JP2021156962A - Multistage optical filter device and manufacturing method of multistage optical filter device - Google Patents

Abstract

To provide a multistage optical filter that can easily adjust a position and direction of a planar optical filter with respect to input light to a predetermined position and direction.SOLUTION: A multistage optical filter device (1) comprises: an optical filter group (11) including at least two planar optical filters; and a mirror structure (13) for reflecting light transmitted through a first planar optical filter (11a1) belonging to the optical filter group (11) to guide the light to a second planar optical filter (11a2) belonging to the optical filter group (11).SELECTED DRAWING: Figure 1

Description

The present invention relates to a multi-stage optical filter device including a plurality of planar optical filters. Further, the present invention relates to a method for manufacturing such a multi-stage optical filter device.

Patent Document 1 discloses a technique in which a plurality of optical elements such as a lens and a filter are superposed on an optical path of an input light, and these optical elements act on the input light in order.

International Publication No. 2013/027340

In a multi-stage optical filter device in which a plurality of planar optical filters act on input light in order, it is important to adjust the position and direction of these planar optical filters with respect to the input light to predetermined positions and directions. This is because if the position and direction of the planar optical filter with respect to the input light deviates from the predetermined position and direction, it becomes difficult to exert the desired action on the input light. However, in a multi-stage optical filter device in which a plurality of planar optical filters are arranged in an overlapping manner, it is difficult to adjust the position and direction of these planar optical filters with respect to the input light to a predetermined position and direction.

As an example, it has a plurality of microcells with individually set refractive indexes, and by interfering with each other the light transmitted through each microcell, space-saving and low power consumption, a predetermined calculation is optically performed. Planar optical filters designed to perform are known. In a multi-stage optical filter device configured by such a planar optical filter, the desired optical calculation is performed even if the position and direction of the planar optical filter with respect to the input light are slightly deviated from a predetermined position and direction. Can be difficult to carry out.

One aspect of the present invention has been made in view of the above problems, and realizes a multi-stage optical filter in which the position and direction of the planar optical filter with respect to the input light can be easily adjusted to a predetermined position and direction. The purpose is to do.

The multi-stage optical filter device according to the first aspect of the present invention reflects light transmitted through an optical filter group including at least two planar optical filters and a first planar optical filter belonging to the optical filter group. It has a mirror structure that leads to a second planar optical filter belonging to the optical filter group.

According to the above configuration, a planar optical filter belonging to the optical filter group is formed by adjusting one or both of the position (for example, the center position) and the direction (for example, the normal direction) of the reflecting surface included in the mirror structure. The position and direction of the light with respect to the input light can be adjusted to a predetermined position and direction. Therefore, the position and direction of the planar light filter belonging to the optical filter group with respect to the input light can be easily adjusted to a predetermined position and direction.

In the multi-stage optical filter device according to the second aspect of the present invention, in addition to the configuration of the first aspect, the first planar optical filter and the second planar optical filter are arranged on the same plane. , Is adopted.

According to the above configuration, it is not necessary to adjust the directions of the first planar filter and the second planar filter. Therefore, the position and direction of the planar light filter belonging to the optical filter group with respect to the input light can be more easily adjusted to the predetermined position and direction.

In the multi-stage optical filter device according to the third aspect of the present invention, in addition to the configuration of the second aspect, the mirror structure is (1) a first reflecting surface that reflects light transmitted through the first planar optical filter. The first reflecting surface, which is arranged on the first side of the plane and has an angle of 45 ° with the plane, and (2) the light reflected by the first reflecting surface are further added. A second reflecting surface that reflects and leads to the second planar light filter, which is arranged on the first side of the plane and has an angle of 45 ° with the plane. And, is adopted.

According to the above configuration, the light transmitted vertically through the first planar optical filter can be vertically incident on the second planar optical filter.

In the multi-stage optical filter device according to the fourth aspect of the present invention, in addition to the configuration of the third aspect, the first reflecting surface and the second reflecting surface are formed on two surfaces orthogonal to each other of the right-angled prism mirror. The configuration is adopted.

According to the above configuration, the first reflecting surface and the second reflecting surface can be realized by one right-angle prism mirror. Therefore, it is possible to configure the multi-stage optical filter device with a smaller number of parts.

