JP7627606B2 - Compound eye imaging device - Google Patents

Description

This invention relates to a compound eye imaging device.

Conventionally, there is known a compound-eye imaging device that has multiple lenses and images the light incident from the multiple lenses by focusing the light onto multiple regions of an image sensor (for example, Patent Document 1).

The above-mentioned Patent Document 1 discloses a compound eye image input device that includes a microlens array in which microlenses are arranged, a light receiving element array arranged below the microlens array, and a lattice-shaped partition layer arranged between the microlens array and the light receiving element array. A specific area of the light receiving element array corresponds to each microlens, and the lattice-shaped partition layer regulates the optical path to prevent the ingress of optical signals from adjacent microlenses. The partition layer extends downward from the microlens array to a position midway between the microlens array and the light receiving element array.

Patent No. 3821614

In a compound eye imaging device such as that disclosed in Patent Document 1, there is a need to perform close-up photography by shortening the shooting distance from the image sensor to the subject. However, the shorter the shooting distance is relative to infinity, the greater the extension amount of the lens toward the subject for focusing, so that the regulating member (partition layer) moves away from the light receiving surface along with the lens. As a result of the regulating member moving away from the light receiving surface, some of the light beams that have passed through adjacent lenses overlap with each other, forming overlapping areas in which images are superimposed in each image corresponding to the individual lenses (individual lenses). Thus, conventional compound eye imaging devices have a problem in that they are unable to suppress image overlap in adjacent individual lenses (adjacent optical systems) when performing close-up photography.

Conversely, if the regulating member is fixed in an appropriate position for close-up photography to avoid this problem, the light rays will not be regulated sufficiently for distant photography, resulting in overlap. On the other hand, if the regulating member is fixed in an appropriate position for distant photography, the light beam will be excessively regulated for close-up photography, and the entire shooting area of each image sensor (each individual eye) will not be utilized.

In this way, when the shooting distance changes in a compound eye photography device, even if the position of the regulating member and the lens are adjusted together, or conversely, if only the regulating member is fixed in a predetermined position, the entire imaging area of the image sensor cannot be effectively used.

This invention has been made to solve the problems described above, and one object of the invention is to provide a compound-eye imaging device that can make the most efficient use of the entire imaging area of the image sensor by appropriately suppressing image overlap between adjacent ommatidium when taking close-up shots.

In order to achieve the above object, a compound eye imaging device according to a first aspect of the present invention includes a plurality of lenses, a lens holding part for holding the plurality of lenses, an image sensor for forming a plurality of images formed by each of the plurality of lenses, a restricting member for restricting an optical path from each of the plurality of lenses to the image sensor, a first adjusting member for adjusting at least a first position among a first position of the lens holding part in the optical axis direction of the plurality of lenses and a second position of the restricting member in the optical axis direction, and a second adjusting member for adjusting a second position among the first position and the second position , and the first adjusting member and the second adjusting member are arranged so as not to overlap each other as viewed in the optical axis direction. Note that in the present invention, the first adjusting member may adjust only the first position , or may adjust both the first position and the second position. In a configuration in which the first adjusting member adjusts only the first position among the first position and the second position, the second adjusting member is configured to adjust the second position , and in a configuration in which the first adjusting member adjusts both the first position and the second position, the second adjusting member adjusts the second position .

In the compound eye imaging device according to the first aspect of the present invention, the first position in the optical axis direction of the lens holding part and the second position in the optical axis direction of the regulating member can be adjusted separately by combining the first adjustment member and the second adjustment member. Therefore, when the first position of the lens holding part is adjusted (extended) for focus adjustment of close-up photography, the second position of the regulating member can be adjusted to a position where the light beams passing through adjacent lenses (adjacent ommatidium) can be appropriately suppressed from overlapping with each other according to the adjusted first position of the lens holding part. As a result, when performing close-up photography, the entire imaging area of the image sensor can be used as effectively as possible by appropriately suppressing the overlap of images in adjacent ommatidium. In addition, this allows compound eye photography with a wider shooting distance range to be realized with the same device configuration by simply changing the adjustment amounts of the first adjustment member and the second adjustment member.

In the compound eye imaging device according to the first aspect, preferably, the lens holding part and the regulating member are connected to each other, the first adjustment member is provided to adjust both the first position and the second position integrally, and the second adjustment member is provided between the lens holding part and the regulating member to adjust the second position. With this configuration, the lens holding part and the regulating member can be connected to each other and integrated. The lens holding part and the regulating member need to be aligned not only in the optical axis direction but also in the direction perpendicular to the optical axis (parallel to the light receiving surface of the image sensor) and in the relative angle (i.e., the inclination angle of the regulating member relative to the lens optical axis). Therefore, by integrating the lens holding part and the regulating member, it is possible to prevent the relative positions and relative angles between the two members from varying independently of each other, and therefore the assembly accuracy of the lens holding part and the regulating member can be improved. Even in this case, the relative position (distance) in the optical axis direction of the lens holding portion and the regulating member can be adjusted by the second adjustment member between the lens holding portion and the regulating member, so that the first position and the second position can be adjusted separately by combining the first adjustment member and the second adjustment member.

A compound eye imaging device according to a second aspect of the present invention comprises a plurality of lenses, a lens holding portion that holds the plurality of lenses, an image sensor that forms a plurality of images formed by each of the plurality of lenses, a regulating member that regulates the optical path incident on the image sensor from each of the plurality of lenses, a first adjustment member that adjusts at least a first position among a first position of the lens holding portion in the optical axis direction of the plurality of lenses and a second position of the regulating member in the optical axis direction, and a second adjustment member that adjusts a second position among the first position and the second position, wherein the lens holding portion and the regulating member are connected to each other, the first adjustment member is arranged to adjust both the first position and the second position integrally, and the second adjustment member is arranged between the lens holding portion and the regulating member and is arranged to adjust the second position, and further comprises a base member to which the lens holding portion and the regulating member are assembled, wherein the lens holding portion is stacked on the base member via the first adjustment member at a first portion, and the regulating member is connected to a second portion different from the first portion of the lens holding portion via the second adjustment member. As a result , the first and second adjustment members are provided in parallel with respect to the first and second portions of the lens holding part, respectively. The position (first position) of the lens holding part relative to the base member can be determined by the adjustment amount (thickness) of the first adjustment member, and the position (second position) of the regulating member relative to the base member can be determined by the sum of the adjustment amounts of the first and second adjustment members.

A compound eye imaging device according to a third aspect of the present invention includes a plurality of lenses, a lens holding unit that holds the plurality of lenses, an image sensor that forms a plurality of images formed by each of the plurality of lenses, a restricting member that restricts an optical path from each of the plurality of lenses to the image sensor, a first adjustment member that adjusts at least a first position among a first position of the lens holding unit in the optical axis direction of the plurality of lenses and a second position of the restricting member in the optical axis direction, and a second adjustment member that adjusts a second position among the first position and the second position, the first adjustment member is provided to adjust the first position of the lens holding unit independently of the second position of the restricting member, and the second adjustment member is provided to adjust the second position of the restricting member independently of the first position of the lens holding unit . This allows the first position of the lens holding unit and the second position of the restricting member to be independently adjusted by the first adjustment member and the second adjustment member. Since the adjustment amount of the first adjustment member and the adjustment amount of the second adjustment member can be determined independently, the adjustment amount of each adjustment member can be easily determined.

In the compound eye imaging device according to the first to third aspects, at least one of the first adjustment member and the second adjustment member is preferably a spacer member that is made of a laminate of a plurality of thin plates and adjusts the position by thickness. With this configuration, the first position and/or the second position can be adjusted by the number of laminated thin plates. Thin plates with small thicknesses can be easily manufactured, so that highly accurate position adjustment can be achieved with an extremely simple structure, unlike the case where a mechanical precision positioning mechanism is provided, for example.

A compound eye imaging device according to a fourth aspect of the present invention includes a plurality of lenses, a lens holding section for holding the plurality of lenses, an image sensor for forming a plurality of images formed by each of the plurality of lenses, a restricting member for restricting an optical path from each of the plurality of lenses to the image sensor, a first adjusting member for adjusting at least a first position of a first position of the lens holding section in the optical axis direction of the plurality of lenses and a second position of the restricting member in the optical axis direction, and a second adjusting member for adjusting the second member between the first position and the second position, one of the first adjusting member and the second adjusting member being formed of a stack of a plurality of thin plates and including a spacer member for adjusting the position by a thickness , and the other of the first adjusting member and the second adjusting member including a position adjusting screw for adjusting the position in the optical axis direction by being rotated. This allows a wide range of position adjustment to be performed steplessly by the position adjusting screw, while a precise position adjustment can be performed by the number of stacked thin plates constituting the spacer member.

In the compound eye imaging device according to the first to fourth aspects, the restricting member preferably includes a partition wall that divides the optical path from each of the plurality of lenses to the image sensor, and is disposed at a second position away from the light receiving surface of the image sensor in the optical axis direction. With this configuration, the optical path can be divided so as to minimize the area on the light receiving surface of the image sensor where the light beam from each of the plurality of lenses is not incident. That is, when the partition wall is in contact with the light receiving surface of the image sensor, the pixel area in contact with the partition wall cannot receive the light beam and is an area that cannot be used as an image. With a configuration in which the partition wall is away from the light receiving surface of the image sensor, the optical path can be divided so that the light beam that has passed through the lens is also incident on the pixel area directly below the partition wall, and therefore the pixel area of the image sensor can be effectively utilized.

