Filter unit

Abstract

To provide a filter unit that is suitable for the arrangement of a Fabry-Perot interference filter in an area narrow in an optical axis direction.SOLUTION: A filter unit 1 comprises: a support 2 that has an opening 23; a Fabry-Perot interference filter 10 that is arranged on the support 2 to overlap the opening 23 when seen from a Z-axis direction; and a wiring board 4 that is arranged on the support 2 not to overlap the Fabry-Perot interference filter 10 when seen from the Z-axis direction, and is electrically connected with the Fabry-Perot interference filter 10. The support 2 is formed with a first concave part 21 and a second concave part 22 with the Z-axis direction as a depth direction. The first concave part 21 and the second concave part 22 are arranged side by side in an X-axis direction perpendicular to the Z-axis direction. The Fabry-Perot interference filter 10 is arranged inside the first concave part 21. The wiring board 4 is arranged inside the second concave part 22. The support 2 includes a partition part 26 arranged between the first concave part 21 and the second concave part 22.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a filter unit comprising a Fabry-Perot interference filter. [Background technology]

[0002] In order to configure a filter unit using a Fabry-Perot interference filter including a pair of mirror parts whose distance from each other is variable, it is possible to use the following structure: a CAN package having a stem and a cap, a wiring board arranged on the stem in the CAN package, a Fabry-Perot interference filter arranged on the wiring board in the CAN package, and a plurality of lead pins penetrating the stem (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2017 / 0350760 Summary of the Invention [Problem to be solved by the invention]

[0004] However, a filter unit to which the above-described structure is applied has a problem in that it is difficult to make the filter unit thin in the optical axis direction of the Fabry-Perot interference filter (i.e., the direction in which the pair of mirror portions face each other), and therefore it is unsuitable for placement in a narrow area in the optical axis direction of the Fabry-Perot interference filter (for example, the area between lenses inside the lens barrel).

[0005] An object of the present invention is to provide a filter unit suitable for arrangement in a narrow area in the optical axis direction of a Fabry-Perot interference filter. [Means for solving the problem]

[0006] The filter unit of the present invention is [1] "a filter unit comprising: a support having a light passing portion; a Fabry-Perot interference filter including a pair of mirror portions facing each other in a first direction and having a variable distance therebetween, the Fabry-Perot interference filter being arranged on the support so as to overlap with the light passing portion when viewed from the first direction; and a wiring board arranged on the support so as not to overlap with the Fabry-Perot interference filter when viewed from the first direction and electrically connected to the Fabry-Perot interference filter, wherein a first recess and a second recess are formed in the support with the first direction as a depth direction, the first recess and the second recess are aligned in a second direction perpendicular to the first direction, the Fabry-Perot interference filter is arranged in the first recess, the wiring board is arranged in the second recess, and the support includes a partition portion arranged between the first recess and the second recess."

[0007] In the filter unit described in [1] above, the Fabry-Perot interference filter is disposed in a first recess formed in the support with the first direction as the depth direction, and the wiring board is disposed in a second recess formed in the support with the first direction as the depth direction so as not to overlap with the Fabry-Perot interference filter on the support when viewed from the first direction. This allows the filter unit to be made thinner in the first direction, which is the optical axis direction of the Fabry-Perot interference filter (i.e., the direction in which the pair of mirror parts face each other). In addition, in a configuration in which the Fabry-Perot interference filter is disposed so as not to overlap with the wiring board, the degree of freedom in arranging the Fabry-Perot interference filter and the wiring board is improved compared to a conventional configuration in which the Fabry-Perot interference filter is disposed on the wiring board, but the positioning of these may become more difficult. However, in the filter unit described in [1] above, the support includes a partition portion disposed between the first and second recesses. This allows the Fabry-Perot interference filter and the wiring board to be positioned easily and accurately with respect to the support by using the partition portion as a reference (for example, a mechanical positioning portion or a reference coordinate). Therefore, the filter unit described in [1] above is suitable for arrangement in a narrow area in the optical axis direction of a Fabry-Perot interference filter.

[0008] The filter unit of the present invention may be the filter unit described in [1] above, [2] "wherein the first recess has a pair of first surfaces facing each other with the Fabry-Perot interference filter in between in a third direction perpendicular to both the first direction and the second direction, the second recess has a pair of second surfaces facing each other with the wiring board in between, and the partition portion is connected to at least one of the pair of first surfaces or at least one of the pair of second surfaces." According to the filter unit described in [2], since the partition portion is connected to at least one of the pair of first surfaces or at least one of the pair of second surfaces, the mechanical strength of the support is increased, and for example, deformation of the shape of the light passing portion in the support can be suppressed.

[0009] The filter unit of the present invention may be [3] "the filter unit described in [2] above, in which the partition portion is continuously formed so as to reach from one of the pair of first surfaces to the other, or from one of the pair of second surfaces to the other." According to the filter unit described in [3], the partition portion is continuously formed so as to reach from one of the pair of first surfaces to the other, or from one of the pair of second surfaces to the other, so that the mechanical strength of the support is further increased, and, for example, deformation of the shape of the light passing portion in the support can be further suppressed.

[0010] The filter unit of the present invention may be [4] "the filter unit described in [1] above, wherein the first recess has a pair of first surfaces facing each other with the Fabry-Perot interference filter in between in a third direction perpendicular to both the first direction and the second direction, the second recess has a pair of second surfaces facing each other with the wiring board in between in the third direction, and the partition portion is spaced apart from the pair of first surfaces and the pair of second surfaces." According to the filter unit described in [4], the partition portion can be made small, and the Fabry-Perot interference filter and the wiring board can be easily and accurately positioned with respect to the support body using the partition portion.

[0011] The filter unit of the present invention may be [5] "the filter unit according to any one of the above [1] to [4], in which the height of the partition in the first direction is equal to or less than the height of the Fabry-Perot interference filter in the first direction." According to the filter unit described in [5], for example, when the Fabry-Perot interference filter and a wiring board are connected by a wire, the wire can be easily connected to the Fabry-Perot interference filter.

[0012] The filter unit of the present invention may be [6] "the filter unit according to any one of the above [1] to [5], in which the height of the partition in the first direction is equal to or less than the height of the wiring board in the first direction." According to the filter unit described in [6], for example, when the Fabry-Perot interference filter and the wiring board are connected by a wire, the wire can be easily connected to the wiring board.

[0013] The filter unit of the present invention may be [7] "the filter unit according to any one of the above [1] to [6], in which the Fabry-Perot interference filter is located at the center of the support when viewed from the first direction." According to the filter unit described in [7], even if an external force acts on the support from the side with respect to the first direction, the external force can be prevented from being exerted on the Fabry-Perot interference filter. Furthermore, for example, by fitting the support inside a cylindrical body such as a lens barrel, the Fabry-Perot interference filter can be disposed on the center line of the cylindrical body.

[0014] The filter unit of the present invention may be [8] "the filter unit according to [7] above, in which the outer edge of the support has a circular shape when viewed from the first direction." According to the filter unit according to [8], even if an external force acts on the support from the side in the first direction, the external force can be suppressed from affecting the Fabry-Perot interference filter in a well-balanced manner. Furthermore, for example, when the cylinder is cylindrical, the Fabry-Perot interference filter can be easily and accurately positioned on the center line of the cylindrical cylinder.

[0015] The filter unit of the present invention may be [9] "the filter unit according to any one of the above [1] to [6], in which an outer edge of the Fabry-Perot interference filter and an inner edge of the first recess each have a rectangular shape when viewed from the first direction." According to the filter unit according to [9], the Fabry-Perot interference filter can be easily and accurately positioned with respect to the support.

[0016] The filter unit of the present invention may be

[10] "the filter unit according to any one of the above [1] to [9], wherein the Fabry-Perot interference filter is disposed on a first mounting surface of the support, the wiring board is disposed on a second mounting surface of the support, and the first mounting surface and the second mounting surface are located on the same plane." According to the filter unit described in

[10] , the filter unit can be made thinner in a first direction which is the optical axis direction of the Fabry-Perot interference filter.

[0017] The filter unit of the present invention may be

[11] "the filter unit according to any one of the above [1] to

[10] , in which the second recess reaches the outer edge of the support when viewed from the first direction." According to the filter unit described in

[11] , the second recess in which the wiring board is disposed reaches the outer edge of the support when viewed from the first direction, so that electrical connection can be made laterally in the first direction with a simple configuration.

[0018] The filter unit of the present invention may be

[12] "the filter unit according to any one of the above [1] to

[11] , further comprising a light-transmitting member and an adhesive member, the light-transmitting member covering at least the opening of the first recess, and the adhesive member being disposed between the wiring board and the support, and between the wiring board and the light-transmitting member." According to the filter unit according to

[12] , a package for accommodating a Fabry-Perot interference filter can be formed by the support, the wiring board, the light-transmitting member, and the adhesive member, while suppressing an increase in thickness in a first direction, which is the optical axis direction of the Fabry-Perot interference filter. This makes it possible to protect the Fabry-Perot interference filter from moisture, particles, and the like.

[0019] The filter unit of the present invention may be

[13] "the filter unit according to any one of the above [1] to

[12] , in which, when viewed from the first direction, the distance from an inner edge of the first recess to an outer edge of the support in the one direction is greater than the width of the Fabry-Perot interference filter in the one direction." According to the filter unit described in

[13] , even if an external force acts on the support from a side in the first direction, the external force can be prevented from affecting the Fabry-Perot interference filter.

[0020] The filter unit of the present invention may be

[14] "the filter unit according to any one of the above [1] to

[13] , wherein the light passing portion is an opening formed in the support, an outer edge of the Fabry-Perot interference filter has a rectangular shape when viewed from the first direction, a distance from the outer edge of the Fabry-Perot interference filter to the outer edge of the support in a direction perpendicular to one side of the outer edge of the Fabry-Perot interference filter when viewed from the first direction is greater than a diagonal length of the outer edge of the Fabry-Perot interference filter, and a width of the opening is smaller than a width of the Fabry-Perot interference filter in the direction perpendicular to the one side" according to the filter unit described in

[14] . Since the opening is very small compared to the support when viewed from the first direction, it is possible to suppress stray light from entering the Fabry-Perot interference filter.

