JP2017067937A - Lens sheet unit, imaging module, imaging device, and cover member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens sheet unit that allows an imaging module and an imaging device to be made thinner, and can suppress deformation and the like due to heating upon driving an image sensor, and to provide the imaging module, an imaging device and a cover member that include the lens sheet unit.SOLUTION: A lens sheet unit 10 is used in an imaging module 20, is a member that is disposed closer to an incidence side of light than an image sensor 21, and is formed by having a protection sheet 13, a first lens sheet 11, and a second lens sheet 12 integrally laminated. Each lens sheet is formed into a columnar shape, is arrayed in one direction along a sheet surface and includes: light transmission sections 111 and 121 that have a convex-shape unit lens shape; and light absorption sections 113 and 123 that are arrayed alternately with the light transmission sections 111 and 121, and extend onto a rear surface side in a thickness direction. An array direction of the light transmission sections 111 and 121 of each lens sheet crosses at an angle α when viewing from a normal line direction of the sheet surface.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a lens sheet unit, an imaging module, an imaging device, and a cover member.

  In recent years, various developments such as improvement of image quality have been performed on cameras provided in portable terminals such as smartphones and tablets (see, for example, Patent Document 1). In particular, mobile terminals such as smartphones are becoming thinner, and a camera provided in the mobile terminal (hereinafter referred to as a mobile terminal camera) is also being reduced in thickness.

  In addition, a camera called a light field camera, which can change a focal length and a depth of field after photographing, has been developed and spread in recent years (for example, see Patent Document 2). This light field camera uses a microlens array placed on an image sensor to divide incident light and shoot light in multiple directions, thereby performing predetermined image processing based on the incident direction and intensity of light after shooting. To change the focal length and depth of field of the image.

JP2015-99345A Special table 2015-520992 gazette

  In a camera for a portable terminal, correction of lens aberration or the like is necessary to capture a high-quality image. Therefore, an imaging lens including a plurality of lenses is used in the mobile terminal camera. However, since this imaging lens is composed of a plurality of lenses, the imaging lens occupies about 80% (about 4 mm) of the overall camera thickness (about 5 to 7 mm). For this reason, in a camera for a mobile terminal, it is a big problem to achieve both high-quality image shooting and thinning.

On the other hand, in the light field camera, in order to prevent the light (image) from each lens of each microlens array arranged on the image sensor from overlapping on the light receiving surface, each of the imaging lens and each microlens array. A partition sheet or the like having a partition corresponding to the lens is required.
As described above, since the imaging lens is composed of a plurality of lenses, it is large and it is difficult to reduce the size and thickness of the light field camera. Further, when the partition sheet is disposed, there is a problem that it is difficult to align the partition wall with each lens of the microlens array.

  Furthermore, in the light field camera, since the microlens array is arranged close to the image sensor, when the microlens array is made of resin, the microlens array is warped or bent due to heat generation on the light receiving surface when the image sensor is driven. There was a problem that occurred. In order to solve this problem, when a microlens array is manufactured using a resin having a low coefficient of thermal expansion, there are problems that manufacturing becomes difficult and production costs increase.

  An object of the present invention is to provide a lens sheet unit that can reduce the thickness of an imaging module and an imaging device, and can suppress deformation due to heat generated when the image sensor is driven, and an imaging module, an imaging device, and a cover member including the lens sheet unit. It is.

The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected and demonstrated, it is not limited to this.
The invention of claim 1 is a lens sheet unit that is used in an imaging module and is disposed closer to the light incident side than the imaging element unit, and includes a first optical shape surface (11a) having an optical shape formed on one side. A second lens sheet (12) having a first lens sheet (11) having a second optical shape surface (12a) disposed on the light emission side of the first lens sheet and having an optical shape formed on one side thereof. And a protective sheet (13) that is disposed closer to the light incident side than the first lens sheet and protects the first lens sheet and the second lens sheet, and the first lens sheet has a columnar shape. A first light transmitting portion (111) arranged in one direction along the sheet surface and having a convex first unit lens shape (112) on the first optical shape surface side, and the first light transmitting portion And the first array A first portion extending in the longitudinal direction of the transmission portion and extending from the first unit lens shape side to the back surface (11b) side opposite to the first unit lens shape side along the thickness direction of the first lens sheet. The second lens sheet is columnar and arranged in one direction along the sheet surface, and is convex toward the second optical shape surface. The second light transmission part (121) having (122) and the second light transmission part are alternately arranged, extend in the longitudinal direction of the second light transmission part, and the thickness of the second lens sheet A second light absorbing portion (123) extending along the direction from the second unit lens shape side to the back surface (12b) side of the second lens sheet, which is the opposite side, from the normal direction of the sheet surface As seen, the arrangement direction of the first light transmission part and the second light transmission part The lens sheet unit (10) is characterized in that the first lens sheet, the second lens sheet, and the protective sheet are integrally laminated, intersecting with the column direction at an angle α. .
The invention according to claim 2 is the lens sheet unit according to claim 1, wherein the angle α satisfies 80 ° ≦ α ≦ 100 °.
The invention according to claim 3 is the lens sheet unit according to claim 1 or 2, characterized in that the lens sheet unit has a layer (115) that shields light in a wavelength region of 700 to 1100 nm. The lens sheet unit (10).
According to a fourth aspect of the present invention, in the lens sheet unit according to any one of the first to third aspects, the refractive index N1 of each light transmitting portion (111, 121) and each light absorbing portion (113). , 123) is a lens sheet unit (10) characterized in that N1 ≦ N2 is satisfied.
According to a fifth aspect of the present invention, in the lens sheet unit according to any one of the first to fourth aspects, the light absorbing portions (113.123) and the light transmitting portions (111, 121) The lens sheet unit (10) is characterized in that an angle θ between the interface and the thickness direction of each lens sheet satisfies 0 ° ≦ θ ≦ 10 °.

According to a sixth aspect of the present invention, an image sensor section (21) in which a plurality of pixels for converting incident light into an electric signal are two-dimensionally arranged, and an object side with respect to the image sensor section, are arranged. An imaging module (20) comprising: the lens sheet unit (10) according to any one of items up to item 5.
The invention of claim 7 is an image pickup apparatus comprising the image pickup module (20) according to claim 6, wherein an opening (31) for allowing light to enter the image pickup module into a housing (30) of the image pickup apparatus. The image pickup device portion (21) is disposed in the housing in the vicinity of the opening, and the lens sheet unit (10) is disposed in the opening. An imaging device (1).
The invention of claim 8 is an image pickup apparatus comprising the image pickup module according to claim 6, wherein an opening (31) for allowing light to enter the image pickup module is formed in a housing (30) of the image pickup apparatus. A cover member (40) that covers at least the opening and the periphery of the opening, is detachable from the housing, and has a window (41) at a position corresponding to the opening; The image pickup device (2) is characterized in that the element portion (21) is disposed in the housing in the vicinity of the opening, and the lens sheet unit (10) is provided in the window portion.

  The invention of claim 9 can be detachably attached to an image pickup apparatus having an opening (31) for allowing light to enter the image pickup device part (21) on one side surface of the housing (30). A cover member comprising the lens sheet unit (10) according to any one of the above and a window portion (41) including the lens sheet unit, wherein the window portion is attached to the imaging device. Is a position corresponding to the opening of the imaging device, and the lens sheet unit can form an image on the light receiving surface of the imaging device unit.

