Filter unit

Abstract

This filter unit (1) is provided with: a support body (2) having an opening; and a Fabry-Perot interference filter (10) that includes a pair of mirror sections that face each other in the Z-axis direction and have a variable distance from each other, the Fabry-Perot interference filter (10) being disposed on the support body (2) so as to overlap the opening section when viewed from the Z-axis direction. In the support body (2), a first recess (21) is formed in the depth direction of the Z-axis direction. The Fabry-Perot interference filter (10) is disposed in the first recess (21). 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 greater than the width (Wf) of the Fabry-Perot interference filter (10) in the Y-axis direction.

Description

Technical Field

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

[0002] In order to configure a filter unit using a Fabry - Perot interference filter including a pair of mirror portions with variable distance from each other, the following structure is considered. That is, a structure including a CAN package having a base and a cover, a wiring board disposed on the base within the CAN package, a Fabry - Perot interference filter disposed on the wiring board within the CAN package, and a plurality of pins penetrating the base (for example, refer to Patent Document 1).

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: U.S. Patent Application Publication No. 2017 / 0350760 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] However, in the filter unit adopting the above structure, it is difficult to thin the filter unit in the optical axis direction of the Fabry - Perot interference filter (that is, the direction in which the pair of mirror portions face each other). Therefore, there is a problem that it is not suitable for being disposed in a narrow area in the optical axis direction of the Fabry - Perot interference filter (for example, the area between lenses in a lens barrel).

[0008] An object of the present invention is to provide a filter unit suitable for being disposed in a narrow area in the optical axis direction of a Fabry - Perot interference filter.

[0009] Means for Solving the Problems

[0010] A filter unit according to an aspect of the present invention is [1] "a filter unit including: a support having a light passing portion; and a Fabry - Perot interference filter including a pair of mirror portions facing each other in a first direction and having a variable distance from each other, and disposed on the support so as to overlap the light passing portion when viewed from the first direction. In the support, a first recess is formed with the first direction as the depth direction, the Fabry - Perot interference filter is disposed in the first recess, and 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".

[0011] In the filter unit described in the above [1], the Fabry - Perot interference filter is disposed in the first recess formed in the support body with the first direction as the depth direction. Thereby, it is possible to thin the filter unit 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), that is, the first direction. In addition, if a part of the support body is formed thinner by forming the first recess, the external force acting on the support body easily reaches the Fabry - Perot interference filter. However, in the filter unit described in the above [1], when viewed from the first direction, the distance from the inner edge of the first recess to the outer edge of the support body in one direction is greater than the width of the Fabry - Perot interference filter in that one direction. Thus, even if an external force acts on the support body from the side with respect to the optical axis direction of the Fabry - Perot interference filter, that is, the first direction, it is possible to suppress the external force from reaching the Fabry - Perot interference filter. Therefore, the filter unit described in the above [1] is suitable for being disposed in a narrow area in the optical axis direction of the Fabry - Perot interference filter.

[0012] A filter unit according to an aspect of the present invention may also be [2] "the filter unit according to the above [1], wherein, when viewed from the first direction, the inner edge of the first recess includes a first portion and a second portion that face each other with the Fabry - Perot interference filter interposed therebetween in one direction, and when viewed from the first direction, the distance from the first portion to the outer edge of the support body in one direction and the distance from the second portion to the outer edge of the support body in one direction are each greater than the width of the Fabry - Perot interference filter in that one direction". According to the filter unit described in this [2], on both sides of the first recess in one direction, the distance from the inner edge of the first recess to the outer edge of the support body is greater than the width of the Fabry - Perot interference filter in that one direction, so even if an external force acts on the support body from the side with respect to the first direction, it is possible to further suppress the external force from reaching the Fabry - Perot interference filter.

[0013] A filter unit according to an aspect of the present invention may also be [3] "the filter unit according to the above [1] or [2], wherein the support body includes an enclosing portion that encloses the first recess when viewed from the first direction, and the height of the enclosing portion in the first direction is greater than the thickness of the Fabry - Perot interference filter in the first direction". According to the filter unit described in this [3], since the first recess is surrounded by an enclosing portion with a wall thickness whose height in the first direction is greater than the thickness of the Fabry - Perot interference filter, even if an external force acts on the support body from the side with respect to the first direction, it is possible to further suppress the external force from reaching the Fabry - Perot interference filter.

[0014] The filter unit according to one aspect of the present invention may also be "[4] The filter unit according to [3] above, wherein, when viewed from the first direction, the width of the surrounding portion 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 [4], since the width of the surrounding portion in the one direction is greater than the width of the Fabry-Perot interference filter in the one direction, even if an external force acts on the support body from the side with respect to the first direction, it is possible to further suppress the external force from reaching the Fabry-Perot interference filter.

[0015] The filter unit according to one aspect of the present invention may also be "[5] The filter unit according to any one of [1] to [4] above, wherein, when viewed from the first direction, the Fabry-Perot interference filter is located at the center of the support body". According to the filter unit described in [5], even if an external force acts on the support body from the side with respect to the first direction, it is possible to suppress the external force from reaching the Fabry-Perot interference filter. In addition, for example, by fitting the support body inside a cylindrical body such as a lens barrel, it is possible to arrange the Fabry-Perot interference filter on the center line of the cylindrical body.

[0016] The filter unit according to one aspect of the present invention may also be "[6] The filter unit according to [5] above, wherein, when viewed from the first direction, the outer edge of the support body has a circular shape". According to the filter unit described in [6], even if an external force acts on the support body from the side with respect to the first direction, it is possible to suppress the external force from reaching the Fabry-Perot interference filter with good balance. In addition, for example, when the cylindrical body is cylindrical, it is possible to easily and highly accurately arrange the Fabry-Perot interference filter on the center line of the cylindrical body.

[0017] The filter unit according to one aspect of the present invention may also be "[7] The filter unit according to any one of [1] to [6] above, wherein, when viewed from the first direction, the outer edge of the Fabry-Perot interference filter and the inner edge of the first recess are each rectangular". According to the filter unit described in [7], it is possible to more easily and highly accurately perform the positioning of the Fabry-Perot interference filter with respect to the support body.

[0018] The filter unit according to one aspect of the present invention may also be "[8] The filter unit according to any one of [1] to [7] above, further comprising a wiring substrate electrically connected to the Fabry - Perot interference filter, the wiring substrate being disposed on the support body so as not to overlap the Fabry - Perot interference filter when viewed from the first direction". According to the filter unit described in [8], since the wiring substrate does not overlap the Fabry - Perot interference filter on the support body when viewed from the first direction, the filter unit can be made thinner in the optical axis direction of the Fabry - Perot interference filter, that is, the first direction.

[0019] The filter unit according to one aspect of the present invention may also be "[9] The filter unit according to any one of [1] to [8] above, further comprising a wiring substrate electrically connected to the Fabry - Perot interference filter, the Fabry - Perot interference filter being disposed on the first mounting surface of the support body, the wiring substrate being disposed on the second mounting surface of the support body, and the first mounting surface and the second mounting surface being in the same plane". According to the filter unit described in [9], the filter unit can be made thinner in the optical axis direction of the Fabry - Perot interference filter, that is, the first direction.

[0020] The filter unit according to one aspect of the present invention may also be "

[10] The filter unit according to any one of [1] to [9] above, further comprising a wiring substrate electrically connected to the Fabry - Perot interference filter, a second recess being formed in the support body with the first direction as the depth direction, the wiring substrate being disposed in the second recess, and when viewed from the first direction, the second recess reaching the outer edge of the support body". According to the filter unit described in

[10] , since the wiring substrate is disposed in the second recess formed in the support body with the first direction as the depth direction, the filter unit can be made thinner in the optical axis direction of the Fabry - Perot interference filter, that is, the first direction. In addition, since the second recess in which the wiring substrate is disposed reaches the outer edge of the support body when viewed from the first direction, electrical connection can be performed from the side with respect to the first direction.

[0021] The filter unit according to one aspect of the present invention may also be "

[11] The filter unit according to any one of [1] to

[10] above, further comprising a wiring substrate electrically connected to the Fabry - Perot interference filter. In the support body, a second recess is formed with the first direction as the depth direction, the wiring substrate is disposed in the second recess, and the support body further comprises a partition portion disposed between the first recess and the second recess". According to the filter unit described in

[11] , since the wiring substrate is disposed in the second recess formed in the support body with the first direction as the depth direction, the filter unit can be made thinner in the first direction, which is the optical axis direction of the Fabry - Perot interference filter. Thus, based on the partition portion, the positioning of the Fabry - Perot interference filter and the wiring substrate relative to the support body can be performed more easily and with higher precision.

