of second lenses 152 are provided so as to face a portion other than the central portion of the image sensor 102. The plurality of second lenses 152 are provided so as to surround the first lens 151. Specifically, the plurality of second lenses 152 are provided so as to surround the first lens 151 in eight directions. Further, the plurality of second lenses 152 are provided in a point-symmetrical manner with the first lens 151 as the center. The first lens 151 and the plurality of second lenses 152 are arranged in a 3×3 matrix with the first lens 151 at the center.

The other configurations of the first modified example of the above-described embodiment are the same as those of the above-described embodiment.

[Second Modification of One Embodiment]
Next, a second modification of the embodiment will be described with reference to FIG. 7. In the second modification of this one embodiment, unlike the above-described embodiment in which the lens array includes five lenses and the first modification in which the lens array includes nine lenses, there are 15 lens arrays. An example including the lens will be described.

The lens array 231 according to the second modified example of the embodiment of the present invention includes a plurality (15) of odd numbered lenses 231a, as shown in FIG. The first lens 251 for a color image including a plurality of colors among the lenses 231a of the lens array 231 is provided at the center of the image sensor 202 so as to face the optical axis direction (Z direction). Specifically, the first lens 251 is provided so that the optical axis center faces the image capturing center of the image sensor 202 in the optical axis direction. On the other hand, the first lens 251 is provided at the end of the image sensor 202 so as not to face the optical axis direction (Z direction).

The lens 231a of the lens array 231 includes a plurality (14) of second lenses 252 for images other than color images including a plurality of colors. The plurality of second lenses 252 include, for example, a lens 231a for infrared image and a lens 231a for monochromatic image. In addition, the plurality of second lenses 252 are provided so as to face a portion other than the central portion of the image sensor 202. Further, the plurality of second lenses 252 are provided so as to surround the first lens 251. Further, the plurality of second lenses 252 are provided in a point-symmetrical manner with the first lens 251 as the center. The first lens 251 and the plurality of second lenses 252 are arranged in a 3×5 matrix with the first lens 251 at the center.

The other configurations of the first modified example of the above-described embodiment are the same as those of the above-described embodiment.

[Modification]
It should be considered that the embodiments disclosed this time are exemplifications in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of the claims, and further includes meanings equivalent to the scope of the claims and all modifications (modifications) within the scope.

For example, in the above-described embodiment, the example in which the compound-eye imaging device is configured to be able to form a plurality of images having the same viewpoint at the same time has been shown, but the present invention is not limited to this. In the present invention, the compound-eye imaging device may be configured to be able to form a plurality of images from different viewpoints at one time.

Further, in the above embodiment, the filter holding portion of the filter portion, the lens holding portion of the lens portion, and the partition wall portion has an example having a structure in which a plurality of thin plates are laminated, the present invention is Not limited to In the present invention, at least one of the filter holding portion of the filter portion, the lens holding portion of the lens portion, and the partition wall portion may have a structure in which a plurality of thin plates are laminated. Further, the filter holding part of the filter part, the lens holding part of the lens part, and the partition wall may not have a structure in which a plurality of thin plates are laminated. For example, the filter holding portion of the filter portion, the lens holding portion of the lens portion, and the partition wall portion may have a structure obtained by cutting a thick plate.

Further, in the above-described embodiment, an example in which the lens array includes five lenses is shown, in the first modified example, an example in which the lens array includes nine lenses is shown, and in the second modified example. , The example in which the lens array includes 15 lenses has been shown, but the present invention is not limited to this. In the present invention, the lens array may include a plurality of lenses other than 5, 9, or 15.

Further, in the above-described embodiment, an example in which the plurality of lenses of the lens array are arranged in a substantially H shape is shown. In the first and second modifications, the plurality of lenses of the lens array are arranged in a matrix. Although the arrayed example is shown, the present invention is not limited to this. In the present invention, the plurality of lenses of the lens array do not necessarily have to be arranged in a substantially H shape or a matrix. For example, the plurality of lenses of the lens array may be arranged in a line or zigzag.

Further, in the above embodiment, the example in which the second lens is configured to include both the infrared image lens and the monochromatic image lens has been shown, but the present invention is not limited to this. In the present invention, the second lens may be configured to include only one of an infrared image lens and a monochromatic image lens.

Further, in the above embodiment, an example in which the color filter array of the image sensor is a Bayer array color filter array has been described, but the present invention is not limited to this. In the present invention, the color filter array of the image sensor does not necessarily have to be the Bayer array color filter array. Further, the color filter array of the image sensor may be configured to have complementary color system color filters instead of primary color system color filters.

2, 102, 202 Image sensor 31, 131, 231 Lens array 31a, 131a, 231a Lens 51, 151, 251 First lens 52, 152, 252 Second lens 100 Compound eye imaging device 121 Light receiving element array 121a Light receiving element 122 Color filter array 123 Micro lens array 123a Micro lens

Claims (5)

A lens array including a plurality of lenses,
An image sensor, the imaging surface of which is provided so as to face the lens array in the optical axis direction, and which forms an image for each lens of the lens array,
The image sensor includes a light receiving element array, a color filter array provided on the light receiving element array, and a microlens array provided on the color filter array,
The image sensor is provided such that the center of the microlens of the microlens array is opposed to the center of the light receiving element of the light receiving element array in the optical axis direction at the center of the image sensor. At the end of the sensor, the center of the microlens of the microlens array is provided so as to be closer to the center side of the image sensor with respect to the center of the light receiving element of the light receiving element array,
A first compound lens for a color image including a plurality of colors among the lenses of the lens array is provided in a central portion of the image sensor so as to face the optical axis direction. The second lens, which is configured as a lens for an image other than a color image including a plurality of colors among the lenses of the lens array by combining with a wavelength selection filter, is provided at a portion other than the central portion of the image sensor. The compound-eye imaging device according to claim 1, wherein the compound-eye imaging device is provided so as to face each other in the optical axis direction. The second lens is for an infrared image lens in combination with the filter for wavelength selection in the infrared region, and for a single color image in combination with the filter for wavelength selection in the wavelength region of a specific color. The compound eye imaging device of claim 2, including at least one of the lenses. The second lens includes a plurality of the second lenses,
The compound-eye imaging device according to claim 2, wherein the plurality of second lenses are provided so as to surround the first lens. The compound eye imaging device according to claim 1, wherein the color filter array of the image sensor is a Bayer array color filter array.

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