[0021] The filter unit of the present invention is "

[15] where the width of the Fabry - Perot interference filter in a third direction perpendicular to both the first direction and the second direction is Wf, the width of the wiring board in the third direction is Ws, the width of the first recess in the third direction is W1, and the width of the second recess in the third direction is W2, the relationship of "Wf≤W1<Ws≤W2" or the relationship of "Ws≤W2<Wf≤W1" holds, and the filter unit according to any one of the above [1] to

[14] ". According to the filter unit described in

[15] , since the width W1 of the first recess and the width W2 of the second recess are different from each other, by using the boundary between the first recess and the second recess as a reference (for example, a mechanical positioning part or a reference coordinate), the positioning of the Fabry - Perot interference filter and the wiring board with respect to the support can be easily and accurately performed. Also, compared with the case where the smaller width is combined with the larger width among the width W1 of the first recess and the width W2 of the second recess, the strength of the support can be ensured. Further, when the relationship of "Wf≤W1<Ws≤W2" holds, even if an external force acts on the wiring board from the side with respect to the first direction, the external force can be released from the boundary between the first recess and the second recess to the support, and the influence of the external force on the Fabry - Perot interference filter can be suppressed. On the other hand, when the relationship of "Ws≤W2<Wf≤W1" holds, the incidence of stray light on the Fabry - Perot interference filter through the second recess where the wiring board is arranged can be suppressed.

[0022] The filter unit of the present invention may be "

[16] the filter unit according to

[14] where the relationship of "Wf = W1" holds". According to the filter unit described in

[16] , the positioning of the Fabry - Perot interference filter with respect to the support can be performed more easily and accurately.

[0023] The filter unit of the present invention may be "

[17] the filter unit according to

[14] or

[15] where the relationship of "Ws = W2" holds". According to the filter unit described in

[17] , the positioning of the wiring board with respect to the support can be performed more easily and accurately.

[0024] The filter unit of the present invention may be

[18] "the filter unit according to any one of the above [1] to

[17] , wherein the support has through holes that open to the inner surface of the first recess and the outer surface of the support." According to the filter unit described in

[18] , for example, even if gas is generated in the first recess while the opening of the first recess is covered with some member during manufacture of the filter unit, the gas can be released to the outside through the through holes. Effect of the Invention

[0025] According to the present invention, it is possible to provide a filter unit suitable for arrangement in a narrow area in the optical axis direction of a Fabry-Perot interference filter. [Brief description of the drawings]

[0026] [Figure 1] 1 is a perspective view of a Fabry-Perot interference filter included in a filter unit of an embodiment. FIG. [Diagram 2] 2 is a cross-sectional view of the Fabry-Perot interference filter taken along line II-II shown in FIG. 1. [Diagram 3] FIG. 2 is a plan view of the filter unit according to the embodiment. [Figure 4] 4 is a cross-sectional view of the filter unit taken along line IV-IV shown in FIG. 3. [Diagram 5] FIG. 2 is a plan view of a portion of the filter unit of one embodiment. [Figure 6] FIG. 2 is a plan view of a portion of the filter unit of one embodiment. [Figure 7] FIG. 2 is a bottom view of the filter unit of one embodiment. [Figure 8] 1 is a cross-sectional view of a lens barrel including a filter unit according to an embodiment. [Figure 9] FIG. 13 is a plan view of a portion of a modified filter unit. [Figure 10] 13 is a cross-sectional view of a portion of a lens barrel including a filter unit according to a modified example. [Figure 11] FIG. 11 is a cross-sectional view of a modified Fabry-Perot interference filter. [Figure 12] FIG. 13 is a plan view of a portion of a modified filter unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In each drawing, the same or corresponding parts are denoted by the same reference numerals, and duplicated explanations will be omitted. [Configuration of the Fabry-Perot interference filter in the filter unit]

[0028] As shown in Fig. 1, the Fabry-Perot interference filter 10 has a light-transmitting region 10a. The Fabry-Perot interference filter 10 is a rectangular plate-shaped element with its thickness direction in the Z-axis direction. The light-transmitting region 10a is a cylindrical region having a center line parallel to the Z-axis direction. When viewed from the Z-axis direction, the center of the light-transmitting region 10a coincides with the center of the Fabry-Perot interference filter 10.

[0029] As shown in Fig. 2, the Fabry-Perot interference filter 10 includes a substrate 11 whose thickness direction is in the Z-axis direction. The material of the substrate 11 is, for example, silicon, quartz, glass, or the like. The substrate 11 has a pair of surfaces 11a, 11b. The pair of surfaces 11a, 11b face each other in the Z-axis direction. A first laminate structure 12 is laminated on the surface 11a of the substrate 11. A second laminate structure 13 is laminated on the surface 11b of the substrate 11.

[0030] The first stacked structure 12 includes an anti-reflection layer 121, a first stacked body 122, an intermediate layer 123, and a second stacked body 124. The anti-reflection layer 121, the first stacked body 122, the intermediate layer 123, and the second stacked body 124 are stacked in this order on the surface 11a of the substrate 11. Between the first stacked body 122 and the second stacked body 124, an air gap S is formed by the frame-shaped intermediate layer 123. When the material of the substrate 11 is silicon, the material of each of the anti-reflection layer 121 and the intermediate layer 123 is, for example, silicon oxide or the like. The thickness of the intermediate layer 123 is, for example, an integral multiple of 1 / 2 the design central wavelength. The thickness of the intermediate layer 123 may be larger than an integral multiple of 1 / 2 the design central wavelength as necessary.

[0031] A portion of the first stack 122 corresponding to the light transmitting region 10a functions as the mirror section 14. The mirror section 14 is supported on the substrate 11 via an anti-reflection layer 121. As an example, the first stack 122 is configured by alternately stacking a plurality of polysilicon layers and a plurality of silicon nitride layers. The optical thickness of each layer constituting the mirror section 14 is, for example, an integral multiple of ¼ of the design central wavelength. Note that a silicon oxide layer may be used instead of the silicon nitride layer.

[0032] The portion of the second stack 124 corresponding to the light transmitting region 10a functions as the mirror section 15. The mirror section 15 is supported by the substrate 11 via the anti-reflection layer 121, the first stack 122, and the intermediate layer 123, and faces the mirror section 14 via the gap S. As an example, the second stack 124 is configured by alternately stacking a plurality of polysilicon layers and a plurality of silicon nitride layers. The optical thickness of each layer constituting the mirror section 15 is, for example, an integral multiple of ¼ of the design central wavelength. Note that a silicon oxide layer may be used instead of the silicon nitride layer. Note that a plurality of through holes are formed in the portion of the second stack 124 corresponding to the gap S to an extent that does not substantially affect the function of the mirror section 15. The plurality of through holes are used when forming the gap S by removing a part of the intermediate layer 123 by etching.

[0033] A first electrode 125 and a second electrode 126 are formed on the mirror section 14. The first electrode 125 surrounds the light-transmitting region 10a when viewed from the Z-axis direction. The second electrode 126 overlaps with the light-transmitting region 10a when viewed from the Z-axis direction. The shape of the second electrode 126 when viewed from the Z-axis direction is substantially the same as the shape of the light-transmitting region 10a when viewed from the Z-axis direction. Each of the first electrode 125 and the second electrode 126 is formed by doping an impurity into a portion of a polysilicon layer to reduce the resistance of that portion.

[0034] A third electrode 127 is formed on the mirror section 15. The third electrode 127 faces the first electrode 125 and the second electrode 126 across a gap S. The third electrode 127 is formed by doping a portion of a polysilicon layer with an impurity to reduce the resistance of the portion. As an example, the distance between the second electrode 126 and the third electrode 127 is approximately the same as the distance between the first electrode 125 and the third electrode 127.

[0035] A pair of terminals 16 are provided on the first laminate structure 12 to sandwich the light transmitting region 10a (see FIG. 1). Each terminal 16 is disposed in a through hole formed in the second laminate 124 and the intermediate layer 123 so as to open to the opposite side to the substrate 11 and reach the first laminate 122. Each terminal 16 is electrically connected to the first electrode 125 via a wiring 125a.

[0036] A pair of terminals 17 are provided on the first laminate structure 12 so as to sandwich the light-transmitting region 10a therebetween (see FIG. 1). Each terminal 17 is disposed in a through-hole formed in the second laminate 124 and the intermediate layer 123 so as to open on the opposite side to the substrate 11 and reach the intermediate layer 123. Each terminal 17 is electrically connected to the second electrode 126 via a wiring 126a, and is also electrically connected to the third electrode 127 via a wiring 127a. The direction in which the pair of terminals 17 sandwich the light-transmitting region 10a is perpendicular to the direction in which the pair of terminals 16 sandwich the light-transmitting region 10a therebetween (see FIG. 1).

[0037] A pair of trenches 122a are formed in the first laminate 122. Each trench 122a extends in an annular shape so as to surround a portion of the wiring 126a extending from each terminal 17 in the Z-axis direction. Each trench 122a electrically insulates the first electrode 125 from the wiring 126a. A trench 122b is formed in the first laminate 122. The trench 122b extends in an annular shape along the inner edge of the first electrode 125. The trench 122b electrically insulates the first electrode 125 from the second electrode 126. The area inside each trench 122a, 122b may be filled with an insulating material or may be a void.

[0038] A pair of trenches 124a are formed in the second stack 124. Each trench 124a extends in an annular shape so as to surround each terminal 16. Each trench 124a electrically insulates each terminal 16 from the third electrode 127. The area within each trench 124a may be filled with an insulating material or may be an empty space.

[0039] The second laminated structure 13 includes an anti-reflection layer 131, a third laminate 132, an intermediate layer 133, and a fourth laminate 134. The anti-reflection layer 131, the third laminate 132, the intermediate layer 133, and the fourth laminate 134 are laminated in this order on the surface 11b of the substrate 11. The anti-reflection layer 131 and the intermediate layer 133 have the same configurations as the anti-reflection layer 121 and the intermediate layer 123, respectively. The third laminate 132 and the fourth laminate 134 have laminated structures symmetrical to the first laminate 122 and the second laminate 124, respectively, with respect to the substrate 11. The anti-reflection layer 131, the third laminate 132, the intermediate layer 133, and the fourth laminate 134 have the function of suppressing warping of the substrate 11.