[0022] The filter unit according to one aspect of the present invention may also be "

[12] The filter unit according to any one of [1] to

[11] above, wherein the light passing portion is an opening formed in the support body. When viewed from the first direction, the outer edge of the Fabry - Perot interference filter is rectangular. 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 body in the 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. 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". According to the filter unit described in

[12] , when viewed from the first direction, the opening is very small compared to the support body, so that stray light incident on the Fabry - Perot interference filter can be suppressed.

[0023] The filter unit according to one aspect of the present invention may also be "

[13] The filter unit according to any one of [1] to

[12] above, further comprising: a wiring substrate electrically connected to the Fabry - Perot interference filter; a light - transmitting member; and an adhesive member. In the support body, a second recess is formed with the first direction as the depth direction, the wiring substrate is disposed in the second recess, the light - transmitting member at least covers the opening of the first recess, and the adhesive member is disposed between the wiring substrate and the support body and between the wiring substrate and the light - transmitting member". According to the filter unit described in

[13] , an increase in the thickness in the first direction, which is the optical axis direction of the Fabry - Perot interference filter, can be suppressed, and an encapsulation member for accommodating the Fabry - Perot interference filter is formed by the support body, the wiring substrate, the light - transmitting member, and the adhesive member. Thus, the Fabry - Perot interference filter can be protected from the influence of moisture or particles, etc.

[0024] The filter unit

[14] of one aspect of the present invention may also be "the filter unit according to any one of the above [1] to

[13] , further comprising a wiring substrate electrically connected to the Fabry - Perot interference filter. In the support body, a second recess is formed in the first direction as the depth direction, the first recess and the second recess are arranged in a second direction perpendicular to the first direction, the wiring substrate is disposed in the second recess. If 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 substrate 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, then the relationship of "Wf≤W1<Ws≤W2" or the relationship of "Ws≤W2<Wf≤W1" holds." According to the filter unit described in

[14] , 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 portion or a reference coordinate), it is possible to easily and highly accurately perform the positioning of the Fabry - Perot interference filter and the wiring substrate relative to the support body. In addition, compared with the case where the smaller width among the width W1 of the first recess and the width W2 of the second recess is made to coincide with the larger width, the strength of the support body can be ensured. Further, when the relationship of "Wf≤W1<Ws≤W2" holds, even if an external force acts on the wiring substrate from the side in the first direction, the external force can be released from the boundary between the first recess and the second recess to the support body, and the spread of the external force to the Fabry - Perot interference filter can be suppressed. On the other hand, when the relationship of "Ws≤W2<Wf≤W1" holds, it is possible to suppress stray light from entering the Fabry - Perot interference filter through the second recess in which the wiring substrate is disposed.

[0025] The filter unit of one aspect of the present invention may also be

[15] "the filter unit according to the above

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

[15] , it is possible to more easily and highly accurately perform the positioning of the Fabry - Perot interference filter relative to the support body.

[0026] The filter unit of one aspect of the present invention may also be

[16] "the filter unit according to the above

[14] or

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

[16] , it is possible to more easily and highly accurately perform the positioning of the wiring substrate relative to the support body. [[ID=...]]

[0027] The filter unit according to one aspect of the present invention may also be "

[17] The filter unit according to any one of [1] to

[16] , wherein a through hole that opens on the inner surface of the first recess and the outer surface of the support body is formed in the support body". According to the filter unit described in

[17] , for example, when manufacturing the filter unit, even if gas is generated in the first recess in a state where the opening of the first recess is covered by some members, the gas can escape to the outside through the through hole.

[0028] Advantages of the Invention

[0029] According to the present invention, a filter unit suitable for being arranged in a narrow region in the optical axis direction of a Fabry - Perot interference filter can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a perspective view of a Fabry - Perot interference filter included in a filter unit according to an embodiment.

[0031] Figure 2 is along Figure 1 a cross - sectional view of the Fabry - Perot interference filter taken along the line II - II shown.

[0032] Figure 3 is a top view of a filter unit according to an embodiment.

[0033] Figure 4 is along Figure 3 a cross - sectional view of the filter unit taken along the line IV - IV shown.

[0034] Figure 5 is a top view of a part of a filter unit according to an embodiment.

[0035] Figure 6 is a top view of a part of a filter unit according to an embodiment.

[0036] Figure 7 is a bottom view of a filter unit according to an embodiment.

[0037] Figure 8 is a cross - sectional view of a lens barrel including a filter unit according to an embodiment.

[0038] Figure 9 is a top view of a part of a filter unit according to a modified example.

[0039] Figure 10 is a cross - sectional view of a part of a lens barrel including a filter unit according to a modified example.

[0040] Figure 11 is a cross - sectional view of a Fabry - Perot interference filter according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0041] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, in each figure, the same or corresponding parts are denoted by the same reference numerals, and repeated descriptions are omitted.

[0042] [Structure of Fabry - Perot interference filter included in the filter unit]

[0043] As Figure 1 shown, the Fabry - Perot interference filter 10 has a light transmission region 10a. The Fabry - Perot interference filter 10 is a rectangular plate - shaped element with the Z - axis direction as the thickness direction. The light transmission 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 transmission region 10a coincides with the center of the Fabry - Perot interference filter 10.

[0044] As Figure 2 shown, the Fabry - Perot interference filter 10 includes a substrate 11 with the Z - axis direction as the thickness direction. The material of the substrate 11 is, for example, silicon, quartz, glass, etc. 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 stacked structure 12 is stacked on the surface 11a of the substrate 11. A second stacked structure 13 is stacked on the surface 11b of the substrate 11.

[0045] The first stacked structure 12 includes an antireflection layer 121, a first stacked body 122, an intermediate layer 123, and a second stacked body 124. The antireflection 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. A gap (air gap) S is formed between the first stacked body 122 and the second stacked body 124 by the frame - shaped intermediate layer 123. When the material of the substrate 11 is silicon, the materials of the antireflection layer 121 and the intermediate layer 123 are, for example, silicon oxide, etc. The thickness of the intermediate layer 123 is, for example, an integer multiple of 1 / 2 of the designed center wavelength. In addition, the thickness of the intermediate layer 123 can also be greater than an integer multiple of 1 / 2 of the designed center wavelength as needed.

[0046] The part of the first stacked body 122 corresponding to the light transmission region 10a functions as a mirror part 14. The mirror part 14 is supported on the substrate 11 via the antireflection layer 121. As an example, the first stacked body 122 is formed by alternately stacking a plurality of polysilicon layers and a plurality of silicon nitride layers layer by layer. The optical thickness of each layer constituting the mirror part 14 is, for example, an integer multiple of 1 / 4 of the designed center wavelength. In addition, a silicon oxide layer can also be used instead of the silicon nitride layer.

[0047] The portion of the second laminate 124 corresponding to the light transmission region 10a functions as a mirror portion 15. The mirror portion 15 is supported on the substrate 11 via the antireflection layer 121, the first laminate 122, and the intermediate layer 123, and faces the mirror portion 14 via the gap S. As an example, the second laminate 124 is formed by alternately laminating a plurality of polysilicon layers and a plurality of silicon nitride layers. The optical thickness of each layer constituting the mirror portion 15 is, for example, an integer multiple of 1 / 4 of the design center wavelength. Alternatively, a silicon oxide layer can be used instead of the silicon nitride layer. In addition, in the portion of the second laminate 124 corresponding to the gap S, a plurality of through holes are formed to such an extent that the function of the mirror portion 15 is not substantially affected. The plurality of through holes are used when forming the gap S by etching away a part of the intermediate layer 123.

[0048] A first electrode 125 and a second electrode 126 are formed in the mirror portion 14. The first electrode 125 surrounds the light transmission region 10a when viewed from the Z-axis direction. When viewed from the Z-axis direction, the second electrode 126 overlaps with the light transmission region 10a. The shape of the second electrode 126 when viewed from the Z-axis direction is substantially the same as the shape of the light transmission region 10a when viewed from the Z-axis direction. The first electrode 125 and the second electrode 126 are respectively formed by doping impurities in a part of the polysilicon layer and making that part have a low resistance.

[0049] A third electrode 127 is formed in the mirror portion 15. The third electrode 127 faces the first electrode 125 and the second electrode 126 with the gap S therebetween. The third electrode 127 is formed by doping impurities in a part of the polysilicon layer and making that part have a low resistance. As an example, the distance between the second electrode 126 and the third electrode 127 and the distance between the first electrode 125 and the third electrode 127 are substantially the same.

[0050] In the first laminate structure 12, a pair of terminals 16 (see Figure 1 ) are provided so as to sandwich the light transmission region 10a. 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 side opposite 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.

