JP6459983B2 - Lens unit and imaging device - Google Patents

Description

  The present invention relates to a lens unit in which a plurality of optical elements are overlapped, and an imaging apparatus incorporating the lens unit.

  As a method of assembling a lens unit in which a plurality of optical elements are stacked, a pair of corresponding fitting shapes that are accurately formed with reference to the optical axis or the like are provided for a pair of adjacent lenses, and these fitting shapes are combined. Many proposals have been made to precisely align both lenses in a direction perpendicular to the optical axis (see Patent Documents 1 to 5).

  For example, Patent Document 1 discloses a compound lens that positions a pair of lenses by a fitting structure, and includes a tapered portion provided on an outer peripheral portion of one lens and having an inward slope, and an outer peripheral portion of the other lens. And positioning with a tapered portion having an outward slope. The lens of Patent Document 2 is also provided with a lens inwardly tapered surface and an outwardly tapered surface provided in each lens, and positioning is performed so that the optical axes are matched by surface contact or fitting.

  Patent Document 3 discloses a compound lens that positions a pair of lenses by a reference plane perpendicular to the optical axis and a fitting structure, and includes a plurality of arc-shaped protrusions provided on the outer periphery of one lens. Positioning in the direction perpendicular to the optical axis is performed by the cylindrical surface and the stepped outer cylindrical surface provided on the outer periphery of the other lens. Also in the lens of Patent Document 4, annular concavo-convex portions are provided on both lenses, and positioning is performed to match the optical axes by fitting the inner peripheral surface and the outer peripheral surface thereof.

  In Patent Document 5, in order to position the centers of the two lens array substrates, both ends of the shaft-shaped fitting portion are rotatably fitted in the recesses provided at the centers of the two substrates, and the rotation directions of both the substrates are marked. It is positioned by. Alternatively, the tip of a shaft-shaped fitting portion protruding from the center of one lens array substrate is rotatably fitted in a fitting hole formed in the center of the other lens array substrate, and the rotation direction of both substrates is marked. It is positioned by.

  However, each lens constituting the lens unit may have some variation in shape and size. In particular, when the lens is made of a resin, variations in the dimensions of the fitting structure are likely to occur due to the effects of mold processing accuracy and manufacturing conditions.

The fitting of the tapered surface used in the above Patent Documents 1 and 2 can be precisely aligned if it is an ideal shape, but the so-called minus which makes the outside of the fitting portion narrower. When it becomes a gap, floating occurs in the optical axis direction, and when it becomes a positive gap, the optical axis shifts due to play. Furthermore, adjustment of the relative rotational position of the lenses is not considered.
When the cylindrical surface used in Patent Documents 3 and 4 has a minus gap such that the outside of the fitting portion becomes narrow, the fitting becomes impossible or the optical surface is pressed into the optical surface. When deformation or the like occurs or a positive gap is formed, the optical axis shift occurs due to play. Furthermore, adjustment of the relative rotational position of the lenses is not considered.
Although the method of the above-mentioned patent document 5 has a fitting portion at the center even when the outer size of the lens is increased as in a lens array, the optical axis shift is less likely to occur and the problem of poor fitting is less likely to occur. Positioning is separately required, and a complicated adjustment process using a microscope or the like is indispensable.

JP 2002-196221 A JP 2007-163656 A JP 2010-197816 A JP 2005-258329 A JP 2012-78675 A

  The present invention has been made in view of the above background art, and a lens unit that can be manufactured by precise alignment with a simple method even if there are some dimensional differences in a plurality of optical elements, and an imaging apparatus incorporating the lens unit The purpose is to provide.

In order to achieve the above object, a lens unit according to the present invention includes a plurality of optical elements that are overlapped and fixed to each other, and a plurality of optical elements that are spaced apart from each other at an outer peripheral portion that surrounds the main body of each optical element. Each of the positioning units is provided at a position opposite to the plurality of optical elements and abuts with each other to thereby form an optical axis. Including a pair of contact portions for restricting relative movement of the plurality of optical elements with respect to the direction and the inherent restriction direction around the central axis of the main body portion on a plane perpendicular to the optical axis, and at least two of the three positioning portions The two positioning portions are formed so that the inherent restriction directions are different from each other. Of the pair of contact portions, one contact portion is a convex portion having a spherical surface, and the other contact portion is light Through a groove extending in the radial direction and the optical axis direction and the limitations inherent direction which is perpendicular, projections, radial movement is allowed against the groove. Here, the main body portion of the optical element means a central lens portion in the case of a single lens, and means the whole of a plurality of individual lenses in the case of a lens array having a plurality of individual lenses. Further, the inherent restriction direction is a direction that restricts relative movement or rotation of the plurality of optical elements in each positioning unit.