[0040] The third laminate 132, the intermediate layer 133, and the fourth laminate 134 have openings 18 formed therein so as to include the light-transmitting region 10a. The openings 18 overlap the light-transmitting region 10a when viewed from the Z-axis direction. The shape of the openings 18 when viewed from the Z-axis direction is substantially the same as the shape of the light-transmitting region 10a when viewed from the Z-axis direction. In other words, the center line of the openings 18 coincides with the center line of the light-transmitting region 10a. The openings 18 open on the side opposite to the substrate 11, and reach the antireflection layer 131.

[0041] A light-shielding layer 135 is formed on the surface of the fourth stack 134 opposite to the substrate 11. The material of the light-shielding layer 135 is, for example, aluminum. A protective layer 136 is formed on the surface of the light-shielding layer 135 and the inner surface of the opening 18. The material of the protective layer 136 is, for example, aluminum oxide. By setting the thickness of the protective layer 136 to 100 nm or less (preferably, about 30 nm), the optical effect of the protective layer 136 can be ignored.

[0042] In the Fabry-Perot interference filter 10 configured as above, when a voltage is applied to the first electrode 125 and the third electrode 127 via the multiple terminals 16 and 17 to generate a potential difference between the first electrode 125 and the third electrode 127, an electrostatic force corresponding to the potential difference is generated between the first electrode 125 and the third electrode 127. The electrostatic force generated between the first electrode 125 and the third electrode 127 attracts the mirror portion 15 to the mirror portion 14, and the distance between the mirror portion 14 and the mirror portion 15 is adjusted. At this time, the second electrode 126, which has the same potential as the third electrode 127, functions as a compensation electrode, and the mirror portion 15 is kept flat in the light transmission region 10a.

[0043] In this way, in the Fabry-Perot interference filter 10, a pair of mirror sections 14, 15 facing each other in the Z-axis direction function as a pair of mirror sections whose distance from each other is variable. Here, the wavelength of light transmitted through the Fabry-Perot interference filter 10 depends on the distance between the mirror section 14 and the mirror section 15. Therefore, by adjusting the voltages applied to the first electrode 125 and the third electrode 127 (the potential difference generated between the first electrode 125 and the third electrode 127), the wavelength of light transmitted through the Fabry-Perot interference filter 10 can be selected. [Filter unit configuration]

[0044] 3 and 4, the filter unit 1 includes a support 2, a light-transmitting member 3, a wiring board 4, a connector 5, a cover 6, and the above-mentioned Fabry-Perot interference filter 10. In addition, in Fig. 3, the light-transmitting member 3 and adhesive members 73 and 75 described later are indicated by two-dot chain lines.

[0045] The support 2 is a circular plate-shaped member whose thickness direction is the Z-axis direction (first direction). That is, when viewed from the Z-axis direction, the outer edge 2E of the support 2 has a circular shape. The support 2 has a pair of surfaces 2a, 2b and a side surface 2c. The pair of surfaces 2a, 2b face each other in the Z-axis direction. The side surface 2c connects the outer edge of the surface 2a and the outer edge of the surface 2b. The material of the support 2 is, for example, a metal material such as stainless steel, or a resin material. The outer diameter of the support 2 is, for example, 20 mm to 50 mm. The thickness of the support 2 in the Z-axis direction is, for example, 2 mm to 5 mm.

[0046] As shown in FIG. 4 and FIG. 5, the support 2 is formed with a first recess 21 and a second recess 22. The first recess 21 and the second recess 22 are each open to the surface 2a side with the Z-axis direction as the depth direction. The bottom surface (first mounting surface) 21a of the first recess 21 and the bottom surface (second mounting surface) 22a of the second recess 22 are located on the same plane perpendicular to the Z-axis direction. The thickness from the bottom surfaces 21a, 22a to the surface 2b of the support 2 in the Z-axis direction is, for example, about 100 μm. The first recess 21 and the second recess 22 are aligned in the X-axis direction (second direction perpendicular to the first direction). Note that in FIG. 5, the light transmitting member 3 and adhesive members 73, 75 described later are omitted from the illustration.

[0047] The first recess 21 includes the center C of the support 2 when viewed from the Z-axis direction. The first recess 21 does not reach the outer edge 2E of the support 2 when viewed from the Z-axis direction. When viewed from the Z-axis direction, the inner edge 21E of the first recess 21 has a rectangular shape. In this embodiment, when viewed from the Z-axis direction, the inner edge 21E of the first recess 21 has a rectangular shape with the X-axis direction as the longitudinal direction. The width of the first recess 21 in the X-axis direction is, for example, 5 mm to 20 mm. The width of the first recess 21 in the Y-axis direction is, for example, 2.2 mm to 22 mm. The depth of the first recess 21 in the Z-axis direction is, for example, 0.2 mm to 2 mm.

[0048] The second recess 22 does not include the center C of the support 2 when viewed from the Z-axis direction. The second recess 22 reaches the outer edge 2E of the support 2 when viewed from the Z-axis direction. The inner edge 22E of the second recess 22 has a rectangular shape when viewed from the Z-axis direction. In this embodiment, the inner edge 22E of the second recess 22 has a rectangular shape with the X-axis direction as the longitudinal direction when viewed from the Z-axis direction. In this embodiment, the second recess 22 reaches the side surface 2c of the support 2 on the opposite side to the first recess 21 in the X-axis direction. The second recess 22 reaches the outer edge 2E of the support 2 on the short side of the second recess 22 when viewed from the Z-axis direction. Since the second recess 22 does not cross the support 2 when viewed from the Z-axis direction, the rigidity of the support 2 is higher than that of a configuration in which the second recess 22 crosses the support 2. The width of the second recess 22 in the X-axis direction is, for example, 8 mm to 23 mm. The width of the second recess 22 in the Y-axis direction is, for example, 3 mm to 24 mm. The depth of the second recess 22 in the Z-axis direction is, for example, 0.2 mm to 2 mm.

[0049] A width W2 of the second recess 22 in the Y-axis direction (a third direction perpendicular to both the first and second directions) is larger than a width W1 of the first recess 21 in the Y-axis direction. In this embodiment, when viewed from the Z-axis direction, the center line of the first recess 21 parallel to the X-axis direction passes through the center C of the support 2. In this embodiment, when viewed from the Z-axis direction, the center line of the second recess 22 parallel to the X-axis direction coincides with the center line of the first recess 21 parallel to the X-axis direction.

[0050] The support 2 has an opening (light passing portion) 23 and a through hole 24 formed therein. The opening 23 and the through hole 24 open to the bottom surface (inner surface) 21a of the first recess 21 and the surface (outer surface) 2b of the support 2, respectively. That is, the first recess 21 opens to the opposite side to the opening 23 with the Z-axis direction being the depth direction. The opening 23 and the through hole 24 are aligned in the X-axis direction. The opening 23 defines a cylindrical space having a center line parallel to the Z-axis direction. When viewed from the Z-axis direction, the center of the opening 23 coincides with the center C of the support 2. The inner diameter of the opening 23 is, for example, 2 mm to 15 mm.

[0051] The first recess 21 has a pair of side surfaces (first surfaces) 21b, 21c facing each other in the Y-axis direction. Each of the side surfaces 21b, 21c is perpendicular to the Y-axis direction. The second recess 22 has a pair of side surfaces (second surfaces) 22b, 22c facing each other in the Y-axis direction. Each of the side surfaces 22b, 22c is perpendicular to the Y-axis direction.

[0052] The support 2 is formed with a widened portion 25. The widened portion 25 is widened on the side opposite the second recess 22 in the X-axis direction and on both sides in the Y-axis direction with respect to the opening of the first recess 21. The widened portion 25 is a recess formed in the support 2 so as to open on the front surface 2a side and reach the opening of the first recess 21 with the Z-axis direction as the depth direction. In this embodiment, the width of the widened portion 25 in the Y-axis direction is equal to the width W2 of the second recess 22 in the Y-axis direction.

[0053] The support 2 includes a partition 26. The partition 26 is disposed between the first recess 21 and the second recess 22. The partition 26 is formed integrally with other parts of the support 2 as a part of the support 2. In this embodiment, the partition 26 is a wall extending in the Y-axis direction between the bottom surface 21a of the first recess 21 and the bottom surface 22a of the second recess 22. In this embodiment, the partition 26 is formed continuously from the side surface 22b to the side surface 22c. When viewed from the Z-axis direction, one end of the partition 26 is connected to the end of the side surface 22b closer to the first recess 21, and the other end of the partition 26 is connected to the end of the side surface 22c closer to the first recess 21. In this embodiment, with respect to the plane on which the bottom surfaces 21a and 22a are located, the height of the partition portion 26 in the Z-axis direction is lower than the height of the surface 2a of the support body 2 in the Z-axis direction and lower than the height of the bottom surface 25a of the widened portion 25 in the Z-axis direction. The width of the partition portion 26 in the X-axis direction is, for example, 0.5 mm to 5 mm. The height of the partition portion 26 in the Z-axis direction is, for example, 0.1 mm to 2 mm.

[0054] The Fabry-Perot interference filter 10 is disposed on the support 2 with the Z-axis direction as the thickness direction so as to overlap the opening 23 when viewed from the Z-axis direction. More specifically, the Fabry-Perot interference filter 10 is disposed in the first recess 21 with the Z-axis direction as the thickness direction so as to overlap the opening 23 when viewed from the Z-axis direction. In this embodiment, the Fabry-Perot interference filter 10 is disposed so as to be sandwiched between a pair of side surfaces 21b, 21c in the Y-axis direction. The Fabry-Perot interference filter 10 contacts the partition 26 and the pair of side surfaces 21b, 21c in the first recess 21. The side surfaces of the Fabry-Perot interference filter 10 are covered by the partition 26 and the pair of side surfaces 21b, 21c. In this embodiment, when the bottom surface 21a of the first recess 21 is used as a reference, the height of the Fabry-Perot interference filter 10 in the Z-axis direction is lower than the height of the surface 2a of the support 2 in the Z-axis direction and lower than the height of the bottom surface 25a of the widening portion 25 in the Z-axis direction. In this embodiment, with respect to the bottom surface 21a of the first recess 21, the height of the partition 26 in the Z-axis direction is equal to or less than the height of the Fabry-Perot interference filter 10 in the Z-axis direction. The width of the Fabry-Perot interference filter 10 in the X-axis direction is, for example, 2 mm to 20 mm. The width of the Fabry-Perot interference filter 10 in the Y-axis direction is, for example, 2 mm to 20 mm. The thickness of the Fabry-Perot interference filter 10 in the Z-axis direction is, for example, 300 μm to 650 μm.