  ADVANTAGE OF THE INVENTION According to this invention, an imaging module and an imaging device can be reduced in thickness, and the lens sheet unit which can suppress the deformation | transformation etc. by the heat_generation | fever at the time of an image sensor drive, and an imaging module, an imaging device, and a cover member provided with this can be provided.

It is a figure explaining the camera 1 of 1st Embodiment. It is a figure explaining the imaging module 20 of 1st Embodiment. It is a figure explaining the lens sheet unit 10 of 1st Embodiment. It is a figure explaining the 1st lens sheet 11 and the 2nd lens sheet 12 of a 1st embodiment. It is a figure explaining the arrangement direction of the light transmission part 111 of the 1st lens sheet of 1st Embodiment, and the light transmission part 121 of the 2nd lens sheet. It is a figure explaining the mode of image formation on the light-receiving surface of the image sensor 21 of the imaging module 20 of 1st Embodiment. It is a figure explaining the camera 2 of 2nd Embodiment. It is a figure explaining the direction of the lens-shaped surfaces 11a and 12a of the 1st lens sheet 11 and the 2nd lens sheet 12. FIG. 3 is a diagram illustrating a relationship between an arrangement direction of light transmitting portions 111 and 121 of the lens sheet unit 10 and an arrangement direction of pixels of the image sensor 21. FIG. It is a figure which shows the deformation | transformation form of the lens sheet unit.

Embodiments of the present invention will be described below with reference to the drawings. In addition, each figure shown below including FIG. 1 is the figure shown typically, and the magnitude | size and shape of each part are exaggerated suitably for easy understanding.
Numerical values such as dimensions and material names of the respective members described in the present specification are examples of the embodiment, and the present invention is not limited thereto, and may be appropriately selected and used.
In this specification, terms that specify shape and geometric conditions, for example, terms such as parallel and orthogonal, are strictly meanings, have similar optical functions, and can be regarded as parallel and orthogonal It also includes a state having an error of.
In the present specification, the sheet surface refers to a surface which is a planar direction of the sheet when viewed as the entire sheet in each sheet-like member.

(First embodiment)
FIG. 1 is a diagram illustrating a camera 1 according to the first embodiment.
FIG. 2 is a diagram illustrating the imaging module 20 according to the first embodiment.
In each of the following drawings including FIG. 1, an XYZ orthogonal coordinate system is provided as appropriate for easy understanding. In this coordinate system, when the photographer supports the imaging apparatus in a basic posture and takes an image with the optical axis O being horizontal, the horizontal direction (left-right direction) is the X direction and the vertical direction (up-down direction) is Y. The direction toward the left side when viewed from the photographer side (the right side when viewed from the subject side) is the + X direction, the direction toward the upper side in the vertical direction is the + Y direction, the optical axis O direction is the Z direction, and the direction toward the subject side The + Z direction is assumed.

As shown in FIG. 1, the camera 1 according to the present embodiment is an imaging device including an imaging module 20 in a housing 30 having an opening 31.
The camera 1 is an imaging device used for a mobile phone such as a smartphone or a mobile terminal such as a tablet terminal, and the housing 30 corresponds to a housing of the mobile terminal body. The camera 1 further includes a control unit (not shown), a storage unit, and the like.
The opening 31 is an opening that takes light from the subject side into the imaging module 20 of the camera 1. The opening 31 is provided with a lens sheet unit 10 constituting an imaging module 20 described later.

The imaging module 20 of the present embodiment includes a lens sheet unit 10, an image sensor 21, and the like in order from the subject side (+ Z side) that is the light incident side along the optical axis O (Z direction). The imaging module 20 captures an image using an output signal from the control unit described above.
The lens sheet unit 10 and the image sensor 21 are rectangular flat members, and the optical axis O is orthogonal to the geometric center.
As described above, the lens sheet unit 10 is provided in the opening 31 of the housing 30. The image sensor 21 is provided in the housing 30 at a position close to the opening 31. In the present embodiment, the lens sheet unit 10 and the image sensor 21 are in contact with each other in the optical axis O direction.

FIG. 3 is a diagram illustrating the lens sheet unit 10 according to the first embodiment.
FIG. 4 is a diagram illustrating the first lens sheet 11 and the second lens sheet 12 according to the first embodiment. 4A shows an enlarged part of a cross section parallel to the arrangement direction of the light transmission portions 111 of the first lens sheet 11 and the thickness direction of the first lens sheet 11, and FIG. A part of the cross section shown in FIG. In FIG. 4, the reference numerals of the respective parts in the first lens sheet 11 are shown, and the reference numerals of the corresponding parts in the second lens sheet 12 are shown in parentheses.
FIG. 5 is a diagram for explaining the arrangement direction of the light transmission part 111 of the first lens sheet 11 and the light transmission part 121 of the second lens sheet 12 according to the first embodiment.
The lens sheet unit 10 is located on the subject side (+ Z side) of the image sensor 21 in the optical axis O direction (Z direction). The lens sheet unit 10 includes a protective sheet 13, a first lens sheet 11, and a second lens sheet 12 in order from the subject side (+ Z side) along the optical axis O direction (Z direction).

In the lens sheet unit 10, a protective sheet 13, a first lens sheet 11, and a second lens sheet 12 are integrally laminated and fixed, supported by a support member (not shown), and in a horizontal direction (X direction) with respect to the image sensor 21. Positions in the vertical direction (Y direction) and the optical axis O direction (Z direction) are determined.
In the present embodiment, the protective sheet 13 and the first lens sheet 11 are integrally bonded by a bonding layer (not shown). Further, the first lens sheet 11 and the second lens sheet 12 are laminated integrally with each other without a bonding layer, and are in contact with each other.
The protective sheet 13 is a sheet-like member having light transmittance. It has a function of preventing foreign matter such as dust and dirt from entering the imaging module 20, protecting the first lens sheet 11 and the second lens sheet 12, and preventing damage and the like.

The protective sheet 13 of this embodiment is made of synthetic quartz glass. The protective sheet 13 may be made of glass such as BK7 or white plate glass, or may be made of resin such as acrylic resin or polycarbonate resin.
From the viewpoint of protecting the first lens sheet 11 and the second lens sheet 12, the protective sheet 13 has higher rigidity and heat resistance, such as being thicker than the first lens sheet 11 and the second lens sheet 12. Is preferred.
The refractive index N3 of the protective sheet 13 is about 1.43 to 1.60. The refractive index N3 of the protective sheet 13 is equal to the refractive index N1 of the light transmitting portion 111 of the first lens sheet 11 described later, or is as small as possible as the refractive index difference between the refractive index N3 and the refractive index N1. It is preferable.

An infrared shielding layer (not shown) is formed on the subject side (+ Z side) surface of the protective sheet 13. This infrared shielding layer has a function of absorbing or reflecting light (near infrared light) in a wavelength range of 700 to 1100 nm and transmitting light outside the wavelength range. Such an infrared shielding layer is formed by depositing a general-purpose material having a function of absorbing or reflecting light in the wavelength range on the surface of the protective sheet 13 or laminating a resin layer containing these materials on the surface of the protective sheet 13. It is formed by doing. Moreover, it is good also as a form which mix | blends the material etc. which absorb infrared rays with the material which forms the protective sheet 13, and the protective sheet 13 itself has a function as an infrared shielding layer.
In the imaging module 20, an antireflection layer (not shown) that prevents incident light from being reflected at the interface is formed on the surface closer to the subject (+ Z side) than the infrared shielding layer of the protective sheet 13. It is preferable from the viewpoint of improving the amount of light incident on. This antireflection layer is formed by coating a material having an antireflection function (for example, MgF ₂ , SiO ₂ , fluorine-based optical coating agent, etc.) with a predetermined film thickness.