In this case, the restricting member is preferably adjusted to a second position that restricts the optical path so that the image areas formed by the light beams incident from each of the multiple lenses on the light receiving surface of the image sensor do not overlap each other and are arranged at a distance smaller than the thickness of the partition. With this configuration, the optical path can be restricted so that two image areas formed on the light receiving surface by adjacent ommatidium are as close as possible without overlapping each other. As a result, the pixel area that cannot be used for image formation in the image sensor can be reduced as much as possible.

A compound eye imaging device according to a fifth aspect of the present invention includes a plurality of lenses, a lens holding unit that holds the plurality of lenses, an image sensor that forms a plurality of images formed by each of the plurality of lenses, a restricting member that restricts the optical path of each of the plurality of lenses entering the image sensor, a first adjustment member that adjusts at least the first position of the first position of the lens holding unit in the optical axis direction of the plurality of lenses and the second position of the restricting member in the optical axis direction, and a second adjustment member that adjusts the second position of the first position and the second position, and the lens holding unit is adjusted to a first position where each lens is focused at a shooting distance of 10 times or less than the focal length. Here, the change in the lens extension amount when shortening the shooting distance increases rapidly when the shooting distance is about 10 times or less than the focal length. As a result, in a configuration in which the restricting member is extended integrally with the lens holding unit, the overlapping area of the images also expands significantly. Therefore, the present invention, which can suppress the overlapping of images by separately adjusting the first position of the lens holding unit and the second position of the restricting member, is particularly useful in ultra-close shooting with a shooting distance of 10 times or less than the focal length. As a result, with the same device configuration, by simply varying the adjustment amounts of the first adjustment member and the second adjustment member, it is possible to achieve compound eye photography over a wide range from infinity to ultra-close-up photography (shooting distance less than 10 times the focal length).

According to the present invention, as described above, it is possible to provide a compound-eye imaging device that can make the most efficient use of the entire imaging area of the image sensor by appropriately suppressing image overlap between adjacent individual eyes when performing close-up photography.

FIG. 1 is a perspective view showing a compound eye imaging device. 2 is a perspective cross-sectional view taken along the optical axis of a lens of the compound eye imaging device shown in FIG. 1 . FIG. 2 is an exploded perspective view showing the compound eye imaging device shown in FIG. 1 . 1 is a schematic cross-sectional view showing a compound-eye imaging device according to a first embodiment. 2 is a schematic diagram for explaining the optical system and position adjustment of the compound-eye imaging device according to the first embodiment. FIG. 4 is an enlarged cross-sectional view showing a first adjustment member and a second adjustment member made of thin plates. FIG. FIG. 13 is a schematic diagram showing an optical system in a comparative example in which the shooting distance is set to infinity. FIG. 13 is a schematic diagram showing an optical system in a comparative example in which the shooting distance is shorter than infinity. FIG. 9 is a schematic diagram showing an optical system in a comparative example in which the shooting distance is further shortened compared to that in FIG. 8 . 13 is a schematic diagram showing a case in which a regulating member is fixed at a reference distance in a comparative example. FIG. 1 is a schematic diagram showing an optical system in which the shooting distance is shorter than infinity in the first embodiment. FIG. FIG. 2 is a schematic diagram showing an optical system for performing ultra-close-up photography in the first embodiment. 11 is a graph showing an example of the relationship between the shooting distance and the thicknesses of the first and second adjustment members. FIG. 11 is a schematic cross-sectional view showing a compound-eye imaging device according to a second embodiment. 13A and 13B are schematic diagrams for explaining optical systems and position adjustment of a compound-eye imaging device according to a second embodiment. 13A and 13B are schematic diagrams for explaining optical systems and position adjustment of a compound-eye imaging device according to a first modified example. 13A and 13B are schematic diagrams for explaining optical systems and position adjustment of a compound-eye imaging device according to a second modified example.

The following describes an embodiment of the present invention with reference to the drawings.

[First embodiment]
(Configuration of compound eye imaging device)
The configuration of a compound-eye imaging device 100 according to a first embodiment will be described with reference to Figures 1 to 5. In the following description, the optical axis direction of the lens 31 (the direction in which the optical axis AL (see Figure 5) extends) is defined as the Z direction, one side of the Z direction is defined as the Z1 direction, and the other side is defined as the Z2 direction. Furthermore, two directions that are perpendicular to each other in a plane perpendicular to the Z direction are defined as the X direction and the Y direction, respectively.

As shown in Figures 1 and 2, the compound eye imaging device 100 includes a plurality of lenses 31, a lens holding section 30, an image sensor 51 (see Figure 2), a regulating member 41 (see Figure 2), a first adjustment member 42, and a second adjustment member 43 (see Figure 2). The compound eye imaging device 100 also includes a filter holding section 10, an aperture section 20, a support structure section 40, and a substrate section 50.

The compound eye imaging device 100 is a device that simultaneously forms multiple images (multiple unitary images) by each of multiple lenses 31 (multiple units) on a single image sensor 51 (see FIG. 2). As a result, the compound eye imaging device 100 is configured to be able to simultaneously form multiple images by each of the multiple lenses 31 using the single image sensor 51. In this specification, an optical system made up of each lens 31 is called a "unitary image." An image formed on the image sensor 51 by each unitary image is called a "unitary image." The output image of the image sensor 51 includes multiple unitary images. In this embodiment, an example of a compound eye imaging device 100 equipped with four units is shown.

The compound-eye imaging device 100 is also configured to be capable of forming multiple single-eye images from substantially the same viewpoint in a single output image. For example, the compound-eye imaging device 100 can simultaneously form multiple images from the same viewpoint that have different spectral characteristics by combining spectral filters with different characteristics for each of the lenses 31. This makes it possible to obtain various information regarding the spectral characteristics of the subject by capturing an image in a single capture.

As shown in FIG. 3, in the compound eye imaging device 100, the filter holding section 10, the aperture section 20, the lens holding section 30, the support structure section 40, and the substrate section 50 are stacked in this order along the optical axis direction from the Z1 direction side to the Z2 direction side. The support structure section 40 is a section that includes the above-mentioned regulating member 41, the first adjustment member 42, the second adjustment member 43, and the base member 44. The compound eye imaging device 100 forms an image using light that passes through the filter holding section 10, the aperture section 20, the lens holding section 30, and the support structure section 40 in the Z2 direction and is incident on the image sensor 51 of the substrate section 50.

<Filter holding section>
The filter holding portion 10 is configured to be able to hold an optical filter Ft (see FIG. 4) for each unit. That is, the filter holding portion 10 is formed with a plurality of holding holes corresponding to the plurality of lenses 31 (multiple units), and each of the holding holes is able to hold an optical filter Ft.

The filter holding portion 10 includes a first filter retaining plate 11, a first filter retaining plate 12, a second filter retaining plate 13, and a second filter retaining plate 14. The filter retaining portion 10 is constructed by stacking these plate-like members, and has a flat plate shape as a whole. Each member of the filter retaining portion 10 is provided with holes in the number (four) that corresponds to the number of individual units.

The first filter retaining plate 11 has a through hole 11a smaller than the outer shape of the optical filter Ft (see FIG. 4). The first filter retaining plate 12 has a filter installation hole 12a, which is a through hole having a shape corresponding to the outer shape of the optical filter Ft. An optical filter is placed inside the filter installation hole 12a. The second filter retaining plate 13 has a through hole 13a smaller than the outer shape of the optical filter Ft. The first filter retaining plate 11 and the second filter retaining plate 13 hold the Z1 side and the Z2 side of the first optical filter Ft placed on the first filter retaining plate 12. The second filter retaining plate 14 has a filter installation hole 14a, which is a through hole having a shape corresponding to the outer shape of the optical filter Ft. An optical filter is placed inside the filter installation hole 14a. The second filter retaining plate 13 and the diaphragm section 20 described later hold the Z1 side and the Z2 side of the second optical filter Ft (see FIG. 4) placed on the second filter retaining plate 14. In this way, the filter holder 10 is configured to allow two optical filters to be placed per unit.

The optical filter Ft to be placed can be selected from, for example, a polarizing filter, a spectroscopic filter (band-pass filter, high-pass filter, low-pass filter), a light-reducing filter (ND (Neutral Density) filter), etc. In each holding hole of the filter holding section 10, one or two optical filters Ft are placed according to the optical characteristics required for the unitary image, but there may be units in which no optical filter Ft is placed.

<Through hole>
The diaphragm unit 20 is configured to adjust the amount of light incident on each of the multiple lenses 31 (multiple units). The diaphragm unit 20 is also provided to improve imaging performance such as aberration correction and focal depth adjustment. The diaphragm unit 20 is made of a plate member in which multiple (four) diaphragm holes 20a are formed, the number of which corresponds to the number of units. The diaphragm unit 20 is disposed between the filter holding unit 10 and the lens holding unit 30.

