Filter device, hyperspectral camera, and filter system

Abstract

To provide a filter device, a hyperspectral camera, and a filter system capable of improving convenience.SOLUTION: The filter unit 22 of the filter device 2 includes the support body 31, the FPI filter 10 disposed on the support body 31, and the wiring part having the first terminal electrically connected to the FPI filter 10 and the second terminal for electrical connection with the outside of the housing 21 and disposed on the support body 31. An insertion portion 24 is formed in a side 21d of the housing 21. The support 31 has a first portion 41 on which the FPI filter 10 is disposed, and a second portion 42 extending so as to intersect the first portion 41. The first part 41 is inserted into the insertion portion 24 of the housing 21 such that the light transmission region of the FPI filter 10 is located on the optical axis A. The second portion 42 faces the side surface 21d of the housing 21. The filter unit 22 is detachably fixed to the side 21d of the housing 21 at the second portion 42.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a filter device with a Fabry-Perot interference filter, a hyperspectral camera, and a filter system. [Background technology]

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

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

[0004] It is conceivable that the above-described filter device could be applied to a hyperspectral camera that separates light into wavelengths using a Fabry-Perot interference filter and captures the separated light. However, such a configuration leaves room for improvement, for example, in terms of convenience.

[0005] Therefore, an object of the present invention is to provide a filter device, a hyperspectral camera, and a filter system that can improve convenience. [Means for solving the problem]

[0006] The filter device of the present invention is [1] "comprised of a filter unit and a housing having a light incident portion into which light is incident and through which the light incident from the light incident portion travels along an optical axis, the filter unit comprising a support body having a light passing portion formed therein, and a Fabry-Perot interference filter having a pair of mirror portions facing each other in an optical axis direction parallel to the optical axis and having a variable distance therebetween, the filter unit comprising: a first terminal electrically connected to the Fabry-Perot interference filter; and a second terminal for electrical connection to the outside of the housing, the Fabry-Perot interference filter having a first terminal electrically connected to the Fabry-Perot interference filter when viewed from the optical axis direction. a wiring section arranged on the support so as not to overlap with the light transmission region of the interference filter, an insertion section being formed on the side surface of the housing, the support having a first section in which the light passing section is formed and in which the Fabry-Perot interference filter is arranged, and a second section extending to intersect with the first section, the first section being inserted into the insertion section of the housing so that the light transmission region of the Fabry-Perot interference filter is positioned on the optical axis, the second section facing the side surface of the housing, and the filter unit being detachably fixed to the side surface of the housing at the second section.

[0007] In this filter device, an insertion section is formed on the side surface of the housing, and the support has a first section in which a light transmitting section is formed and in which a Fabry-Perot interference filter is disposed, and a second section extending to intersect with the first section. The first section is inserted into the insertion section of the housing so that the light transmission region of the Fabry-Perot interference filter is positioned on the optical axis, and the second section faces the side surface of the housing. The filter unit is removably fixed to the side surface of the housing at the second section. By adopting this structure, the filter unit can be easily replaced by inserting and removing it from the insertion section of the housing, which improves convenience compared to, for example, a case in which the filter unit is non-removably disposed within the housing. For example, in this filter device, the filter unit can be easily replaced with another filter unit having different transmission wavelength characteristics. In this way, this filter device improves convenience.

[0008] The filter device of the present invention may be [2] "the filter device according to [1], wherein one of the second part and the housing is provided with a positioning pin, and the other of the second part and the housing is provided with an insertion hole into which the positioning pin is inserted." In this case, the filter unit can be positioned relative to the housing by inserting the positioning pin into the insertion hole, and the Fabry-Perot interference filter can be positioned with high precision.

[0009] The filter device of the present invention may be [3] "the filter device according to [2], wherein a plurality of the positioning pins are provided, and the number of the insertion holes is the same as the number of the positioning pins." In this case, it is possible to suppress deviation of the arrangement angle of the filter unit (Fabry-Perot interference filter) with respect to the optical axis. Since deviation of the arrangement angle of the Fabry-Perot interference filter with respect to the optical axis significantly affects the transmission wavelength characteristics of the Fabry-Perot interference filter, suppressing such deviation is important.

[0010] The filter device of the present invention may be [4] "the filter device according to any one of [1] to [3], wherein a cover member for covering the second portion is provided on the side surface of the housing so that the second portion is not exposed to the outside of the housing." In this case, the influence of external factors (e.g., physical impact, stray light from outside the housing, etc.) on the filter unit can be suppressed.