The layer formed on the subject side (+ Z side) surface of the protective sheet 13 is not limited to the above-described antireflection layer or infrared shielding layer, and includes, for example, a hard coat layer, an antifouling layer having an antifouling function, and the like. It is good.
Setting the thickness (dimension in the Z direction) of the protective sheet 13 to 100 to 1000 μm protects the first lens sheet 11 and the second lens sheet 12, suppresses deformation thereof, and the entire imaging module 20. And the thickness of the whole lens sheet unit 10 does not become too large, and it is preferable for the reason that thickness reduction is not prevented.

A bonding layer (not shown) that bonds the protective sheet 13 and the first lens sheet 11 is formed of a pressure-sensitive adhesive or an adhesive, and has light transmittance.
The bonding layer has a refractive index N4 of the bonding layer and a light transmission portion 111 of the first lens sheet 11 from the viewpoint of suppressing a decrease in light amount due to light reflection at the interface between the protective sheet 13 and the first lens sheet 11. It is preferable that the refractive index N1 of this and the refractive index N3 of the protective sheet 13 are equal, or these refractive index difference is as small as possible.
Further, the image sensor 21 to be described later generates heat during driving, and its surface temperature rises to about 40 ° C. Therefore, this bonding layer may have heat resistance from the viewpoint of suppressing deformation such as warpage of the lens sheet unit 10 (the first lens sheet 11 and the second lens sheet 12) due to heat generated by the image sensor 21. .
As a material for forming such a bonding layer, an adhesive such as an epoxy resin or a urethane resin, or an adhesive is suitable.
Note that a bonding layer having a refractive index N4 smaller than the refractive index N3 of the protective sheet 13 and the refractive index N1 of the light transmitting portion 111 is also applicable. Examples of such a bonding layer include a silicone-based pressure-sensitive adhesive.

The first lens sheet 11 has a columnar shape and is arranged in one direction along the sheet surface, and in the arrangement direction of the light transmission portions 111, the light absorption portions are arranged alternately with the light transmission portions 111. 113 is a lens sheet. In the first lens sheet 11 of the present embodiment, the light transmission part 111 is arranged in the vertical direction (Y direction), and its longitudinal direction (ridge line direction) is parallel to the horizontal direction (X direction).
The light transmitting portion 111 is a portion that transmits light, and has a convex unit lens shape 112 on the image sensor 21 side (−Z side). The surface on the image sensor 21 side (−Z side) of the first lens sheet 11 is a lens shape surface 11 a in which a plurality of unit lens shapes 112 are arranged. Further, the back surface 11b which is the subject side (+ Z side) surface of the first lens sheet 11 (the surface opposite to the lens-shaped surface 11a) is substantially flat.

The unit lens shape 112 of the first lens sheet 11 is convex toward the image sensor 21 side (−Z side), and the arrangement direction (Y direction) of the light transmission portions 111 and the thickness direction (Z of the first lens sheet 11). The cross-sectional shape in a cross section parallel to (direction) is a partial shape of a circle. The unit lens shape 112 has a cross-sectional shape extending in the longitudinal direction of the light transmitting portion 111.
On the back surface 11b side (+ Z side) of the light transmission part 111, the light absorption part 113 is not formed, and the land part 114 in which the light transmission part 111 is continuous in the direction parallel to the sheet surface (XY surface) is formed. Is formed. The land portion 114 is preferably as thin as possible. The land portion 114 has a thickness of 0 (that is, a form in which the land portion 114 does not exist), which prevents stray light and the like, and produces a high-quality image. Ideal from the point of view.

The light transmission part 111 is formed of a resin having a light transmission property, and its refractive index N1 is about 1.43 to 1.60.
The light transmitting portion 111 of the present embodiment is formed by an ultraviolet molding method or the like using an ultraviolet curable resin such as urethane acrylate, polyester acrylate, or epoxy acrylate.
In addition, the light transmission part 111 may be formed of other ionizing radiation curable resins such as an electron beam curable resin. The light transmitting portion 111 may be formed by a hot melt extrusion molding method using a thermoplastic resin such as PET (polyethylene terephthalate) resin or the like, or may be formed by glass.

The light absorbing portion 113 has a function of absorbing light, and the surface (back surface) 11b side opposite to the lens shape surface 11a side where the unit lens shape 112 is formed along the thickness direction of the first lens sheet 11. It is a wall-like part extending to In addition, the light absorbing portion 113 extends along the longitudinal direction of the light transmitting portion 111.
The light absorbing portion 113 has a wedge shape or a rectangular cross section in a cross section parallel to the arrangement direction and the thickness direction of the first lens sheet 11. As used herein, the wedge shape refers to a shape in which one end is wide and gradually narrows toward the other, and includes a triangular shape, a trapezoidal shape, and the like.
The light absorbing portion 113 of this embodiment has a trapezoidal shape in which the cross-sectional shape in a cross section parallel to the arrangement direction and the thickness direction of the first lens sheet 11 is larger on the lens-shaped surface 11a side than on the back surface 11b side. It has a shape. Not only this but the cross section shape in the cross section parallel to the arrangement direction and the thickness direction of the 1st lens sheet 11 as for the light absorption part 113 is good also as a triangular shape which makes the back surface 11b side a vertex.

The light absorption unit 113 has a function of absorbing stray light that travels in the light transmission unit 111 and travels toward another adjacent light transmission unit 111.
The light absorbing portion 113 is formed of a light absorbing material such as carbon black (hereinafter referred to as a light absorbing material), a resin containing the light absorbing material, or the like.
The light absorbing material used for the light absorbing portion 113 is preferably a particulate member having a function of absorbing light in the visible light region. Examples of such members include metal salts such as carbon black, graphite and black iron oxide, pigments and dyes, resin particles colored with pigments and dyes, and the like.

When resin particles colored with pigments or dyes are used, the resin particles may be acrylic resin, PC (polycarbonate) resin, PE (polyethylene) resin, PS (polystyrene) resin, MBS (methyl methacrylate, butadiene, Styrene) resin, MS (methyl methacrylate / styrene) resin or the like is used.
As the light absorbing material, a combination of carbon black or the like and the colored resin particles as described above may be used.
Examples of the resin containing the light absorbing material include ultraviolet curable resins such as urethane acrylate and epoxy acrylate, and ionizing radiation curable resins such as electron beam curable resins.
The light absorption part 113 of this embodiment is formed of an acrylic resin containing carbon black.

  The refractive index N2 of the light absorbing portion 113 is about 1.45 to 1.60. Further, the refractive index N2 of the light absorbing portion 113 is preferably N2 ≧ N1 with respect to the refractive index N1 of the light transmitting portion 111. This is to prevent unnecessary light from reaching the image sensor 21 by totally reflecting light at the interface between the light absorbing portion 113 and the light transmitting portion 111.