<Lens holder>
The lens holding portion 30 is configured to hold a plurality of lenses 31. The lens holding portion 30 is configured to be able to hold the lenses 31 individually, one by one, for each unitary eye. That is, the lens holding portion 30 has a plurality of lens installation holes 30a, the same number as the number of lenses 31 to be held (four). Each of the plurality of lens installation holes 30a holds a plurality of lenses 31 individually, one by one.

The lens holding section 30 comprises a lens retaining plate 32, a lens holding plate 33, and a lens support plate 34. The lens holding section 30 is constructed by stacking these plate-like members, and has a flat plate shape as a whole. Each member of the lens holding section 30 is provided with holes in a number that corresponds to the number of lenses.

The lens retaining plate 32 has a through hole 32a that is smaller than the outer shape of the lens 31. The lens holding plate 33 has a lens installation hole 33a that is a through hole with a shape corresponding to the outer shape of the lens 31. The lens 31 is placed inside the lens installation hole 33a. The lens support plate 34 has a through hole 34a that is smaller than the outer shape of the lens 31.

The lens installation hole 30a is composed of the through hole 32a, the lens installation hole 33a, and the through hole 34a. The lens retaining plate 32 and the lens support plate 34 hold the Z1 side and the Z2 side of the lens 31 arranged on the lens holding plate 33.

<lens>
The multiple lenses 31 are provided to form an image of light that has passed through the diaphragm unit 20. Each of the multiple lenses 31 is held by the lens holding unit 30. In this embodiment, as described above, four lenses 31 are respectively held in the lens installation holes 30a of the lens holding unit 30. The multiple lenses 31 include monocular lenses made of glass or resin. Each of the individual lenses 31 has a predetermined focal length.

The focal length of each lens 31 does not necessarily have to be the same, and can be set arbitrarily within the tolerance of the device configuration. For example, by forming steps (concave portions) of different depths for each lens unit on the Z1 side surface of the lens support plate 34, the position of each lens 31 in the optical axis direction can be finely adjusted. This absorbs the difference in the focal positions of each lens 31 whose focal lengths differ within the tolerance range, and allows the focal points of each lens 31 to be set on the same plane.

<Support structure>
As described above, the support structure 40 includes the regulating member 41, the first adjustment member 42, the second adjustment member 43, and the base member 44. The support structure 40 has a function of supporting the filter holding portion 10, the diaphragm portion 20, and the lens holding portion 30. First, the base member 44 is placed on the substrate portion 50 (Z1 side), and the lens holding portion 30 is placed on the base member 44 (Z1 side) via the first adjustment member 42.

The base member 44 has a rectangular frame shape with an opening 44a formed therein that is large enough to include the area in which the multiple ommatidium are formed. The image sensor 51 is disposed inside the opening 44a, and the base member 44 is provided so as to surround the periphery of the image sensor 51. The base member 44 has a predetermined height H (see FIG. 4) and has the function of creating a reference position for adjusting the positions of the lens holding portion 30 and the regulating member 41 by the first adjustment member 42 and the second adjustment member 43.

The first adjustment member 42 and the second adjustment member 43 are provided to adjust a first position P1 (see FIG. 4) of the lens holding part 30 in the optical axis direction of the multiple lenses 31 and a second position P2 (see FIG. 4) of the regulating member 41 in the optical axis direction. Details of the adjustment of the first position P1 and the second position P2 will be described later.

The first adjustment member 42 is disposed on the Z1 side surface of the base member 44. The first adjustment member 42 has a planar shape that is approximately the same as the base member 44. Therefore, the first adjustment member 42 has a rectangular frame-like flat plate shape with an opening 42a (through hole) formed in a range that is the same as the opening 44a of the base member 44. The first adjustment member 42 is disposed on the Z2 side of the lens holding portion 30.

The second adjustment member 43 is disposed inside the opening 42a of the first adjustment member 42 and contacts the Z2 side surface of the lens holding unit 30. Therefore, the first adjustment member 42 and the second adjustment member 43 are provided in parallel with each other on the Z2 side surface of the lens holding unit 30.

The second adjustment member 43 has a rectangular frame-like flat plate shape with an opening 43a (through hole) large enough to include the area where multiple unitaries are formed. The opening 43a is smaller than the opening 44a of the base member 44 and the opening 42a of the first adjustment member 42, but larger than the area where multiple unitaries are formed.

The restricting member 41 is configured to restrict the optical path from each of the multiple lenses 31 to the image sensor 51. The restricting member 41 is disposed inside the opening 44a of the base member 44 so as to face the image sensor 51 in the Z direction.

The regulating member 41 is provided in a substantially rectangular parallelepiped shape. When viewed from the optical axis direction (Z direction), the regulating member 41 has a substantially rectangular shape. The regulating member 41 also includes a plurality (four) of optical path partitions 41a so as to correspond one-to-one to the plurality of lenses 31 (plurality of individual lenses). The optical path partitions 41a are through holes that penetrate the regulating member 41 in the optical axis direction. The regulating member 41 includes partitions 41b that partition the optical paths that enter the image sensor 51 from each of the plurality of lenses 31. The inner walls of the regulating member 41 that partition the optical path partitions 41a are the partitions 41b. In each optical path partition 41a, the partitions 41b provide light shielding between the other optical path partitions 41a, while the light that passes through the lens 31 is guided to the image sensor 51.

The regulating member 41 is disposed at a second position P2 (see FIG. 4) that is spaced from the light receiving surface 51a of the image sensor 51 in the optical axis direction. Specifically, the regulating member 41 is disposed so as to contact the Z2 side surface of the second adjustment member 43. The regulating member 41 is connected to the lens holding portion 30 via the second adjustment member 43.

<Board>
The substrate unit 50 includes an image sensor 51 and a sensor substrate 52 .

The image sensor 51 is configured to form a plurality of images formed by each of the plurality of lenses 31. The image sensor 51 is, for example, 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 51 has a light receiving surface 51a (see FIG. 4) composed of a group of pixels arranged in an array in the X direction and the Y direction. The light receiving surface 51a is a plane perpendicular to the optical axis direction (Z direction) and is the Z1 direction side surface of the image sensor 51. The image sensor 51 has a substantially rectangular shape when viewed from the optical axis direction (Z direction). The image sensor 51 is provided on a sensor substrate 52.

The image sensor 51 is housed in a sensor package 51b. The image sensor 51 receives light on the light receiving surface 51a through a cover member 51c, which is a light transmitting portion of the sensor package 51b.

The sensor board 52 is a printed circuit board on which a circuit pattern connected to the image sensor 51 is formed, and has a common mounting surface 52a on which the image sensor 51 and the above-mentioned components are mounted. The mounting surface 52a is the Z1 side surface of the sensor board 52. The image sensor 51 is mounted in the center of the mounting surface 52a. A base member 44 that surrounds the periphery of the image sensor 51 is mounted on the mounting surface 52a via an insulating sheet 53.

(Layer structure of each part of the compound eye imaging device)
Next, the layered structure of each part of the compound eye imaging device 100 will be described with reference to Fig. 4. Fig. 4 shows a schematic diagram of the layered structure of the compound eye imaging device 100, and the scale of each component is different from that in Figs. 1 to 3. In Fig. 4, holes in each component that constitutes the optical system are not shown.

The lens holding unit 30 is stacked on the base member 44 via the first adjustment member 42 in the first portion 30b. The lens holding unit 30 is disposed at a first position P1 in the optical axis direction (Z direction). The lens holding unit 30 is connected to the regulating member 41 via the second adjustment member 43 in the second portion 30c, which is different from the first portion 30b.

The first portion 30b and the second portion 30c are both surfaces on the Z2 side (light receiving surface 51a side) of the plate-shaped lens holding portion 30. The first portion 30b is a contact portion of the lens holding portion 30 with the rectangular frame-shaped first adjustment member 42 (see FIG. 3), and the first portion 30b has a rectangular frame shape. The first portion 30b is disposed closer to the outer periphery of the lens holding portion 30 than the second portion 30c. The second portion 30c is an area surrounded by the frame-shaped first portion 30b. The second portion 30c is a contact portion with the rectangular frame-shaped second adjustment member 43 (see FIG. 3), and the second portion 30c has a rectangular frame shape.

The regulating member 41 is held by the lens holding part 30 so as to be suspended from the second part 30c on the Z2 side surface of the lens holding part 30 to the image sensor 51 side (Z2 side) via the second adjustment member 43. As a result, the regulating member 41 is held at a position away from the light receiving surface 51a of the image sensor 51 on the Z1 side.

Next, the mounting structure of each component will be described. In the following description, a non-threaded hole (a through hole with no thread groove) for inserting a screw component will be called an "insertion hole." A threaded hole (a hole with a thread groove, through or non-through) that engages with and fastens to the threaded portion of a screw component will be called a "threaded hole."

<Installation of base member>
The base member 44 has a screw hole SH1 that engages with a first fixing screw SC1 for fixing the base member 44. The sensor board 52 has an insertion hole IH1 for inserting the first fixing screw SC1. Note that a similar insertion hole is also formed in the insulating sheet 53.