[0055] As described above, the Fabry-Perot interference filter 10 is a rectangular plate-shaped element with the thickness direction being the Z-axis direction. Therefore, when viewed from the Z-axis direction, the outer edge 10E of the Fabry-Perot interference filter 10 has a rectangular shape. The Fabry-Perot interference filter 10 is disposed on the bottom surface 21a of the first recess 21 so that, when viewed from the Z-axis direction, each side of the outer edge 10E is parallel to the X-axis direction or the Y-axis direction and the opening 18 faces the opening 23. The center line of the opening 18 coincides with the center line of the opening 23. In other words, when viewed from the Z-axis direction, the Fabry-Perot interference filter 10 is located at the center C of the support 2. When viewed from the Z-axis direction, the opening 18 is located inside the opening 23.

[0056] The Fabry-Perot interference filter 10 is fixed to the bottom surface 21a by an adhesive member 71. The adhesive member 71 is arranged in a dot pattern between the bottom surface 21a and one corner of the Fabry-Perot interference filter 10. This makes it possible to prevent stress caused by deformation of the support 2 and / or the adhesive member 71 due to temperature change from being applied to the Fabry-Perot interference filter 10. The material of the adhesive member 71 is, for example, a polyimide resin, a silicone resin, an epoxy resin, an acrylic resin, or a hybrid resin thereof.

[0057] 4 and 6, the light transmitting member 3 is disposed on the support 2 with the Z-axis direction as the thickness direction so as to cover the opening of the first recess 21. More specifically, the light transmitting member 3 is disposed in the widened portion 25 with the Z-axis direction as the thickness direction so as to cover the opening of the first recess 21. In this embodiment, the light transmitting member 3 covers the opening of the first recess 21 as well as a part of the opening of the second recess 22. In this embodiment, when the bottom surface 25a of the widened portion 25 is used as a reference, the height of the light transmitting member 3 in the Z-axis direction is lower than the height of the surface 2a of the support 2 in the Z-axis direction.

[0058] The light transmitting member 3 is a rectangular plate-like member with the thickness direction being the Z-axis direction and the longitudinal direction being the X-axis direction. Therefore, when viewed from the Z-axis direction, the outer edge 3E of the light transmitting member 3 has a rectangular shape with the longitudinal direction being the X-axis direction. The light transmitting member 3 is disposed on the bottom surface 25a of the widening portion 25 so that each side of the outer edge 3E is parallel to the X-axis direction or the Y-axis direction when viewed from the Z-axis direction. As an example, the light transmitting member 3 is a bandpass filter that transmits light in a predetermined wavelength range.

[0059] The light transmitting member 3 is fixed to the bottom surface 25a and the side surface 25b of the widening portion 25 by adhesive members 72 and 73. The adhesive members 72 are arranged in a dot pattern between the bottom surface 25a and one corner of the light transmitting member 3. The adhesive members 73 are arranged along a corner formed by the side surface 25b and the surface 3a of the light transmitting member 3. The surface 3a is the surface of the light transmitting member 3 on the opposite side to the first recess 21. A part of the adhesive member 73 also penetrates between the side surface 25b of the widening portion 25 and the side surface of the light transmitting member 3. The material of the adhesive members 72 and 73 is, for example, a polyimide resin, a silicone resin, an epoxy resin, an acrylic resin, or a hybrid resin thereof.

[0060] As shown in FIG. 4 and FIG. 5, the wiring board 4 is disposed on the support 2 with the Z-axis direction as the thickness direction so as not to overlap with the Fabry-Perot interference filter 10 when viewed from the Z-axis direction. More specifically, the wiring board 4 is disposed in the second recess 22 with the Z-axis direction as the thickness direction so as not to overlap with the Fabry-Perot interference filter 10 when viewed from the Z-axis direction. In this embodiment, the wiring board 4 is disposed so as to be sandwiched between a pair of side surfaces 22b, 22c in the Y-axis direction. The wiring board 4 is in contact with the partition portion 26 in the second recess 22. In this embodiment, when the bottom surface 22a of the second recess 22 is taken as a reference, the height of the wiring board 4 in the Z-axis direction is lower than the height of the surface 2a of the support 2 in the Z-axis direction and lower than the height of the bottom surface 25a of the widening portion 25 in the Z-axis direction. In this embodiment, when the bottom surface 22a of the second recess 22 is taken as a reference, the height of the partition portion 26 in the Z-axis direction is equal to or lower than the height of the wiring board 4 in the Z-axis direction.

[0061] The wiring board 4 is a rectangular plate-like board with the thickness direction being the Z-axis direction and the longitudinal direction being the X-axis direction. Therefore, when viewed from the Z-axis direction, the outer edge 4E of the wiring board 4 has a rectangular shape with the longitudinal direction being the X-axis direction. The wiring board 4 is disposed on the bottom surface 22a of the second recess 22 so that each side of the outer edge 4E is parallel to the X-axis direction or the Y-axis direction when viewed from the Z-axis direction.

[0062] The wiring board 4 is fixed to the bottom surface 22a of the second recess 22 by an adhesive member 74. The adhesive member 74 includes a pair of first portions 74a and a second portion 74b. The pair of first portions 74a face each other between the bottom surface 22a and the wiring board 4, and each extends in the X-axis direction. A part of each first portion 74a also enters between the side surface of the second recess 22 and the side surface of the wiring board 4. The second portion 74b faces the partition portion 26 between the bottom surface 22a and the wiring board 4, and extends in the Y-axis direction. The material of the adhesive member 74 is, for example, a polyimide resin, a silicone resin, an epoxy resin, an acrylic resin, or a hybrid resin thereof.

[0063] The wiring board 4 is electrically connected to the Fabry-Perot interference filter 10. More specifically, the terminal 41 of the wiring board 4 is electrically connected to the terminal 16 of the pair of terminals 16 of the Fabry-Perot interference filter 10 that is closer to the partitioning portion 26 by a wire 8, and the terminal 42 of the wiring board 4 is electrically connected to the terminal 17 of the pair of terminals 17 of the Fabry-Perot interference filter 10 that is closer to the partitioning portion 26 by a wire 8. The pair of terminals 41, 42 are disposed in an area along the partitioning portion 26 on the surface 4a of the wiring board 4 on the light transmitting member 3 side. Each wire 8 passes through the gap between the partitioning portion 26 and the light transmitting member 3. When viewed from the X-axis direction, each wire 8 is contained within the first recess 21 and the second recess 22. The width of the partitioning portion 26 in the X-axis direction is smaller than the width of the Fabry-Perot interference filter 10 in the X-axis direction. This allows the distance between the Fabry-Perot interference filter 10 and the wiring board 4 to be shortened.

[0064] The connector 5 is mounted on the surface 4a of the wiring board 4 and is electrically connected to the wiring board 4. A part 5a of the connector 5 is located outside the side surface 2c of the support 2 through a region of the second recess 22 that reaches the side surface 2c of the support 2. A connection port 51 that opens on the opposite side to the center C of the support 2 is provided in the part 5a of the connector 5. The connector 5 is accommodated within the second recess 22 in the Z-axis direction. In the filter unit 1, a voltage is applied to a pair of terminals 16, 17 from an external wiring connected to the connector 5 via the wiring board 4 and a pair of wires 8.

[0065] As shown in FIG. 4 and FIG. 6, an adhesive member 75 is disposed between the wiring board 4 and the light transmitting member 3. The adhesive member 75 extends along a portion of the outer edge 3E of the light transmitting member 3 that overlaps with the wiring board 4 when viewed from the Z-axis direction. The adhesive member 75 seals the gap between the wiring board 4 and the light transmitting member 3 on the outer side (opposite side to the center C of the support 2) of the pair of terminals 41, 42. The material of the adhesive member 75 is, for example, a polyimide resin, a silicone resin, an epoxy resin, an acrylic resin, or a hybrid resin thereof. In this embodiment, the adhesive members 74 and 75 constitute "adhesive members 7 disposed between the wiring board 4 and the support 2 and between the wiring board 4 and the light transmitting member 3."

[0066] As shown in FIG. 4 and FIG. 7, the cover 6 is disposed on the surface 2b of the support 2 so as to cover the opening 23 and the through hole 24. The cover 6 is a plate-like member having optical transparency, and is disposed on the surface 2b of the support 2 with the Z-axis direction as the thickness direction. As an example, the cover 6 has a circular plate shape, and when viewed from the Z-axis direction, the outer edge 6E of the cover 6 is located inside the outer edge 2E of the support 2. The cover 6 is fixed to the surface 2b by an adhesive member 76 disposed along the outer edge 6E of the cover 6. The material of the adhesive member 76 is, for example, a polyimide resin, a silicone resin, an epoxy resin, an acrylic resin, or a hybrid resin thereof. A light-shielding film 61 is provided on the surface 6a of the cover 6 opposite the support 2. The light-shielding film 61 overlaps with the through hole 24 when viewed from the Z-axis direction. The light-shielding film 61 has a size sufficient to prevent light from entering the through hole 24 through the cover 6. The light-shielding film 61 is, for example, a chrome-plated film.

[0067] As shown in FIG. 4, in the filter unit 1, the support 2 and the light transmitting member 3 constitute a housing 200 including a first wall 210, a second wall 220, and an enclosure 230. More specifically, a part of the support 2 constitutes the first wall 210, and a part of the light transmitting member 3 constitutes the second wall 220. Another part of the support 2 and another part of the light transmitting member 3 constitute the enclosure 230. The first wall 210 is a wall having an opening 23, and specifically, a part of the support 2 that overlaps with the area in the first recess 21 when viewed from the Z-axis direction (i.e., the bottom wall of the first recess 21). The second wall 220 is a wall facing the first wall 210 in the Z-axis direction, and specifically, a part of the light transmitting member 3 that overlaps with the area in the first recess 21 when viewed from the Z-axis direction. The surrounding portion 230 is a portion that surrounds the area between the first wall portion 210 and the second wall portion 220, and specifically, is a portion of the support body 2 and the light-transmitting member 3 that surrounds the area within the first recess 21 when viewed from the Z-axis direction.