The dimensions of each part of the first lens sheet 11 are as follows.
The arrangement pitch P of the light transmitting portions 111 (unit lens shape 112) is preferably about 20 to 230 μm.
The radius of curvature R of the unit lens shape 112 is preferably about 10 to 180 μm.
The lens opening width D1 of the unit lens shape 112 is the dimension on the lens shape surface 11a side of the light transmission portion 111 in the arrangement direction of the light transmission portions 111 (the light transmission portion 111 and the light absorption portion 113 closest to the lens shape surface 11a side). The dimension between the point t1 and the point t2 serving as a boundary with the end), and is preferably about 20 to 200 μm.
The lens height H1 of the unit lens shape 112 is from the surface on the lens shape surface 11a side of the light absorbing portion 113 to the point t3 where the unit lens shape 112 is most convex in the thickness direction (Z direction) of the first lens sheet 11. And preferably about 2 to 40 μm.

The total thickness T of the first lens sheet 11 is a dimension from the surface of the back surface 11b to the point t3 in the thickness direction (Z direction) of the first lens sheet 11, and is preferably about 30 to 480 μm.
The width D2 of the light absorbing portion 113 is the dimension closest to the lens-shaped surface 11a of the light absorbing portion 113 in the arrangement direction of the light transmitting portions 111, and is preferably about 1 to 30 μm.
The height H2 of the light absorbing portion 113 is the dimension of the light absorbing portion 113 in the thickness direction (Z direction) of the first lens sheet 11, and is preferably about 20 to 470 μm.
The angle θ formed by the interface between the light absorbing portion 113 and the light transmitting portion 111 and the normal direction of the sheet surface is preferably about 0 to 10 °.

  The land thickness D3 is the thickness of the land portion 114, and is a dimension from the front end of the light absorbing portion 113 on the back surface 11b side to the back surface 11b of the first lens sheet 11 in the thickness direction of the first lens sheet 11. When it is set to ˜50 μm, stray light or light incident on the predetermined light transmitting portion 111 (unit lens shape 112) may be propagated toward the other adjacent light transmitting portion 111 (unit lens shape 112). It is preferable from the viewpoint of suppressing.

The second lens sheet 12 is an optical sheet positioned on the image sensor 21 side (−Z side) of the first lens sheet 11.
The second lens sheet 12 has substantially the same shape as the first lens sheet 11 described above, and includes a light transmission part 121 having a unit lens shape 122, a light absorption part 123, and the like. The position and the arrangement direction of the light transmission part 121 and the light absorption part 123 are different from those of the first lens sheet 11.

In the second lens sheet 12, the lens-shaped surface 12a on which the convex unit lens shape 122 is formed is located on the subject side (+ Z side) that is the light incident side, and the back surface 12b is on the image sensor 21 side (- (Z side).
As shown in FIG. 5, in the second lens sheet 12, the arrangement direction R <b> 12 of the light transmission part 121 and the light absorption part 123 is the light of the first lens sheet 11 when viewed from the optical axis O direction (Z direction). It intersects with the arrangement direction R11 of the transmission part 111 and the light absorption part 113 and forms an angle α.
In the present embodiment, this angle α is 90 °, and the light transmitting portion 121 (unit lens shape 122) of the second lens sheet 12 is arranged in the horizontal direction (X direction) and the longitudinal direction is the vertical direction ( (Y direction).
The second lens sheet 12 is formed using the same material as the first lens sheet 11.

The light transmitted through the lens sheet unit 10 is condensed by the unit lens shapes 112 and 122 so that the light receiving surface of the image sensor 21 described later becomes a focal point. That is, the radius of curvature R and the refractive index N1 of the unit lens shapes 112 and 122 are set so that the light receiving surface of the image sensor 21 is in focus.
The first lens sheet 11 and the second lens sheet 12 are arranged in a state where the unit lens shapes 112 and 122 are in contact with each other at the apex (point t3) or close to each other. In the gap portion between 11 and the second lens sheet 12, air is positioned.

  As shown in FIG. 5, the first lens sheet 11 and the second lens sheet 12 have a light transmission part 111 and a light transmission part 121 (unit lens shape 112 and unit when viewed from the optical axis O direction (Z direction). The lens shape 122) is arranged such that the arrangement direction forms an angle α = 90 °. Further, the first lens sheet 11 and the second lens sheet 12 have light absorbing portions 113 and 123 between the light transmitting portions 111 and 121. Therefore, the lens sheet unit 10 is optically equivalent to a state in which microlenses are arranged in a two-dimensional direction (X direction and Y direction) and a light shielding wall is formed between the microlenses.

The image sensor 21 is a part that converts the light received by the light receiving surface into an electrical signal and outputs it. In the image sensor 21, a plurality of pixels are arranged in a two-dimensional direction, and the intensity of light incident on the pixels can be detected by each pixel.
A plurality of pixels constituting the image sensor 21 are arranged in a two-dimensional direction on the surface on the subject side which is a light receiving surface of the image sensor 21. In the present embodiment, it is assumed that a plurality of pixels of the image sensor 21 are arranged in the horizontal direction and the vertical direction (X direction and Y direction).
As such an image sensor 21, for example, a CCD (Charge Coupled Device), a CMOS (Complementary Metal Oxide Semiconductor), or the like is preferably used.
The image sensor 21 of this embodiment uses a CMOS.

Light from the subject enters the protective sheet 13 of the lens sheet unit 10 disposed in the opening 31 and travels through the imaging module 20. The light that has passed through the protective sheet 13 passes through the first lens sheet 11 and the second lens sheet 12.
At this time, the light transmitted through the lens sheet unit 10 is condensed in the Y direction (vertical direction) that is the arrangement direction by the unit lens shape 112 of the first lens sheet 11, and the unit of the second lens sheet 12. The lens shape 122 collects light in the X direction (left-right direction) that is the arrangement direction. In addition, at least a part of the light traveling in the direction that forms a large angle with respect to the optical axis O direction in the light transmitting portions 111 and 121 is incident on and absorbed by the light absorbing portions 113 and 123. The light transmitted through the lens sheet unit 10 is focused on the light receiving surface of the image sensor 21.

As described above, the first lens sheet 11 and the second lens sheet 12 are arranged so that the longitudinal directions (ridge line directions) of the unit lens shapes 112 and 122 are orthogonal to each other. Is close to a form in which a plurality of microlenses are arranged in the horizontal direction and the vertical direction (X direction and Y direction).
On the light receiving surface of the image sensor 21, images formed by the pseudo microlens are formed without overlapping each other.

In the present embodiment, a plurality of pixels of the image sensor 21 are arranged so as to correspond to each of the pseudo microlenses. At the time of photographing, the light divided by the corresponding pseudo microlens enters each pixel, and the intensity of the light is detected by each pixel. In addition, from the relationship between each pixel and which position of the unit lens shape 112, 122 on the XY plane (the position of the pseudo microlens on the XY plane), the incident direction of the light incident on the pixel is It can be detected.
The information on the intensity and direction of incident light detected by each pixel obtained by the imaging module 20 at the time of shooting is stored in the storage unit, and the focal length is obtained by performing various calculations and the like by the control unit. Or image data with the depth of field changed or the like (refocus processing performed).