[0011] The filter device of the present invention may be [5] "the filter device according to [4], wherein the cover member has an extraction hole for extracting wiring electrically connected to the second terminal to the outside of the housing." In this case, the wiring can be easily extracted to the outside of the housing.

[0012] The filter device of the present invention may be [6] "the filter device according to any one of [1] to [5], wherein the first terminal and the second terminal are disposed in the first portion, and the distance from the second terminal to the second portion is shorter than the distance from the first terminal to the second portion." In this case, since the second terminal is disposed relatively close to the second portion, the second terminal can be easily electrically connected to the outside of the housing via, for example, a wire.

[0013] The filter device of the present invention may be [7] "the filter device according to any one of [1] to [6], wherein the filter unit further includes a bandpass filter, and the first portion has a convex portion formed therein that protrudes from the surface on which the Fabry-Perot interference filter is disposed, and the bandpass filter is disposed on the convex portion." In this case, by disposing the bandpass filter on the convex portion, the bandpass filter can be disposed so as to overlap with the Fabry-Perot interference filter when viewed from the optical axis direction, which makes it easier to align the Fabry-Perot interference filter and the bandpass filter.

[0014] The filter device of the present invention may be [8] "the filter device according to any one of [1] to [7], wherein the filter unit further includes an aperture member having an aperture formed therein, the aperture member being disposed in the first portion such that the aperture overlaps the light-transmitting region and the light incident from the light incident portion toward the Fabry-Perot interference filter passes through the aperture." In this case, the aperture member can be disposed on the light incident side of the Fabry-Perot interference filter. Also, the aperture member can prevent light from being incident obliquely on the Fabry-Perot interference filter.

[0015] The filter device of the present invention may be [9] "the filter device according to [8], wherein the aperture member has light absorption properties." In this case, for example, light reflected by a Fabry-Perot interference filter can be absorbed by the aperture member, and the light reflected by the Fabry-Perot interference filter can be prevented from becoming stray light within the housing.

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

[10] "the filter device according to [8] or [9], in which the aperture is smaller than the light transmission area of ​​the Fabry-Perot interference filter when viewed from the optical axis direction." In this case, for example, it is possible to further prevent light reflected by the Fabry-Perot interference filter from becoming stray light within the housing. In addition, the aperture member can further prevent light from being incident obliquely on the Fabry-Perot interference filter.

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

[11] "a filter device according to any one of [8] to

[10] , in which the aperture member is disposed on a surface of the first portion on one side in the optical axis direction, and the Fabry-Perot interference filter is disposed on a surface of the first portion on the other side in the optical axis direction." In this case, the Fabry-Perot interference filter and the aperture member can be suitably disposed on a support. Furthermore, because the Fabry-Perot interference filter and the aperture member are disposed to face each other across the first portion, the aperture member can further prevent light from being obliquely incident on the Fabry-Perot interference filter.

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

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

[11] , further comprising: a first lens unit that condenses or collimates the light traveling from the light incident unit toward the Fabry-Perot interference filter; and a second lens unit that forms an image of the light transmitted through the Fabry-Perot interference filter, wherein the first lens unit and the second lens unit are disposed within the housing." In this case, a filter device including the first lens unit and the second lens unit can be configured. Furthermore, the filter device can be made smaller than when, for example, the first lens unit and the second lens unit are disposed outside the housing.

[0019] The hyperspectral camera of the present invention is

[13] "a hyperspectral camera comprising the filter device according to any one of [1] to

[12] and an image sensor that captures the light transmitted through the Fabry-Perot interference filter." This hyperspectral camera can improve convenience for the reasons described above.

[0020] The filter system of the present invention is

[14] "a filter system using the filter device according to any one of [1] to

[13] , comprising a plurality of filter units, each of which has a transmission wavelength characteristic of the Fabry-Perot interference filter different from one another, and the housing, and one of the plurality of filter units is fixed to the housing." This filter system can improve convenience for the reasons described above. [Effects of the Invention]

[0021] According to the present invention, it is possible to provide a filter device, a hyperspectral camera, and a filter system that can improve convenience. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a cross-sectional view of a hyperspectral camera. [Figure 2] FIG. 2 is a cross-sectional view of the filter device. [Figure 3] FIG. [Figure 4] FIG. 2 is a perspective view of a filter unit. [Figure 5] FIG. 2 is a perspective view of a filter unit. [Figure 6] FIG. 2 is a perspective view of a filter unit. [Figure 7] FIG. 2 is a cross-sectional view of the filter unit. [Figure 8] 10 is a diagram showing the relationship between the light passing portion of the support, the light transmitting region of the Fabry-Perot interference filter, and the size of the aperture of the aperture member. FIG. [Figure 9] FIG. 1 is a perspective view of a Fabry-Perot interference filter. [Figure 10] 10 is a cross-sectional view of the Fabry-Perot interference filter taken along line XX in FIG. 9. [Figure 11] FIG. 1 is a configuration diagram of a filter system. DETAILED DESCRIPTION OF THE INVENTION

[0023] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same or equivalent elements are designated by the same reference numerals, and redundant description will be omitted.