In the multi-stage optical filter device according to the fifth aspect of the present invention, in addition to the configuration of the third aspect, the first reflecting surface intersects each of the two planes orthogonal to each other of the first right-angled prism mirror at 45 °. A configuration is adopted in which the second reflecting surface is formed on a slope, and the second reflecting surface is formed on a slope that intersects each of the two surfaces orthogonal to each other of the second right-angled prism mirror at 45 °.

According to the above configuration, the first reflecting surface and the second reflecting surface can be individually realized by the two right-angle prism mirrors. Therefore, the position and direction of the first reflecting surface and the position and direction of the second reflecting surface can be adjusted independently.

In the multi-stage optical filter device according to the sixth aspect of the present invention, in addition to the configuration of any one aspect of the third to fifth aspects, the optical filter group includes a third planar optical filter arranged on the plane and a third planar optical filter. A fourth planar light filter is further included, and the mirror structure is (3) a third reflecting surface that reflects light transmitted through the second planar light filter, and is a second side of the plane. A third reflecting surface having an angle of 45 ° with the plane, and (4) further reflecting the light reflected by the third reflecting surface, the fourth plane light filter. A configuration is adopted in which a fourth reflecting surface is arranged on the second side of the plane and includes a fourth reflecting surface having an angle of 45 ° with the plane. Has been done.

According to the above configuration, (1) the light transmitted vertically through the first planar light filter is vertically incident on the second planar light filter, and (2) the second planar light filter is vertically incident. The light transmitted through the third planar light filter can be vertically incident on the third planar light filter, and (3) the light transmitted vertically through the third planar light filter can be incident on the fourth planar light filter.

In the multi-stage optical filter device according to the seventh aspect of the present invention, in addition to the configuration of any one of the first to sixth aspects, the planar optical filter belonging to the optical filter group is integrally molded. It has been adopted.

According to the above configuration, the relative positional relationship of the planar optical filters belonging to the optical filter group can be set to the desired positional relationship with high accuracy without performing ex post facto adjustment.

In the multi-stage optical filter device according to the eighth aspect of the present invention, in addition to the configuration of any one aspect of the first to seventh aspects, the optical filter group has a plurality of microcells in which the refractive index is individually set. A configuration is adopted in which at least one planar optical filter is included.

According to the above configuration, it is possible to realize a multi-layer optical filter device capable of performing multi-step optical calculation.

In the multi-stage optical filter device according to the ninth aspect of the present invention, in addition to the configuration of the eighth aspect, the plurality of microcells are composed of a plurality of pillars whose heights are individually set, and the planar optical filter is A configuration is adopted in which a frame portion having a height higher than that of the pillar is provided so as to surround the region in which the plurality of microcells are formed.

According to the above configuration, when a mirror structure (for example, a right-angle prism mirror) is placed on a planar optical filter having a plurality of microcells, the plurality of pillars constituting the plurality of microcells are damaged. The possibility can be reduced.

The manufacturing method according to the tenth aspect of the present invention is the manufacturing method of the multi-stage optical filter according to any one of the first to ninth aspects, and includes a step of integrally molding a planar optical filter belonging to the optical filter group. It is characterized by being.

According to the above manufacturing method, the relative positional relationship of the planar optical filters belonging to the optical filter group can be set to the desired positional relationship with high accuracy without performing subsequent adjustment.

The manufacturing method according to the tenth aspect of the present invention is the manufacturing method of the multi-stage optical filter according to any one of the first to ninth aspects, wherein one or both of the positions and directions of the reflecting surfaces constituting the mirror structure are described. It includes a step of adjusting while monitoring the light transmitted through the planar optical filter belonging to the filter group.

According to the above manufacturing method, the position and direction of the planar optical filter belonging to the optical filter group with respect to the input light can be easily adjusted to a predetermined position and direction.

According to one aspect of the present invention, it is possible to realize a multi-stage optical filter in which the position and direction of the planar optical filter with respect to the input light can be easily adjusted to a predetermined position and direction.