  In the lens unit described above, the pair of contact portions provided in the three positioning portions are relatively moved with respect to the optical axis direction and the inherent restriction direction around the central axis on a plane perpendicular to the optical axis. The at least two positioning portions are formed so that the inherent restriction directions are different from each other, so that not only precise positioning is possible with respect to the optical axis direction and the plane direction perpendicular to the optical axis, With respect to rotation around the central axis, precise positioning that allows some dimensional difference is possible.

  An imaging device according to the present invention includes the lens unit described above and a sensor that detects an image formed by the lens unit.

FIG. 1A is a plan view illustrating the lens knit of the first embodiment, and FIG. 1B is a cross-sectional view taken along the line AA of the lens unit in FIG. 1A. FIG. 2A is a rear view of the first single lens, and FIG. 2B is a plan view of the second single lens. 3A is a view of the protruding member of the first positioning portion viewed from the central axis direction, and FIG. 3B is a cross-sectional view of the protruding member viewed from the direction perpendicular to the central axis. It is sectional drawing explaining the shaping | molding method of a single lens. FIG. 5A is a plan view for explaining a lens knit or the like of the second embodiment, and FIG. 5B is a cross-sectional view of the lens unit of FIG. 6A is a rear view of the first lens array, and FIG. 6B is a plan view of the second lens array.

[First Embodiment]
Hereinafter, a lens unit according to a first embodiment of the present invention and an imaging apparatus incorporating the lens unit will be described with reference to the drawings.

  An imaging apparatus 100 illustrated in FIGS. 1A and 1B has a square or rectangular plate-like outer shape, and includes a lens unit 20, a filter 40, a single sensor 50, and a holder 60. Among these, the imaging optical system 200 is configured by the lens unit 20, the filter 40, and the holder 60.

  The lens unit 20 forms a subject image by a single compound optical system. The lens unit 20 includes a first single lens 21, a second single lens 22, and an intermediate diaphragm 23. These members 21, 22, and 23 are stacked in the optical axis AX direction or the Z-axis direction. The lens unit 20 has a function of forming a subject image on the image plane or the imaging plane (projected plane) I of the single sensor 50. The lens unit 20 itself may be called an imaging optical system.

  The first single lens 21 of the lens unit 20 is an optical element that is disposed on the most object side of the imaging device 100. As shown in FIGS. 1B and 2A, the first single lens (optical element) 21 includes a main body portion, that is, a central first lens portion 21a, and an outer peripheral portion, that is, a surrounding frame portion 21b, which are integrated. For example, it is a resin molded product (plastic molded product) formed of a thermoplastic material, and has a circular outline when viewed from the optical axis AX direction. The first lens unit 21a includes a first optical surface 21c that is a convex aspheric surface on the object side, and a second optical surface 21d that is a concave aspheric surface on the image side. The frame portion (outer peripheral portion) 21b of the first lens portion 21a has flat first and second frame surfaces 21e and 21f extending perpendicularly to the optical axis AX around the first and second optical surfaces 21c and 21d. The frame portion 21 b includes a thin portion 25 that is recessed in a step shape on the outer periphery, and receives the spacer portion 26 of the second single lens 22. In the present embodiment, the optical axis AX coincides with the central axis of the main body.

  The second single lens 22 is an optical element disposed on the image side of the first single lens 21. The second single lens (optical element) 22 has a structure similar to that of the first single lens 21. That is, as shown in FIGS. 1B and 2B, the second single lens 22 includes a main body portion, that is, a central second lens portion 22a, and an outer peripheral portion, that is, a surrounding frame portion 22b. It is a resin molded product formed of a thermoplastic material, and has a circular outline when viewed from the optical axis AX direction. The second lens unit 22a includes a third optical surface 22c that is a concave aspheric surface on the object side, and a fourth optical surface 22d that is a convex aspheric surface on the image side. The frame portion (outer peripheral portion) 22b of the second lens portion 22a has flat third and fourth frame surfaces 22e and 22f extending perpendicularly to the optical axis AX around the third and fourth optical surfaces 22c and 22d. The frame portion 22 b includes a spacer portion 26 protruding in a step shape on the outer periphery, and faces the thin portion 25 of the first single lens 21.