[0051] In the first laminate structure 12, a pair of terminals 17 (see Figure 1)。Each terminal 17 is arranged in a through-hole formed in the second laminate 124 and the intermediate layer 123 so as to open to the side opposite 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. In addition, the direction in which a pair of terminals 17 sandwich the light transmission region 10a is perpendicular to the direction in which a pair of terminals 16 sandwich the light transmission region 10a (see Figure 1 ).

[0052] A pair of grooves 122a are formed in the first laminate 122. Each groove 122a extends in a ring shape so as to surround a portion of the wiring 126a that extends in the Z-axis direction from each terminal 17. Each groove 122a electrically insulates the first electrode 125 from the wiring 126a. A groove 122b is formed in the first laminate 122. The groove 122b extends in a ring shape along the inner edge of the first electrode 125. The groove 122b electrically insulates the first electrode 125 from the second electrode 126. The regions within the grooves 122a and 122b may be filled with an insulating material or may be voids.

[0053] A pair of grooves 124a are formed in the second laminate 124. Each groove 124a extends in a ring shape so as to surround each terminal 16. Each groove 124a electrically insulates each terminal 16 from the third electrode 127. The regions within the grooves 124a may be filled with an insulating material or may be voids.

[0054] The second laminate structure 13 includes an antireflection layer 131, a third laminate 132, an intermediate layer 133, and a fourth laminate 134. The antireflection 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 antireflection layer 131 and the intermediate layer 133 respectively have the same structure as the antireflection layer 121 and the intermediate layer 123. The third laminate 132 and the fourth laminate 134 respectively have a laminated structure that is symmetric with respect to the first laminate 122 and the second laminate 124 with the substrate 11 as a reference. The antireflection layer 131, the third laminate 132, the intermediate layer 133, and the fourth laminate 134 have a function of suppressing warping of the substrate 11.

[0055] In the third laminate 132, the intermediate layer 133, and the fourth laminate 134, an opening 18 is formed so as to include the light transmission region 10a. The opening 18 overlaps with the light transmission region 10a when viewed from the Z-axis direction. The shape of the opening 18 when viewed from the Z-axis direction is substantially the same as the shape of the light transmission region 10a when viewed from the Z-axis direction. That is, the center line of the opening 18 coincides with the center line of the light transmission region 10a. The opening 18 opens to the side opposite to the substrate 11 and reaches the antireflection layer 131.

[0056] A light-shielding layer 135 is formed on the surface of the fourth laminate 134 opposite to the substrate 11. The material of the light-shielding layer 135 is, for example, aluminum or the like. 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, alumina or the like. In addition, by making the thickness of the protective layer 136 100 nm or less (preferably about 30 nm), the optical influence of the protective layer 136 can be ignored.

[0057] In the Fabry-Perot interference filter 10 configured as described above, if a potential difference is generated between the first electrode 125 and the third electrode 127 by applying a voltage to the first electrode 125 and the third electrode 127 via a plurality of terminals 16, 17, an electrostatic force corresponding to the potential difference is generated between the first electrode 125 and the third electrode 127. By generating an electrostatic force between the first electrode 125 and the third electrode 127, the mirror unit 15 is attracted to the mirror unit 14, thereby adjusting the distance between the mirror unit 14 and the mirror unit 15. At this time, the second electrode 126 having the same potential as the third electrode 127 functions as a compensation electrode, and the mirror unit 15 remains flat in the light transmission region 10a.

[0058] In this way, in the Fabry-Perot interference filter 10, a pair of mirror units 14 and 15 facing each other in the Z-axis direction function as a pair of mirror units with variable distance from each other. Here, the wavelength of the light transmitted through the Fabry-Perot interference filter 10 depends on the distance between the mirror unit 14 and the mirror unit 15. Therefore, by adjusting the voltage 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 the light transmitted through the Fabry-Perot interference filter 10 can be selected.

[0059] [Structure of the filter unit]

[0060] As Figure 3 and Figure 4 shown, 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 Fabry-Perot interference filter 10. In addition, in Figure 3 it, the light-transmitting member 3 and the adhesive members 73 and 75 described later are indicated by double-dashed lines.

[0061] The support body 2 is a circular plate-shaped member with the Z-axis direction (the first direction) as the thickness direction. That is, when viewed from the Z-axis direction, the outer edge 2E of the support body 2 is circular. The support body 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 body 2 is, for example, a metal material such as stainless steel or a resin material. The outer diameter of the support body 2 is, for example, 20 mm to 50 mm. The thickness of the support body 2 in the Z-axis direction is, for example, 2 mm to 5 mm.

[0062] As Figure 4 and Figure 5 shown, a first recess 21 and a second recess 22 are formed in the support body 2. The first recess 21 and the second recess 22 each open on the surface 2a side with the Z-axis direction as the depth direction. The bottom surface (the first placement surface) 21a of the first recess 21 and the bottom surface (the second placement surface) 22a of the second recess 22 are located in the same plane perpendicular to the Z-axis direction. The thickness from the bottom surfaces 21a, 22a to the surface 2b of the support body 2 in the Z-axis direction is, for example, about 100 μm. The first recess 21 and the second recess 22 are arranged in the X-axis direction (the second direction perpendicular to the first direction). In addition, in Figure 5 the illustration of the light-transmitting member 3 and the adhesive members 73, 75 described later is omitted.

[0063] The first recess 21 includes the center C of the support body 2 when viewed from the Z-axis direction. When viewed from the Z-axis direction, the first recess 21 does not reach the outer edge 2E of the support body 2. When viewed from the Z-axis direction, the inner edge 21E of the first recess 21 is rectangular. In the present embodiment, when viewed from the Z-axis direction, the inner edge 21E of the first recess 21 is rectangular with the X-axis direction as the long side 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.

[0064] 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. When viewed from the Z-axis direction, the inner edge 22E of the second recess 22 is rectangular. In the present embodiment, when viewed from the Z-axis direction, the inner edge 22E of the second recess 22 is rectangular with the X-axis direction as the long side direction. In the present embodiment, the second recess 22 reaches the side surface 2c of the support 2 on the side opposite to the first recess 21 in the X-axis direction. When viewed from the Z-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, the second recess 22 does not cross the support 2, so the support 2 has higher rigidity compared to a structure 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.

[0065] The width W2 of the second recess 22 in the Y-axis direction (the third direction perpendicular to the two directions of the first direction and the second direction) is greater than the width W1 of the first recess 21 in the Y-axis direction. In the present 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 the present 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.

[0066] An opening (light passing portion) 23 and a through hole 24 are formed in the support 2. The opening 23 and the through hole 24 open on 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 on the side opposite to the opening 23 with the Z-axis direction as the depth direction. The opening 23 and the through hole 24 are arranged in the X-axis direction. The opening 23 delimits 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.

[0067] A widened portion 25 is formed in the support 2. The widened portion 25 widens toward the side opposite to the second recess 22 in the X-axis direction and 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 surface 2a side with the Z-axis direction as the depth direction and reach the opening of the first recess 21. In the present 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.

[0068] The support body 2 includes a partition portion 26. The partition portion 26 is disposed between the first concave portion 21 and the second concave portion 22. The partition portion 26 is integrally formed with the other portions of the support body 2 as a part of the support body 2. In the present embodiment, the partition portion 26 is a wall portion extending in the Y-axis direction between the bottom surface 21a of the first concave portion 21 and the bottom surface 22a of the second concave portion 22. In the present embodiment, when taking the plane where the bottom surface 21a and the bottom surface 22a are located as a reference, 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.

[0069] The Fabry - Perot interference filter 10 is disposed on the support body 2 with the Z-axis direction as the thickness direction so as to overlap the opening portion 23 when viewed from the Z-axis direction. More specifically, the Fabry - Perot interference filter 10 is disposed in the first concave portion 21 with the Z-axis direction as the thickness direction so as to overlap the opening portion 23 when viewed from the Z-axis direction. The Fabry - Perot interference filter 10 contacts the partition portion 26 in the first concave portion 21. In the present embodiment, if taking the bottom surface 21a of the first concave portion 21 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 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. In the present embodiment, if taking the bottom surface 21a of the first concave portion 21 as a reference, the height of the partition portion 26 in the Z-axis direction is less than or equal to 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.

[0070] As described above, the Fabry - Perot interference filter 10 is a rectangular plate - shaped element with the Z-axis direction as the thickness direction. Therefore, when viewed from the Z-axis direction, the outer edge 10E of the Fabry - Perot interference filter 10 is rectangular. The Fabry - Perot interference filter 10 is disposed on the bottom surface 21a of the first concave portion 21 such that each side of the outer edge 10E is parallel to the X-axis direction or the Y-axis direction and the opening portion 18 faces the opening portion 23 when viewed from the Z-axis direction. The center line of the opening portion 18 coincides with the center line of the opening portion 23. That is, when viewed from the Z-axis direction, the Fabry - Perot interference filter 10 is located at the center C of the support body 2. When viewed from the Z-axis direction, the opening portion 18 is located inside the opening portion 23.