It is a perspective view which shows the structure of the multi-stage optical filter apparatus which concerns on one Embodiment of this invention. It is sectional drawing which shows the AA'cross section of the multistage optical filter apparatus of FIG. It is a perspective view which shows a specific example of the planar optical filter provided in the multi-stage optical filter apparatus of FIG. It is a perspective view which shows one modification of the multi-stage optical filter apparatus of FIG. It is sectional drawing which shows the BB'cross section of the multi-stage optical filter apparatus of FIG. It is a figure which shows typically the manufacturing method of the multi-stage optical filter apparatus of FIG. It is a figure which shows typically one modification of the manufacturing method of the multi-stage optical filter apparatus of FIG.

(Configuration of multi-stage optical filter device)
The configuration of the multi-stage optical filter device 1 according to the embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view showing the configuration of the multi-stage optical filter device 1, and FIG. 2 is a cross-sectional view showing the AA'cross section of the multi-stage optical filter device 1.

The multi-stage optical filter device 1 includes an optical filter group 11, a transparent substrate 12, and a mirror structure 13. In the present embodiment, the transparent substrate 12 is composed of a glass layer 12a and a resin layer 12b. The optical filter group 11 is integrally molded in the resin layer 12b by, for example, nanoimprint. The glass layer 12a has light transmission through which light (for example, red light) subject to optical calculation and light for curing the resin layer 12b (for example, ultraviolet light) are transmitted, and the shape of the resin layer 12b. It is composed of a material having rigidity to keep the flat plate. Any plate-shaped member made of a material having these properties can be used instead of the glass layer 12.

The optical filter group 11 is a set of N planar optical filters 11a1 to 11aN. In FIG. 1, an optical filter group 11 composed of four planar optical filters 11a1 to 11a4 is illustrated. However, the number N of the planar optical filters 11a1 to 11aN is not limited to 4 as long as it is an arbitrary natural number of 2 or more.

In the present embodiment, each planar optical filter 11ai (i is a natural number of 1 or more and N or less) has a square shape in a plan view. Further, in the present embodiment, the planar optical filters 11a1 to 11aN face parallel to one side of the planar optical filter 11aj + 1 on which one side of each planar optical filter 11aj (j is a natural number of 1 or more and N-1 or less) is adjacent. They are arranged in a straight line on the same plane.

Further, in the present embodiment, each planar optical filter 11ai has a plurality of microcells in which the refractive index is individually set, and interferes with each other with light transmitted through each microcell (mainly assuming visible light). It is designed to perform a predetermined optical calculation by letting it perform. When the planar optical filters 11a1 to 11aN are applied to the input light in order to execute N times of optical calculations in sequence, it is important to keep the relative positional relationship of the planar optical filters 11a1 to 11aN in the desired relationship. However, in the present embodiment, this requirement is satisfied by integrally molding the planar optical filters 11a1 to 11aN. In addition, in this specification, a "microcell" means a cell whose size is on the order of micrometers or less, that is, less than 10 μm. The lower limit of the size of the microcell is not particularly limited, but is, for example, 1 nm.

The mirror structure 13 (1) reflects the light transmitted through the first planar light filter 11a1 and guides it to the second planar light filter 11a2, and (2) the light transmitted through the second planar light filter 11a2. Is reflected and guided to the third planar light filter 11a3, and (3) the light transmitted through the third planar light filter 11a3 is reflected and guided to the fourth planar light filter 11a4. In the present embodiment, the mirror structure 13 is composed of N-1 right-angle prism mirrors 13a1 to 13aN-1.

The first right-angled prism mirror 13a1 has a first reflecting surface 13b1 and a second reflecting surface 13b2, and is an example of the upper surface side (“first side” in the range of patent displacement) of the transparent substrate 12. ) Is placed. The first reflecting surface 13b1 is a reflecting surface that reflects the light transmitted through the first planar optical filter 11a1, and the angle formed by the upper surface of the transparent substrate 12 is 45 °. The second reflecting surface 13b2 is a reflecting surface that further reflects the light reflected by the first reflecting surface 13b1 and guides it to the second planar optical filter 11a2, and the angle formed by the upper surface of the transparent substrate 12 is It is 45 °. Therefore, the light vertically incident on the first planar light filter 11a1 from the lower surface side of the transparent substrate 12 is sequentially reflected by the first reflecting surface 13b1 and the second reflecting surface 13b2, and is reflected from the upper surface side of the transparent substrate 12 in order. It is vertically incident on the second planar light filter 11a2.