[0068] Therefore, in the filter unit 1, the following can be said. The first recess 21 is defined by the first wall portion 210 and the surrounding portion 230. The region within the first recess 21 corresponds to the region within the housing 200. The second recess 22 is formed in the surrounding portion 230 so as to open toward the second wall portion 220 with the Z-axis direction as the depth direction. When viewed from the Z-axis direction, the outer edge 200E of the housing 200 coincides with the outer edge 2E of the support 2 (see FIG. 3). The wiring board 4 is attached to the housing 200 so as not to overlap with the Fabry-Perot interference filter 10 when viewed from the Z-axis direction. The wiring board 4 is attached to the housing 200 so that the entire wiring board 4 is embedded in the surrounding portion 230. Note that "the entire wiring board 4 is embedded in the surrounding portion 230" means that the entire wiring board 4 overlaps with the surrounding portion 230 when viewed from any of the X-axis direction, Y-axis direction, and Z-axis direction. At least a part of the wiring board 4 is exposed outside the housing 200. In the present embodiment, at least a part of the wiring board 4 is exposed outside the housing 200 through a region of the opening of the second recess 22 that is not covered by the light transmissive member 3 and a region of the second recess 22 that reaches the side surface 2c of the support 2.

[0069] As shown in FIG. 5, the width Wf of the Fabry-Perot interference filter in the Y-axis direction is equal to or less than the width W1 of the first recess in the Y-axis direction. The width Ws of the wiring board in the Y-axis direction is larger than the width W1 of the first recess in the Y-axis direction and equal to or less than the width W2 of the second recess in the Y-axis direction. Therefore, in the filter unit 1, the relationship of "Wf ≦ W1 < Ws ≦ W2" holds. In the present embodiment, the relationships of "Wf = W1" and "Ws = W2" hold. In the filter unit 1, it is preferable that the relationship of "W1 < 2Wf" holds. Also, in the filter unit 1, it is preferable that the relationship of "W2 < 2Ws" holds.

[0070] Note that "Wf=W1" means that Wf and W1 are substantially equal, and "Ws=W2" means that Ws and W2 are substantially equal. As an example, "Wf=W1" means that W1 is a value equal to or greater than "Wf" and equal to or less than "1.1Wf", and "Ws=W2" means that W2 is a value equal to or greater than "Ws" and equal to or less than "1.1Ws".

[0071] As shown in FIG. 3, when viewed from the Z-axis direction, the "distance D1 from the inner edge 21E of the first recess 21 to the outer edge 2E of the support 2" in the Y-axis direction (one direction) is larger than the width Wf of the Fabry-Perot interference filter 10 in the Y-axis direction. The thickness of the "portion from the inner edge 21E of the first recess 21 to the outer edge 2E of the support 2" in the Y-axis direction is larger than the thickness of the Fabry-Perot interference filter 10. When viewed from the Z-axis direction, the "distance D2 from the outer edge 10E of the Fabry-Perot interference filter 10 to the outer edge 2E of the support 2" in the Y-axis direction (direction perpendicular to one side of the outer edge 10E of the Fabry-Perot interference filter 10) is larger than the diagonal length L of the outer edge 10E of the Fabry-Perot interference filter 10. The "distance D2 from the outer edge 10E of the Fabry-Perot interference filter 10 to the outer edge 2E of the support 2" in the Y-axis direction may be about 2 to 3 times the diagonal length L of the outer edge 10E of the Fabry-Perot interference filter 10. When viewed from the Z-axis direction, the width W3 of the opening 23 is smaller than the width Wf of the Fabry-Perot interference filter 10 in the Y-axis direction. The "distance D2 from the outer edge 10E of the Fabry-Perot interference filter 10 to the outer edge 2E of the support 2" is about 2 to 3 times the length L of the diagonal line of the outer edge 10E of the Fabry-Perot interference filter 10, and the wide "distance D2 from the outer edge 10E of the Fabry-Perot interference filter 10 to the outer edge 2E of the support 2" surrounds the opening 23. The support 2, which is integrally formed without combining multiple parts, includes a thick portion surrounding the first recess 21 and the second recess 22. The thick portion is a portion of the support 2 whose thickness in the Z-axis direction is greater than the depth of the first recess 21 in the Z-axis direction. The area of ​​the thick portion when viewed from the Z-axis direction is 50% or more of the area of ​​the support 2 when viewed from the Z-axis direction.

[0072] Note that "distance D1 from the inner edge 21E of the first recess 21 to the outer edge 2E of the support 2" in the predetermined direction corresponds to "distance from the inner edge of the surrounding portion 230 to the outer edge of the surrounding portion 230" in the predetermined direction. Also, "distance D2 from the outer edge 10E of the Fabry-Perot interference filter 10 to the outer edge 2E of the support 2" in the predetermined direction corresponds to "distance from the outer edge 10E of the Fabry-Perot interference filter 10 to the outer edge of the surrounding portion 230" in the predetermined direction. [Filter unit manufacturing method]

[0073] A manufacturing method of the above-mentioned filter unit 1 will be described with reference to FIG. 4. First, the support 2 is prepared, and the adhesive member 71 before hardening is disposed on the bottom surface 21a of the first recess 21, and the adhesive member 74 before hardening is disposed on the bottom surface 22a of the second recess 22. Next, the Fabry-Perot interference filter 10 is disposed on the bottom surface 21a of the first recess 21, and the wiring board 4 is disposed on the bottom surface 22a of the second recess 22. The connector 5 is mounted in advance on the front surface 4a of the wiring board 4. Next, the adhesive members 71 and 74 are hardened. At this time, the Fabry-Perot interference filter 10 is fitted into the first recess 21 while being brought into contact with the partitioning portion 26, and therefore is accurately positioned with respect to the opening 23. Moreover, the wiring board 4 is fitted into the second recess 22 while being brought into contact with the partitioning portion 26, and therefore is accurately positioned with respect to the Fabry-Perot interference filter 10. Next, the terminal 41 of the wiring board 4 is electrically connected to the terminal 16 of the Fabry-Perot interference filter 10 by the wire 8, and the terminal 42 of the wiring board 4 is electrically connected to the terminal 17 of the Fabry-Perot interference filter 10 by the wire 8. It is important that the wiring board 4 is accurately positioned with respect to the Fabry-Perot interference filter 10 in order to reliably perform wire bonding between the Fabry-Perot interference filter 10 and the wiring board 4. The terminal 16 of the pair of terminals 16 to which the wire 8 is connected is located closer to the partition 26 (wiring board 4) than the center of the Fabry-Perot interference filter 10. Similarly, the terminal 17 of the pair of terminals 17 to which the wire 8 is connected is located closer to the partition 26 (wiring board 4) than the center of the Fabry-Perot interference filter 10. This allows the length of each wire 8 to be shortened.

[0074] Next, the adhesive member 72 before curing is placed on the bottom surface 25a of the widening portion 25. Next, the light transmitting member 3 is placed on the bottom surface 25a of the widening portion 25. Next, the adhesive member 72 is cured. Next, the adhesive member 73 before curing is placed along the corner formed by the side surface 25b of the widening portion 25 and the surface 3a of the light transmitting member 3, and the adhesive member 75 before curing is placed between the wiring board 4 and the light transmitting member 3. Next, the adhesive members 73 and 75 are cured. At this time, gas generated from the adhesive members 73 and 75 is released from inside the first recess 21 to the outside through the through hole 24. Next, the cover 6 is placed on the surface 2b of the support 2. Next, the adhesive member 76 before curing is placed along the outer edge 6E of the cover 6. Next, the adhesive member 76 is cured. The light shielding film 61 is provided in advance on the surface 6a of the cover 6. In this manner, the filter unit 1 is obtained. [Structure of the telescope barrel equipped with the filter unit]

[0075] 8, the lens barrel 300 includes a cylindrical body 310, a light collecting optical system 320 including a plurality of lenses, an imaging optical system 330 including a plurality of lenses, and the above-mentioned filter unit 1. The lens barrel 300 is used as an interchangeable lens for a hyperspectral camera. A hyperspectral camera is a camera that can disperse light into tens to hundreds of bands and acquire images for each band.

[0076] The cylinder 310 includes a main body 311 and a base end 312. The main body 311 holds a focusing optical system 320, an imaging optical system 330, and a filter unit 1. The base end 312 is configured to be detachable from the camera body of the hyperspectral camera.

[0077] The focusing optical system 320 is disposed in an area opposite the base end 312 within the inner area of ​​the main body 311. The imaging optical system 330 is disposed in an area on the base end 312 side within the inner area of ​​the main body 311. The filter unit 1 is disposed in an area between the focusing optical system 320 and the imaging optical system 330 within the inner area of ​​the main body 311. The optical axis of the focusing optical system 320, the optical axis of the imaging optical system 330, and the optical axis of the filter unit 1 (i.e., the center lines of the openings 18 and 23) coincide with the center line of the cylindrical body 310.

[0078] The light collecting optical system 320 and the imaging optical system 330 constitute a non-telecentric optical system. The light collecting optical system 320 is an optical system that collects on-axis incident light and off-axis incident light. The filter unit 1 is disposed at a position where the on-axis incident light and the off-axis incident light intersect in the light collecting optical system 320. The filter unit 1 functions as an aperture at that position. The imaging optical system 330 forms an image of the light that has passed through the filter unit 1 on the image sensor of the hyperspectral camera. The light collecting optical system 320 and the imaging optical system 330 may constitute a telecentric optical system.

[0079] The filter unit 1 is fixed to the inside of the main body 311 by being sandwiched between a flange surface 311a provided on the main body 311 and a fixing ring 313. The flange surface 311a is an inward flange surface provided on the main body 311 so as to face the focusing optical system 320. The filter unit 1 is fixed to the inside of the main body 311 with the opening 23 positioned on the focusing optical system 320 side with respect to the Fabry-Perot interference filter 10. As an example, the opening 23 of the filter unit 1 is positioned at a position where on-axis incident light and off-axis incident light of the focusing optical system 320 intersect.