[0071] 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. Thereby, stress waves caused by deformation of the support 2 and / or the adhesive member 71 due to temperature change can be suppressed from reaching the Fabry - Perot interference filter 10. The material of the adhesive member 71 is, for example, a polyimide - type resin, a silicone resin, an epoxy - type resin, an acrylic resin, or a mixed resin thereof, etc.

[0072] As Figure 4 and Figure 6 shown, the light - transmitting member 3 is arranged 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 arranged 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 the present embodiment, the light - transmitting member 3 covers the opening of the first recess 21 and a part of the opening of the second recess 22. In the present embodiment, when taking the bottom surface 25a of the widened portion 25 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.

[0073] The light - transmitting member 3 is a rectangular plate - shaped member with the Z - axis direction as the thickness direction and the X - axis direction as the length direction. Therefore, when viewed from the Z - axis direction, the outer edge 3E of the light - transmitting member 3 is in a rectangular shape with the X - axis direction as the long - side direction. The light - transmitting member 3 is arranged on the bottom surface 25a of the widened portion 25 such 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 band - pass filter that transmits light in a specified wavelength range.

[0074] The light - transmitting member 3 is fixed to the bottom surface 25a and the side surface 25b of the widened portion 25 by an adhesive member 72 and an adhesive member 73. The adhesive member 72 is arranged in a dot pattern between the bottom surface 25a and one corner of the light - transmitting member 3. The adhesive member 73 is arranged along the 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 opposite to the first recess 21. A part of the adhesive member 73 also enters between the side surface 25b of the widened portion 25 and the side surface of the light - transmitting member 3. The materials of the adhesive members 72 and 73 are, for example, a polyimide - type resin, a silicone resin, an epoxy - type resin, an acrylic resin, or a mixed resin thereof, etc.

[0075] As Figure 4 and Figure 5As shown, the wiring substrate 4 is arranged 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 substrate 4 is arranged 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. The wiring substrate 4 contacts the partition portion 26 within the second recess 22. In the present embodiment, when the bottom surface 22a of the second recess 22 is used as a reference, the height of the wiring substrate 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 widened portion 25 in the Z-axis direction. In the present embodiment, when the bottom surface 22a of the second recess 22 is used 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 substrate 4 in the Z-axis direction.

[0076] The wiring substrate 4 is a rectangular plate-shaped substrate with the Z-axis direction as the thickness direction and the X-axis direction as the long side direction. Therefore, when viewed from the Z-axis direction, the outer edge 4E of the wiring substrate 4 has a rectangular shape with the X-axis direction as the long side direction. The wiring substrate 4 is arranged on the bottom surface 22a of the second recess 22 such 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.

[0077] The wiring substrate 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 substrate 4 and extend along the X-axis direction respectively. 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 substrate 4. The second portion 74b faces the partition portion 26 between the bottom surface 22a and the wiring substrate 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 mixed resin thereof.

[0078] The wiring substrate 4 is electrically connected to the Fabry - Perot interference filter 10. More specifically, the terminal 41 of the wiring substrate 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 partition portion 26 through the wire 8, and the terminal 42 of the wiring substrate 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 partition portion 26 through the wire 8. The pair of terminals 41 and 42 are arranged in a region along the partition portion 26 on the surface 4a of the wiring substrate 4 on the side of the light - transmitting member 3. Each metal wire 8 passes through the gap between the partition portion 26 and the light - transmitting member 3. When viewed in the X - axis direction, each wire 8 is received in the first recess 21 and the second recess 22. The width of the partition portion 26 in the X - axis direction is smaller than the width of the Fabry - Perot interference filter 10 in the X - axis direction. Thus, the distance between the Fabry - Perot interference filter 10 and the wiring substrate 4 can be shortened.

[0079] The connector 5 is mounted on the surface 4a of the wiring substrate 4 and is electrically connected to the wiring substrate 4. A part 5a of the connector 5 is located at a position more outside than the side surface 2c of the support body 2 via a region in the second recess 22 that reaches the side surface 2c of the support body 2. A connection port 51 that opens on the side opposite to the center C of the support body 2 is provided in a part 5a of the connector 5. The connector 5 is received in the second recess 22 in the Z - axis direction. In the filter unit 1, a voltage is applied to the pair of terminals 16 and 17 from an external wiring connected to the connector 5 via the wiring substrate 4 and the pair of wires 8.

[0080] As Figure 4 and Figure 6 shown, an adhesive member 75 is disposed between the wiring substrate 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 the wiring substrate 4 when viewed in the Z - axis direction. The adhesive member 75 seals the gap between the wiring substrate 4 and the light - transmitting member 3 at a position more outside (on the side opposite to the center C of the support body 2) than the pair of terminals 41 and 42. The material of the adhesive member 75 is, for example, a polyimide - based resin, a silicone resin, an epoxy - based resin, an acrylic - based resin, or a mixed resin thereof. In addition, in the present embodiment, the adhesive members 74 and 75 constitute the "adhesive member 7 disposed between the wiring substrate 4 and the support body 2 and between the wiring substrate 4 and the light - transmitting member 3".

[0081] As Figure 4 and Figure 7As shown, 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-shaped member having light transmissibility 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 is in the shape of a circular plate, 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 mixed resin thereof. A light-shielding film 61 is provided on the surface 6a of the cover 6 on the side opposite to the support 2. The light-shielding film 61 overlaps 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 via the cover 6. The light-shielding film 61 is, for example, a chromium coating film or the like.

[0082] As Figure 4 shown, in the light filtering unit 1, the support 2 and the light transmissive member 3 form a housing 200 including a first wall portion 210, a second wall portion 220, and an enclosing portion 230. More specifically, a part of the support 2 forms the first wall portion 210, and a part of the light transmissive member 3 forms the second wall portion 220. Another part of the support 2 and another part of the light transmissive member 3 form the enclosing portion 230. The first wall portion 210 is a wall portion having an opening 23, specifically, the part of the support 2 that overlaps the area within the first recess 21 when viewed from the Z-axis direction (i.e., the bottom wall portion of the first recess 21). The second wall portion 220 is a wall portion that faces the first wall portion 210 in the Z-axis direction, specifically, the part of the light transmissive member 3 that overlaps the area within the first recess 21 when viewed from the Z-axis direction. The enclosing portion 230 is the part that encloses the area between the first wall portion 210 and the second wall portion 220, specifically, the part of the support 2 and the light transmissive member 3 that encloses the area within the first recess 21 when viewed from the Z-axis direction.

[0083] Therefore, in the light filtering unit 1, as follows. The first recess 21 is defined by the first wall portion 210 and the enclosing portion 230. The area within the first recess 21 corresponds to the area within the housing 200. The second recess 22 is formed in the enclosing 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 Figure 3)。The wiring board 4 is mounted on the housing 200 in such a manner that it does not overlap with the Fabry - Perot interference filter 10 when viewed from the Z - axis direction. The wiring board 4 is mounted on the housing 200 in such a manner that the entire wiring board 4 is buried in the surrounding portion 230. Additionally, "the entire wiring board 4 is buried in the surrounding portion 230" means that when viewed from any one of the X - axis direction, Y - axis direction, and Z - axis direction, the entire wiring board 4 overlaps with the surrounding portion 230. At least a part of the wiring board 4 is exposed to the outside of the housing 200. In the present embodiment, at least a part of the wiring board 4 is exposed to the outside of the housing 200 via the region in the opening of the second recess 22 that is not covered by the light - transmitting member 3 and the region in the second recess 22 that reaches the side surface 2c of the support 2.

[0084] As Figure 5 shown, 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 greater 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 "Wf≤W1<Ws≤W2" holds. In the present embodiment, the relationships "Wf = W1" and "Ws = W2" hold. In the filter unit 1, it is preferable that the relationship "W1<2Wf" holds. Additionally, in the filter unit 1, it is preferable that the relationship "W2<2Ws" holds.

[0085] Furthermore, "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 greater than or equal to "Wf" and less than or equal to "1.1Wf", and "Ws = W2" means that W2 is a value greater than or equal to "Ws" and less than or equal to "1.1Ws".