The second right-angled prism mirror 13a2 has a third reflecting surface 13b3 and a fourth reflecting surface 13b4, and is an example of the lower surface side (“second side” in the range of patent displacement) of the transparent substrate 12. ) Is placed. The third reflecting surface 13b3 is a reflecting surface that reflects the light transmitted through the second planar optical filter 11a2, and the angle formed by the lower surface of the transparent substrate 12 is 45 °. The fourth reflecting surface 13b4 is a reflecting surface that further reflects the light reflected by the third reflecting surface 13b3 and guides it to the third planar optical filter 11a3, and the angle formed by the lower surface of the transparent substrate 12 is It is 45 °. Therefore, the light vertically incident on the second planar light filter 11a2 from the upper surface side of the transparent substrate 12 is sequentially reflected by the third reflecting surface 13b3 and the fourth reflecting surface 13b4, and is reflected from the lower surface side of the transparent substrate 12 in order. It is vertically incident on the third planar light filter 11a3.

The third right-angled prism mirror 13a3 has a fifth reflecting surface 13b5 and a sixth reflecting surface 13b6, and is arranged on the upper surface side of the transparent substrate 12. The fifth reflecting surface 13b5 is a reflecting surface that reflects the light transmitted through the third planar optical filter 11a3, and the angle formed by the upper surface of the transparent substrate 12 is 45 °. The sixth reflecting surface 13b6 is a reflecting surface that further reflects the light reflected by the fifth reflecting surface 13b5 and guides it to the fourth planar optical filter 11a4, and the angle formed by the upper surface of the transparent substrate 12 is It is 45 °. Therefore, the light vertically incident on the third planar light filter 11a3 from the lower surface side of the transparent substrate 12 is sequentially reflected by the fifth reflecting surface 13b5 and the sixth reflecting surface 13b6, and is reflected from the upper surface side of the transparent substrate 12 in order. It is vertically incident on the fourth planar light filter 11a4.

(Specific example of planar optical filter)
A specific example of the planar optical filter 11ai included in the multi-stage optical filter device 1 will be described with reference to FIG. FIG. 3 is a perspective view of the planar optical filter 11ai according to this specific example.

The planar optical filter 11ai according to this specific example is a square with a side of 1.0 mm, and is composed of 100 × 100 microcells arranged in a matrix. Each microcell is composed of a square columnar pillar having a bottom surface of a square having a side of 1 μm formed on a base having a thickness of 100 μm. The height of each pillar is 0 nm, 100 nm, 200 nm, ... It is decided to.

The cell size of the planar optical filter 11ai is 1 μm in this specific example, but is not limited to this. That is, the cell size of the planar optical filter 11ai may be less than 10 μm. Further, the number of cells and the effective area size of the planar optical filter 11ai are also arbitrary.

The planar optical filter 11ai is surrounded by a frame portion 11bi. The height of the frame portion 11bi is higher than the height of the highest pillar provided in the planar optical filter 11ai. Therefore, as shown in FIGS. 1 and 2, even if the right-angled prism mirrors 13a1 to 13aN-1 are brought into contact with the upper surface of the transparent substrate 12 provided with the planar optical filter 11ai, the planar optical filter 11ai is formed. The pillars will not be damaged. In the present embodiment, the pillars constituting the planar optical filter 11ai are separated from the right-angle prism mirrors 13a1 to 13aN-1 by providing the frame portion 11bi, but the configuration is limited to this. No. For example, a configuration may be adopted in which the pillars constituting the planar optical filter 11ai are separated from the right-angle prism mirrors 13a1 to 13aN-1 by providing a recess in the right-angle prism mirrors 13a1 to 13aN-1. Alternatively, by arranging an annular spacer between the planar optical filter 11ai and the right-angle prism mirrors 13a1 to 13aN-1, the pillars constituting the planar optical filter 11ai are separated from the right-angle prism mirrors 13a1 to 13aN-1. The configuration may be adopted.

In the present embodiment, the refractive index of each microcell of the planar optical filter ai is set by setting the height of the pillars constituting the cell, but the present invention is limited to this. is not it. For example, the refractive index of each microcell of the planar optical filter ai may be set by selecting the material of the cell. Alternatively, the refractive index of each microcell of the planar optical filter ai may be set by selecting the amount and / type of the additive to be added to the material of the cell.