[0024] 1, a hyperspectral camera 1 according to an embodiment includes a filter device 2 and an imaging device 7 (camera unit). The filter device 2 is detachably attached to the imaging device 7. The hyperspectral camera 1 is a camera that can disperse light into tens to hundreds of bands according to wavelength and acquire images for each band.

[0025] The filter device 2 includes a housing 21, a filter unit 22, and an optical system 23. The filter unit 22 includes a support member 31 and a Fabry-Perot interference filter (hereinafter also referred to as an FPI filter) 10 fixed to the support member 31. The imaging device 7 includes a housing 71 and an imaging element 72 disposed within the housing 71. In the hyperspectral camera 1, light L passes through the FPI filter 10 along an optical axis A, and the light L that has passed through the FPI filter 10 is captured by the imaging element 72. First, the FPI filter 10 will be described below with reference to FIGS. 9 and 10. [Fabry-Perot interference filter]

[0026] As shown in Figures 9 and 10, the FPI filter 10 has a light-transmitting region 10a. The FPI filter 10 is, for example, a rectangular plate-shaped element. The FPI filter 10 is arranged so that its thickness direction is parallel to the optical axis direction D (a direction parallel to the optical axis A). The light-transmitting region 10a is, for example, a cylindrical region having a center line parallel to the optical axis direction D. When viewed from the optical axis direction D, the center of the light-transmitting region 10a coincides with the center of the FPI filter 10.

[0027] The FPI filter 10 includes a substrate 11 whose thickness direction is the optical axis direction D. The material of the substrate 11 is, for example, silicon, quartz, or glass. The substrate 11 has a first surface 11a and a second surface 11b opposite the first surface 11a. The first surface 11a and the second surface 11b are, for example, flat surfaces perpendicular to the optical axis direction D. A first laminate structure 12 is laminated on the first surface 11a, and a second laminate structure 13 is laminated on the second surface 11b.

[0028] 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 first surface 11a of the substrate 11. That is, the first stacked body 122 is disposed on the first surface 11a via the antireflection layer 121, and the second stacked body 124 is disposed on the opposite side of the first stacked body 122 from the substrate (upper side in FIG. 10). An 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 substrate 11 is made of silicon, the antireflection layer 121 and the intermediate layer 123 are each made of, for example, silicon oxide. The thickness of the intermediate layer 123 is, for example, an integral multiple of ½ of the design center wavelength. The thickness of the intermediate layer 123 may be larger than an integral multiple of 1 / 2 of the design central wavelength, if necessary.

[0029] A portion of the first stack 122 corresponding to the light-transmitting region 10a functions as the mirror section 14. That is, the first stack 122 has the mirror section 14. The mirror section 14 is supported on the substrate 11 via an anti-reflection layer 121. As an example, the first stack 122 is configured by alternately stacking multiple polysilicon layers and multiple silicon nitride layers. The optical thickness of each layer that configures the mirror section 14 is, for example, an integral multiple of ¼ of the design central wavelength. Note that a silicon oxide layer may be used instead of the silicon nitride layer.

[0030] The portion of the second stack 124 corresponding to the light-transmitting region 10a functions as the mirror portion 15. That is, the second stack 124 includes the mirror portion 15. The mirror portion 15 is supported on the substrate 11 via the anti-reflection layer 121, the first stack 122, and the intermediate layer 123, and faces the mirror portion 14 across the gap S in the optical axis direction D. As an example, the second stack 124 is configured by alternately stacking multiple polysilicon layers and multiple silicon nitride layers. The optical thickness of each layer constituting the mirror portion 15 is, for example, an integral multiple of ¼ of the design center wavelength. Note that a silicon oxide layer may be used instead of the silicon nitride layer. A plurality of through-holes are formed in the portion of the second stack 124 corresponding to the gap S to an extent that does not substantially affect the function of the mirror portion 15. The multiple through-holes are used when forming the gap S by removing a portion of the intermediate layer 123 by etching.