[0086] As Figure 3 shown, 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 greater than the width Wf of the Fabry - Perot interference filter 10 in the Y - axis direction. In the present embodiment, when viewed from the Z - axis direction, the inner edge 21E of the first recess 21 includes a first part 21Ea and a second part 21Eb that face each other across the Fabry - Perot interference filter 10 in the Y - axis direction. When viewed from the Z - axis direction, the distance D1 "from the first part 21Ea to the outer edge 2E of the support 2" in the Y - axis direction and the distance D1 "from the second part 21Eb to the outer edge 2E of the support 2" in the Y - axis direction are each greater than the width Wf of the Fabry - Perot interference filter 10 in the Y - axis direction.

[0087] In the present embodiment, the "distance D1 from the first portion 21Ea to the outer edge 2E of the support 2" in the Y-axis direction and the "distance D1 from the second portion 21Eb to the outer edge 2E of the support 2" in the Y-axis direction respectively correspond to the width of the surrounding portion 230 in the Y-axis direction. That is, in the present embodiment, the width of the surrounding portion 230 in the Y-axis direction is greater than the width Wf of the Fabry-Perot interference filter 10 in the Y-axis direction. The height of the surrounding portion 230 in the Z-axis direction is greater than the thickness of the Fabry-Perot interference filter 10. The height of the surrounding portion 230 in the Z-axis direction refers to the height of the surface 2a of the support 2 in the Z-axis direction with respect to the bottom surface 21a of the first recess 21. The support 2 integrally formed without combining a plurality of members includes a thick wall portion surrounding the first recess 21 and the second recess 22. The thick wall portion is a portion of the support 2 where the 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 wall portion as viewed from the Z-axis direction is 50% or more of the area of the support 2 as viewed from the Z-axis direction.

[0088] 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 greater 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 (the direction perpendicular to one side of the outer edge 10E of the Fabry-Perot interference filter 10) is greater than the length L of the diagonal 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 can be about 2 to 3 times the length L of the diagonal 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 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.

[0089] In addition, the "distance D1 from the inner edge 21E of the first recess 21 to the outer edge 2E of the support 2" in a specified direction corresponds to the "distance from the inner edge to the outer edge of the surrounding portion 230" in the specified direction. Further, 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 a specified direction corresponds to the "distance from the outer edge 10E of the Fabry-Perot interference filter 10 to the outer edge of the surrounding portion 230" in the specified direction.

[0090] [Method for manufacturing a filter unit]

[0091] Refer to Figure 4 The method for manufacturing the filter unit 1 will be described. First, a support 2 is prepared, a pre-cured bonding member 71 is disposed on the bottom surface 21a of the first recess 21, and a pre-cured bonding member 74 is disposed on the bottom surface 22a of the second recess 22. Next, a Fabry-Perot interference filter 10 is disposed on the bottom surface 21a of the first recess 21, and a wiring substrate 4 is disposed on the bottom surface 22a of the second recess 22. A connector 5 is pre-mounted on the surface 4a of the wiring substrate 4. Next, the bonding members 71 and 74 are cured. At this time, since the Fabry-Perot interference filter 10 is fitted into the first recess 21 while contacting the partition portion 26, it is positioned with high precision with respect to the opening 23. In addition, since the wiring substrate 4 is fitted into the second recess 22 while contacting the partition portion 26, it is positioned with high precision with respect to the Fabry-Perot interference filter 10. Next, the terminal 41 of the wiring substrate 4 is electrically connected to the terminal 16 of the Fabry-Perot interference filter 10 through a wire 8, and the terminal 42 of the wiring substrate 4 is electrically connected to the terminal 17 of the Fabry-Perot interference filter 10 through a wire 8. The high-precision positioning of the wiring substrate 4 with respect to the Fabry-Perot interference filter 10 is important for reliably performing wire bonding between the Fabry-Perot interference filter 10 and the wiring substrate 4. The terminal 16 of the pair of terminals 16 to which the wire 8 is connected is located closer to the partition portion 26 (wiring substrate 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 portion 26 (wiring substrate 4) than the center of the Fabry-Perot interference filter 10. Thereby, the length of each wire 8 can be shortened.

[0092] Next, a pre-cured bonding member 72 is disposed on the bottom surface 25a of the widened portion 25. Next, an optical transmission member 3 is disposed on the bottom surface 25a of the widened portion 25. Next, the bonding member 72 is cured. Next, a pre-cured bonding member 73 is disposed along the corner formed by the side surface 25b of the widened portion 25 and the surface 3a of the optical transmission member 3, and a pre-cured bonding member 75 is disposed between the wiring substrate 4 and the optical transmission member 3. Next, the bonding members 73 and 75 are cured. At this time, the gas generated from the bonding members 73 and 75 is released to the outside from the inside of the first recess 21 through the through hole 24. Next, a cover 6 is disposed on the surface 2b of the support 2. Next, a pre-cured bonding member 76 is disposed along the outer edge 6E of the cover 6. Next, the bonding member 76 is cured. A light-shielding film 61 is pre-set on the surface 6a of the cover 6. Through the above, the filter unit 1 is obtained.

[0093] [Structure of a lens barrel including a filter unit]

[0094] As shown Figure 8 in FIG. 3, the lens barrel 300 includes a barrel body 310, a condenser optical system 320 including a plurality of lenses, an imaging optical system 330 including a plurality of lenses, and the filter unit 1 described above. The lens barrel 300 serves as a replaceable lens of a hyperspectral camera. A hyperspectral camera is a camera that can split light into dozens of bands to hundreds of bands and obtain images for each band.

[0095] The barrel body 310 includes a main body portion 311 and a root end portion 312. The main body portion 311 holds the condenser optical system 320, the imaging optical system 330, and the filter unit 1. The root end portion 312 is configured to be detachable from and attachable to the camera body of the hyperspectral camera.

[0096] The condenser optical system 320 is disposed in a region on the side opposite to the root end portion 312 in the region inside the main body portion 311. The imaging optical system 330 is disposed in a region on the root end portion 312 side in the region inside the main body portion 311. The filter unit 1 is disposed in a region between the condenser optical system 320 and the imaging optical system 330 in the region inside the main body portion 311. The optical axis of the condenser 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 barrel body 310.

[0097] The condenser optical system 320 and the imaging optical system 330 constitute a non-telecentric optical system. The condenser optical system 320 is an optical system that condenses 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 condenser optical system 320. The filter unit 1 functions as an aperture at this position. The imaging optical system 330 forms an image of the light passing through the filter unit 1 on the image sensor of the hyperspectral camera. In addition, the condenser optical system 320 and the imaging optical system 330 may also constitute a telecentric optical system.

[0098] The filter unit 1 is fixed to the inside of the main body portion 311 by being sandwiched between the flange surface 311a provided on the main body portion and the fixing ring 313. The flange surface 311a is an inward flange surface provided on the main body portion 311 so as to face the condenser optical system 320 side. The filter unit 1 is fixed to the inside of the main body portion 311 in a state where the opening 23 is on the condenser 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 located at a position where the on-axis incident light and the off-axis incident light of the condenser optical system 320 intersect.

[0099] The connector 5 is disposed within the opening 311b formed in the main body portion 311. The connection port 51 of the connector 5 is exposed to the outside of the cylindrical body 310 via 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. Thereby, the gap between the side surface of the connector 5 and the inner surface of the opening 311b is sealed.

[0100] [Function and effect]

[0101] In the filter unit 1, the Fabry - Perot interference filter 10 is disposed within the first recess 21. Thereby, it is possible to make the filter unit 1 thinner in the optical axis direction of the Fabry - Perot interference filter 10 (i.e., the direction in which the pair of mirror portions 14, 15 face each other), that is, the Z - axis direction. In addition, if a part of the support 2 is formed thinner by forming the first recess 21, an external force acting on the support 2 easily reaches the Fabry - Perot interference filter 10. However, in the filter unit 1, when viewed from the Z - axis direction, the distance D1 in the Y - axis direction "from the inner edge 21E of the first recess 21 to the outer edge 2E of the support 2" is greater than the width Wf of the Fabry - Perot interference filter 10 in the Y - axis direction. Thereby, even if an external force acts on the support 2 from the side with respect to the Z - axis direction, it is possible to suppress the external force from reaching the Fabry - Perot interference filter 10. Thus, the filter unit 1 described above is suitable for being disposed in a narrow region in the optical axis direction of the Fabry - Perot interference filter 10.

[0102] In the filter unit 1, the optical characteristics of the filter unit 1 can be adjusted by changing the design of the depth of the first recess 21. For example, by designing the depth of the first recess 21 to be larger (designing the thickness from the bottom surface 21a of the first recess 21 to the surface 2b of the support 2 in the Z - axis direction to be smaller), light traveling obliquely with respect to the center C is less likely to be cut off in the opening 23, and the numerical aperture (NA) increases. On the other hand, by designing the depth of the first recess 21 to be small (designing the thickness from the bottom surface 21a of the first recess 21 to the surface 2b of the support 2 in the Z - axis direction to be large), light traveling obliquely with respect to the center C becomes more likely to be cut off in the opening 23, and the resolution of the Fabry - Perot interference filter 10 can be improved.