(Modification example of multi-stage optical filter device)
A modified example of the multi-stage optical filter device 1 (hereinafter, referred to as “multi-stage optical filter device 1A”) will be described with reference to FIGS. 4 and 5. FIG. 4 is a perspective view showing the configuration of the multi-stage optical filter device 1A, and FIG. 5 is a cross-sectional view showing a BB'cross section of the multi-stage optical filter device 1A.

In the multi-stage optical filter device 1 shown in FIGS. 1 and 2, four (generally N) planar filters 11a1 to 11a4 are arranged close to each other.

On the other hand, in the multi-stage optical filter device 1A shown in FIGS. 4 and 5, four (generally N) planar filters 11a1 to 11a4 are arranged apart from each other.

Further, the multi-stage optical filter device 1 shown in FIGS. 1 and 2 includes three (generally N-1) right-angle prism mirrors 13a1 to 13a3. The first reflecting surface 13b1 and the second reflecting surface 13b2 are provided on two surfaces of the first right-angled prism mirror 13a1 that are orthogonal to each other. Further, the third reflecting surface 13b3 and the fourth reflecting surface 13b4 are provided on two surfaces orthogonal to each other of the second right-angled prism mirror 13a2. Further, the fifth reflecting surface 13b5 and the sixth reflecting surface 13b6 are provided on two surfaces orthogonal to each other of the third right-angled prism mirror 13a3.

On the other hand, the multi-stage optical filter device 1A shown in FIGS. 4 and 5 includes 6 (generally (N-1) × 2) right-angle prism mirrors 13a1 to 13a6. Then, (1) the first reflecting surface 13b1 is provided on a slope that intersects each of the two surfaces orthogonal to each other of the first right-angled prism mirror 13a1 at 45 °, and (2) the second reflecting surface 13b2 is It is provided on a slope that intersects each of the two planes orthogonal to each other of the second right-angled prism mirror 13a2 at 45 °. Further, (3) the third reflecting surface 13b3 is provided on a slope that intersects each of the two surfaces orthogonal to each other of the third right-angled prism mirror 13a3 at 45 °, and (4) the fourth reflecting surface 13b4 is provided. It is provided on a slope that intersects each of the two planes orthogonal to each other of the fourth right-angled prism mirror 13a4 at 45 °. Further, (5) the fifth reflecting surface 13b5 is provided on a slope that intersects each of the two planes orthogonal to each other of the fifth right-angled prism mirror 13a5 at 45 °, and (6) the sixth reflecting surface 13b6 is provided. It is provided on a slope that intersects each of the two planes orthogonal to each other of the sixth right-angled prism mirror 13a6 at 45 °.

Further, in the multi-stage optical filter device 1 shown in FIGS. 1 and 2, the optical path of light transmitted through the planar optical filters 11a1 to 11a4 draws a linear trajectory when the transparent substrate 12 is viewed from above.

On the other hand, in the multi-stage optical filter device 1A shown in FIGS. 4 and 5, the optical path of light transmitted through the planar optical filters 11a1 to 11a4 draws an orbit when the transparent substrate 12 is viewed from above. ..

As described above, the multi-stage optical filter device 1 shown in FIGS. 1 and 2 has an advantage that the mirror structure 13 can be realized by a smaller number of right-angle prism mirrors 13a1 to 13a3. On the other hand, the multi-stage optical filter device 1 shown in FIGS. 4 and 5 has an advantage that the directions of the reflecting surfaces 13b1 to 13b6 can be individually adjusted. Which form should be adopted may be appropriately selected in consideration of the advantages of each form and the shape and size required for the multi-stage optical filter device 1.

(Manufacturing method of multi-stage optical filter device)
A method of manufacturing the multi-stage optical filter device 1 will be described with reference to FIG. FIG. 6 is a diagram schematically showing each stage of the present manufacturing method.