  The first and second single lenses 21 and 22 can be formed of resin, glass, or the like. When the single lenses 21 and 22 are formed of a resin, they are integrally formed by, for example, injection molding using a mold or press molding using a mold or a resin mold.

  The intermediate diaphragm 23 is a rectangular or quadrangular diaphragm member, and is provided between the first single lens 21 and the second single lens 22. The intermediate diaphragm (diaphragm member) 23 is bonded to the frame portion 22b of the second single lens 22 with an adhesive. The intermediate diaphragm 23 has a circular opening 23 a at a position corresponding to the second lens portion 22 a of the second single lens 22. The intermediate diaphragm 23 is a plate-like member made of metal, resin, or the like, and a black or dark material having light absorption by itself, or a material whose surface is painted black or dark is used.

  The filter 40 is a rectangular or quadrangular plate-like member, and is provided between the second single lens 22 and the single sensor 50. The filter 40 is an infrared cut filter having a function of reflecting infrared rays, for example.

  The single sensor 50 detects a subject image formed by the lens unit 20, that is, the pair of lens portions 21a and 22a. The single sensor 50 incorporates an imaging unit 52 that extends along the XY plane perpendicular to the optical axis AX. The imaging unit 52 is a sensor chip made of a solid-state imaging device. The photoelectric conversion unit (not shown) constituting the imaging unit 52 is composed of a CCD or a CMOS, photoelectrically converts incident light for each RGB, and outputs an analog signal thereof. The surface of the photoelectric conversion unit is an imaging surface (projection surface) I. The single sensor 50 is covered with a cover glass 53 on the front side and fixed with a wiring board (not shown) on the back side. The wiring board receives a voltage and a signal for driving the imaging unit 52 from the external circuit 55 and outputs a detection signal to the external circuit 55. The external circuit 55 includes an image processing unit that performs image processing.

  The holder 60 is a frame member for housing and holding the lens unit 20, the filter 40, and the single sensor 50. The holder 60 is formed with a recess 60a having a plurality of step portions T1, T2, T3. The holder 60 has a bowl-like or box-like outer shape as a whole. In the recess 60a, the lens unit 20, the filter 40, and the single sensor 50 are set in order. Each member 20, 40, 50 is positioned by each step T1, T2, T3 of the recess 60a. In the holder 60, a circular opening 60b is formed at a position corresponding to the first optical surface 21c of the lens unit 20. The holder 60 is formed of a light shielding resin, for example, a liquid crystal polymer (LCP) or a polyphthalamide (PPA) containing a colorant such as a black pigment.

  The lens unit 20 is attached to the thin portion 25 and the spacer portion 26 as a plurality of positioning portions in the ring-shaped peripheral portion of the first single lens (optical element) 21 and the second single lens (optical element) 22. It has 1st-3rd positioning part 11,12,13. By these first to third positioning portions 11, 12, and 13, the first single lens 21 and the second single lens 22 are positioned with respect to the optical axis AX direction and the XY direction perpendicular to the optical axis AX. The first to third positioning portions 11, 12, and 13 are symmetrically arranged at an interval of 120 ° around the optical axis AX corresponding to the central axis. Specifically, the first positioning unit 11 is disposed in the 12 o'clock direction with respect to the optical axis AX, and the second positioning unit 12 is disposed in the 4 o'clock direction with respect to the optical axis AX as a third positioning. The unit 13 is arranged in the 8 o'clock direction with respect to the optical axis AX. The first to third positioning portions 11, 12, 13 are formed integrally with the single lenses 21, 22, and it is easy to improve positioning accuracy.