The base member 44 is attached to the sensor board 52 by a first fixing screw SC1 that engages with the screw hole SH1.

<Lens Holding Portion and First Adjustment Member>
The lens holding portion 30 and the first adjustment member 42 each have an insertion hole IH2 for inserting a second fixing screw SC2 for fixing the lens holding portion 30. In addition, the base member 44 has a screw hole SH2 that engages with the second fixing screw SC2.

The lens holder 30 is attached to the base member 44 by a second fixing screw SC2 that engages with the screw hole SH2 of the base member 44. The first adjustment member 42 is also fixed to the base member 44 by being fastened together between the lens holder 30 and the base member 44 by the second fixing screw SC2.

In the first embodiment, the regulating member 41 is arranged inside the opening 44a of the frame-shaped base member 44 so as to be suspended from the lens holding portion 30, and therefore there is a range Hr where the base member 44 and the regulating member 41 overlap in the XY direction. The height H of the base member 44 is designed to be large enough to allow for a sufficient margin, taking into consideration that the size of this overlapping range Hr varies depending on the adjustment amount (thickness) of the second adjustment member 43. Therefore, the height H of the base member 44 is large, and a large range for forming the screw hole SH2 can be secured. Therefore, even if it is not necessary to prepare many types of second fixing screws SC2 with different lengths depending on the adjustment amount (thickness) of the first adjustment member 42, a wide range of adjustment amounts can be accommodated with the second fixing screws SC2 of the same length.

<Attachment of the Restriction Member and the Second Adjustment Member>
The lens holding portion 30 and the second adjustment member 43 have an insertion hole IH3 for inserting a third fixing screw SC3 for fixing the restricting member 41. To be precise, the insertion hole IH3 is formed in the lens holding plate 33 and the lens support plate 34 of the lens holding portion 30, excluding the lens pressing plate 32. The restricting member 41 has a screw hole SH3 that engages with the third fixing screw SC3.

The regulating member 41 is attached to the lens holding part 30 (lens holding plate 33) by a third fixing screw SC3 that engages with the screw hole SH3 of the regulating member 41. In addition, the second adjustment member 43 is fixed to the lens holding part 30 (lens holding plate 33) by being fastened together between the lens holding part 30 and the regulating member 41 by the third fixing screw SC3. With this configuration, the lens holding part 30 and the regulating member 41 are connected to each other.

<Installation of filter and throttle>
The filter holding portion 10 and the diaphragm portion 20 are attached to the lens holding portion 30. Specifically, the lens holding portion 30 (lens holding plate 33) has a screw hole SH4 that engages with a fourth fixing screw SC4 for fixing the filter holding portion 10 and the diaphragm portion 20. The lens retaining plate 32 of the lens holding portion 30, the diaphragm portion 20, and the second filter holding plate 14 are each formed with an insertion hole IH4 for inserting the fourth fixing screw SC4 therethrough.

The lens retaining plate 32, the aperture section 20, and the second filter retaining plate 14 are fixed to the lens retaining plate 33 by a fourth fixing screw SC4 that engages with the screw hole SH4 of the lens retaining plate 33.

Furthermore, the lens holding portion 30 (lens holding plate 33) has a screw hole SH5 that engages with a fifth fixing screw SC5 for fixing the entire filter holding portion 10 and the aperture portion 20. An insertion hole IH5 for inserting the fifth fixing screw SC5 is formed in each of the lens retaining plate 32 of the lens holding portion 30, the aperture portion 20, and the filter holding portion 10 (first filter retaining plate 11, first filter retaining plate 12, second filter retaining plate 13, and second filter retaining plate 14).

The lens retaining plate 32, the aperture section 20, and the entire filter retaining section 10 are fixed to the lens retaining plate 33 by a fifth fixing screw SC5 that engages with the screw hole SH5 of the lens retaining plate 33.

With the above configuration, each component that makes up the compound eye imaging device 100 is assembled and fixed.

As a result, the optical filter holding hole (optical filter) of the filter holding portion 10, the aperture hole 20a of the aperture portion 20, the lens installation hole 30a (lens 31) of the lens holding portion 30, and the optical path partition portion 41a of the regulating member 41 are arranged along the optical axis direction to form an optical system corresponding to one unitary eye. As shown in FIG. 1, the four unitsary eyes are formed in a lattice pattern with two rows and two columns in the XY direction. As a result, four unitary images in two rows and two columns are formed on the light receiving surface 51a of the image sensor 51.

(Detailed configurations of the first adjustment member and the second adjustment member)
Next, the detailed configuration of the first adjustment member 42 and the second adjustment member 43 will be described with reference to Fig. 5. Fig. 5 is a schematic diagram showing the optical systems of two adjacent individual eyes in a simplified form, with the filter holding portion 10 and the like omitted and the lens holding portion 30 simplified.

In the first embodiment, the compound eye imaging device 100 is configured to be able to separately adjust the first position P1 of the lens holding part 30 in the optical axis direction and the second position P2 of the regulating member 41 by using the first adjustment member 42 and the second adjustment member 43.

Specifically, the first adjustment member 42 is configured to adjust at least one of the first position P1 of the lens holding portion 30 in the optical axis direction (Z direction) of the multiple lenses 31 and the second position P2 of the regulating member 41 in the optical axis direction, and the second adjustment member 43 is configured to adjust the other of the first position P1 and the second position P2.

Methods for adjusting the first position P1 of the lens holding portion 30 and the second position P2 of the regulating member 41 using the first adjustment member 42 and the second adjustment member 43 include the following (1) and (2).
(1) A method of adjusting only one of the first position P1 of the lens holding portion 30 and the second position P2 of the regulating member 41 with a first adjustment member 42, and adjusting only the other of the first position P1 and the second position P2 with a second adjustment member 43 (see Figure 16).
(2) A method in which both the first position P1 of the lens holding portion 30 and the second position P2 of the regulating member 41 are adjusted with a first adjustment member 42, and either the first position P1 or the second position P2 is adjusted with a second adjustment member 43 (see Figure 5).

In the adjustment method (1), the first position P1 and the second position P2 are adjusted independently. In the adjustment method (2), one of the first position P1 and the second position P2 is determined by the first adjustment member 42. At this time, the other of the first position P1 and the second position P2 is also adjusted, so the second adjustment member 43 determines the other of the first position P1 and the second position P2, taking into account the amount of position adjustment by the first adjustment member 42.

In the first embodiment, the adjustment method (2) is adopted. That is, the first adjustment member 42 is provided to adjust both the first position P1 and the second position P2 integrally, and the second adjustment member 43 is provided between the lens holding part 30 and the regulating member 41 and is provided to adjust the first position P1 or the second position P2.

In detail, the lens holding unit 30 shown in FIG. 5 is stacked on the base member 44 via the first adjustment member 42, and is connected to the regulating member 41 via the second adjustment member 43 separately from the first adjustment member 42. Therefore, the first adjustment member 42 adjusts the Z1-direction positions of both the lens holding unit 30 and the regulating member 41 relative to the base member 44. Meanwhile, the second adjustment member 43 is provided between the lens holding unit 30 and the regulating member 41, and therefore the second adjustment member 43 adjusts the amount of protrusion of the regulating member 41 in the Z2 direction relative to the lens holding unit 30.

As a result, the first position P1 of the lens holding portion 30 is determined by the thickness (adjustment amount) t1 of the first adjustment member 42. When the top surface height (height of the Z1 side surface) of the base member 44 is used as a reference, the first position P1 can be offset in the Z1 direction from the base member 44 by the thickness t1 of the first adjustment member 42.

The second position P2 of the regulating member 41 is determined by the sum of the thickness (adjustment amount) t1 of the first adjustment member 42 and the thickness (adjustment amount) t2 of the second adjustment member 43. In other words, when the top surface height of the base member 44 is used as a reference, the second position P2 can be offset in the Z1 direction from the base member 44 by the difference between the thickness t1 of the first adjustment member 42 and the thickness t2 of the second adjustment member 43. In this way, the second position P2 can be adjusted separately from the first position P1 by the thickness t2 of the second adjustment member 43.

The regulating member 41 is offset in the Z1 direction by an offset amount ΔP2 smaller than the extension amount according to the extension amount ΔP1 of the lens 31 in the Z1 direction. Therefore, the thickness t2 of the second adjustment member 43 is usually smaller than the thickness t1 of the first adjustment member 42, and the offset amount ΔP2 of the second position P2 is a positive value (offset in the Z1 direction). As described below, the extension amount ΔP1 is an offset amount from the distance (reference distance R1) from the light receiving surface 51a to the lens holding part 30 when focused at infinity. The offset amount ΔP2 of the second position P2 is also an offset amount from the distance (reference distance R2) from the light receiving surface 51a to the regulating member 41 when focused at infinity.

As shown in FIG. 6, at least one of the first adjustment member 42 and the second adjustment member 43 is a spacer member that is made of a laminate of multiple thin plates 60 and adjusts the position by the thickness (t1, t2). In the first embodiment, an example is shown in which both the first adjustment member 42 and the second adjustment member 43 are made of a laminate of multiple thin plates 60.