In the present manufacturing method, first, planar optical filters 11a1 to 11a4 constituting the optical filter group 11 are formed on the upper surface of the transparent substrate 12 by using the nanoimprint method. After that, the right-angle prism mirrors 13a1 to 13a3 are adhesively fixed to the transparent substrate 12. Since the former process is known, the latter process will be described below. In the following description, the X-axis parallel to the main surfaces (upper surface and lower surface) of the transparent substrate 12, the Y-axis parallel to the main surface of the transparent substrate 12 and orthogonal to the X-axis, and the transparent substrate 12 A coordinate system with a Z axis perpendicular to the main surface is used.

First, as shown in FIG. 6A, on the upper surface of the transparent substrate 12, the uncured ultraviolet curable resin R1 is formed around the first planar optical filter 11a1 and the second planar optical filter 11a2. Is applied as an adhesive. Next, the bottom surface of the first right-angle prism mirror 13a1 is brought into contact with the upper surface of the transparent substrate 12, and as shown in FIG. 6B, the first right-angle prism mirror 13a1 is actively aligned. That is, while the light output from the light source 21 is input to the first planar light filter 11a1, the light transmitted through the second planar light filter 11a2 is monitored by using the image sensor 22. Then, the position and direction of the first right-angle prism mirror 13a1 are adjusted so that the light intensity distribution monitored by the image sensor 22 becomes the desired distribution (predetermined distribution as a target). Here, the adjustable position is the position in the X-axis direction, the Y-axis direction, and the Z-axis direction shown in FIG. 6B, and the adjustable position is the X-axis shown in FIG. 6B. , Y-axis, and Z-axis as rotation axes. The position is adjusted after the direction is adjusted (the bottom surface of the first right-angle prism mirror 13a1 is parallel to the XY plane). Then, when the light intensity distribution monitored by the image sensor 22 matches the desired distribution, the first right-angle prism mirror 13a1 is formed on the transparent substrate 12 by irradiating ultraviolet rays to cure the ultraviolet curable resin R1. Fix on the top surface of. In the present embodiment, the ultraviolet curable resin R1 is applied so as to surround the first planar optical filter 11a1, but the present invention is not limited to this. For example, the ultraviolet curable resin R1 may be applied so as to cover the first planar optical filter 11a1.

Secondly, as shown in FIG. 6C, the uncured ultraviolet curable resin R2 is formed on the lower surface of the transparent substrate 12 around the second planar optical filter 11a2 and the third planar optical filter 11a3. Is applied as an adhesive. Next, the bottom surface of the second right-angle prism mirror 13a2 is brought into contact with the lower surface of the transparent substrate 12, and the second right-angle prism mirror 13a2 is actively aligned as shown in FIG. 6D. That is, while the light output from the light source 21 is input to the first planar optical filter 11a1, the light transmitted through the third planar optical filter 11a3 is monitored by using the image sensor 22. Then, the position and direction of the second right-angle prism mirror 13a2 are adjusted so that the light intensity distribution monitored by the image sensor 22 becomes the desired distribution. Here, the adjustable position is the position in the X-axis direction, the Y-axis direction, and the Z-axis direction shown in FIG. 6D, and the adjustable position is the X-axis shown in FIG. 6D. , Y-axis, and Z-axis as rotation axes. The position is adjusted after the direction is adjusted (the bottom surface of the second right-angle prism mirror 13a2 is parallel to the XY plane). Then, when the light intensity distribution monitored by the image sensor 22 matches the desired distribution, the second right-angle prism mirror 13a2 is attached to the transparent substrate 12 by irradiating ultraviolet rays to cure the ultraviolet curable resin R2. Fix to the underside of. In the present embodiment, the ultraviolet curable resin R2 is applied so as to surround the second planar optical filter 11a2, but the present invention is not limited to this. For example, the ultraviolet curable resin R2 may be applied so as to cover the second planar optical filter 11a2.