  The first positioning unit 11 not only restricts the relative movement of the single lenses 21 and 22 with respect to the optical axis AX direction, but also the direction around the central axis of the main body on a plane perpendicular to the optical axis AX, specifically This contributes to positioning by restricting the relative movement or rotation of the single lenses 21 and 22 with respect to the inherent restriction direction P1 parallel to the XY plane and perpendicular to the radial direction D1 outward from the optical axis AX. The second positioning unit 12 not only restricts the relative movement of the single lenses 21 and 22 with respect to the optical axis AX direction, but also inherently restricts the radial direction D2 parallel to the XY plane and outward from the optical axis AX. Limiting the relative movement or rotation of the single lenses 21 and 22 with respect to the direction P2 contributes to positioning. The third positioning unit 13 not only restricts the relative movement of the single lenses 21 and 22 with respect to the optical axis AX direction, but also inherently restricts the radial direction D3 parallel to the XY plane and outward from the optical axis AX. Limiting the relative movement or rotation of the single lenses 21 and 22 with respect to the direction P3 contributes to positioning. In the above, the inherent restriction directions P1, P2, and P3 of positioning by the first to third positioning portions 11, 12, and 13 are in the tangential direction in the positioning portions 11, 12, and 13 on the circumference around the optical axis AX. It is equivalent. Thereby, the support by the three positioning parts 11, 12, and 13 is balanced, and stable and highly accurate positioning is facilitated.

  As shown in FIGS. 3A and 3B, the first positioning portion 11 includes a pair of abutting portions that are provided at opposite positions of the first and second single lenses 21 and 22 and abut against each other. Specifically, the first positioning portion 11 includes a hemispherical convex portion 11a as one abutting portion, and a groove portion 11b having a V-shaped cross section as the other abutting portion. The hemispherical surface 11t of the convex portion 11a contacts the groove slope 11s of the groove portion 11b during positioning. The convex portion 11 a is integrated with the thin portion 25 of the first single lens 21 and protrudes from the surface 21 k of the thin portion 25. The groove portion 11 b is integrated with the spacer portion 26 of the second single lens 22, and is formed to be recessed from the surface 22 k of the spacer portion 26. Here, since the groove portion 11b extends in the radial direction D1, the hemispherical surface 11t of the convex portion 11a passes through the optical axis AX while being in contact with the groove inclined surface 11s of the groove portion 11b, and the optical axis AX direction. It slides in the radial direction D1, which is a direction perpendicular to the inherent restriction direction P1. That is, in the first positioning portion 11, the convex portion 11a is restricted from moving in the optical axis AX direction with respect to the groove portion 11b, and the first positioning portion 11 as a whole can be positioned in the optical axis AX direction. To do. Further, the protrusion 11a is allowed to move in the radial direction D1 with respect to the groove 11b, but is restricted from moving in the inherent restriction direction P1 perpendicular to the radial direction D1, and the first positioning part 11 as a whole The positioning in the tangential direction along the circumference of the thin portion 25 is enabled.

  The second positioning portion 12 has the same structure as that of the first positioning portion 11 and includes a hemispherical convex portion 11a as one abutting portion and a groove portion 12b having a V-shaped cross section as the other abutting portion. . The groove portion 12b of the second positioning portion 12 has the same shape as the groove portion 11b of the first positioning portion 11 and is formed as a recess from the surface 22k of the spacer portion 26. However, the radial direction D1 of the groove portion 11b extends. Extend in the radial direction D2 which differs by 120 °. As a result, the second positioning part 12 enables positioning in the optical axis AX direction by the convex part 11a and the groove part 12b. Further, in the second positioning part 12, the thin part 25 is formed by restricting the movement of the convex part 11a in the inherent restriction direction P2 perpendicular to the radial direction D2 while being allowed to move in the radial direction D2 with respect to the groove part 12b. Positioning in the tangential direction along the circumference is performed.

  The 3rd positioning part 13 has the same structure as the 1st positioning part 11, is equipped with the hemispherical convex part 11a as one contact part, and is provided with the groove part 13b of a V-shaped cross section as the other contact part. . The groove portion 13b of the third positioning portion 13 has the same shape as the groove portion 11b of the first positioning portion 11 and is formed as a recess from the surface 22k of the spacer portion 26, but the radial direction in which the groove portions 11b and 12b extend. It extends in a radial direction D3 that is 120 ° different from D1 and D2. As a result, the 3rd positioning part 13 enables positioning regarding the optical axis AX direction by the convex part 11a and the groove part 13b. Further, in the third positioning portion 13, the projection 11 a is allowed to move in the radial direction D <b> 3 with respect to the groove portion 13 b, but is restricted from moving in the inherent limiting direction P <b> 3 perpendicular to the radial direction D <b> 3. Positioning in the tangential direction along the circumference is performed.