FIG. 6 is a diagram for explaining a state of image formation on the light receiving surface of the image sensor 21 of the imaging module 20 of the first embodiment.
In general, in a light field camera, a plurality of pixels 211 located in a predetermined region correspond to one microlens of the microlens array. And it is important that the image by each microlens is projected in a corresponding area | region, as shown to Fig.6 (a), for example.
At this time, for example, as shown in FIG. 6B, when the images of the respective microlenses are projected onto the adjacent area and the images overlap, light having different positions and angles on the subject surface is applied to the same pixel 211. A phenomenon called incident crosstalk occurs, and the incident direction and intensity of light cannot be decomposed. In order to solve this problem, a conventional light field camera uses a diaphragm of an imaging lens provided on the subject side of the micro lens array, or a partition sheet having a partition corresponding to a unit lens of the micro lens array. It was necessary to prepare it separately on the image sensor side of the microlens array.

  However, according to the present embodiment, the light absorbing portions 113 and 123 are formed between the light transmitting portions 111 and 121 and extend in the thickness direction (Z direction) of each lens sheet. 6 and without causing crosstalk, the light collected by the unit lens shapes 112 and 122 is applied to the pixels 211 in the corresponding region of the image sensor 21 as shown in FIG. It can be made incident. Thereby, the pixel 211 can output the intensity | strength and incident direction information of incident light with high precision.

From the above, according to the present embodiment, an imaging lens composed of a plurality of optical lenses is unnecessary, and the thickness of the lens sheet unit 10 can be suppressed to about several hundred μm, and the imaging module 20 and the camera 1 are thin. And weight reduction can be achieved.
Further, since an imaging lens is not necessary, the production cost of the imaging module 20 and the camera 1 can be reduced. Furthermore, it is possible to contribute to the improvement of the design of the mobile terminal without hindering the thinning of the mobile terminal body on which the imaging module 20 is mounted.
Moreover, according to this embodiment, since the light absorption parts 113 and 123 are integrally formed in each lens sheet 11 and 12 corresponding to the light transmission parts 111 and 121 (unit lens shape 112 and 122), High-precision alignment between the partition sheet and the microlens array, which is necessary when using the partition sheet and the microlens array, is not necessary. Therefore, it is possible to suppress a decrease in yield due to misalignment accuracy between the microlens array and the partition sheet. Further, since the alignment as described above becomes unnecessary, handling becomes easy, manufacture can be performed easily, and production cost can be reduced.
Further, according to the present embodiment, since the first lens sheet 11 is integrally bonded to the protective sheet 13 by the bonding layer, the assembling work of the lens sheet unit 10 and the imaging module 20 is easy and the work efficiency is improved. Can be made.

Further, when the camera 1 is used, the image sensor 21 generates heat during driving, and its surface temperature rises to around 40 ° C. For this reason, the first lens sheet 11 and the second lens sheet 12 that are close to the image sensor 21 may be deformed such as warpage or deflection due to the heat.
However, according to the present embodiment, the lens sheet unit 10 includes the protective sheet 13 having higher rigidity than the first lens sheet 11 and the second lens sheet 12, and the first lens sheet 11 is attached to the protective sheet 13. Since the second lens sheet 12 is integrally bonded by the bonding layer and is supported by being laminated integrally with the first lens sheet 11 and the like, deformation of each lens sheet due to heat generated by the image sensor 21 is prevented. It can be effectively suppressed.

Furthermore, according to the present embodiment, it is easy to increase the unit lens shapes 112 and 122 arranged in the X direction and the Y direction by reducing the lens opening width D1 of the light transmitting portions 111 and 121, and light. Since the absorption portions 113 and 123 are integrally formed, the pseudo microlens by the lens sheet unit 10 can be further refined, and the spatial resolution of the image can be improved.
According to the present embodiment, a function as a light field camera capable of changing a focal length and a depth of field after photographing can be given to a camera for a mobile terminal, and high performance can be achieved. Can do. In addition, the imaging module 20 and the camera 1 of the present embodiment can also form captured images with pan focus, and can form captured images with various focal lengths and depths of field, thereby improving the camera function. be able to.
Furthermore, the conventional light field camera requires an imaging lens, a partition sheet for dividing light separate from the microlens array, and the like. However, according to the present embodiment, none of them is necessary, and therefore, a light field camera can be reduced in thickness and weight, production cost can be reduced, and the like.

(Second Embodiment)
FIG. 7 is a diagram illustrating the camera 2 according to the second embodiment.
The camera 2 of the second embodiment is that the lens sheet unit 10 is arranged in the window 41 of the cover member 40 that covers at least the surface 30a side of the housing 30 having the opening 31. Except for the point different from 1, it is the same form as the first embodiment described above. Therefore, parts having the same functions as those in the first embodiment described above are denoted by the same reference numerals or the same reference numerals at the end, and repeated description is appropriately omitted.
The camera 2 according to the second embodiment has an opening 31 in a surface 30 a that is a surface on the subject side, a housing 30 having the image sensor 21 and the like therein, and a position corresponding to the opening 31 of the housing 30. And a cover member 40 on which the lens sheet unit 10 is disposed.

The cover member 40 covers at least the opening 31 of the surface 30 a of the housing 30 and the periphery thereof, and is detachable from the housing 30. The cover member 40 of the present embodiment includes a surface 30a, at least a part of four side surfaces 30b adjacent to the surface 30a, and a corner portion formed by these side surfaces 30b and opposite to the surface 30a. The part is covered.
The cover member 40 has a window 41 at a position corresponding to the opening 31 of the housing 30, and the lens sheet unit 10 is disposed in the window 41. The size, shape, and position of the window 41 coincide with the opening 31 of the housing 30 when viewed from the optical axis O direction (Z direction) when the cover member 40 is mounted.
The cover member 40 may be made of resin such as acrylic resin, polycarbonate resin, ABS resin, epoxy resin, PET resin, polyamide, or rubber such as silicone rubber or ethylene propylene rubber, or made of wood, paper, leather, or the like. It is good.

  The image sensor 21 is disposed close to the opening 31 in the optical axis O direction (Z direction). The lens sheet unit 10 is positioned in contact with the light receiving surface of the image sensor 21 or close to the light receiving surface of the image sensor 21 with the cover member 40 attached to the housing 30. In addition, the distance in the optical axis O direction (Z direction) between the light receiving surface of the image sensor 21 and the surface on the image sensor 21 side of the lens sheet unit 10 (in this embodiment, the back surface 12b of the second lens sheet 12) is possible. It is preferable to be as small as possible from the viewpoint of providing a high-quality image by suppressing crosstalk and stray light, and it is ideal that the surface on the image sensor 21 side of the lens sheet unit 10 and the light receiving surface of the image sensor 21 are in contact with each other. .

According to this embodiment, in addition to the effects described in the first embodiment, the following effects can be further achieved.
According to the present embodiment, for example, a plurality of cover members 40 including the lens sheet units 10 having different lens opening widths D1 and different radii of curvature R of the light transmitting portions 111 and 121 of the first lens sheet 11 and the second lens sheet 12 are provided. By preparing and replacing the cover member 40, the lens sheet unit 10 for the image sensor 21 can be exchanged, and images with different angles of view and depth of field can be taken.
Further, according to the present embodiment, since the lens sheet unit 10 is integrated with the cover member 40, the housing 30 of the camera 2 can be further reduced in thickness.
In addition, according to the present embodiment, since the lens sheet unit 10 is integrated with the cover member 40, deformations such as warping and bending of the first lens sheet 11 and the second lens sheet 12 due to heat generation of the image sensor 21 are prevented. The suppressing effect can be further enhanced.
Moreover, according to this embodiment, the design of the cover member 40 surface can be changed variously, and the designability as the camera 2 whole can be improved more easily.