Thirdly, as shown in FIG. 6E, the uncured ultraviolet curable resin R3 is formed around the third planar optical filter 11a3 and the fourth planar optical filter 11a4 on the upper surface of the transparent substrate 12. Is applied as an adhesive. Next, the bottom surface of the third right-angle prism mirror 13a3 is brought into contact with the upper surface of the transparent substrate 12, and the third right-angle prism mirror 13a3 is actively aligned as shown in FIG. 6 (f). That is, while the light output from the light source 21 is input to the first planar optical filter 11a1, the light transmitted through the fourth planar optical filter 11a4 is monitored by using the image sensor 22. Then, the position and direction of the third right-angle prism mirror 13a3 are adjusted so that the light intensity distribution monitored by the image sensor 22 becomes the desired distribution. Here, the adjustable positions are the positions in the X-axis direction, the Y-axis direction, and the Z-axis direction shown in FIG. 6 (f), and the adjustable positions are the X-axis shown in FIG. 6 (f). , Y-axis, and Z-axis as rotation axes. The position is adjusted after the direction is adjusted (the bottom surface of the third right-angle prism mirror 13a3 is parallel to the XY plane). Then, when the light intensity distribution monitored by the image sensor 22 matches the desired distribution, the third right-angle prism mirror 13a3 is formed on the transparent substrate 12 by irradiating ultraviolet rays to cure the ultraviolet curable resin R3. Fix on the top surface of. In the present embodiment, the ultraviolet curable resin R3 is applied so as to surround the third planar optical filter 11a3, but the present invention is not limited to this. For example, the ultraviolet curable resin R3 may be applied so as to cover the third planar optical filter 11a3.

As a result, as shown in FIG. 6 (g), the multi-stage optical filter device 1 is completed.

The adhesive used to bond and fix the right-angle prism mirrors 13a1 to 13a3 to the transparent substrate 12 is not limited to the ultraviolet curable resin. That is, a resin that cures by any stimulus such as light other than ultraviolet rays, heat, or humidity can be used. Further, the adhesive may be epoxy-based or acrylic-based. In each case, the viscosity can be adjusted and the film thickness can be easily controlled.

(Modified example of manufacturing method of multi-stage optical filter device)
As shown in FIG. 6, the right-angle prism mirrors 13a1 to 13a3 may be mounted by adhering and fixing a preformed one to the transparent substrate 12, or as shown in FIG. 7, on the transparent substrate 12. It may be mounted by molding with. In the latter case, the right-angle prism mirror 13a1 is formed, for example, as follows. The same applies to the molding of the right-angle prism mirrors 13a2 and 12a3.

First, as shown in FIG. 7A, a mold 23 having a shape complementary to the right-angle prism mirror 13a1 is placed on the transparent substrate 12. Next, as shown in FIG. 7B, the mold 23 is actively aligned. That is, while the light output from the light source 21 is input to the first planar light filter 11a1, the light transmitted through the second planar light filter 11a2 is monitored by using the image sensor 22. Then, the position and direction of the mold 23 are adjusted so that the light intensity distribution monitored by the image sensor 22 becomes the desired distribution. Here, the adjustable position is the position in the X-axis direction, the Y-axis direction, and the Z-axis direction shown in FIG. 7B, and the adjustable position is the X-axis shown in FIG. 7B. , Y-axis, and Z-axis as rotation axes. Then, when the light intensity distribution monitored by the image sensor 22 matches the desired distribution, the position and direction of the mold 23 are fixed.

Next, as shown in FIG. 7 (c), the inside of the mold 23 is filled with an uncured ultraviolet curable resin. After that, as shown in FIG. 7D, the position of the mold 23 is finely adjusted. That is, while the light output from the light source 21 is input to the first planar light filter 11a1, the light transmitted through the second planar light filter 11a2 is monitored by using the image sensor 22. Then, the position of the mold 23 is finely adjusted so that the light intensity distribution monitored by the image sensor 22 becomes the desired distribution. Here, the adjustable positions are the positions in the X-axis direction and the Y-axis direction shown in FIG. 7D. Then, when the light intensity distribution monitored by the image sensor 22 matches the desired distribution, as shown in FIG. 7 (e), the ultraviolet curable resin inside the mold 23 is irradiated with ultraviolet rays. Cure.

Next, as shown in FIG. 7 (f), after removing the mold 23, a metal film is formed on the surface of the cured ultraviolet curable resin (excluding the surface that contacts the upper surface of the transparent substrate 12). As a result, the two surfaces of the cured ultraviolet curable resin that intersect with the upper surface of the transparent substrate 12 at an angle of 45 ° more preferably function as the first reflecting surface 13b1 and the second reflecting surface 13b2. .. As a result, the right-angle prism mirror 13a1 is completed. If it is not necessary to pursue high reflectance, the metal film may be omitted. Even in this case, the two surfaces of the cured ultraviolet curable resin that intersect with the upper surface of the transparent substrate 12 at an angle of 45 ° function as the first reflecting surface 13b1 and the second reflecting surface 13b2.