The thin plate 60 is formed of a metal plate-like member. The metal material is, for example, stainless steel. The planar shape of the thin plate 60, including the openings and the insertion holes, matches that of each adjustment member, and has a thickness sufficiently smaller than the total thickness of each adjustment member. That is, the thin plate 60a constituting the first adjustment member 42 is a plate member having a rectangular frame shape with an opening 42a (see FIG. 3) and an insertion hole IH2 (see FIG. 4) for inserting the second fixing screw SC2. The thin plate 60b constituting the second adjustment member 43 is a plate member having an outer size slightly smaller than the opening 42a, a rectangular frame shape with an opening 43a (see FIG. 3), and an insertion hole IH3 (see FIG. 4) for inserting the third fixing screw SC3.

The thickness of the thin plate 60 is, for example, several tens of μm or more and one hundred μm or less. Preferably, the thickness of the thin plate 60 is 20 μm or more and 100 μm or less. Each adjustment member may be configured by combining multiple types of thin plates 60 with different thicknesses. For example, each adjustment member includes three types of thin plates 60 with thicknesses of 20 μm, 30 μm, and 100 μm. By combining a 20 μm thin plate 60 and a 30 μm thin plate 60, position adjustment in 10 μm increments is possible, and when the adjustment amount is large, the total number of laminated thin plates 60 can be reduced by using a 100 μm thin plate 60. Since the thin plate 60 is very thin in this way, it may be referred to as a sheet-like member or a film-like member. The first adjustment member 42 and the second adjustment member 43 are integrally formed by, for example, bonding a plurality of laminated thin plates 60 by diffusion bonding.

(Adjustment of the first position and the second position)
Next, adjustment of the first position P1 and the second position P2 will be described. The compound eye imaging device 100 of the first embodiment is configured so that the shooting distance can be set within a range from infinity to extremely close-up shooting.

In other words, whether the shooting distance is infinity or ultra-close shooting, the basic device configuration of the compound eye imaging device 100 is the same, and the shooting distance can be changed by setting the adjustment amounts (thicknesses t1 and t2) of the first adjustment member 42 and the second adjustment member 43. Note that in this specification, ultra-close shooting means that the shooting distance is 10 times or less the focal length of the lens.

The compound eye imaging device 100 is assembled with the lens holding part 30 and the regulating member 41 adjusted in position by the first adjustment member 42 and the second adjustment member 43, whose thicknesses t1 and t2 have been adjusted in advance to provide a predetermined shooting distance. The shooting distance of the assembled compound eye imaging device 100 is a fixed value.

Referring to FIG. 5, in adjusting the first position P1 and the second position P2, first, the extension amount ΔP1 of the lens 31 for focusing according to the shooting distance is calculated. The thickness t1 of the first adjustment member 42 is determined so that the lens holding part 30 is positioned at the first position P1 corresponding to the calculated extension amount ΔP1.

Next, a position on the light receiving surface 51a of the image sensor 51 where the regulating member 41 can restrict the light flux 70 to a range where the image areas 72 formed by each unit do not overlap each other is determined as the second position P2. The thickness t2 of the second adjustment member 43 is determined according to the offset amount ΔP2 for positioning the regulating member 41 at the determined second position P2.

Below, we will first explain the relationship between the first position P1 (extension amount of the lens 31) and the overlap of adjacent image areas 72 with reference to Figures 7 to 10.

Comparative Example
7 to 10 show an optical system according to a comparative example in which the regulating member 41 is directly attached to the lens holding part 30 without using the first adjustment member 42 and the second adjustment member 43. Fig. 7 shows the positions of the lens holding part 30 and the regulating member 41 when the shooting distance is set to infinity.

The first position P1 of the lens holder 30 is adjusted to focus on infinity. In other words, the first position P1 is adjusted so that the light receiving surface 51a (imaging position) is located at the focal length (back focus) f of the lens 31.

The partitions 41b constituting the optical path partitions 41a of the regulating member 41 block the outer periphery of the light beam 70 incident from each lens 31, thereby determining the position of the outermost principal ray 71 of the light beam 70. In FIG. 7, the area between the respective incident positions of the outermost principal ray 71 at both ends of the light beam 70 incident from one unitary eye becomes the image area 72 that forms the unitary image.

In the example of FIG. 7, the second position P2 of the regulating member 41 is adjusted so that the image areas 72 of adjacent ommatidium are as close as possible to each other. In other words, the distance CL between two adjacent image areas 72 on the light receiving surface 51a is minimized. In the following explanation, the distance from the light receiving surface 51a to the lens holding part 30 at the first position P1 shown in FIG. 7, which is focused on infinity, is defined as the reference distance R1. The distance from the light receiving surface 51a to the regulating member 41 at the second position P2 at this time is defined as the reference distance R2.

Figures 8 and 9 show an example in which the shooting distance is reduced from infinity (see Figure 7). When the shooting distance is shortened, the lens 31 is extended in the Z1 direction to focus on the light receiving surface 51a. In other words, the lens holding part 30 is offset in the Z1 direction from the reference distance R1 by an extension amount ΔP. Figure 9 shows an example in which the extension amount ΔP is greater than that in Figure 8, further shortening the shooting distance.

As can be seen from Figures 8 and 9, in the comparative example in which the regulating member 41 is directly attached to the lens holding unit 30, the lens holding unit 30 (lens 31) is offset in the Z1 direction by the extension amount ΔP, so it is possible to focus at each shooting distance. However, at this time, the regulating member 41 is also offset in the Z1 direction by the same amount (ΔP) as the lens holding unit 30. As a result, the outermost chief rays 71 of the light beams 70 in adjacent units intersect, and an overlap region RO is formed in which the image regions 72 overlap in two adjacent image regions 72. In this case, in the captured unit image, the images obtained by the adjacent units overlap each other in the part corresponding to the overlap region RO.

On the other hand, as shown in FIG. 10, when the regulating member 41 is separated from the lens holding unit 30 and fixed at a position a reference distance R2 away from the light receiving surface 51a, the image area 72 on the light receiving surface 51a becomes smaller as the extension amount ΔP of the lens holding unit 30 from the reference distance R1 increases. Therefore, when the image areas 72 of adjacent ommatidium are separated from each other, a non-image area equivalent to the distance CL between the adjacent image areas 72 is formed in the output image of the image sensor 51, and the pixel utilization efficiency of the image sensor 51 decreases.

First Embodiment
Therefore, in the compound eye imaging device 100 of the first embodiment, as shown in Fig. 5, the first position P1 of the lens holding part 30 and the second position P2 of the regulating member 41 can be adjusted separately by the first adjustment member 42 and the second adjustment member 43. Figs. 11 and 12 show an example in which the lens holding part 30 is offset in the Z1 direction by an amount of extension ΔP1 from the reference distance R1 during infinity shooting, and Fig. 12 shows an example in which the amount of extension ΔP1 is larger than that in Fig. 11, making the shooting distance even shorter.

In the first embodiment, as shown in Figures 11 and 12, the lens holding part 30 is positioned at a first position P1, which is obtained by adding an extension amount ΔP1 that matches the shooting distance to the reference distance R1. In other words, the thickness t1 of the first adjustment member 42 is determined so that the first position P1 = R1 + ΔP1.

Then, with the first position P1 of the lens holding part 30 adjusted to the extension amount ΔP1 that focuses at the set shooting distance, the second position P2 of the regulating member 41 is adjusted so that the two image areas 72 of adjacent individual eyes do not overlap.

The position of the image area 72 (shape of the light beam 70) formed on the light receiving surface 51a by the optical system after the adjustment of the first position P1 varies strictly depending on the aperture diameter and the specifications of the lens 31, so the second position P2 is calculated by ray tracing (simulation). Based on the light beam 70 obtained as a result of ray tracing, the second position P2 of the regulating member 41 is determined so that the image areas 72 formed by the light beam 70 do not overlap each other and are arranged at a distance CL smaller than the thickness of the partition 41b. By determining the second position P2, the offset amount ΔP2 of the regulating member 41 from the reference distance R2 is determined. As a result, the thickness t2 of the second adjustment member 43 is determined so that the regulating member 41 is disposed at the determined second position P2. In other words, the thickness t2 of the second adjustment member 43 is determined so that the second position P2 = R2 + ΔP2.

In this manner, the adjustment amount (thickness t1) of the first adjustment member 42 and the adjustment amount (thickness t2) of the second adjustment member 43 are determined. A laminate of thin plates 60 is manufactured so as to achieve the determined adjustment amount, thereby forming the first adjustment member 42 and the second adjustment member 43. The obtained first adjustment member 42 and second adjustment member 43 are used to assemble each component, thereby obtaining a compound eye imaging device 100 in which the first position P1 and the second position P2 are adjusted.

In the first embodiment, the second position P2 of the regulating member 41 is adjusted so that the outer peripheries of the image areas 72 of adjacent individual eyes are in contact with each other. In this way, with the regulating member 41 adjusted in position, the non-image area (see FIG. 10) in the output image of the image sensor 51 can be reduced as much as possible regardless of the shooting distance designed, so that the pixel utilization efficiency of the image sensor 51 can be increased.