(Another embodiment of the lens sheet unit 10)
Hereinafter, other embodiments of the lens sheet unit 10 will be described.
<Direction of Lens Shape Surfaces 11a and 12a of Each Lens Sheet>
FIG. 8 is a diagram illustrating the orientation of the lens-shaped surfaces 11a and 12a of the first lens sheet 11 and the second lens sheet 12.
In FIG. 8, for easy understanding, only the first lens sheet 11 and the second lens sheet 12 constituting the lens sheet unit 10 are shown, and the protective sheet 13 is omitted. In FIG. 8, the first lens sheet 11 and the second lens sheet 12 are separated from each other in the Z direction. However, actually, they are integrally laminated or arranged close to each other. It is assumed that
As shown in FIG. 8, the first lens sheet 11 and the second lens sheet 12 of the lens sheet unit 10 have lens-shaped surfaces 11a and 12a on the subject side (+ Z side) or on the image sensor 21 side (−Z Side)) can be selected as appropriate.

As shown in FIG. 8A, the first lens sheet 11 and the second lens sheet 12 may be arranged so that the lens-shaped surfaces 11a and 12a are both on the subject side (+ Z side).
Further, as shown in FIG. 8B, the first lens sheet 11 and the second lens sheet 12 constituting the lens sheet unit 10 have lens shape surfaces 11a and 12a both on the image sensor side (−Z side). It may be arranged so that.
Further, as shown in FIG. 8C, the first lens sheet 11 is arranged so that its lens-shaped surface 11a is on the subject side (+ Z side), and the second lens sheet 12 is its lens-shaped surface 12a. May be arranged on the image sensor side (−Z side).

  Further, as shown in FIG. 8C, the surface of the first lens sheet 11 on the second lens sheet 12 side (−Z side) is the back surface 11 b on which the unit lens shape 112 is not formed, and the second lens sheet 12. When the surface on the first lens sheet 11 side is also the back surface 12b, a spacer (not shown) is arranged between the first lens sheet 11 and the second lens sheet 12 from the viewpoint of suppressing the generation of stray light due to optical contact. Alternatively, both the back surfaces 11b and 12b may be mat surfaces on which fine irregularities are formed.

In the case of the form shown in FIG. 8C, a bonding layer (not shown) is provided between the first lens sheet 11 and the second lens sheet 12 from the viewpoint of suppressing the generation of stray light due to optical adhesion. The first lens sheet 11 and the second lens sheet 12 may be joined together. In the case of this embodiment, the refractive index of the bonding layer that bonds the first lens sheet 11 and the second lens sheet 12 is the reflection of light at the interface between the bonding layer and the back surfaces 11b and 12b of the lens sheets 11 and 12. From the viewpoint of preventing the above, it is preferable that the refractive index of the light transmitting portions 111 and 121 is equal.
Even when the lens sheet unit 10 having the above-described form is used, it is possible to capture an image with good image quality.

<About the arrangement direction of the light transmitting portions 111 and 121 of each lens sheet>
The lens sheet unit 10 is configured such that the light transmissive portions 111 of the first lens sheet 11 are arranged in the left-right direction (X direction) and the light transmissive portions 121 of the second lens sheet 12 are arranged in the vertical direction (Y direction). Also good.

The angle α formed by the arrangement direction R11 of the light transmission part 111 (unit lens shape 112) of the first lens sheet 11 and the arrangement direction R12 of the light transmission part 121 (unit lens shape 122) of the second lens sheet 12 is In the range of 90 ° ± 10 °, that is, in the range of 80 ° to 100 °, the optical function desired as the lens sheet unit 10 is maintained. Therefore, the angle α is not limited to 90 °, and may be in the range of 80 ° to 100 °.
Thereby, when the imaging module 20 is assembled as the lens sheet unit 10 by integrally stacking the protective sheet 13, the first lens sheet 11, and the second lens sheet 12, the arrangement direction of the light transmission portions 111 of the first lens sheet 11. The angle α formed by R11 and the arrangement direction R12 of the light transmission part 121 of the second lens sheet 12 does not have to be set at 90 ° strictly, facilitating assembly work of the lens sheet unit 10 and the imaging module 20, and work efficiency. And the yield can be improved.

<Regarding the Image Sensor 21 Side of the Lens Sheet Unit 10>
As shown in FIG. 2, FIG. 3 and FIG. 8A described above, the surface on the image sensor 21 side (−Z side) of the second lens sheet 12 is the back surface 12b on which the unit lens shape 122 is not formed. In this case, from the viewpoint of preventing the light receiving surface of the image sensor 21 from being scratched or preventing the optical contact between the image sensor 21 and the second lens sheet 12, the back surface 12b is a mat surface on which fine irregularities are formed. It is preferable.
In addition, a spacer is disposed between the second lens sheet 12 and the image sensor 21 to prevent optical contact between the image sensor 21 and the second lens sheet 12, damage to the light receiving surface of the image sensor 21, and the like. May be.

<Regarding the arrangement direction of the light transmitting portions 111 and 121 of each lens sheet and the arrangement direction of the pixels of the image sensor 21>
FIG. 9 is a diagram illustrating a relationship between the arrangement direction of the light transmission units 111 and 121 of the lens sheet unit 10 and the arrangement direction of the pixels of the image sensor 21.
In the first embodiment and the second embodiment described above, as shown in FIG. 9A, the pixels of the image sensor 21 are in two directions G1, G2 (Y that are orthogonal to the optical axis O direction (Z direction). And the arrangement direction R11 of the light transmission portions 111 of the first lens sheet 11 is parallel to one direction G1 (Y direction) of the arrangement direction of the pixels, and the light of the second lens sheet 12 The example in which the arrangement direction R12 of the transmission unit 121 is parallel to another direction G2 (X direction) of the pixel arrangement direction is shown.
At this time, when viewed from the optical axis O direction (Z direction), an angle β between the arrangement direction R11 of the light transmission portions 111 of the first lens sheet 11 and one direction G1 of the arrangement direction of the pixels, the second lens sheet 12 An angle γ formed by the arrangement direction R12 of the light transmission portion 121 and another direction G2 in the arrangement direction of the pixels is 0 °.

However, not limited to this, as shown in FIG. 9B, for example, when viewed from the optical axis O direction (Z direction), the angle β and the angle γ are within a range of 0 ° to 10 °. Since the optical function is maintained, it may be appropriately selected and set within this range. By adopting such a configuration, it becomes easy to align the image sensor 21 and the lens sheet unit 10 (the first lens sheet 11 and the second lens sheet 12), thereby simplifying the manufacturing work, shortening the work time, and yield. The improvement etc. can be aimed at.
9B shows an example in which the pixel arrangement directions G1 and G2 are parallel to the Y direction and the X direction, respectively. However, the arrangement direction is not limited to this, and the arrangement direction R11 of the light transmission portions 111 and 121 is not limited thereto. , R12 may be parallel to the Y direction and the X direction, and may form angles β, γ with the pixel arrangement directions G1, G2, respectively. Alternatively, the pixel arrangement directions G1, G2 and the arrangement of the light transmitting portions 111, 121 may be used. The directions R11 and R12 may form angles β and γ, respectively, and neither may be parallel to the Y direction and the X direction.