[0080] The connector 5 is disposed in an opening 311b formed in the main body 311. The connection port 51 of the connector 5 is exposed to the outside of the cylindrical body 310 through the opening 311b. An adhesive member 77 is disposed between the side surface of the connector 5 and the inner surface of the opening 311b. This seals the gap between the side surface of the connector 5 and the inner surface of the opening 311b. [Action and Effects]

[0081] In the filter unit 1, the Fabry-Perot interference filter 10 is disposed in the first recess 21, and the wiring board 4 is disposed in the second recess 22 so as not to overlap the Fabry-Perot interference filter 10 on the support 2 when viewed from the Z-axis direction. This allows the filter unit 1 to be thin in the Z-axis direction, which is the optical axis direction of the Fabry-Perot interference filter 10 (i.e., the direction in which the pair of mirror parts 14, 15 face each other). In addition, in the filter unit 1 in which the Fabry-Perot interference filter 10 is disposed so as not to overlap the wiring board 4, the degree of freedom in disposing the Fabry-Perot interference filter 10 and the wiring board 4 is improved compared to the conventional configuration in which the Fabry-Perot interference filter is disposed on the wiring board, but the positioning of these may become more difficult. However, in the filter unit 1, the support 2 includes a partition part 26 disposed between the first recess 21 and the second recess 22. As a result, by using the partition 26 as a reference (for example, a mechanical positioning portion or a reference coordinate), the Fabry-Perot interference filter 10 and the wiring board 4 can be positioned easily and accurately with respect to the support body 2. Therefore, the filter unit 1 is suitable for arrangement in a narrow area in the optical axis direction of the Fabry-Perot interference filter 10.

[0082] In the filter unit 1, the side of the Fabry-Perot interference filter 10 is covered by the partition 26 and the pair of side surfaces 21b, 21c. As a result, stray light leaking from the side of the Fabry-Perot interference filter 10 is absorbed by the partition 26 and the pair of side surfaces 21b, 21c, and the stray light can be prevented from spreading from the first recess 21 to the second recess 22. In addition, in the filter unit 1, the partition 26 prevents the Fabry-Perot interference filter 10 from contacting the wiring board 4. Therefore, for example, even if the surface of the wiring board 4 on the Fabry-Perot interference filter 10 side is uneven or the wiring board 4 is tilted, the Fabry-Perot interference filter 10 can be positioned easily and accurately. In addition, in the filter unit 1, the partition 26 is provided, so that the mechanical strength of the support 2 is improved, and for example, deformation of the shape of the opening 23 can be prevented.

[0083] In the filter unit 1, the first recess 21 has a pair of side surfaces 21b, 21c facing each other in the Y-axis direction with the Fabry-Perot interference filter 10 in between, the second recess 22 has a pair of side surfaces 22b, 22c facing each other in the Y-axis direction with the wiring board 4 in between, and the partition 26 is connected to at least one of the pair of side surfaces 22b, 22c. This increases the mechanical strength of the support 2, and can suppress deformation of the shape of the opening 23, for example.

[0084] In filter unit 1, partition 26 is continuously formed from side surface 22b to side surface 22c. This further increases the mechanical strength of support 2, and can further suppress deformation of the shape of opening 23, for example.

[0085] In the filter unit 1, the height of the partition 26 in the Z-axis direction is equal to or less than the height of the Fabry-Perot interference filter 10 in the Z-axis direction. This makes it possible to easily connect the wire to the Fabry-Perot interference filter 10, for example, when connecting the Fabry-Perot interference filter 10 and the wiring board 4 with a wire.

[0086] In the filter unit 1, the height of the partition 26 in the Z-axis direction is equal to or less than the height of the wiring board 4 in the Z-axis direction. This makes it possible to easily connect the wire to the wiring board 4, for example, when connecting the Fabry-Perot interference filter 10 and the wiring board 4 with a wire.

[0087] In the filter unit 1, when viewed from the Z-axis direction, the Fabry-Perot interference filter 10 is located at the center of the support 2. This makes it possible to prevent an external force from acting on the support 2 from the side in the Z-axis direction from affecting the Fabry-Perot interference filter 10. In addition, for example, by fitting the support 2 inside a cylindrical body 310 such as a lens barrel 300, the Fabry-Perot interference filter 10 can be disposed on the center line of the cylindrical body 310.

[0088] In the filter unit 1, the outer edge 2E of the support 2 has a circular shape when viewed from the Z-axis direction. This makes it possible to prevent an external force from acting on the support 2 from the side in the Z-axis direction in a well-balanced manner from affecting the Fabry-Perot interference filter 10. In addition, for example, when the cylinder 310 is cylindrical, the Fabry-Perot interference filter 10 can be easily and accurately positioned on the center line of the cylindrical body 310.

[0089] In filter unit 1, support body 2 is a circular plate-shaped member, so that when filter unit 1 is installed inside cylindrical body 310, filter unit 1 can be prevented from rolling down inside cylindrical body 310.

[0090] In the filter unit 1, when viewed from the Z-axis direction, the outer edge 10E of the Fabry-Perot interference filter 10 and the inner edge 21E of the first recess 21 each have a rectangular shape. This makes it possible to easily and accurately position the Fabry-Perot interference filter 10 with respect to the support 2.

[0091] In the filter unit 1, the Fabry-Perot interference filter 10 is disposed on the bottom surface 21a, the wiring board 4 is disposed on the bottom surface 22a, and the bottom surfaces 21a and 22a are located on the same plane. This allows the filter unit 1 to be made thinner in the Z-axis direction which is the optical axis direction of the Fabry-Perot interference filter 10.

[0092] In filter unit 1, second recess 22 reaches outer edge 2E of support 2 when viewed from the Z-axis direction. This allows electrical connection to be made laterally in the Z-axis direction with a simple configuration.

[0093] The filter unit 1 includes a light-transmitting member 3 and an adhesive member 7 (adhesive members 74, 75). In the filter unit 1, the light-transmitting member 3 covers the opening of the first recess 21, and the adhesive member 7 is disposed between the wiring board 4 and the support 2, and between the wiring board 4 and the light-transmitting member 3. This makes it possible to form a package that houses the Fabry-Perot interference filter 10 by the support 2, the wiring board 4, the light-transmitting member 3, and the adhesive member 7, while suppressing an increase in the thickness of the Fabry-Perot interference filter 10 in the Z-axis direction, which is the optical axis direction. This makes it possible to protect the Fabry-Perot interference filter 10 from moisture, particles, and the like.

[0094] In the filter unit 1, when viewed from the Z-axis direction, "the distance D1 from the inner edge 21E of the first recess 21 to the outer edge 2E of the support 2" in the Y-axis direction is larger than the width Wf of the Fabry-Perot interference filter 10 in the Y-axis direction. This makes it possible to prevent an external force from acting on the support 2 from the side in the Z-axis direction.

[0095] In the filter unit 1, the "distance from the outer edge 10E of the Fabry - Perot interference filter 10 to the outer edge 2E of the support 2 in the Y - axis direction" is larger than the length L of the diagonal line of the outer edge 10E of the Fabry - Perot interference filter 10. When viewed from the Z - axis direction, the width W3 of the opening 23 is smaller than the width Wf of the Fabry - Perot interference filter 10 in the Y - axis direction. As a result, when viewed from the Z - axis direction, the opening 23 becomes very small compared to the support 2, so that it is possible to suppress the incidence of stray light on the Fabry - Perot interference filter 10.

[0096] In the filter unit 1, in the above - mentioned lens barrel 300, it functions as a diaphragm between the condenser optical system 320 and the imaging optical system 330. Thereby, it is possible to increase the depth of field of the hyper - spectral camera to which the lens barrel 300 is attached.

[0097] In the filter unit 1, regarding the width Wf of the Fabry - Perot interference filter 10 in the Y - axis direction, the width Ws of the wiring board 4 in the Y - axis direction, the width W1 of the first recess 21 in the Y - axis direction, and the width W2 of the second recess 22 in the Y - axis direction, the relationship of "Wf≦W1<Ws≦W2" holds. As a result, since the width W1 of the first recess 21 and the width W2 of the second recess 22 are different from each other, by using the boundary between the first recess 21 and the second recess 22 as a reference (for example, a mechanical positioning part or a reference coordinate), it is possible to easily and accurately position the Fabry - Perot interference filter 10 and the wiring board 4 with respect to the support 2. Also, compared to the case where the width W1 of the first recess 21 is added to the width W2 of the second recess 22, the strength of the support 2 can be ensured. Further, even if an external force acts on the wiring board 4 from the side with respect to the Z - axis direction, the external force can be released from the boundary between the first recess 21 and the second recess 22 to the support 2, and it is possible to suppress the external force from reaching the Fabry - Perot interference filter 10. Also, in the filter unit 1, the portions on both sides of the first recess 21 in the Y - axis direction of the support 2 approach the wiring board 4 compared to the case where the width W1 of the first recess 21 is added to the width W2 of the second recess 22, so that the heat generated in the wiring board 4 can be efficiently released to the support 2.

[0098] In the filter unit 1, for the width Wf of the Fabry - Perot interference filter 10 in the Y - axis direction and the width W1 of the first recess 21 in the Y - axis direction, the relationship of "Wf = W1" holds. Thereby, the positioning of the Fabry - Perot interference filter 10 with respect to the support 2 can be carried out more easily and with higher accuracy.

[0099] In the filter unit 1, for the width Ws of the wiring board 4 in the Y - axis direction and the width W2 of the second recess 22 in the Y - axis direction, the relationship of "Ws = W2" holds. Thereby, the positioning of the wiring board 4 with respect to the support 2 can be carried out more easily and with higher accuracy.