[0031] A first electrode 125 and a second electrode 126 are formed on the mirror section 14. The first electrode 125 surrounds the light-transmitting region 10a when viewed from the optical axis direction D. The second electrode 126 overlaps with the light-transmitting region 10a when viewed from the optical axis direction D. The shape of the second electrode 126 when viewed from the optical axis direction D is substantially the same as the shape of the light-transmitting region 10a when viewed from the optical axis direction D. Each of the first electrode 125 and the second electrode 126 is formed by doping impurities into a portion of a polysilicon layer to reduce the resistance of that portion.

[0032] A third electrode 127 is formed on the mirror section 15. The third electrode 127 faces the first electrode 125 and the second electrode 126 across a gap S. The third electrode 127 is formed by doping an impurity into a portion of a polysilicon layer to reduce the resistance of that portion.

[0033] A pair of terminals 16 is provided on the first laminate structure 12 so as to sandwich the light-transmitting region 10a (see FIG. 9). Each terminal 16 is disposed in a through-hole formed in the second laminate 124 and the intermediate layer 123 so as to open on the opposite side from the substrate 11 and reach the first laminate 122. Each terminal 16 is electrically connected to the first electrode 125 via a wiring 125a.

[0034] The first laminate structure 12 is provided with a pair of terminals 17 sandwiching the light-transmitting region 10a therebetween (see FIG. 9). Each terminal 17 is disposed in a through-hole formed in the second laminate 124 and the intermediate layer 123 so as to open on the 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. The direction in which the pair of terminals 17 sandwich the light-transmitting region 10a is perpendicular to the direction in which the pair of terminals 16 sandwich the light-transmitting region 10a therebetween (see FIG. 9).

[0035] A pair of trenches 122a are formed in the first stack 122. Each trench 122a extends in an annular shape so as to surround a portion of the wiring 126a extending from each terminal 17 in the optical axis direction D. Each trench 122a electrically insulates the first electrode 125 from the wiring 126a. A trench 122b is formed in the first stack 122. The trench 122b extends in an annular shape along the inner edge of the first electrode 125. The trench 122b electrically insulates the first electrode 125 from the second electrode 126. The area inside each trench 122a, 122b may be filled with an insulating material or may be an empty space.

[0036] A pair of trenches 124a are formed in the second stack 124. Each trench 124a extends in an annular shape so as to surround each terminal 16. Each trench 124a electrically insulates each terminal 16 from the third electrode 127. The area within each trench 124a may be filled with an insulating material or may be an empty space.

[0037] The second stacked structure 13 includes an antireflection layer 131, a third stacked body 132, an intermediate layer 133, and a fourth stacked body 134. The antireflection layer 131, the third stacked body 132, the intermediate layer 133, and the fourth stacked body 134 are stacked in this order on the second surface 11b of the substrate 11. The antireflection layer 131 and the intermediate layer 133 have the same structures as the antireflection layer 121 and the intermediate layer 123, respectively. The third stacked body 132 and the fourth stacked body 134 have stacked structures symmetrical to the first stacked body 122 and the second stacked body 124, respectively, with respect to the substrate 11. The antireflection layer 131, the third stacked body 132, the intermediate layer 133, and the fourth stacked body 134 have the function of suppressing warpage of the substrate 11.

[0038] A recess 18 is formed on the surface 13a of the second laminate structure 13 opposite the substrate 11. The recess 18 is open on the side opposite the substrate 11. The recess 18 overlaps with the light-transmitting region 10a when viewed from the optical axis direction D. The shape of the recess 18 when viewed from the optical axis direction D is substantially the same as the shape of the light-transmitting region 10a when viewed from the optical axis direction D, and is circular in this example. The center line of the recess 18 coincides with the center line of the light-transmitting region 10a. The recess 18 is formed in the third laminate 132, the intermediate layer 133, and the fourth laminate 134, and extends to the anti-reflection layer 131.