(Deformation)
Without being limited to the embodiments described above, various modifications and changes are possible, and these are also within the scope of the present invention.
(1) In each embodiment, the cameras 1 and 2 may be general cameras having the housing 30 as the housing of the camera body. In this case, the cameras 1 and 2 include a shutter unit, a shutter drive unit, and the like (not shown) in addition to the control unit and the storage unit.

(2) In each embodiment, although the example in which the protective sheet 13 and the first lens sheet 11 are bonded by the bonding layer is shown, the present invention is not limited thereto, and for example, the protective sheet 13 and the first lens sheet 11 are bonded. It is good also as a form which is not laminated | stacked integrally.
At this time, the refractive index N3 of the protective sheet 13 and the light of the first lens sheet 11 are suppressed from the viewpoint of suppressing a decrease in the amount of light due to light reflection at the interface between the protective sheet 13 and the first lens sheet 11 (light transmitting portion 111). It is preferable that the refractive index N1 of the transmission part 111 is equal to or as small as possible.
Further, from the viewpoint of suppressing optical adhesion, the surface of the protective sheet 13 on the first lens sheet 11 side or the back surface 11b of the first lens sheet 11 is preferably a mat surface having a fine uneven shape.
Moreover, it is good also as a form which has an air layer (air gap) by arrange | positioning a spacer etc. between the protection sheet 13 and the 1st lens sheet 11 from a viewpoint of suppressing optical contact | adherence. In this case, it is preferable to form an antireflection layer on the surface of the back surface 11b of the first lens sheet 11 in order to suppress a decrease in the amount of light due to light reflection at the interface.

Alternatively, the first lens sheet 11 and the second lens sheet 12 may be integrally bonded by a bonding layer. At this time, the bonding layer includes, for example, a region other than an effective portion of the sheet (a region through which light is transmitted), a region having a small optical influence (for example, corner portions of the four corners), the first lens sheet 11 and the first layer. It is preferable to form in the area | region etc. which were provided in the peripheral part etc. of the 2 lens sheet | seat 12 so that it might become convex outward from a viewpoint of obtaining a favorable image.
As described above, the bonding layer used in such a form is formed of a pressure-sensitive adhesive or an adhesive and has light transmittance. Further, from the viewpoint of suppressing a decrease in the amount of light due to reflection of light at the interface, the refractive index N5 of the bonding layer, the refractive index N1 of the light transmitting portion 111 of the first lens sheet 11, and the light of the second lens sheet 12 It is preferable that the refractive index N2 of the transmission part 121 is equal or the refractive index difference is as small as possible.

In addition, from the viewpoint of suppressing deformation such as warpage of the first lens sheet 11 and the second lens sheet 12 due to heat generated by the image sensor 21, the bonding layer may have heat resistance.
Such a bonding layer is preferably formed using an adhesive such as an epoxy resin or a urethane resin, or an adhesive.
Note that a bonding layer whose refractive index N5 is smaller than the refractive index N1 of the light transmitting portion 111 and the refractive index N2 of the light transmitting portion 121 is also applicable. Examples of such a bonding layer include a silicone-based pressure-sensitive adhesive.
Further, the lens sheet unit 10 may be configured such that the protective sheet 13, the first lens sheet 11, and the second lens sheet 12 are integrally bonded by the above-described bonding layers.

(3) The unit lens shapes 112 and 122 are, for example, an ellipse in which the cross-sectional shape in the arrangement direction of the light transmitting portions 111 and 121 and the thickness direction (Z direction) of each lens sheet is an ellipse whose major axis is orthogonal to the sheet surface. It is good also as a part shape, a polygonal shape, etc., It is good also as a shape which a top part is curves, such as a circular arc, and the trough side of a unit lens shape consists of a straight line.

(4) The 1st lens sheet 11 and the 2nd lens sheet 12 are good also as a form provided with a base material layer in the back surfaces 11b and 12b side rather than the light transmission parts 111 and 121. FIG. This base material layer is a resin-made sheet-like member having light permeability, and is a member that becomes a base material (base) when the light transmitting portions 111 and 121 are formed by ultraviolet molding or the like.
It is preferable that the first lens sheet 11 and the second lens sheet 12 have a small thickness from the back surface side end portions to the back surface of the light absorbing portions 113 and 123 from the viewpoint of suppressing crosstalk and the like. Therefore, it is preferable to peel off the base material layer after forming the light transmitting portions 111 and 121 and the light absorbing portions 113 and 123 on the base material layer using a base material layer having peelability on the surface. However, when the base material layer is sufficiently thin, etc., it may be used as a lens sheet with the base material layer being laminated.
Moreover, when the base material layer does not have releasability, the thickness from the back side end to the back side of the light absorbing portions 113 and 123 can be reduced by cutting a portion corresponding to the base material layer. Good.

(5) The lens sheet unit 10 may include a lens sheet 15 as shown in FIG. 10 on the image sensor 21 side of the protective sheet 13.
FIG. 10 is a view showing a modified form of the lens sheet unit 10.
In the lens sheet 15, light transmitting portions 111 and 121 and light absorbing portions 113 and 123 having unit lens shapes 112 and 122 are formed on both surfaces of a single sheet-like base material layer 151. The lens sheet 15 is equivalent to a form in which the first lens sheet 11 and the second lens sheet 12 are integrally formed on both surfaces of the base material layer 151.
The base material layer 151 is a resin sheet-like member, and has light transmittance. Examples of such a base material layer 151 include a sheet-like member made of PET resin or triacetyl cellulose (TAC).
In addition, the thickness of the base material layer 151 is as thin as possible from the viewpoint of suppressing stray light, reducing crosstalk, and improving the intensity of light incident on each pixel and the accuracy of the incident direction. preferable.

(6) The lens sheet unit 10 may have a configuration in which three or more lens sheets are arranged along the optical axis O direction (Z direction) on the image sensor 21 side (−Z side) with respect to the protective sheet 13. .
At this time, for example, a third lens sheet (hereinafter referred to as a third lens sheet) is a lens sheet having the same shape as the first lens sheet 11 and the second lens sheet 12, and the arrangement direction of the light transmitting portions thereof However, it is preferable that each of the first lens sheet 11 and the second lens sheet 12 forms 45 ° ± 10 ° with respect to the arrangement directions R11 and R12 of the light transmission portions 111 and 121.
The lens shape surface of the third lens sheet may be on the subject side (+ Z side) or on the image sensor 21 side (−Z side).

Furthermore, when the fourth lens sheet (fourth lens sheet), which is a lens sheet having the same shape as the first lens sheet 11 and the second lens sheet 12, is arranged, the arrangement direction of the light transmitting portions is 45 ° ± 10 ° with respect to the arrangement directions R11 and R12 of the light transmission portions 111 and 121 of the first lens sheet 11 and the second lens sheet 12, respectively, and with respect to the arrangement direction of the light transmission portions of the third lens sheet It is preferable that the angle is 90 ° ± 10 °.
The lens shape surface of the fourth lens sheet may be on the subject side (+ Z side) or on the image sensor 21 side (−Z side).
Note that the positions of the third lens sheet and the fourth lens sheet in the lens sheet unit 10 in the optical axis O direction (Z direction) are not particularly limited as long as they are positioned closer to the image sensor 21 than the protective sheet 13. .