<Ultra close-up photography>
The compound eye imaging device 100 according to the first embodiment is particularly useful in close-up photography where the shooting distance is 10 times or less than the focal length f (see FIG. 7) of the lens 31. In the example shown in FIG. 12, the lens holding part 30 is adjusted to a first position P1 where each lens 31 is focused at a shooting distance of 10 times or less than the focal length f. In accordance with this first position P1, the restricting member 41 is adjusted to a second position P2 that restricts the optical path so that the image areas 72 formed by the light beams 70 incident from each of the lenses 31 do not overlap each other on the light receiving surface 51a of the image sensor 51.

Figure 13 is a graph showing the change in thickness t1 of the first adjustment member 42 and thickness t2 of the second adjustment member 43 when the shooting distance is changed in a compound eye imaging device 100 of the same specifications. The horizontal axis of the graph indicates the shooting distance, and the vertical axis of the graph indicates the thickness of each adjustment member for achieving the first position P1 and the second position P2 corresponding to that shooting distance. The shooting distance is expressed as a multiple of the focal length. For each shooting distance, the thickness t1 of the first adjustment member 42 is represented by a white bar graph, and the thickness t2 of the second adjustment member 43 is represented by a hatched bar graph.

The graph in FIG. 13 shows the optical principle that the change in thickness t1 of the first adjustment member 42, which corresponds to the extension amount ΔP1 of the lens 31 responsible for focus adjustment, is inversely proportional to the shooting distance (a value obtained by subtracting 1 from a multiple of the focal length). On the other hand, the change in thickness t2 of the second adjustment member 43, as shown in FIG. 12, indicates that the amount by which the optimal position of the regulating member 41 is pushed up (offset amount ΔP2) changes as the quadrangular pyramid shape formed by the outermost chief ray 71 of each individual eye rises in response to the change in thickness t1 of the first adjustment member 42 (change in first position P1). For this reason, the change in thickness t2 of the second adjustment member 43 is theoretically smaller than the change in thickness t1 of the first adjustment member 42, and the difference in the amount of change (t1-t2) becomes larger as the shooting distance becomes closer.

Therefore, as can be seen from the curve (dashed line) in FIG. 13, the shooting distance and the extension amount ΔP1 (thickness t1 of the first adjustment member 42) are not in a linear relationship, and in the case of ultra-close shooting where the shooting distance is 10 times the focal length or less, the thickness t1 of the first adjustment member 42 (i.e., the extension amount ΔP1) increases rapidly. In FIG. 13, the thickness t1 when adjusted to a shooting distance of 50 times the focal length is about 1.8 times the thickness t1 at infinity, whereas the thickness t1 when adjusted to a shooting distance of 5 times the focal length is about 10 times or more. Therefore, in a configuration in which the lens holding portion 30 and the regulating member 41 are adjusted in position as a unit as in the comparative example shown in FIG. 9, the size of the overlap area RO formed in the case of ultra-close shooting increases significantly.

Therefore, in the compound eye imaging device 100 according to the first embodiment, as shown in FIG. 12, the second position P2 of the regulating member 41 is adjusted separately from the first position P1 by the second adjustment member 43, so that even in close-up photography where the extension amount of the lens 31 becomes significantly large, the occurrence of the overlap area RO is suppressed and the invalid area (area where images overlap) in the output image of the image sensor 51 is effectively reduced.

(Effects of the First Embodiment)
The compound-eye imaging device 100 according to this embodiment can provide the following advantages.

In this embodiment, as described above, the first position P1 in the optical axis direction of the lens holding unit 30 and the second position P2 in the optical axis direction of the regulating member 41 can be adjusted separately by combining the first adjustment member 42 and the second adjustment member 43. Therefore, for example, the compound eye imaging device 100 is designed based on the first position P1 and the second position P2 when the shooting distance is set to infinity, and when the first position P1 of the lens holding unit 30 is adjusted (extended) for focus adjustment of close-up photography, the second position P2 of the regulating member 41 can be adjusted to a position where the light beams 70 passing through adjacent lenses 31 (adjacent ommatidium) can be appropriately suppressed from overlapping with each other according to the adjusted first position P1 of the lens holding unit 30. As a result, when performing close-up photography, the entire imaging area of the image sensor 51 can be used as effectively as possible by appropriately suppressing the overlap of images in adjacent ommatidium. In addition, this allows compound eye photography with a wider shooting distance range to be realized with the same device configuration by simply changing the adjustment amounts of the first adjustment member 42 and the second adjustment member 43.

In addition, in this embodiment, as described above, the lens holding unit 30 and the regulating member 41 are connected to each other, the first adjustment member 42 is provided to adjust both the first position P1 and the second position P2 integrally, and the second adjustment member 43 is provided between the lens holding unit 30 and the regulating member 41 to adjust the first position P1 or the second position P2. This allows the lens holding unit 30 and the regulating member 41 to be connected to each other and integrated. The lens holding unit 30 and the regulating member 41 need to be aligned not only in the optical axis direction (Z direction) but also in the direction perpendicular to the optical axis AL (parallel to the light receiving surface 51a of the image sensor 51) and in the relative position and relative angle (i.e., the inclination angle of the regulating member 41 relative to the optical axis AL). Therefore, by integrating the lens holding unit 30 and the regulating member 41, it is possible to avoid the relative positions and relative angles between the two members being independent of each other, so that the assembly accuracy of the lens holding unit 30 and the regulating member 41 can be increased. Even in this case, the relative positions (distance) of the lens holding part 30 and the regulating member 41 in the optical axis direction can be adjusted by the second adjustment member 43 between the lens holding part 30 and the regulating member 41, so the first position P1 and the second position P2 can be adjusted separately by combining the first adjustment member 42 and the second adjustment member 43.

In addition, in this embodiment, as described above, the lens holding unit 30 further includes a base member 44 to which the lens holding unit 30 and the regulating member 41 are assembled, and the lens holding unit 30 is stacked on the base member 44 at the first portion 30b via the first adjustment member 42, and the regulating member 41 is connected to the second portion 30c, which is different from the first portion 30b of the lens holding unit 30, via the second adjustment member 43. In this case, the first adjustment member 42 and the second adjustment member 43 are provided in parallel with respect to the first portion 30b and the second portion 30c of the lens holding unit 30, respectively. The position (first position P1) of the lens holding unit 30 based on the base member 44 can be determined by the adjustment amount (thickness t1) of the first adjustment member 42, and the position (second position P2) of the regulating member 41 based on the base member 44 can be determined by the sum of the adjustment amount of the first adjustment member 42 and the adjustment amount of the second adjustment member 43.

In addition, in this embodiment, as described above, at least one of the first adjustment member 42 and the second adjustment member 43 is a spacer member that is composed of a stack of multiple thin plates 60 and adjusts the position by thickness. This allows the position of the first position P1 and/or the second position P2 to be adjusted by the number of stacked thin plates 60. Thin plates 60 with small thicknesses can be easily manufactured, so that highly accurate position adjustment can be achieved with an extremely simple structure, unlike, for example, a case where a mechanical precision positioning mechanism is provided.

In addition, in this embodiment, as described above, the regulating member 41 includes a partition 41b that divides the optical path from each of the lenses 31 to the image sensor 51, and is disposed at a second position P2 away from the light receiving surface 51a of the image sensor 51 in the optical axis direction. This allows the optical path to be divided so as to minimize the area on the light receiving surface 51a of the image sensor 51 where the light beam 70 from each of the lenses 31 is not incident. That is, when the partition 41b is in contact with the light receiving surface 51a of the image sensor 51, the pixel area in contact with the partition 41b cannot receive the light beam 70 and is an area that cannot be used as an image. In a configuration in which the partition 41b is separated from the light receiving surface 51a of the image sensor 51, the optical path can be divided so that the light beam 70 that has passed through the lens 31 also enters the pixel area directly below the partition 41b, so that the pixel area of the image sensor 51 can be effectively utilized.

In addition, in this embodiment, as described above, the regulating member 41 is adjusted to a second position P2 that restricts the optical path so that the image areas 72 formed by the light beams 70 incident from each of the multiple lenses 31 on the light receiving surface 51a of the image sensor 51 do not overlap each other and are arranged at an interval smaller than the thickness of the partition 41b. With this configuration, the optical path can be restricted so that the two image areas 72 formed on the light receiving surface 51a by adjacent ommatidium are as close as possible to each other without overlapping each other. As a result, the pixel area that cannot be used for image formation in the image sensor 51 can be reduced as much as possible.

In addition, in this embodiment, as described above, the lens holding unit 30 is adjusted to the first position P1 where each lens 31 is focused at a shooting distance of 10 times or less than the focal length f. As shown in FIG. 13, the extension amount ΔP1 of the lens 31 required for focusing when the shooting distance is shortened increases rapidly when the shooting distance is 10 times or less than the focal length. Therefore, the compound eye imaging device 100 of the first embodiment, which can suppress image overlap by separately adjusting the first position P1 of the lens holding unit 30 and the second position P2 of the regulating member 41, is particularly useful for ultra-close shooting with a shooting distance of 10 times or less than the focal length. As a result, with the same device configuration, compound eye shooting over a wide range from infinity to ultra-close shooting (shooting distance is 10 times or less than the focal length) can be realized simply by changing the adjustment amounts of the first adjustment member 42 and the second adjustment member 43.