[0039] A light-shielding layer 135 is formed on the surface 13a of the second stacked structure 13. The light-shielding layer 135 is formed, for example, over the entire surface 13a. The material of the light-shielding layer 135 is, for example, aluminum. The light-shielding layer 135 blocks light L. In this example, the light-shielding layer 135 is a reflective layer that blocks light L by reflecting it. On the other hand, in areas where the light-shielding layer 135 is not formed (areas where the recesses 18 are formed in this example), the light L passes through. In other words, the light-transmitting region 10a corresponds to the area where the light-shielding layer 135 is not formed. In this way, in the FPI filter 10, the light-transmitting region 10a (aperture P1, light entrance opening) is defined by the light-shielding layer 135. That is, the light-transmitting region 10a (aperture P1, light entrance opening) is formed by providing a light-shielding layer 135 (reflective layer) in the region of the FPI filter 10 other than the light-transmitting region 10a when viewed from the optical axis direction D, while not providing the light-shielding layer 135 in the light-transmitting region 10a. Also, the aperture P1 is formed integrally with the FPI filter 10. The width of the aperture P1 is fixed (does not change).

[0040] A protective layer 136 is formed on the light-shielding layer 135 and on the inner surface of the recess 18. The material of the protective layer 136 is, for example, aluminum oxide. Note that by setting the thickness of the protective layer 136 to 100 nm or less (preferably about 30 nm), the optical influence of the protective layer 136 can be ignored.

[0041] In the FPI filter 10 configured as described above, when a voltage is applied to the first electrode 125 and the third electrode 127 via the multiple terminals 16 and 17, generating a potential difference between the first electrode 125 and the third electrode 127, an electrostatic force corresponding to the potential difference is generated between the first electrode 125 and the third electrode 127. The generation of the electrostatic force between the first electrode 125 and the third electrode 127 attracts the mirror portion 15 to the mirror portion 14, thereby adjusting the distance between the mirror portion 14 and the mirror portion 15. At this time, the second electrode 126, which has the same potential as the third electrode 127, functions as a compensation electrode, and the mirror portion 15 is kept flat in the light-transmitting region 10a.

[0042] In this way, in the FPI filter 10, the pair of mirror sections 14 and 15 facing each other in the optical axis direction D function as a pair of mirror sections with a variable distance between them. Here, the wavelength of light that passes through the FPI filter 10 depends on the distance between the mirror sections 14 and 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), it is possible to select the wavelength of light that passes through the FPI filter 10. In this way, the FPI filter 10 transmits light of a wavelength that corresponds to the distance between the mirror sections 14 and 15 out of the incident light. [Filter device]

[0043] 1 to 3, the filter device 2 includes a housing 21, a filter unit 22, and an optical system 23. The following description will be made with reference to the X direction perpendicular to the optical axis direction D and the Y direction perpendicular to the optical axis direction D and the X direction shown in FIGS.

[0044] The housing 21 is formed, for example, in a substantially cylindrical shape having a center line parallel to the optical axis direction D. The housing 21 has an incident portion 21a (light incident portion) into which light L enters, an exit portion 21b (light exit portion) from which the light L exits, and an attachment portion 21c to which the imaging device 7 is detachably attached. In this example, the incident portion 21a is configured as an end portion on one side of the housing 21 in the optical axis direction D, and the exit portion 21b is configured as an end portion on the other side of the housing 21 in the optical axis direction D. In the filter device 2, the light L incident from the incident portion 21a travels inside the housing 21 along the optical axis A and is emitted from the exit portion 21b toward the imaging device 7. In this example, the housing 21 is configured to include a substantially cylindrical main body portion and a cylindrical mount member M attached to the outer surface of the main body portion on the exit portion 21b side.

[0045] The mounting portion 21c is provided at the end of the housing 21 on the emission portion 21b side (the other end in the optical axis direction D). The mounting portion 21c detachably engages with a mounting portion 71b of the imaging device 7, which will be described later. For example, when the filter device 2 and the imaging device 7 are detachably attached by screwing, the mounting portion 21c is provided with one of a screw thread and a screw groove, and the mounting portion 71b is provided with the other of a screw thread and a screw groove that screws into the one. In this example, the mounting portion 21c is provided on a mount member M.

[0046] An insertion portion 24 is formed on a side surface 21d of the housing 21. The insertion portion 24 is formed to penetrate the housing 21 from the side surface 21d along the Y direction and is connected to the inside of the housing 21. In this example, the insertion portion 24 is formed on a flat portion 21e of the side surface 21d. That is, in this example, the side surface 21d has a cylindrical portion as well as a flat portion 21e that is a flat surface perpendicular to the Y direction. The insertion portion 24 has a shape corresponding to a first portion 41 of the support body 31 (a shape into which the first portion 41 can be inserted), which will be described later, and in this example, is formed as a slot portion that has a rectangular shape when viewed from the Y direction. The insertion portion 24 includes a through-hole portion that penetrates the housing 21 from the side surface 21d and a portion located inside the housing 21.