(7) In each embodiment, an example in which the protective sheet 13 includes an infrared shielding layer on the subject side surface is shown. However, the present invention is not limited thereto, and for example, a separate filter having a function of shielding infrared rays, etc. It is good also as a form arrange | positioned between the protection sheet 13 and the 1st lens sheet 11. FIG.
Further, the first lens sheet 11 may have an infrared shielding layer on the back surface 11b side with respect to the light transmission portion 111, and the second lens sheet 12 may have an infrared shielding layer on the back surface 12b side with respect to the light transmission portion 121. It is good also as a form.
From the viewpoint of suppressing crosstalk and displaying a good image, the light receiving surface of the image sensor 21 in the optical axis O direction and the end closest to the image sensor 21 (−Z side) of the light absorbing portion 113 of the second lens sheet. It is not preferable that the distance between the parts increases. In addition, it is not preferable that the distance between the first lens sheet 11 and the second lens sheet 12 increases.
Therefore, in each of the above-described embodiments, an infrared shielding layer is formed on the subject side surface of the protective sheet 13.
When the first lens sheet 11 and the protective sheet 13 are bonded, the bonding layer contains an infrared absorber that absorbs light in the wavelength range of 700 to 1100 nm. It is good also as a form which fulfills these functions.

(8) The interface between the light transmitting portions 111 and 121 and the light absorbing portions 113 and 123 may be a folded surface formed of a plurality of planes, or a combination of a plurality of planes and curved surfaces. It is good.

(9) In each embodiment, the arrangement pitch P of the unit lens shapes 112 and 122, the lens aperture width D1, the radius of curvature R, the refractive index N1 of the light transmission portions 111 and 121, and the like are the first lens sheet 11 and the second lens. Although the example which is the same with the sheet | seat 12 was shown, not only this but the 1st lens sheet 11 and the 2nd lens sheet 12 may differ.

(10) The first lens sheet 11 and the second lens sheet 12 are provided with notches for distinguishing the front and back surfaces so that the front and back surfaces (lens-shaped surfaces 11a and 12a and the back surfaces 11b and 12b) can be easily distinguished. May be.
Further, in order to facilitate the arrangement and assembly of the lens sheet unit 10, alignment marks may be provided on the first lens sheet 11 and the second lens sheet 12.

(11) The size of the light receiving surface of the image sensor 21 may be appropriately adopted according to the size of the cameras 1 and 2 and the mobile terminal in which the imaging module 20 is used, the desired image quality, camera performance, and the like. The size of the light receiving surface of the image sensor 21, for example, when mounted on a portable terminal such as a smartphone, the horizontal x vertical size is 4.8 x 3.6 mm, 4.4 x 3.3 mm, etc. When mounted on (mainly a compact digital camera) or the like, 6.2 × 4.7 mm, 7.5 × 5.6 mm, or the like can be given.
Further, for example, by using the image sensor 21 having a large light receiving surface such as 23.6 × 15.8 mm, 36 × 24 mm, 43.8 × 32.8 mm, the noise can be reduced, the focal length to be acquired, The accuracy of information such as depth of field and the amount of information may be improved to further improve the image quality and the performance of the cameras 1 and 2.

  Each embodiment and modification may be used in appropriate combination, but detailed description is omitted. Further, the present invention is not limited to the above-described embodiments.

DESCRIPTION OF SYMBOLS 1, 2 Camera 10 Lens sheet unit 11 1st lens sheet 12 2nd lens sheet 111,121 Light transmission part 112,122 Unit lens shape 113,123 Light absorption part 13 Protection sheet 20 Imaging module 21 Image sensor 30 Case 31 Opening 40 Cover member 41 Window

Claims (9)

A lens sheet unit used in an imaging module and disposed on the light incident side of the imaging element unit,
A first lens sheet having a first optical shape surface having an optical shape formed on one side;
A second lens sheet having a second optical shape surface disposed on the light emission side of the first lens sheet and having an optical shape formed on one side;
A protective sheet that is disposed closer to the light incident side than the first lens sheet and protects the first lens sheet and the second lens sheet;
With
The first lens sheet is
A first light transmitting portion that is columnar and arranged in one direction along the sheet surface and has a first unit lens shape that is convex on the first optical shape surface side;
Alternatingly arranged with the first light transmission parts, extending in the longitudinal direction of the first light transmission parts, and opposite from the first unit lens shape side along the thickness direction of the first lens sheet A first light absorbing portion extending to the back side of the first lens sheet,
With
The second lens sheet is
A second light transmission part that is columnar and arranged in one direction along the sheet surface, and has a second unit lens shape that is convex on the second optical shape surface side;
Alternatingly arranged with the second light transmission parts, extending in the longitudinal direction of the second light transmission parts, and opposite from the second unit lens shape side along the thickness direction of the second lens sheet A second light absorbing portion extending to the back side of the second lens sheet,
With
When viewed from the normal direction of the sheet surface, the arrangement direction of the first light transmission portions and the arrangement direction of the second light transmission portions intersect at an angle α,
The first lens sheet, the second lens sheet, and the protective sheet are laminated together;
Lens sheet unit featuring. The lens sheet unit according to claim 1,
The angle α satisfies 80 ° ≦ α ≦ 100 °,
Lens sheet unit characterized by In the lens sheet unit according to claim 1 or 2,
The lens sheet unit has a layer that shields light in a wavelength range of 700 to 1100 nm;
Lens sheet unit characterized by In the lens sheet unit according to any one of claims 1 to 3,
The refractive index N1 of each light transmitting portion and the refractive index N2 of each light absorbing portion satisfy N1 ≦ N2.
Lens sheet unit characterized by In the lens sheet unit according to any one of claims 1 to 4,
The angle θ between the interface between each light absorbing portion and each light transmitting portion and the thickness direction of each lens sheet satisfies 0 ° ≦ θ ≦ 10 °,
Lens sheet unit characterized by An image sensor unit in which a plurality of pixels that convert incident light into an electrical signal are two-dimensionally arranged;
The lens sheet unit according to any one of claims 1 to 5, wherein the lens sheet unit is disposed on a subject side with respect to the imaging element unit.
An imaging module comprising: An imaging apparatus comprising the imaging module according to claim 6,
An opening for allowing light to enter the imaging module is formed in the casing of the imaging device,
The imaging element unit is disposed in the casing in proximity to the opening,
The lens sheet unit is disposed in the opening;
An imaging apparatus characterized by the above. An imaging apparatus comprising the imaging module according to claim 6,
An opening for allowing light to enter the imaging module is formed in the casing of the imaging device,
A cover member that covers at least the opening and the periphery of the opening, is detachable from the housing, and has a window at a position corresponding to the opening;
The imaging element unit is disposed in the casing in proximity to the opening,
The lens sheet unit is provided in the window;
An imaging apparatus characterized by the above. It can be detachably attached to an image pickup apparatus having an opening that allows light to enter the image pickup device part on one side surface of the housing.
The lens sheet unit according to any one of claims 1 to 5,
A window portion comprising the lens sheet unit;
A cover member comprising:
The window portion is in a position corresponding to the opening of the imaging device in a state of being mounted on the imaging device, and the lens sheet unit can form an image on the light receiving surface of the imaging device portion;
A cover member.

Images