[Second embodiment]
Next, a second embodiment will be described with reference to Fig. 14 and Fig. 15. In the second embodiment, unlike the first embodiment in which the first adjustment member 42 and the second adjustment member 43 are provided in parallel on the lens holding portion 30 (first portion 30b, second portion 30c), the lens holding portion 30 is stacked on the base member 44 via the first adjustment member 42, and the lens holding portion 30 is connected to the regulating member 41 via the second adjustment member 43 separately from the first adjustment member 42, an example will be described in which the first adjustment member 42, the regulating member 41, the second adjustment member 43, and the lens holding portion 30 are stacked in series on the base member 144.

In the second embodiment, the compound eye imaging device 200 is similar to the compound eye imaging device 100 of the first embodiment described above, except for the configuration of the lens holding section 130 and the support structure section 140, so the same reference numerals are used and the description is omitted. In the compound eye imaging device 200 of the second embodiment, the first adjustment member 142, the regulating member 141, the second adjustment member 143, and the lens holding section 130 are stacked on the base member 144 in that order from the base member 144 side.

In other words, in the second embodiment, unlike the first embodiment, the regulating member 141 is stacked on the base member 144 (Z1 side) via the first adjustment member 142. The lens holding unit 130 is stacked on the regulating member 141 (Z1 side) via the second adjustment member 143. Therefore, the first adjustment member 142, the regulating member 141, the second adjustment member 143, and the lens holding unit 130 are lined up in series in that order from the base member 144 side.

Unlike the first embodiment, the second adjustment member 143 and the regulating member 141 have substantially the same outer shape as the base member 144 and the first adjustment member 142. In other words, the second adjustment member 143 and the regulating member 141 are not disposed inside the frame-shaped base member 144 and the first adjustment member 142 as in the first embodiment, but are stacked with the base member 144 and the first adjustment member 142 in the optical axis direction (Z direction). For this reason, in the second embodiment, the range Hr in which the base member 44 and the regulating member 41 overlap in the XY direction shown in FIG. 4 is not formed, and the height H of the base member 144 is smaller than that of the base member 44 in the first embodiment.

In the second embodiment, the lens holder 130 and the regulating member 141 are also connected to each other via the second adjustment member 143.

The first adjustment member 142 is disposed between the base member 144 and the regulating member 141, and is configured to integrally adjust both the first position P1 of the lens holding portion 130 and the second position P2 of the regulating member 141.

The second adjustment member 143 is disposed between the regulating member 141 and the lens holding part 130, thereby determining the distance between the regulating member 141 and the lens holding part 130. As a result, the second adjustment member 143 is provided to adjust the first position P1 of the lens holding part 130.

The first adjustment member 142, the regulating member 141, the second adjustment member 143, and the lens holding part 130 each have an insertion hole IH11 for inserting the second fixing screw SC2. The regulating member 141, the first adjustment member 142, the second adjustment member 143, and the lens holding part 130 are fixed to the base member 144 by the second fixing screw SC2 that engages with the screw hole SH11 of the base member 144.

The restricting member 141 and the second adjustment member 143 each have an insertion hole IH12 for inserting the third fixing screw SC3. The restricting member 141 has a screw hole SH12 that engages with the third fixing screw SC3. The restricting member 141, the second adjustment member 143, and the lens holding portion 130 are connected to each other by the third fixing screw SC3 that passes through the insertion hole IH12 and engages with the screw hole SH12 of the restricting member 141.

(Position Adjustment by First Adjustment Member and Second Adjustment Member)
As shown in Figure 15, the first position P1 of the lens holding portion 130 is determined by the sum of the height (constant value) of the regulating member 141, the adjustment amount (thickness t1) of the first adjustment member 142, and the adjustment amount (thickness t2) of the second adjustment member 143, when the top surface height of the base member 144 is taken as the reference position.

The second position P2 of the regulating member 141 is determined by the adjustment amount (thickness t1) of the first adjustment member 142, assuming that the height of the upper surface of the base member 144 is the reference position. As a result, the regulating member 141 is adjusted to the second position P2 that restricts the optical path so that the image areas 72 formed by the light beams 70 incident on each of the multiple lenses 31 on the light receiving surface 51a of the image sensor 51 do not overlap each other and are arranged with a gap CL smaller than the thickness of the partition wall 41b. Even in the second embodiment, it is particularly useful when the lens holding part 130 is adjusted to the first position P1 where each lens 31 is focused at a shooting distance of 10 times or less than the focal length.

The other configurations of the compound eye imaging device 200 according to the second embodiment are similar to the configurations of the compound eye imaging device 100 according to the first embodiment described above.

(Effects of the Second Embodiment)
In the second embodiment, the following effects can be obtained.

In the second embodiment, as in the first embodiment, the first position P1 and the second position P2 can be adjusted by combining the first adjustment member 142 and the second adjustment member 143, so that when performing close-up photography, the overlap of images in adjacent ommatidium can be appropriately suppressed, thereby making maximum use of the entire imaging area of the image sensor 51.

In the second embodiment, as described above, the first adjustment member 142, the regulating member 141, the second adjustment member 143, and the lens holding part 130 are stacked on the base member 144 in this order from the base member 144 side. With this configuration, the lens holding part 130, the regulating member 141, the first adjustment member 142, and the second adjustment member 143 are stacked and arranged in series. In this case, the position (second position P2) of the regulating member 141 based on the base member 144 can be determined by the adjustment amount (thickness) of the first adjustment member 142, and the position (first position P1) of the lens holding part 130 based on the base member 144 can be determined by the sum of the adjustment amount of the first adjustment member 142 and the adjustment amount of the second adjustment member 143.

The other effects of the second embodiment are the same as those of the first embodiment described above.

[Modification]
It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims, not by the description of the embodiments above, and further includes all modifications (variations) within the meaning and scope of the claims.

(First Modification)
For example, in the first and second embodiments described above, the first adjustment member 42 (142) is provided to adjust both the first position P1 and the second position P2 in an integrated manner, but the present invention is not limited to this. For example, as shown in FIG. 16, the first position P1 and the second position P2 may be configured to be adjusted independently.

In the first modified example shown in FIG. 16, the first adjustment member 42 is provided to adjust one of the first position P1 of the lens holding unit 30 and the second position P2 of the regulating member 41 independently of the other, and the second adjustment member 43 is provided to adjust the other of the first position P1 of the lens holding unit 30 and the second position P2 of the regulating member 41 independently of the other. FIG. 16 shows an example in which the first adjustment member 42 adjusts the first position P1, and the second adjustment member 43 adjusts the second position P2.

In the first modified example, the frame-shaped base member 244 has a first mounting surface 244a and a second mounting surface 244b. The second mounting surface 244b is provided on the inner periphery side of the first mounting surface 244a. The lens holding portion 30 and the restricting member 41 are not connected, but are separately attached to each mounting surface of the base member 244.

Specifically, the lens holding unit 30 is installed on the first installation surface 244a via the first adjustment member 42. As a result, the first position P1 of the lens holding unit 30 is determined by the adjustment amount (thickness) of the first adjustment member 42. The regulating member 41 is installed on the second installation surface 244b via the second adjustment member 43. As a result, the second position P2 of the regulating member 41 is determined by the adjustment amount (thickness) of the second adjustment member 43.

With this configuration, the first position P1 of the lens holding part 30 and the second position P2 of the regulating member 41 can be adjusted independently by the first adjustment member 42 and the second adjustment member 43. Since the adjustment amount of the first adjustment member 42 and the adjustment amount of the second adjustment member 43 can be determined independently, the adjustment amount of each adjustment member can be easily determined.

(Second Modification)
In the above first and second embodiments, an example has been shown in which both the first adjustment member 42 and the second adjustment member 43 are spacer members formed of a laminate of a plurality of thin plates 60, but the present invention is not limited to this. For example, as shown in Fig. 17, one of the first adjustment member 42 and the second adjustment member 43 may be formed of a structure other than the laminate of thin plates 60.

For example, in FIG. 17, one of the first and second adjustment members includes a spacer member, and the other of the first and second adjustment members includes a position adjustment screw that adjusts the position in the optical axis direction by being rotated. In FIG. 17, the first adjustment member 342 is configured with a position adjustment screw, and the second adjustment member 43 is configured with a spacer member.

The first adjustment member 342 includes an adjustment screw 342a and a fixing screw 342b. The adjustment screw 342a engages with an adjustment screw hole 330a formed in the lens holding portion 30, and the tip 342c passes through the adjustment screw hole 330a and abuts against the installation surface of the base member 44. By rotating the adjustment screw 342a, the protruding amount of the tip 342c from the lens holding portion 30 can be adjusted. This protruding amount is the adjustment amount in the optical axis direction by the first adjustment member 342 (corresponding to the thickness t1). The fixing screw 342b passes through an insertion hole 330b formed in the lens holding portion 30 and engages with a fixing screw hole 344a formed on the installation surface of the base member 44. With the adjustment amount of the first adjustment member 342 determined by the adjustment screw hole 330a, the lens holding portion 30 is fixed to the base member 44 by tightening the fixing screw 342b.