[0047] The flat portion 21e is provided with a plurality of positioning pins 21f (two in this example). The two positioning pins 21f are aligned along the X direction. The positioning pins 21f are inserted into insertion holes 48 formed in the support body 31, which will be described later. The flat portion 21e is also provided with fixing holes 21g to which fixing members 61, which will be described later, are fixed.

[0048] The filter unit 22 has a support 31, the above-mentioned FPI filter 10, a wiring portion 32, a bandpass filter 33, and an aperture member 34 (FIGS. 4 to 8). The filter unit 22 will be described in detail later.

[0049] The optical system 23 is disposed inside the housing 21 and guides light L that enters through the incident portion 21a and travels inside the housing 21 along the optical axis A. The optical system 23 includes a first lens portion 25 and a second lens portion 26. The first lens portion 25 is disposed on one side (the incident portion 21a side) of the FPI filter 10 in the optical axis direction D, and the second lens portion 26 is disposed on the other side (the exit portion 21b side) of the FPI filter 10 in the optical axis direction D.

[0050] The first lens unit 25 is a focusing optical system that focuses light L traveling from the incident unit 21a toward the FPI filter 10. The first lens unit 25 includes at least one lens, and in this example, has two lenses 25a and 25b (lens group) aligned along the optical axis direction D. The lenses 25a and 25b are fixed to the housing 21 by retaining rings 27a and 27b, which are annular retaining members. The retaining rings 27a and 27b are fixed to the housing 21 by screw feed (screw engagement). Note that the retaining ring 27a is not shown in FIGS. 1 and 2.

[0051] The second lens unit 26 is an imaging optical system that forms an image of the light L that passes through the FPI filter 10 and is emitted from the emission unit 21b. The second lens unit 26 includes at least one lens, and in this example, has three lenses 26a, 26b, and 26c (a lens group) aligned along the optical axis direction D. The lenses 26a, 26b, and 26c are fixed to the housing 21 by retaining rings 28a, 28b, and 28c, which are annular retaining members. The retaining rings 28a, 28b, and 28c are fixed to the housing 21 by screw feed (screw engagement). Note that the retaining ring 28c is not shown in FIGS. 1 and 2. [Filter unit]

[0052] The filter unit 22 will be described in detail with reference to Figures 1 to 8, and particularly Figures 4 to 8. The filter unit 22 has a support 31, an FPI filter 10, a wiring portion 32, a bandpass filter 33, and an aperture member 34.

[0053] The support 31 is formed in a substantially L-shape when viewed from the X direction, and includes a first portion 41 extending along the Y direction and a second portion 42 extending along the optical axis direction D so as to be perpendicular to the first portion 41. The first portion 41 is formed in a substantially flat plate shape (a substantially rectangular plate shape) overall, and includes a proximal portion 43 on the base end side connected to the second portion 42, and a distal portion 44 located on the opposite side (tip side) of the proximal portion 43 from the second portion 42. The proximal portion 43 is formed in a rectangular shape with long sides parallel to the X direction, and the distal portion 44 is formed in a substantially square shape. The width of the proximal portion 43 in the X direction is wider than the width of the distal portion 44 in the X direction. The wiring portion 32 is disposed in the proximal portion 43, and the FPI filter 10, the bandpass filter 33, and the aperture member 34 are disposed in the distal portion 44.

[0054] The first portion 41 has a first surface 41a facing one side (toward the incident portion 21a) in the optical axis direction D, and a second surface 41b facing the other side (toward the exit portion 21b) in the optical axis direction D. A light passing portion 45 through which light L passes is formed in the distal portion 44. The light passing portion 45 is a through-hole that passes through the distal portion 44 along the optical axis direction D. In this example, the light passing portion 45 is formed in a circular shape.

[0055] A pair of protrusions 46 are formed on the second surface 41b of the distal portion 44, facing each other in the X direction with the light transmitting portion 45 sandwiched between them. The protrusions 46 protrude from the second surface 41b of the distal portion 44 in the optical axis direction D and extend along the Y direction. In this example, the pair of protrusions 46 are formed on one end and the other end of the distal portion 44 in the X direction, respectively.