[0100] In the filter unit 1, on the support 2, a bottom surface 21a of the first recess 21 and a through - hole 24 that opens to the surface 2b of the support 2 are formed. Thereby, when gas is generated in the first recess 21 in a state where the opening of the first recess 21 is covered by the light - transmitting member 3 during the manufacture of the filter unit 1, the gas can escape to the outside through the through - hole 24. [Modification Example]

[0101] The present invention is not limited to the above - described embodiment. For example, for the width Wf of the Fabry - Perot interference filter 10 in the Y - axis direction, the width Ws of the wiring board 4 in the Y - axis direction, the width W1 of the first recess 21 in the Y - axis direction, and the width W2 of the second recess 22 in the Y - axis direction, when the relationship of "Wf ≤ W1 < Ws ≤ W2" holds (the case shown in FIG. 5), the relationship of "Wf < W1" may hold. Similarly, when the relationship of "Wf ≤ W1 < Ws ≤ W2" holds (the case shown in FIG. 5), the relationship of "Ws < W2" may hold.

[0102] Further, as shown in FIG. 9, with respect to the width Wf of the Fabry-Perot interference filter 10 in the Y-axis direction, the width Ws of the wiring board 4 in the Y-axis direction, the width W1 of the first recess 21 in the Y-axis direction, and the width W2 of the second recess 22 in the Y-axis direction, the relationship of "Ws ≦ W2 < Wf ≦ W1" may be satisfied. Also in this case, the positioning of the Fabry-Perot interference filter 10 and the wiring board 4 with respect to the support 2 can be easily and accurately performed. Further, compared with the case where the width W2 of the second recess 22 is combined with the width W1 of the first recess 21, the strength of the support 2 can be ensured. Further, it is possible to suppress the incidence of stray light on the Fabry-Perot interference filter 10 through the second recess 22 in which the wiring board 4 is disposed. Furthermore, since the portions on both sides of the second recess 22 in the Y-axis direction of the support 2 approach the wiring board 4 compared with the case where the width W2 of the second recess 22 is combined with the width W1 of the first recess 21, the heat generated in the wiring board 4 can be efficiently dissipated to the support 2.

[0103] Further, the widened portion 25 may be widened at least in the Y-axis direction with respect to at least the opening of the first recess 21. As an example, as shown in FIG. 9, the widened portion 25 extends from the opening of the first recess 21 to the opening of the second recess 22 and may be widened at least in the Y-axis direction with respect to the opening of the first recess 21 and the opening of the second recess 22. This is the same not only when the relationship of "Ws ≦ W2 < Wf ≦ W1" is satisfied (the case shown in FIG. 9) but also when the relationship of "Wf ≦ W1 < Ws ≦ W2" is satisfied (the case shown in FIG. 5). When the widened portion 25 extends from the opening of the first recess 21 to the opening of the second recess 22, the thickness increase in the Z-axis direction, which is the optical axis direction of the Fabry-Perot interference filter 10, can be suppressed, and the light transmission member 3 can be more stably supported on the support 2.

[0104] As shown in (a) and (b) of FIG. 10, the filter unit 1 may include a flexible wiring board 9 for connecting to an external wiring. In the example of the lens barrel shown in (a) of FIG. 10, one end of the flexible wiring board 9 is connected to the wiring board 4, and the connector 5 connected to the other end of the flexible wiring board 9 is disposed in the opening 311b of the cylinder 310. In this case, an adhesive member 77 is disposed between the side surface of the connector 5 and the inner surface of the opening 311b. In the example of the lens barrel shown in (b) of FIG. 10, one end of the flexible wiring board 9 is connected to the wiring board 4, and the other end of the flexible wiring board 9 is drawn out to the outside through the opening 311b of the cylinder 310. In this case, an adhesive member 77 is disposed between the flexible wiring board 9 and the inner surface of the opening 311b.

[0105] The filter unit 1 may also include a Fabry-Perot interference filter as shown in FIG. 11. The Fabry-Perot interference filter 400 shown in FIG. 11 will be described. The Fabry-Perot interference filter 400 includes a substrate layer 411, a mirror section 412, and a driving electrode 413. The substrate layer 411 has a surface 411a and a surface 411b facing each other. The substrate layer 411 is formed of a light-transmitting material. The mirror section 412 is, for example, a metal film, a dielectric multilayer film, or a composite film thereof. The driving electrode 413 is, for example, formed of a metal material.

[0106] The Fabry-Perot interference filter 400 further includes a substrate layer 421, a mirror portion 422, and a driving electrode 423. The substrate layer 421 has a surface 421a and a surface 421b facing each other. The substrate layer 421 is formed of a light-transmitting material. The mirror portion 422 is, for example, a metal film, a dielectric multilayer film, or a composite film thereof. The driving electrode 423 is, for example, formed of a metal material.

[0107] A recess 414 is formed on a surface 411a of the substrate layer 411. A protrusion 415 is provided on a bottom surface 414a of the recess 414. When the bottom surface 414a is taken as a reference, the height of an end surface 415a of the protrusion 415 is lower than the height of the surface 411a of the substrate layer 411. The mirror section 412 is provided on the end surface 415a of the protrusion 415. The driving electrode 413 is provided on the bottom surface 414a of the recess 414 so as to surround the protrusion 415. The driving electrode 413 is electrically connected to an electrode pad (not shown) via, for example, a wiring (not shown) provided on the substrate layer 411. The electrode pad is provided, for example, in an area of ​​the substrate layer 411 that is accessible from the outside.

[0108] A surface 421b of the substrate layer 421 is bonded to a surface 411a of the substrate layer 411 by, for example, plasma bonding or the like. A mirror section 422 and a driving electrode 423 are provided on the surface 421b of the substrate layer 421. The mirror section 422 faces the mirror section 412 via a gap S. The driving electrode 423 is provided on the surface 421b of the substrate layer 421 so as to surround the mirror section 422, and faces the driving electrode 413 via a gap S. The driving electrode 423 is electrically connected to an electrode pad (not shown) via, for example, a wiring (not shown) provided on the substrate layer 421. The electrode pad is provided, for example, in an area of ​​the substrate layer 421 that is accessible from the outside.

[0109] A groove 424 is formed on a surface 421a of the substrate layer 421 so as to surround the mirror portion 422 and the driving electrode 423 when viewed from the Z-axis direction. The groove 424 extends in an annular shape. The portion of the substrate layer 421 surrounded by the groove 424 is movable in the direction in which the pair of mirror portions 412, 422 face each other, with the portion in which the groove 424 is formed serving as a diaphragm-shaped holding portion 425.

[0110] Diaphragm-shaped holding portion 425 may be configured by forming a groove surrounding mirror portion 422 and driving electrode 423 when viewed from the Z-axis direction on at least one of surface 421a and surface 421b of substrate layer 421. A diaphragm-shaped holding portion may be configured in substrate layer 411 by forming a groove surrounding mirror portion 412 and driving electrode 413 when viewed from the Z-axis direction in substrate layer 411. Instead of the diaphragm-shaped holding portion, the holding portion may be configured by a plurality of beams arranged radially.

[0111] 11, when a voltage is applied to the driving electrodes 413 and 423 to generate a potential difference between the driving electrodes 413 and 423, an electrostatic force corresponding to the potential difference is generated between the driving electrodes 413 and 423. When an electrostatic force is generated between the driving electrodes 413 and 423, a portion of the substrate layer 421 surrounded by the groove 424 is attracted to the substrate layer 411 side, and the distance between the mirror portion 412 and the mirror portion 422 is adjusted. As a result, light having a wavelength corresponding to the distance between the mirror portion 412 and the mirror portion 422 is transmitted.

[0112] In addition, in the filter unit 1, the outer edge 2E of the support 2 may have a shape other than a circle, such as a rectangle, when viewed from the Z-axis direction. In the filter unit 1, the outer edge 10E of the Fabry-Perot interference filter 10, the outer edge 4E of the wiring board 4, the inner edge 21E of the first recess 21, and the inner edge 22E of the second recess 22 may each have a shape other than a rectangle.

[0113] In the filter unit 1, the Fabry-Perot interference filter 10 may be offset from the center C of the support 2 when viewed from the Z-axis direction. In the filter unit 1, the mounting surface of the support 2 on which the Fabry-Perot interference filter 10 is arranged does not have to be the bottom surface 21a of the first recess 21. In the filter unit 1, the mounting surface of the support 2 on which the wiring board 4 is arranged does not have to be the bottom surface 22a of the second recess 22. In the filter unit 1, the mounting surface of the support 2 on which the Fabry-Perot interference filter 10 is arranged and the mounting surface of the support 2 on which the wiring board 4 is arranged do not have to be located on the same plane.

[0114] In the filter unit 1, the entire Fabry-Perot interference filter 10 may not be disposed in the first recess 21. In the filter unit 1, the entire light transmitting member 3 may not be disposed in the widened portion 25. In the filter unit 1, the entire wiring board 4 may not be disposed in the second recess 22. In the filter unit 1, the wiring board 4 may be attached to the housing 200 so that a part of the wiring board 4 is embedded in the surrounding portion 230. Note that "a part of the wiring board 4 is embedded in the surrounding portion 230" means that the part of the wiring board 4 overlaps with the surrounding portion 230 when viewed from any of the X-axis direction, the Y-axis direction, and the Z-axis direction.

[0115] In the filter unit 1, as shown in FIG. 12(a), a part of the partition 26 may be interrupted. In the modified example shown in FIG. 12(a), the central part of the partition 26 in the Y-axis direction is interrupted. That is, the partition 26 may not completely separate the first recess 21 and the second recess 22, but may only partially separate them. The first recess 21 and the second recess 22 may be connected to each other via the interrupted part of the partition 26. In the modified example shown in FIG. 12(a), the partition 26 has a part connected to the side surface 22b and a part connected to the side surface 22c. The part of the partition 26 connected to the side surface 22b is separated from the part connected to the side surface 22c.

[0116] In the filter unit 1, the partition 26 may be connected to only one of the pair of side surfaces 22b, 22c. For example, in the modification shown in Fig. 12(a), the partition 26 may have only one of a portion connected to the side surface 22b and a portion connected to the side surface 22c.

[0117] In the filter unit 1, as shown in Fig. 12(b), the partition portion 26 may be spaced apart from the pair of side surfaces 22b, 22c. For example, as shown in Fig. 12(b), the partition portion 26 may be a protrusion independent of the side surfaces 22b, 22c (not connected to the side surfaces 22b, 22c).