  In the first to third positioning portions 11, 12, and 13, the groove portions 11b, 12b, and 13b extend radially from a common center point (optical axis AX in the illustrated example). In the first to third positioning portions 11, 12, and 13 described above, one contact portion is a convex portion, and the other contact portion is a groove portion, so that it is easy to ensure accuracy with a simple structure. Yes.

  When combining the single lenses 21 and 22, both the single lenses 21 and 22 are simply overlapped, and the single lenses 21 and 22 in the optical axis AX direction are obtained by the cooperation of the first to third positioning portions 11, 12, and 13. The relative distance between the single lenses 21 and 22 with respect to the optical axis AX direction is prevented. Further, by simply superimposing the single lenses 21 and 22, the cooperation of the first to third positioning portions 11, 12, and 13 allows the relative positions of the single lenses 21 and 22 with respect to the XY direction perpendicular to the optical axis AX direction. Therefore, the optical axis AX of both the single lenses 21 and 22 can be matched. The first and second single lenses 21 and 22 having completed such positioning are cured by supplying an adhesive to an appropriate portion between the surface 21k of the adjacent thin portion 25 and the surface 22k of the spacer portion 26. By this, it joins in the positioned state. Even when both the single lenses 21 and 22 have a shape slightly deviated from a precise design value, the optical axis AX is adjusted by the grooves 11b, 12b, and 13b of the first to third positioning portions 11, 12, and 13. As described above, since the relative movement of both the single lenses 21 and 22 in the direction perpendicular to the optical axis AX is allowed and such a dimensional difference is allowed, the centering for matching the optical axis AX becomes relatively accurate.

  FIG. 4 is a diagram for explaining an example of a manufacturing method of the first single lens 21. The first single lens 21 including the convex portion 11a of the first positioning portion 11 is integrally formed by injection molding. That is, the first single lens 21 is formed of a pair of mold parts 91 and 92 from a thermoplastic resin. The transfer surface 91a of one mold part 91 is obtained by inverting the first optical surface 21c, the first frame surface 21e, and the like. The transfer surface 92a of the other mold part 92 is obtained by inverting the second optical surface 21d, the second frame surface 21f, the surface 21k, the hemispherical surface 11t, and the like. By forming the convex part 11a with the mold part 92 that is common to the frame part 21b, the lens unit 20 that is less dependent on the mold processing and assembly accuracy even if the first single lens 21 is a resin molded product. Can be obtained.

  In addition, although illustration is abbreviate | omitted, the 2nd single lens 22 is manufactured similarly to the 1st single lens 21 by a pair of mold components with the groove parts 11b, 12b, and 13b.

  According to the lens unit 20 and the like of the first embodiment described above, the pair of contact portions (the convex portions 11a and the groove portions 11b, 12b, and 13b) provided in the three positioning portions 11, 12, and 13 are optical axes. The relative movement of the plurality of single lenses 21 and 22 is restricted with respect to the AX direction and the inherent restriction directions P1, P2, and P3 perpendicular to the optical axis AX, and the three positioning portions 11, 12, and 13 are provided with the inherent restriction directions P1, Since P2 and P3 are formed to be different from each other, not only precise positioning is possible with respect to the optical axis AX direction and the direction perpendicular to the optical axis AX, but also with respect to rotation about the optical axis AX, Precise positioning that allows some dimensional difference is possible.

[Second Embodiment]
Hereinafter, a lens unit according to a second embodiment and an imaging apparatus incorporating the lens unit will be described with reference to the drawings.

  An imaging apparatus 1100 illustrated in FIGS. 5A and 5B is for capturing a plurality of images using a plurality of imaging systems and reconstructing one image. The imaging device 1100 has a square or rectangular plate-like outer shape, and includes a lens unit 1020, a filter 40, a sensor array 1050, and a holder 60. Among these, the compound eye imaging optical system 1200 is configured by the lens unit 1020, the filter 40, and the holder 60.