[0056] The FPI filter 10 is fixed on the second surface 41b of the distal portion 44 so as to overlap the light transmitting portion 45 when viewed from the optical axis direction D. The FPI filter 10 is disposed between a pair of protruding portions 46. For example, the distance between the pair of protruding portions 46 in the X direction is set equal to the size of the FPI filter 10 in the X direction, and the FPI filter 10 is disposed between the pair of protruding portions 46 so as to contact the pair of protruding portions 46. As shown in FIG. 7 , in this example, a step portion 47 is formed at the boundary between the proximal portion 43 and the distal portion 44 on the second surface 41b by the proximal portion 43 protruding relative to the distal portion, and the FPI filter 10 is disposed so as to abut against the step portion 47. These arrangement structures enable the FPI filter 10 to be positioned with high precision. Although not shown in the figure, a recess (counterbore) is formed at the boundary between the pair of protruding portions 46 and the step portion 47 to allow for relief of the corners of the FPI filter 10. This makes it possible to prevent damage to the FPI filter 10 even when the FPI filter 10 is placed against the step portion 47.

[0057] A wiring board 51 constituting the wiring section 32 is fixed on the second surface 41b of the proximal section 43. The wiring board 51 has a plurality of terminals formed thereon, including a plurality of (two in this example) first terminals 52 and a plurality of (four in this example) second terminals 53. The first terminals 52 are terminals for electrical connection with terminals 16 and 17 of the FPI filter 10, and the second terminals 53 are terminals for electrical connection with the outside of the housing 21 (e.g., a control device for controlling the FPI filter 10). Various circuits are built into the wiring board 51, including a wiring section that electrically connects the first terminals 52 and the second terminals 53. The wiring board 51 also has a thermistor T formed thereon for detecting the temperature of the FPI filter 10.

[0058] The wiring board 51 is disposed on the second surface 41b of the proximal portion 43 so as to be adjacent to the FPI filter 10 in the Y direction (in this example, in contact with the FPI filter 10). As shown in FIG. 6, in this example, the first terminal 52 is electrically connected to the terminals 16 and 17 of the FPI filter 10 by a wire W1 (bonding wire). The second terminal 53 is electrically connected to the outside of the housing 21 by a wire W2. In this example, the second terminal 53 is disposed closer to the second portion 42 than the first terminal 52, and the distance from the second terminal 53 to the second portion 42 is shorter than the distance from the first terminal 52 to the second portion 42. The wiring board 51 is disposed in the proximal portion 43 and does not overlap with the FPI filter 10 disposed in the distal portion 44 when viewed from the optical axis direction D. That is, the wiring board 51 is disposed on the support 31 so as not to overlap with the light-transmitting region 10a of the FPI filter 10 when viewed from the optical axis direction D. The distance from the first terminal 52 to the second portion 42 is, for example, the distance in the Y direction from the first terminal 52 to a surface 42b (described later) of the second portion 42. The same applies to the distance from the second terminal 53 to the second portion 42.

[0059] The bandpass filter 33 transmits light in a predetermined wavelength range. The bandpass filter 33 is formed, for example, in the shape of a rectangular plate. The bandpass filter 33 is fixed on the pair of protrusions 46 so that the thickness direction of the bandpass filter 33 is parallel to the optical axis direction D. In this manner, the bandpass filter 33 is disposed on the second surface 41b side of the first portion 41.

[0060] The bandpass filter 33 is arranged so as to overlap the light transmission region 10a of the FPI filter 10 when viewed from the optical axis direction D. In this example, the bandpass filter 33 overlaps the entire distal portion 44 (the entire FPI filter 10) when viewed from the optical axis direction D, and also overlaps a portion of the proximal portion 43 on the distal portion 44 side. More specifically, the bandpass filter 33 overlaps the first terminal 52 and the wire W1 when viewed from the optical axis direction D. That is, the bandpass filter 33 is arranged so as to cover the first terminal 52 and the wire W1 when viewed from the optical axis direction D. This makes it possible to prevent breakage of the wire W1 when, for example, replacing the filter unit 22.

[0061] The aperture member 34 is formed, for example, in the shape of a rectangular plate. A circular aperture 34a is formed in the aperture member 34. The aperture member 34 is absorptive of the light L. In this example, the aperture member 34 is configured by forming a film absorptive of the light L on a metal plate-shaped member. The entire aperture member 34 may be formed of a material absorptive of the light L, or the aperture member 34 may be provided with a coating such as plating to provide absorptive properties for the light L. The aperture member 34 is fixed on the first surface 41a of the distal portion 44 so that its thickness direction is parallel to the optical axis direction D. For example, a recess 41c is formed in the first surface 41a of the distal portion 44, and the aperture member 34 is disposed on the bottom surface of the recess 41c. The aperture member 34 is disposed on the first surface 41a side of the first portion 41, opposite the FPI filter 10 and the bandpass filter 33 disposed on the second surface 41b side.