The configuration of the second adjustment member 43 is the same as in the first embodiment described above.

In this configuration, the position adjustment screw (first adjustment member 342) allows for stepless wide-range position adjustment, while the spacer member (second adjustment member 43) allows for precise position adjustment depending on the number of layers of the thin plates 60. As described above, the extension amount of the lens 31 (adjustment amount A1 of the first adjustment member 342) differs significantly between infinity and close-up photography, so it is useful to adjust the first position P1 using the position adjustment screw method, which allows for a large adjustment range. Even in this case, the offset amount of the regulating member 41 is small compared to the extension amount of the lens 31, so a stack of thin plates 60 with excellent positional accuracy is effective because it allows for precise adjustment of the second position P2 so as to minimize the interval between each image area 72 on the light receiving surface 51a. In addition, both the first adjustment member 342 and the second adjustment member 43 may be configured using position adjustment screws.

(Other Modifications)
In the above first and second embodiments, it has been described that the lens holding part 30 can be adjusted to the first position P1 where each lens 31 is focused at a shooting distance of 10 times or less of the focal length, but in the compound eye imaging device according to the present invention, the first position P1 and the second position P2 may be adjusted to any shooting distance from infinity to ultra close-up photography. According to the present invention, such a wide range of shooting distances can be accommodated with the same device configuration by simply changing the adjustment amounts of the first adjustment member 42 and the second adjustment member 43.

In addition, in the above first and second embodiments, an example in which a filter holding portion 10 is provided is shown, but the present invention is not limited to this. The filter holding portion 10 does not have to be provided.

In addition, in the above first and second embodiments, an example is shown in which the filter holding portion 10, the aperture portion 20, and the lens holding portion 30 are arranged in this order from the Z1 direction side toward the Z2 direction side, but the present invention is not limited to this. The aperture portion 20 may be arranged on the Z1 direction side of the filter holding portion 10. The arrangement order of the filter holding portion 10, the aperture portion 20, and the lens holding portion 30 may be any combination.

In addition, in the above first and second embodiments, an example was shown in which the first adjustment member 42 is disposed between the base member 44 and the lens holding portion 30, but the present invention is not limited to this. The first adjustment member 42 may be disposed between the sensor board 52 and the base member 44.

In the above first and second embodiments, the first adjustment member 42 and the second adjustment member 43 are spacer members formed of a laminate of multiple thin plates 60, but the present invention is not limited to this. In the present invention, a non-laminated spacer member made of a single member may be used for the first adjustment member 42 and the second adjustment member 43. In this case, however, it is necessary to manufacture spacer members with various thickness dimensions depending on the amount of adjustment, which increases the number of parts, so it is preferable to configure the first adjustment member 42 and the second adjustment member 43 as a laminate of thin plates 60.

In the above first and second embodiments, an example is shown in which the first adjustment member 42 and the second adjustment member 43 are formed by combining three types of thin plates 60 with thicknesses of 20 μm, 30 μm, and 100 μm, but the present invention is not limited to this. There may be only one type of thin plate 60, or there may be two or four or more types. In a configuration in which multiple types of thin plates 60 are combined, it is preferable to combine thin plates having thicknesses that are not multiples of each other. This is because the total thickness can be finely adjusted by the combination. Although an example is shown in which the thickness of the thin plate 60 is between several tens of μm and one hundred μm, the thickness of the thin plate 60 may be less than ten μm.

In addition, in the above first and second embodiments, the base member 44, the first adjustment member 42 and the second adjustment member 43, the regulating member 41, the lens holding portion 30, the aperture portion 20, and the filter holding portion 10 are fixed by various fixing screws, but the present invention is not limited to this. The method of fixing each member is not particularly limited. Each member may be fixed by one of known fixing methods such as adhesive, welding, crimping, etc., or by a combination of multiple known fixing methods.

In addition, in the above first and second embodiments, an example was shown in which the filter holding unit 10 is configured to be able to hold two optical filters Ft for one unit, but the present invention is not limited to this. The number of optical filters Ft that the filter holding unit 10 can hold for one unit may be one or three or more.

In the above first and second embodiments, the lens holding section 30 has multiple lens installation holes 30a and holds the lens 31 for each lens unit, but the present invention is not limited to this. The lens holding section 30 may be capable of holding a lens array in which multiple lenses are integrally formed. The lens holding section 30 may have one lens hole for holding the lens array.

30, 130 Lens holding portion 30b First portion 30c Second portion 31 Lens 41, 141 Regulating member 41b Partition wall 42, 142, 342 First adjustment member 43, 143 Second adjustment member 44, 144, 244 Base member 51 Image sensor 51a Light receiving surface 60, 60a, 60b Thin plate 70 Light flux 72 Image area 100, 200 Compound eye imaging device P1 First position P2 Second position

Claims (9)

Multiple lenses and
a lens holder for holding the plurality of lenses;
an image sensor for forming a plurality of images formed by each of the plurality of lenses;
a restricting member that restricts an optical path from each of the plurality of lenses to the image sensor;
a first adjustment member that adjusts at least a first position of the lens holding portion in the optical axis direction of the plurality of lenses and a second position of the regulating member in the optical axis direction;
a second adjustment member that adjusts the second position between the first position and the second position ,
A compound eye imaging device , wherein the first adjustment member and the second adjustment member are arranged so as not to overlap each other when viewed in the optical axis direction . The lens holding portion and the regulating member are connected to each other,
the first adjustment member is provided to integrally adjust both the first position and the second position,
2. The compound-eye imaging apparatus according to claim 1, wherein the second adjustment member is provided between the lens holding portion and the regulating member so as to adjust the second position. Multiple lenses and
a lens holder for holding the plurality of lenses;
an image sensor for forming a plurality of images formed by each of the plurality of lenses;
a restricting member that restricts an optical path from each of the plurality of lenses to the image sensor;
a first adjustment member that adjusts at least a first position of the lens holding portion in the optical axis direction of the plurality of lenses and a second position of the regulating member in the optical axis direction;
a second adjustment member that adjusts the second position between the first position and the second position,
The lens holding portion and the regulating member are connected to each other,
the first adjustment member is provided to integrally adjust both the first position and the second position,
the second adjustment member is provided between the lens holding portion and the regulating member and is configured to adjust the second position,
a base member to which the lens holding portion and the regulating member are attached,
the lens holder is laminated to the base member via the first adjustment member at a first portion,
A compound eye imaging device, wherein the regulating member is connected to a second portion of the lens holding portion, the second portion being different from the first portion, via the second adjustment member. Multiple lenses and
a lens holder for holding the plurality of lenses;
an image sensor for forming a plurality of images formed by each of the plurality of lenses;
a restricting member that restricts an optical path from each of the plurality of lenses to the image sensor;
a first adjustment member that adjusts a first position of the lens holding portion in the optical axis direction of the plurality of lenses and a second position of the regulating member in the optical axis direction;
a second adjustment member that adjusts the second position between the first position and the second position,
the first adjustment member is provided to adjust the first position of the lens holding portion independently of the second position of the regulating member ,
The second adjustment member is provided to adjust the second position of the regulating member independently of the first position of the lens holding portion . 5. The compound eye imaging device according to claim 1, wherein at least one of the first adjustment member and the second adjustment member is a spacer member that is made of a laminate of a plurality of thin plates and adjusts its position by its thickness. Multiple lenses and
a lens holder for holding the plurality of lenses;
an image sensor for forming a plurality of images formed by each of the plurality of lenses;
a restricting member that restricts an optical path from each of the plurality of lenses to the image sensor;
a first adjustment member that adjusts at least a first position of the lens holding portion in the optical axis direction of the plurality of lenses and a second position of the regulating member in the optical axis direction;
a second adjustment member that adjusts the second position between the first position and the second position,
one of the first adjustment member and the second adjustment member is formed of a laminate of a plurality of thin plates and includes a spacer member that adjusts a position by a thickness thereof ;
the other of the first adjustment member and the second adjustment member includes a position adjustment screw that is rotated to adjust the position in the optical axis direction . The compound eye imaging device according to any one of claims 1 to 6, wherein the regulating member includes a partition that divides the optical path from each of the plurality of lenses to the image sensor, and is disposed at the second position away from the light receiving surface of the image sensor in the optical axis direction. The compound eye imaging device described in claim 7, wherein the regulating member is adjusted to the second position that limits the optical path so that the image areas formed by the light beams incident from each of the multiple lenses on the light receiving surface of the image sensor do not overlap with each other and are arranged at an interval smaller than the thickness of the partition. Multiple lenses and
a lens holder for holding the plurality of lenses;
an image sensor for forming a plurality of images formed by each of the plurality of lenses;
a restricting member that restricts an optical path from each of the plurality of lenses to the image sensor;
a first adjustment member that adjusts at least a first position of the lens holding portion in the optical axis direction of the plurality of lenses and a second position of the regulating member in the optical axis direction;
a second adjustment member that adjusts the second position between the first position and the second position,
The lens holding portion is positioned at the first position where each of the lenses is focused at a shooting distance that is 10 times or less than a focal length of the lens.

Images