[0103] In the filter unit 1, when viewed from the Z-axis direction, the inner edge 21E of the first recess 21 includes a first portion 21Ea and a second portion 21Eb that face each other across the Fabry-Perot interference filter 10 in the Y-axis direction. When viewed from the Z-axis direction, the distance D1 from the first portion 21Ea to the outer edge 2E of the support 2 and the distance D1 from the second portion 21Eb to the outer edge 2E of the support 2 in the Y-axis direction are each greater than the width Wf of the Fabry-Perot interference filter 10 in the Y-axis direction. Thereby, even if an external force acts on the support 2 from the side with respect to the Z-axis direction, it is possible to further suppress the spread of the external force to the Fabry-Perot interference filter 10.

[0104] In the filter unit 1, the support 2 includes an enclosing portion 230 that encloses the first recess 21 when viewed from the Z-axis direction, and the height of the enclosing portion 230 in the Z-axis direction is greater than the thickness of the Fabry-Perot interference filter 10 in the Z-axis direction. Thereby, even if an external force acts on the support 2 from the side with respect to the Z-axis direction, it is possible to further suppress the spread of the external force to the Fabry-Perot interference filter 10.

[0105] In the filter unit 1, when viewed from the Z-axis direction, the width of the enclosing portion 230 in the Y-axis direction is greater than the width Wf of the Fabry-Perot interference filter 10 in the Y-axis direction. Thereby, even if an external force acts on the support 2 from the side with respect to the Z-axis direction, it is possible to further suppress the spread of the external force to the Fabry-Perot interference filter 10.

[0106] 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. Thereby, even if an external force acts on the support 2 from the side with respect to the Z-axis direction, it is possible to suppress the spread of the external force to the Fabry-Perot interference filter 10. Further, 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 arranged on the center line of the cylindrical body 310.

[0107] In the filter unit 1, when viewed from the Z-axis direction, the outer edge 2E of the support 2 has a circular shape. Thereby, even if an external force acts on the support 2 from the side with respect to the Z-axis direction, it is possible to suppress the spread of the external force to the Fabry-Perot interference filter 10 with good balance. Further, for example, when the cylindrical body 310 is cylindrical, the Fabry-Perot interference filter 10 can be easily and highly accurately arranged on the center line of the cylindrical cylindrical body 310.

[0108] In the filter unit 1, since the support 2 is a circular plate-like member, when the filter unit 1 is provided inside the cylindrical cylindrical body 310, it is possible to prevent the filter unit 1 from rolling inside the cylindrical cylindrical body 310.

[0109] 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 are each rectangular. In this case, the positioning of the Fabry-Perot interference filter 10 relative to the support 2 can also be easily and highly accurately performed.

[0110] In the filter unit 1, the wiring substrate 4 is arranged on the support 2 so as not to overlap the Fabry-Perot interference filter 10 when viewed from the Z-axis direction. Thereby, the filter unit 1 can be made thinner in the optical axis direction of the Fabry-Perot interference filter 10, i.e., the Z-axis direction.

[0111] In the filter unit 1, the Fabry-Perot interference filter 10 is arranged on the bottom surface 21a, and the wiring substrate 4 is arranged on the bottom surface 22a, and the bottom surface 21a and the bottom surface 22a are in the same plane. Thereby, the filter unit 1 can be made thinner in the optical axis direction of the Fabry-Perot interference filter 10, i.e., the Z-axis direction.

[0112] In the filter unit 1, the wiring substrate 4 is arranged in the second recess 22. Thereby, the filter unit 1 can be made thinner in the optical axis direction of the Fabry-Perot interference filter 10, i.e., the Z-axis direction. The second recess 22 reaches the outer edge 2E of the support 2 when viewed from the Z-axis direction. Thereby, electrical connection can be performed from the side with respect to the Z-axis direction.

[0113] In the filter unit 1, the Fabry-Perot interference filter 10 is arranged in the first recess 21, and the wiring substrate 4 is arranged in the second recess 22. Thereby, the height difference between the Fabry-Perot interference filter 10 and the wiring substrate 4 in the Z-axis direction is reduced, so when connecting the Fabry-Perot interference filter 10 and the wiring substrate 4 by the wire 8, the wire 8 can be easily connected to the Fabry-Perot interference filter 10 and the wiring substrate 4.

[0114] In the filter unit 1, the support 2 includes a partition portion 26 arranged between the first recess 21 and the second recess 22. Thereby, based on the partition portion 26, the positioning of the Fabry-Perot interference filter 10 and the wiring substrate 4 relative to the support 2 can be easily and highly accurately performed.

[0115] 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 greater 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. Thus, when viewed from the Z - axis direction, the opening 23 becomes very small compared to the support 2, so that stray light incident on the Fabry - Perot interference filter 10 can be suppressed.

[0116] In the lens barrel 300, the filter unit 1 serves as an aperture between the condenser optical system 320 and the imaging optical system 330. Thus, the depth of field can be deepened in the hyperspectral camera equipped with the lens barrel 300.

[0117] The filter unit 1 includes a wiring substrate 4, a light - transmitting member 3, and adhesive members 7 (adhesive members 74, 75). The light - transmitting member 3 covers at least the opening of the first recess 21, and the adhesive members 7 are disposed between the wiring substrate 4 and the support 2 and between the wiring substrate 4 and the light - transmitting member 3. Thus, an increase in the thickness in the optical axis direction (i.e., the Z - axis direction) of the Fabry - Perot interference filter 10 can be suppressed, and a package for accommodating the Fabry - Perot interference filter 10 can be formed by the support 2, the wiring substrate 4, the light - transmitting member 3, and the adhesive members 7. Thus, the Fabry - Perot interference filter 10 can be protected from the influence of moisture or particles, etc.

[0118] In the filter unit 1, with respect to the width Wf of the Fabry - Perot interference filter 10 in the Y - axis direction, the width Ws of the wiring substrate 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 "Wf ≤ W1 < Ws ≤ W2" holds. Thus, 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 portion between the first recess 21 and the second recess 22 as a reference (for example, a mechanical positioning portion or a reference coordinate), the positioning of the Fabry - Perot interference filter 10 and the wiring substrate 4 relative to the support body 2 can be easily and highly accurately implemented. In addition, compared with the case where the width W1 of the first recess 21 is made to coincide with the width W2 of the second recess 22, the strength of the support body 2 can be ensured. Further, even if an external force acts on the wiring substrate 4 from the side in the Z - axis direction, the external force can be released from the boundary portion between the first recess 21 and the second recess 22 to the support body 2, and the spread of the external force to the Fabry - Perot interference filter 10 can be suppressed. In addition, in the filter unit 1, compared with the case where the width W1 of the first recess 21 is made to coincide with the width W2 of the second recess 22, the portions on both sides of the first recess 21 in the Y - axis direction in the support body 2 are closer to the wiring substrate 4, so the heat generated in the wiring substrate 4 can be efficiently released to the support body 2.

[0119] In the filter unit 1, with respect to 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 "Wf = W1" holds. Thus, the positioning of the Fabry - Perot interference filter 10 relative to the support body 2 can be implemented more easily and with higher accuracy.

[0120] In the filter unit 1, with respect to the width Ws of the wiring substrate 4 in the Y - axis direction and the width W2 of the second recess 22 in the Y - axis direction, the relationship "Ws = W2" holds. Thus, the positioning of the wiring substrate 4 relative to the support body 2 can be implemented more easily and with higher accuracy.

[0121] In the filter unit 1, a through - hole 24 is formed in the support body 2, which opens on the inner surface of the first recess 21 and the surface 2b of the support body 2. Thus, when manufacturing the filter unit 1, even if gas is generated inside the first recess 21 in a state where the opening of the first recess 21 is covered by the light - transmissive member 3, the gas can escape to the outside through the through - hole 24.

[0122] [Modified Example]

[0123] The present invention is not limited to the above-described embodiments. For example, regarding the width Wf of the Fabry - Perot interference filter 10 in the Y - axis direction, the width Ws of the wiring substrate 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 "Wf≤W1<Ws≤W2" holds ( Figure 5 the case shown), the relationship "Wf<W1" may also hold. Similarly, when the relationship "Wf≤W1<Ws≤W2" holds ( Figure 5 the case shown), the relationship "Ws<W2" may also hold.