[0118] In the filter unit 1, when viewed from the Z-axis direction, the partition 26 may be formed between the pair of side surfaces 21b, 21c of the first recess 21. In this case, the partition 26 may be connected to at least one of the pair of side surfaces 21b, 21c. For example, the partition 26 may be formed continuously from the side surface 21b to the side surface 21c. When the partition 26 is connected to at least one of the pair of side surfaces 21b, 21c, a part of the partition 26 may be interrupted, as in the modified example shown in FIG. 12(a). Also, the partition 26 may be separated from the pair of side surfaces 21b, 21c, as in the modified example shown in FIG. 12(b). For example, the partition 26 may be a convex portion independent of the side surfaces 21b, 21c (not connected to the side surfaces 21b, 21c). The Fabry-Perot interference filter 10 and the wiring board 4 may not be in contact with the partition 26, but are preferably disposed as close to the partition 26 as possible. For example, the distance between the Fabry-Perot interference filter 10 and the partitioning portion 26 in the X-axis direction and the distance between the wiring board 4 and the partitioning portion 26 in the X-axis direction may be smaller than the width Wf of the Fabry-Perot interference filter 10. In this case, the length of each wire 8 can be shortened. The partitioning portion 26 may be formed separately from the support body 2 and attached to the support body 2.

[0119] The height of the partition 26 in the Z-axis direction is not limited to the above. For example, the height of the partition 26 in the Z-axis direction may be higher than the height of the Fabry-Perot interference filter 10 in the Z-axis direction, based on the bottom surface 21a of the first recess 21. The height of the partition 26 in the Z-axis direction may be higher than the height of the wiring board 4 in the Z-axis direction, based on the bottom surface 22a of the second recess 22.

[0120] In the filter unit 1, an antireflection film may be formed on at least one of the surface of the partition 26, the side surface 21b, and the side surface 21c. The antireflection film may be formed over the entire surface of the support 2. As an example, when the support 2 is made of stainless steel, the antireflection film may be formed by subjecting the surface of the support 2 to a chrome plating treatment. In the filter unit 1, the Fabry-Perot interference filter 10 may be disposed away from at least one of the partition 26, the side surface 21b, and the side surface 21c.

[0121] In the filter unit 1, when viewed from the Z-axis direction, the "distance from the inner edge 21E of the first recess 21 to the outer edge 2E of the support 2" in a direction other than the Y-axis direction may be larger than the width of the Fabry-Perot interference filter 10 in that direction. In the filter unit 1, the "distance from the outer edge 10E of the Fabry-Perot interference filter 10 to the outer edge 2E of the support 2" in a "direction perpendicular to one side of the outer edge 10E of the Fabry-Perot interference filter 10" other than the Y-axis direction may be larger than the length of the diagonal of the outer edge 10E of the Fabry-Perot interference filter 10, and the width of the opening 23 when viewed from the Z-axis direction may be smaller than the width of the Fabry-Perot interference filter 10 in the direction perpendicular to that side.

[0122] In the filter unit 1, the opening 23 is formed in the support 2 as a light passing portion. However, a light transmitting portion may be formed in the support 2 as a light passing portion, for example, the area in the opening 23 may be filled with a light transmitting material, or an optical element (for example, a lens, a filter, etc.) may be disposed in the opening 23. In either case, the light passing portion may pass light emitted from the Fabry-Perot interference filter 10 (or the Fabry-Perot interference filter 400), or may pass light incident on the Fabry-Perot interference filter 10 (or the Fabry-Perot interference filter 400). In the filter unit 1, the through hole 24 may be opened on the inner surface of the first recess 21 and the outer surface of the support 2. In the filter unit 1, the cover 6 may not be disposed on the surface 2b of the support 2. In the filter unit 1, an antireflection film may be formed on at least one of the surface 2b of the support 2 and the inner surface of the opening 23.

[0123] The filter unit 1 may not include the cover 6. When the filter unit 1 does not include the cover 6, for example, a light-shielding plate may be provided on the surface 2b of the support 2 so as to overlap the through-hole 24. The light-shielding plate may have a size that does not prevent light from entering the opening 23. That is, the light-shielding plate may be arranged so as not to overlap the opening 23 in the Z-axis direction. When the filter unit 1 does not include the cover 6, the adhesive member 71 may be arranged continuously so as to surround the opening 23 when viewed from the Z-axis direction. This allows the gap between the Fabry-Perot interference filter 10 and the bottom surface 21a of the first recess 21 to be sealed by the adhesive member 71. Also, when the filter unit 1 does not include the cover 6, a glass substrate may be arranged between the Fabry-Perot interference filter 10 and the bottom surface 21a of the first recess 21. This prevents the Fabry-Perot interference filter 10 from being exposed to the outside of the filter unit 1 through the opening 23.

[0124] In the filter unit 1, the region within the opening 18 may be filled with a light-transmitting material (e.g., a light-transmitting resin, etc.), or an optical element (e.g., a lens, a filter, etc.) may be disposed within the opening 18. That is, the region within the opening 18 may be formed as a light-transmitting region in the Fabry-Perot interference filter 10. Even in this case, the light-transmitting region is located inside the opening 23 when viewed from the Z-axis direction, so that stray light can be prevented from entering the Fabry-Perot interference filter 10. [Explanation of symbols]

[0125] 1...filter unit, 2...support, 2b...surface (outer surface), 3...light-transmitting member, 4...wiring board, 7...adhesive member, 10,400...Fabry-Perot interference filter, 10E...outer edge, 14, 15, 412, 422...mirror portion, 21...first recess, 21E...inner edge, 21a...bottom surface (first mounting surface, inner surface), 21b, 21c...side surface (first surface), 22...second recess, 22a...bottom surface (second mounting surface), 22b, 22c...side surface (second surface), 23...opening (light passing portion), 24...through hole, 26...partition portion.

Claims

1. A support having a light passage portion, A Fabry-Perot interference filter including a pair of mirror portions facing each other in a first direction and having a variable distance therebetween, and disposed on the support so as to overlap the light passage portion when viewed from the first direction, A wiring board disposed on the support so as not to overlap the Fabry-Perot interference filter when viewed from the first direction and electrically connected to the Fabry-Perot interference filter, In the support, a first recess and a second recess are formed with the first direction as the depth direction, The first recess and the second recess are arranged side by side in a second direction perpendicular to the first direction, The Fabry-Perot interference filter is disposed in the first recess, The wiring board is disposed in the second recess, The support includes a partition portion disposed between the first recess and the second recess, a filter unit.

2. The first recess has a pair of first surfaces facing each other with the Fabry-Perot interference filter interposed therebetween in a third direction perpendicular to both the first direction and the second direction, The second recess has a pair of second surfaces facing each other with the wiring board interposed therebetween in the third direction, The partition portion is connected to at least one of the pair of first surfaces or at least one of the pair of second surfaces, the filter unit according to claim 1.

3. The partition portion is continuously formed so as to extend from one of the pair of first surfaces to the other, or so as to extend from one of the pair of second surfaces to the other, the filter unit according to claim 2.

4. The first recess has a pair of first surfaces facing each other with the Fabry-Perot interference filter interposed therebetween in a third direction perpendicular to both the first direction and the second direction, The second recess has a pair of second surfaces facing each other with the wiring board interposed therebetween in the third direction, The partition portion is spaced apart from the pair of first surfaces and the pair of second surfaces, the filter unit according to claim 1.

5. The height of the partition portion in the first direction is equal to or less than the height of the Fabry-Perot interference filter in the first direction, the filter unit according to claim 1.

6. The height of the partition portion in the first direction is equal to or less than the height of the wiring board in the first direction, the filter unit according to claim 1.

7. The filter unit according to claim 1, wherein when viewed from the first direction, the Fabry - Perot interference filter is located at the center of the support.

8. The filter unit according to claim 7, wherein when viewed from the first direction, the outer edge of the support has a circular shape.

9. The filter unit according to claim 1, wherein when viewed from the first direction, each of the outer edge of the Fabry - Perot interference filter and the inner edge of the first recess has a rectangular shape.

10. The Fabry - Perot interference filter is disposed on the first mounting surface of the support, The wiring board is disposed on the second mounting surface of the support, The filter unit according to claim 1, wherein the first mounting surface and the second mounting surface are located on the same plane.

11. The filter unit according to claim 1, wherein the second recess reaches the outer edge of the support when viewed from the first direction.

12. Further comprising a light - transmitting member and an adhesive member, The light - transmitting member covers at least the opening of the first recess, The filter unit according to claim 1, wherein the adhesive member is disposed between the wiring board and the support and between the wiring board and the light - transmitting member.

13. The filter unit according to claim 1, wherein when viewed from the first direction, the distance from the inner edge of the first recess to the outer edge of the support in one direction is greater than the width of the Fabry - Perot interference filter in the one direction.

14. The light - passing portion is an opening formed in the support, When viewed from the first direction, the outer edge of the Fabry - Perot interference filter has a rectangular shape, When viewed from the first direction, the distance from the outer edge of the Fabry - Perot interference filter to the outer edge of the support in a direction perpendicular to one side of the outer edge of the Fabry - Perot interference filter is greater than the length of the diagonal of the outer edge of the Fabry - Perot interference filter, The filter unit according to claim 1, wherein when viewed from the first direction, the width of the opening is smaller than the width of the Fabry - Perot interference filter in the direction perpendicular to the one side.

15. Let the width of the Fabry - Perot interference filter in a third direction perpendicular to both the first direction and the second direction be \(W_f\), the width of the wiring board in the third direction be \(W_s\), the width of the first recess in the third direction be \(W_1\), and the width of the second recess in the third direction be \(W_2\). Then, the relationship of " \(W_f\leq W_1\lt W_s\leq W_2\)" or the relationship of " \(W_s\leq W_2\lt W_f\leq W_1\)" holds. The filter unit according to claim 1.

16. The filter unit according to claim 15, wherein the relationship of " \(W_f = W_1\)" holds.

17. The filter unit according to claim 15, wherein the relationship of " \(W_s = W_2\)" holds.

18. In the filter unit according to claim 1, through - holes are formed on the inner surface of the first recess and on the outer surface of the support body and open to the outside of the support body.

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