Although the method of individually molding the three right-angle prism mirrors 13a1 to 13a3 has been described here, the present invention is not limited to this. That is, the three right-angled prism mirrors 13a1 to 13a3 may be molded at once. In this case, instead of the mold 23 having one recess having a shape complementary to the right-angle prism mirror 13a1, a mold having three recesses having a shape complementary to the right-angle prism mirror 13a1 may be used.

(Additional notes)
The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the claims, and the present invention can be obtained by appropriately combining the technical means disclosed in each of the above-described embodiments. The form is also included in the technical scope of the present invention.

1 Multi-stage optical filter device 11 Optical filter group 11ai Planar optical filter 11bi Frame part 12 Transparent substrate 12a Glass layer 12b Resin layer 13 Mirror structure 13a1 to 13a3 Right angle prism mirror 13b1 to 13b6 Reflective surface 21 Light source 22 Image sensor

Claims (11)

A group of optical filters including at least two planar optical filters,
It has a mirror structure that reflects light transmitted through a first planar optical filter belonging to the optical filter group to lead to a second planar optical filter belonging to the optical filter group.
A multi-stage optical filter device characterized by this. The first planar optical filter and the second planar optical filter are arranged on the same plane.
The multi-stage optical filter device according to claim 1. The mirror structure is (1) a first reflecting surface that reflects light transmitted through the first planar light filter, is arranged on the first side of the plane, and has an angle formed with the plane. A first reflecting surface having a temperature of 45 ° and (2) a second reflecting surface that further reflects the light reflected by the first reflecting surface and guides the light to the second planar light filter. Includes a second reflective surface that is located on the first side of the plane and has an angle of 45 ° with the plane.
The multi-stage optical filter device according to claim 2. The first reflecting surface and the second reflecting surface are formed on two surfaces of a right-angled prism mirror that are orthogonal to each other.
The multi-stage optical filter device according to claim 3. The first reflecting surface is formed on an inclined surface that intersects each of the two surfaces orthogonal to each other of the first right-angled prism mirror at 45 °, and the second reflecting surface is the second right-angled prism mirror. It is formed on a slope that intersects each of the two faces orthogonal to each other at 45 °.
The multi-stage optical filter device according to claim 3. The optical filter group further includes a third planar optical filter and a fourth planar optical filter arranged on the plane.
The mirror structure is (3) a third reflecting surface that reflects light transmitted through the second planar light filter, is arranged on the second side of the plane, and has an angle formed with the plane. A third reflecting surface having a temperature of 45 ° and (4) a fourth reflecting surface that further reflects the light reflected by the third reflecting surface and guides the light to the fourth planar light filter. Includes a fourth reflective surface that is located on the second side of the plane and has an angle of 45 ° with the plane.
The multi-stage optical filter device according to any one of claims 3 to 5, wherein the multi-stage optical filter device is characterized. The planar optical filters belonging to the optical filter group are integrally molded.
The multi-stage optical filter device according to any one of claims 1 to 6, wherein the multi-stage optical filter device is characterized. The optical filter group includes at least one planar optical filter having a plurality of microcells having individually set refractive indexes.
The multi-stage optical filter device according to any one of claims 1 to 7, wherein the multi-stage optical filter device is characterized. The plurality of microcells are composed of a plurality of pillars having individually set heights.
The planar optical filter has a frame portion having a height higher than that of the pillar, which surrounds the region where the plurality of microcells are formed.
The multi-stage optical filter device according to claim 8. The method for manufacturing a multi-stage optical filter device according to any one of claims 1 to 9.
A step of integrally molding a planar optical filter belonging to the optical filter group is included.
A method for manufacturing a multi-stage optical filter device. The method for manufacturing a multi-stage optical filter device according to any one of claims 1 to 9.
This includes a step of adjusting one or both of the positions and directions of the reflecting surfaces included in the mirror structure while monitoring the light transmitted through the planar optical filter belonging to the optical filter group.
A method for manufacturing a multi-stage optical filter device.

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