[0124] In addition, as Figure 9 shown, regarding the width Wf of the Fabry - Perot interference filter 10 in the Y - axis direction, the width Ws of the wiring substrate 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 "Ws≤W2<Wf≤W1" may also hold. In this case, it is also possible to easily and highly accurately perform the positioning of the Fabry - Perot interference filter 10 and the wiring substrate 4 with respect to the support 2. In addition, compared with the case where the width W2 of the second recess 22 is made to coincide with the width W1 of the first recess 21, the strength of the support 2 can be ensured. In addition, it is possible to suppress stray light from entering the Fabry - Perot interference filter 10 through the second recess 22 in which the wiring substrate 4 is disposed. Moreover, compared with the case where the width W2 of the second recess 22 is made to coincide with the width W1 of the first recess 21, the portions on both sides of the second recess 22 in the Y - axis direction in the support 2 are closer to the wiring substrate 4, so the heat generated in the wiring substrate 4 can be efficiently released to the support 2.

[0125] In addition, the widened portion 25 only needs to be widened at least in the Y - axis direction with respect to the opening of the first recess 21. As an example, as Figure 9 shown, the widened portion 25 may also extend from the opening of the first recess 21 to the opening of the second recess 22 and 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 applicable not only to the case where the relationship "Ws≤W2<Wf≤W1" holds ( Figure 9 the case shown), but also to the case where the relationship "Wf≤W1<Ws≤W2" holds ( Figure 5 the case shown). If the widened portion 25 extends from the opening of the first recess 21 to the opening of the second recess 22, it is possible to suppress an increase in the thickness in the Z - axis direction, which is the optical axis direction of the Fabry - Perot interference filter 10, and to more stably support the light - transmitting member 3 on the support 2.

[0126] In addition, as Figure 10As shown in FIGS. (a) and (b), the filter unit 1 may also include a flexible wiring board 9 for external connection to wiring. In Figure 10 In the example of the lens barrel shown in FIG. (a), 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 within the opening 311b of the barrel 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 Figure 10 In the example of the lens barrel shown in FIG. (b), 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 led out to the outside through the opening 311b of the barrel 310. In this case, an adhesive member 77 is disposed between the flexible wiring board 9 and the inner surface of the opening 311b.

[0127] In addition, the filter unit 1 may also include a Fabry - Perot interference filter as shown in Figure 11 . A Fabry - Perot interference filter 400 shown in Figure 11 will be described. The Fabry - Perot interference filter 400 includes a substrate layer 411, a mirror portion 412, and a drive electrode 413. The substrate layer 411 has opposing surfaces 411a and 411b. The substrate layer 411 is formed of a light - transmissive material. The mirror portion 412 is, for example, a metal film, a dielectric multilayer film, or a composite film thereof. The drive electrode 413 is formed of a metal material, for example.

[0128] The Fabry - Perot interference filter 400 further includes a substrate layer 421, a mirror portion 422, and a drive electrode 423. The substrate layer 421 has opposing surfaces 421a and 421b. The substrate layer 421 is formed of a light - transmissive material. The mirror portion 422 is, for example, a metal film, a dielectric multilayer film, or a composite film thereof. The drive electrode 423 is formed of a metal material, for example.

[0129] A recess 414 is formed on the surface 411a of the substrate layer 411. A protrusion 415 is provided on the bottom surface 41ea of the recess 414. When taking the bottom surface 414a as a reference, the height of the end surface 415a of the protrusion 415 is lower than the height of the surface 411a of the substrate layer 411. The mirror portion 412 is disposed on the end surface 415a of the protrusion 415. The drive electrode 413 is disposed on the bottom surface 414a of the recess 414 so as to surround the protrusion 415. The drive electrode 413 is electrically connected to an electrode pad (not shown) via wiring (not shown) provided on the substrate layer 411. This electrode pad is provided, for example, in an area of the substrate layer 411 that can be accessed from the outside.

[0130] The surface 421b of the substrate layer 421 is joined to the surface 411a of the substrate layer 411, for example, by plasma bonding or the like. A mirror portion 422 and a drive electrode 423 are provided on the surface 421b of the substrate layer 421. The mirror portion 422 faces the mirror portion 412 with a gap S therebetween. The drive electrode 423 is provided on the surface 421b of the substrate layer 421 so as to surround the mirror portion 422 and faces the drive electrode 413 with a gap S therebetween. The drive electrode 423 is electrically connected to an electrode pad (not shown) via a wiring (not shown) provided in the substrate layer 421. The electrode pad is provided, for example, in an area of the substrate layer 421 that can be accessed from the outside.

[0131] On the surface 421a of the substrate layer 421, a groove 424 is formed so as to surround the mirror portion 422 and the drive 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 forms a diaphragm-like holding portion 425 with the portion where the groove 424 is formed as a diaphragm, and can move in the direction in which the pair of mirror portions 412 and 422 face each other.

[0132] In addition, the diaphragm-like holding portion 425 may also be constituted by a groove formed on at least one of the surface 421a and the surface 421b of the substrate layer 421 so as to surround the mirror portion 422 and the drive electrode 423 when viewed from the Z-axis direction. A groove may also be formed in the substrate layer 411 so as to surround the mirror portion 412 and the drive electrode 413 when viewed from the Z-axis direction, thereby constituting a diaphragm-like holding portion in the substrate layer 411. Instead of the diaphragm-like holding portion, the holding portion may be constituted by a plurality of beams arranged radially.

[0133] In Figure 11 In the Fabry - Perot interference filter 400 shown, if a potential difference is generated between the drive electrode 413 and the drive electrode 423 by applying a voltage to the drive electrode 413 and the drive electrode 423, an electrostatic force corresponding to the potential difference is generated between the drive electrode 413 and the drive electrode 423. By generating an electrostatic force between the drive electrode 413 and the drive electrode 423, the portion of the substrate layer 421 surrounded by the groove 424 is attracted to the side of the substrate layer 411, 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 passes through.

[0134] In addition, in the filter unit 1, when viewed from the Z-axis direction, the outer edge 2E of the support 2 may have a shape other than a circular shape such as a rectangular shape. In the filter unit 1, the outer edge 10E of the Fabry - Perot interference filter 10, the outer edge 4E of the wiring substrate 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 rectangular shape.

[0135] In the filter unit 1, when viewed from the Z-axis direction, the Fabry-Perot interference filter 10 may also be offset from the center C of the support 2. In the filter unit 1, the mounting surface of the support 2 on which the Fabry-Perot interference filter 10 is disposed may not 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 substrate 4 is disposed may not 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 disposed and the mounting surface of the support 2 on which the wiring substrate 4 is disposed may not be in the same plane.

[0136] In the filter unit 1, the entire Fabry-Perot interference filter 10 may not be disposed within the first recess 21. In the filter unit 1, the entire light transmission member 3 may not be disposed within the widened portion 25. In the filter unit 1, the entire wiring substrate 4 may not be disposed within the second recess 22. In the filter unit 1, the wiring substrate 4 may be mounted on the housing 200 in such a manner that a part of the wiring substrate 4 is buried in the surrounding portion 230. Further, "a part of the wiring substrate 4 is buried in the surrounding portion 230" means that when viewed from any one of the X-axis direction, the Y-axis direction, and the Z-axis direction, this part of the wiring substrate 4 overlaps with the surrounding portion 230.

[0137] In the filter unit 1, the support 2 may not include the partition portion 26 disposed between the first recess 21 and the second recess 22. In the filter unit 1, the first recess 21 and the second recess 22 may be connected to each other. When the support 2 includes the partition portion 26, the partition portion 26 may not be completely separated from the first recess 21 and the second recess 22, but may be partially separated.

[0138] When the support 2 includes the partition portion 26, the height of the partition portion 26 in the Z-axis direction is not limited to the described height. For example, the height of the partition portion 26 in the Z-axis direction may be higher than the height of the Fabry-Perot interference filter 10 in the Z-axis direction with the bottom surface 21a of the first recess 21 as a reference. The height of the partition portion 26 in the Z-axis direction may be higher than the height of the wiring substrate 4 in the Z-axis direction with the bottom surface 22a of the second recess 22 as a reference. The partition portion 26 may be formed separately from the support 2 and may be mounted on the support 2.

[0139] 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 also be greater than the width of the Fabry-Perot interference filter 10 in this one direction. In this case, the "distance from the inner edge 21E of the first recess 21 to the outer edge 2E of the support 2" in the Y-axis direction may be equal to or less than the width Wf of the Fabry-Perot interference filter 10 in the Y-axis direction.

[0140] In the filter unit 1, when viewed from the Z-axis direction, at least one of the "distance D1 from the first portion 21Ea to the outer edge 2E of the support 2" and the "distance D1 from the second portion 21Eb to the outer edge 2E of the support 2" in the Y-axis direction may be equal to or less than the width Wf of the Fabry-Perot interference filter 10 in the Y-axis direction.