  The lens unit 1020 is a stacked lens array unit that forms a plurality of sets of subject images. The lens unit 1020 includes a first lens array 1021, a second lens array 1022, and an intermediate aperture 23. These members 1021, 1022, and 23 are stacked in the optical axis AX direction or the Z-axis direction. The lens unit 1020 has a function of forming a subject image on the image plane or the imaging plane (projected plane) I of the sensor array 1050. The lens unit 1020 itself may be referred to as a compound eye imaging optical system.

  Of the lens unit 1020, the first lens array 1021 is disposed on the most object side of the imaging apparatus 1100. As shown also in FIG. 6A, the first lens array 1021 includes a plurality of first eye lenses 121a that are two-dimensionally arranged in the XY direction perpendicular to the optical axis AX, and the plurality of first eye lenses 121a. And a frame portion 21b that connects from the periphery, and is a resin molded product formed of, for example, a thermoplastic material, and has a rectangular outline when viewed from the optical axis AX direction. The single lens 121a is two-dimensionally arranged along rectangular lattice points that are repeated in the XY directions. Each single lens 121a has a first optical surface 21c that is a convex aspheric surface on the object side, and a second optical surface 21d that is a concave aspheric surface on the image side. The frame portion 21b around the single lens 121a has flat first and second frame surfaces 21e and 21f extending perpendicularly to the optical axis AX around the first and second optical surfaces 21c and 21d. The frame portion 21 b includes a spacer portion 27 on the outer peripheral portion in order to ensure a distance in the Z-axis direction with respect to the second lens array 1022. In the present embodiment, the main body of the first lens array 1021 that is an optical element is the entire plurality of first single-eye lenses 121a, and the center thereof is the central axis CX.

  The second lens array 1022 is disposed on the image side of the first lens array 1021. As shown in FIG. 6B, the second lens array 1022 includes a plurality of second eye lenses 122a that are two-dimensionally arranged in the XY direction perpendicular to the optical axis AX, like the first lens array 1022. A frame portion 22b that connects the plurality of second eye lenses 122a from the periphery, and is a resin molded product formed of, for example, a thermoplastic material, and has a rectangular outline when viewed from the optical axis AX direction. The single lens 122a is two-dimensionally arranged along the rectangular lattice points. Each single lens 122a has a third optical surface 22c that is a concave aspheric surface on the object side, and a fourth optical surface 22d that is a convex aspheric surface on the image side. The frame portion 22b around the single lens 122a has flat third and fourth frame surfaces 22e and 22f extending perpendicularly to the optical axis AX around the third and fourth optical surfaces 22c and 22d. The frame portion 22 b includes a spacer portion 28 that is joined to the spacer portion 27 of the first lens array 1021 on the outer peripheral portion in order to secure a distance in the Z-axis direction with respect to the first lens array 1021.

  Any one first-eye lens 121a constituting the first lens array 1021, and a second lens array 1021 facing the first lens-eye lens 121a and disposed on the same optical axis AX on the second lens array 1021 side. The two-lens lens 122a functions as one imaging lens that forms an object image (subject image) independently, that is, as an imaging single-eye optical system 20s. The single-eye optical system 20s is arranged in a matrix in the XY direction. The plurality of single-eye optical systems 20s are divided into a plurality of types suitable for, for example, a red (R) subject image, a green (G) subject image, and a blue (R) subject image. They can be of different types, such as having different fields of view, or they can all be of the same type.

  The first and second lens arrays 1021 and 1022 can be formed of resin, glass, or the like. When the first and second lens arrays 1021 and 1022 are formed of resin, they are formed by, for example, injection molding using a mold or press molding using a mold or a resin mold.

  The intermediate diaphragm 23 is a rectangular plate-shaped diaphragm member, and is provided between the first lens array 1021 and the second lens array 1022. The intermediate diaphragm (diaphragm member) 23 is bonded to the frame portion 21b of the first lens array 1021 with an adhesive. The intermediate diaphragm 23 has a circular opening 23a at a position corresponding to the first single-eye lens 121a constituting the first lens array 1021.

  The filter 40 is a rectangular or quadrangular plate-like member, and is provided between the second lens array 1022 and the sensor array 1050. The filter 40 is an infrared cut filter having a function of reflecting infrared rays, for example.