[0141] 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 also be greater than the length of the diagonal of the outer edge 10E of the Fabry-Perot interference filter 10. When viewed from the Z-axis direction, the width of the opening 23 may also be less than the width of the Fabry-Perot interference filter 10 in the direction perpendicular to this one side.

[0142] In the filter unit 1, the opening 23 is formed as a light passage portion in the support 2. However, for example, the region within the opening 23 may be filled with a light-transmissive material, or an optical element (such as a lens, a filter, etc.) may be disposed within the opening 23, etc., and the light-transmissive portion is formed as a light passage portion in the support 2. In any case, the light passage portion can allow the light emitted from the Fabry-Perot interference filter 10 (or the Fabry-Perot interference filter 400) to pass through, or can also allow the light incident on the Fabry-Perot interference filter 10 (or the Fabry-Perot interference filter 400) to pass through. In the filter unit 1, the through-hole 24 only needs to open 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 anti-light reflection film may be formed on at least one of the surface 2b of the support 2 and the inner surface of the opening 23. The anti-light reflection film may also be formed over the entire surface of the support 2. As an example, when the support 2 is formed of stainless steel, the anti-light reflection film may also be formed by performing a chromium plating treatment on the surface of the support 2.

[0143] In the filter unit 1, the height of the surrounding portion 230 in the Z-axis direction may also be smaller than the thickness of the Fabry - Perot interference filter 10. Additionally, in the filter unit 1, for example, a recess may be formed in the surrounding portion 230 to thin a part of the surrounding portion 230. For example, by forming recesses (such as slits along the X-axis direction) that open on the surface 2a in the portion of the support 2 from the first portion 21Ea of the inner edge 21E to the outer edge 2E of the support 2 and in the portion of the support 2 from the second portion 21Eb of the inner edge 21E to the outer edge 2E of the support 2, a part of the surrounding portion 230 can be thinned.

[0144] 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 with 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 with 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 continuously arranged so as to surround the opening 23 when viewed from the Z-axis direction. Thus, the gap between the Fabry - Perot interference filter 10 and the bottom surface 21a of the first recess 21 is sealed by the adhesive member 71. Additionally, 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. Thereby, it is possible to prevent the Fabry - Perot interference filter 10 from being exposed to the outside of the filter unit 1 through the opening 23.

[0145] In the filter unit 1, the Fabry - Perot interference filter 10 needs to be arranged in the first recess 21, but as long as the wiring substrate 4 is arranged on the support 2, it does not need to be arranged in the second recess 22. That is, the second recess 22 for arranging the wiring substrate 4 may not be formed in the support 2.

[0146] In the filter unit 1, the area within the opening 18 may be filled with a light-transmissive material (such as a light-transmissive resin, etc.), or an optical element (such as a lens, a filter, etc.) may be arranged within the opening 18. That is, the area within the opening 18 may also be formed as a light-transmissive area in the Fabry - Perot interference filter 10. Even in this case, when viewed from the Z-axis direction, by having this light-transmissive area located inside the opening 23, it is possible to suppress the incidence of stray light onto the Fabry - Perot interference filter 10.

[0147] Explanation of reference numerals

[0148] 1... Filter unit

[0149] 2... Support

[0150] 2b... Surface (outer surface)

[0151] 2E… Outer edge

[0152] 3… Light transmission member

[0153] 4… Wiring board

[0154] 7… Adhesive member

[0155] 10, 400… Fabry - Perot interference filter

[0156] 10E… Outer edge

[0157] 14, 15, 412, 422… Mirror part

[0158] 21… First recess

[0159] 21E… Inner edge [[ID=z8]]

[0160] 21Ea… First part

[0161] 21Eb… Second part

[0162] 21a… Bottom surface (first mounting surface, inner surface)

[0163] 22… Second recess

[0164] 22a… Bottom surface (second mounting surface)

[0165] 23… Opening (light passing part)[[ID=4s]]

[0166] 24… Through - hole

[0167] 26… Partition part

[0168] 230… Enclosing part. It should be noted that in the original text, there may be some inconsistent or unclear notations. For example, the "z8" in the translated text is likely a misrepresentation in the original text. It's recommended to double - check the original patent text for accuracy.

Claims

1. A filter unit, wherein: It includes: A support having a light passing portion; and A Fabry - Perot interference filter, which includes a pair of mirror portions that face each other in a first direction and the distance between them is variable, and is arranged on the support in a manner that overlaps with the light passing portion when viewed from the first direction. In the support, a first recess is formed with the first direction as the depth direction. The Fabry - Perot interference filter is arranged in the first recess. 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.

2. The filter unit according to claim 1, wherein: When viewed from the first direction, the inner edge of the first recess includes a first portion and a second portion that face each other with the Fabry - Perot interference filter sandwiched therebetween in one direction. When viewed from the first direction, the distance from the first portion to the outer edge of the support in the one direction and the distance from the second portion to the outer edge of the support in the one direction are respectively greater than the width of the Fabry - Perot interference filter in the one direction.

3. The filter unit according to claim 1 or 2, wherein: The support includes an enclosing portion that encloses the first recess when viewed from the first direction. The height of the enclosing portion in the first direction is greater than the thickness of the Fabry - Perot interference filter in the first direction.

4. The filter unit according to claim 3, wherein: When viewed from the first direction, the width of the enclosing portion in the one direction is greater than the width of the Fabry - Perot interference filter in the one direction.

5. The filter unit according to any one of claims 1 to 4, wherein: When viewed from the first direction, the Fabry - Perot interference filter is located at the center of the support.

6. The filter unit according to claim 5, wherein: When viewed from the first direction, the outer edge of the support is circular.

7. The filter unit according to any one of claims 1 to 6, wherein: When viewed from the first direction, the outer edge of the Fabry - Perot interference filter and the inner edge of the first recess are respectively rectangular.

8. The filter unit according to any one of claims 1 to 7, wherein: It further includes a wiring substrate electrically connected to the Fabry - Perot interference filter. The wiring substrate is arranged on the support in a manner that does not overlap with the Fabry - Perot interference filter when viewed from the first direction.

9. The filter unit according to any one of claims 1 to 8, wherein: It further includes a wiring substrate electrically connected to the Fabry - Perot interference filter. The Fabry - Perot interference filter is arranged on the first mounting surface of the support. The wiring substrate is arranged on the second mounting surface of the support. The first mounting surface and the second mounting surface are in the same plane.

10. The filter unit according to any one of claims 1 to 9, wherein, it further includes a wiring substrate electrically connected to the Fabry - Perot interference filter, in the support body, a second recess is formed with the first direction as the depth direction, the wiring substrate is disposed in the second recess, when viewed from the first direction, the second recess reaches the outer edge of the support body.

11. The filter unit according to any one of claims 1 to 10, wherein, it further includes a wiring substrate electrically connected to the Fabry - Perot interference filter, in the support body, a second recess is formed with the first direction as the depth direction, the wiring substrate is disposed in the second recess, the support body further includes a partition portion disposed between the first recess and the second recess.

12. The filter unit according to any one of claims 1 to 11, wherein, the light passing portion is an opening formed in the support body, when viewed from the first direction, the outer edge of the Fabry - Perot interference filter is rectangular, 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 body 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, 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.

13. The filter unit according to any one of claims 1 to 12, wherein, it further includes a wiring substrate electrically connected to the Fabry - Perot interference filter; a light transmission member; and an adhesive member, in the support body, a second recess is formed with the first direction as the depth direction, the wiring substrate is disposed in the second recess, the light transmission member at least covers the opening of the first recess, the adhesive member is disposed between the wiring substrate and the support body and between the wiring substrate and the light transmission member.

14. The filter unit according to any one of claims 1 to 13, wherein, it further includes a wiring substrate electrically connected to the Fabry - Perot interference filter, in the support body, a second recess is formed with the first direction as the depth direction, the first recess and the second recess are arranged in a second direction perpendicular to the first direction, the wiring substrate is disposed in the second recess, if the width of the Fabry - Perot interference filter in a third direction perpendicular to both the first direction and the second direction is set as Wf, the width of the wiring substrate in the third direction is set as Ws, the width of the first recess in the third direction is set as W1, and the width of the second recess in the third direction is set as W2, then the relationship of "Wf≤W1<Ws≤W2” or the relationship of "Ws≤W2<Wf≤W1” holds.

15. The filter unit according to claim 14, wherein, the relationship of "Wf = W1” holds.

16. The optical filter unit according to claim 14 or 15, wherein the relationship "Ws = W2" holds.

17. The optical filter unit according to any one of claims 1 to 16, wherein a through hole that opens on the inner surface of the first concave portion and the outer surface of the support body is formed in the support body.

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