The sensor array 1050 detects a subject image formed by the individual lenses 121a and 122a constituting the lens unit 1020. The sensor array 1050 includes an imaging unit 52 including sensor units 51 that are two-dimensionally arranged along the XY plane perpendicular to the optical axis AX. The imaging unit 52 is a sensor chip made of a solid-state imaging device. The surface of the photoelectric conversion unit constituting the sensor unit 51 of the imaging unit 52 is an imaging surface (projected surface) I. The sensor array 1050 is covered with a cover glass 53 on the front side, and fixed on the back side with a wiring board (not shown). The wiring board receives a voltage and a signal for driving the imaging unit 52 from the external circuit 55 and outputs a detection signal to the external circuit 55. The external circuit 55 includes an image processing unit that performs image processing conforming to the super-resolution method or the visual field division method. Here, the super-resolution method refers to a method of obtaining one high-resolution image by image processing from images of the same field of view formed by individual lenses. The field division method refers to a method of obtaining one image by connecting images of different fields of view formed by individual lenses by image processing.
Instead of the sensor array 1050 in which the sensor unit 51 is provided for each single-eye optical system 20s, a single sensor element that collectively receives and detects a plurality of images from the lens unit 1020 can be used.

  The holder 60 is a frame member that houses and holds the lens unit 1020, the filter 40, and the sensor array 1050. The holder 60 is formed with a recess 60a having a plurality of step portions T1, T2, T3. The holder 60 has a bowl-like or box-like outer shape as a whole. In the recess 60a, the lens unit 1020, the filter 40, and the sensor array 1050 are set in order. Each member 1020, 40, 1050 is positioned by each step T1, T2, T3 of the recess 60a. In the holder 60, circular openings 60b are formed at lattice point positions corresponding to the plurality of first optical surfaces 21c of the lens unit 1020.

  The lens unit 20 includes first to third positioning portions 11, 12, and 13 attached to the spacer portions 27 and 28 at a rectangular outer peripheral portion or peripheral portion as a plurality of positioning portions. The first to third positioning portions 11, 12, and 13 are symmetrically arranged around the central axis CX at intervals of 120 °. These 1st-3rd positioning parts 11, 12, and 13 have the same structure as the case of 1st Embodiment shown to FIG. 3A and 3B. That is, the 1st positioning part 11 is provided with the convex part 11a and the groove part 11b, the 2nd positioning part 12 is provided with the convex part 11a and the groove part 12b, and the 3rd positioning part 13 is the convex part 11a and the groove part 13b. Is provided.

  In the case of the lens unit 1020 of the second embodiment, as in the lens unit 20 of the first embodiment, the first to third positioning portions 11, 12, and 13 can cooperate by simply overlapping both lens arrays 1021 and 1022. Accordingly, the relative distance between the lens arrays 1021 and 1022 with respect to the central axis CX direction is adjusted, and the relative inclination of the lens arrays 1021 and 1022 with respect to the central axis CX direction is prevented. Further, by simply superimposing both lens arrays 1021 and 1022, the two lens arrays 1021, with respect to the XY direction perpendicular to the central axis CX and the optical axis AX direction are obtained by the cooperation of the first to third positioning portions 11, 12, and 13. The relative positional shift of the lens 1022 is prevented, and the central axes CX of the lens arrays 1021 and 1022 and the optical axes AX of the first and second eye lenses 121a and 122a can be matched. The first and second lens arrays 1021 and 1022 that have completed such positioning are cured by supplying an adhesive to an appropriate position between the surface 21k of the spacer portion 27 and the surface 22k of the spacer portion 28 that are adjacent to each other. Are joined in a positioned state. Even if both lens arrays 1021 and 1022 have shapes slightly deviated from precise design values, the groove portions 11b, 12b, and 13b of the first to third positioning portions 11, 12, and 13 have such dimensions. Since the difference is allowed, the centering to match the central axis CX is relatively accurate, and the optical axes AX of the corresponding individual lenses 121a and 122a (that is, the individual optical system 20s) are relatively accurately matched. Can do.

  As described above, the embodiments have been described. However, the lens units 20 and 1020 according to the present invention are not limited to the above examples. For example, the first to third positioning portions 11, 12, and 13 are not limited to the combination of the convex portion 11a and the groove portions 11b, 12b, and 13b, but are fitted with various partial fitting structures or orientations that combine unevenness. It can be a composite structure. The shape of the convex portion 11a is not limited to a hemisphere, and can be various shapes including a spheroid, a quadrangular pyramid, a truncated cone, and the like. The shape of the grooves 11b, 12b, and 13b is not limited to a V-shaped cross section, but can be a curved arc of a cross section, a U-shaped cross section, or other curved shapes.

In addition to the first to third positioning portions 11, 12, and 13, a fourth positioning portion can be provided. In this case, the fourth positioning unit allows relative movement with respect to the radial direction or the radial direction from the optical axis AX or the central axis CX, and the circumferential direction perpendicular thereto is set as an inherent restriction direction in which relative movement is restricted. Shall.
In addition, the inherent restriction directions P1 to P3 allow relative movement in the radial direction from an axis or base point shifted from the central axis CX, and restrict relative movement in the circumferential direction perpendicular thereto. You can also. In this case, for example, in the example using the groove portions 11b, 12b, and 13b, the groove portions 11b, 12b, and 13b extend in a radial direction from an arbitrary base point that is separated from the central axis CX. That is, the positioning base point may not be on the central axis CX of the lens unit 1020 or the like. However, it is easier to increase the alignment accuracy if the positioning base point is near or relatively close to the center axis CX.

  In addition, the shapes of the optical surfaces 21c, 21d,... Of the lens portions 21a, 22a constituting the single lenses 21, 22 can be appropriately changed according to the use or specification of the lens unit 20 or the imaging device 100.

  Further, the arrangement of the single lenses 121a and 122a constituting the lens arrays 1021 and 1022 and the shape of the optical surfaces 21c, 21d,... Can do. For example, the single lenses 121a and 122a are not limited to being arranged at 4 × 4 lattice points, but can be arranged at lattice points such as 3 × 3, 2 × 2, 5 × 5, and the like. Note that the lens array constituting the lens unit 1020 is not limited to the two layers illustrated above, and may be three layers or four or more layers.

  The outline shape of the lens units 20 and 1020 is generally rectangular or quadrangular, but can be slightly modified. For example, a single lens or a lens array having an outline of an octagon or the like close to a quadrangle with a corner dropped can be an element constituting the lens unit according to the present invention.

Claims (10)

A plurality of optical elements that are superimposed and secured to each other;
A lens unit provided with three positioning portions provided in three locations spaced apart from each other in the outer peripheral portion surrounding the main body portion of each optical element among the plurality of optical elements;
Each positioning portion is provided at an opposite location of the plurality of optical elements and abuts with each other to thereby determine the optical axis direction and the inherent restriction direction around the central axis of the main body portion on a plane perpendicular to the optical axis. Including a pair of contact portions for restricting relative movement of the plurality of optical elements;
Of the three positioning parts, at least two positioning parts are formed to make the inherent restriction directions different from each other ,
Of the pair of contact portions, one contact portion is a convex portion having a spherical surface, and the other contact portion passes through the optical axis and is perpendicular to the optical axis direction and the inherent restriction direction. The lens unit is a groove portion extending in a radial direction, which is an arbitrary direction .   2. The lens unit according to claim 1, wherein the pair of contact portions allow relative movement of the plurality of optical elements with respect to a direction that passes through the central axis and is perpendicular to the central axis. 3. The lens unit according to claim 1, wherein the other contact portion of the pair of contact portions is a groove portion having a V-shaped cross section.   The said three positioning part is symmetrically arrange | positioned around the said central axis, The tangential direction in each positioning part on the circumference centering on the said central axis is made into an intrinsic | native restriction | limiting direction. The lens unit according to claim 1.   The lens unit according to any one of claims 1 to 4, wherein the pair of contact portions are formed integrally with the plurality of optical elements.   The plurality of optical elements are resin molded products, and the pair of abutting portions are formed of a mold part common to at least the outer peripheral portion of the optical elements. The lens unit according to claim 1.   The lens unit according to claim 6, wherein the plurality of optical elements are formed of a thermoplastic material.   Each of the optical elements constituting the plurality of optical elements is a lens array having a plurality of single-lens lenses, and the three positioning portions are provided at three locations on the outer peripheral portion of the plurality of lens arrays. The lens unit according to claim 7.   The lens unit according to any one of claims 1 to 7, wherein each optical element constituting the plurality of optical elements is a single lens. The lens unit according to any one of claims 1 to 9,
An imaging device comprising: a sensor that detects an image formed by the lens unit.

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