[0062] The aperture member 34 is arranged so that the aperture 34a overlaps the light transmission region 10a of the FPI filter 10 when viewed from the optical axis direction D. The aperture member 34 is also arranged so that light L, which enters from the incident portion 21a of the housing 21 and travels toward the FPI filter 10, passes through the aperture 34a. In other words, the aperture member 34 is arranged upstream (on the light incident side) of the FPI filter 10 in the traveling direction of the light L.

[0063] FIG. 8 is a diagram showing the size relationship between the light passing portion 45 of the support member 31, the light transmission region 10a (aperture P1) of the FPI filter 10, and the aperture 34a of the aperture member 34. The following size relationship is when viewed from the optical axis direction D. As shown in FIG. 8, the aperture 34a is smaller than the light transmission region 10a (aperture P1). That is, the entire outer edge of the aperture 34a is located inside the outer edge of the light transmission region 10a. The light passing portion 45 (aperture formed in the support member 31) is larger than the light transmission region 10a. That is, the entire outer edge of the light passing portion 45 is located outside the outer edge of the light transmission region 10a. Therefore, the light L traveling toward the FPI filter 10 is narrowed by the aperture 34a.

[0064] The second portion 42 is formed in a substantially flat plate shape (a substantially rectangular plate shape). The second portion 42 has a surface 42a facing one side in the Y direction (the first portion 41 side) and a surface 42b facing the other side in the Y direction (the side opposite to the first portion 41). As shown in FIG. 6, the second portion 42 is formed with a plurality of (two in this example) insertion holes 48 into which positioning pins 21f provided on the housing 21 are inserted. The number of insertion holes 48 is the same as the number of positioning pins 21f, and in this example, they are lined up along the X direction. One of the insertion holes 48 is formed in a circular shape corresponding to the shape of the positioning pins 21f, and the other insertion hole 48 is formed as an elongated hole extending along the X direction. The second portion 42 is further formed with a through hole 49 into which a fixing member 61 (e.g., a screw) is inserted to fix the second portion 42 (support body 31) to the housing 21.

[0065] The filter unit 22 is fixed to the housing 21. Specifically, as particularly shown in FIG. 2, the first portion 41 of the support 31 is inserted (disposed) in the insertion portion 24 of the housing 21. The first portion 41 is inserted into the insertion portion 24 so that the light-transmitting region 10a of the FPI filter 10 is positioned on the optical axis A. The second portion 42 of the support 31 faces the flat portion 21e of the side surface 21d of the housing 21. In this example, the surface 42a of the second portion 42 contacts the flat portion 21e. The filter unit 22 is detachably fixed to the side surface 21d at the second portion 42. In this example, a fixing member 61 is inserted from the outside into a through-hole 49 of the second portion 42 and fixed to a fixing hole 21g provided in the flat portion 21e, thereby fixing the second portion 42 to the side surface 21d. For example, if the fixing member 61 is a screw, the fixing member 61 is fixed by screwing into the fixing hole 21g.

[0066] When assembling the filter unit 22, the first portion 41 is inserted into the insertion portion 24 while the positioning pin 21f provided on the flat portion 21e is inserted (press-fitted) into the insertion hole 48 provided in the second portion 42. This allows the filter unit 22 to be reliably positioned relative to the housing 21, and the FPI filter 10 to be positioned with high precision.

[0067] The filter device 2 further includes a cover member 29 attached to the side surface 21d of the housing 21. The cover member 29 covers the second portion 42 so that the second portion 42 is not exposed to the outside of the housing 21. The cover member 29 is detachably fixed to a fixing hole 21h provided in the side surface 21d of the housing 21 by a fixing member 62, such as a screw. The cover member 29 has an outlet hole 29a formed therein for drawing a wire W2 electrically connected to the second terminal 53 to the outside of the housing 21. The wire W2 is drawn to the outside of the housing 21 through the outlet hole 29a and is electrically connected to, for example, a control device for controlling the FPI filter 10. Note that although the fixing position of the cover member 29 by the fixing member 62 differs between FIGS. 1 and 2 and FIG. 3, the fixing position of the cover member 29 by the fixing member 62 may be any position.

[0068] 1, the imaging device 7 has a housing 71 and an imaging element 72 disposed within the housing 71. The housing 71 has a main body 71a having a bottom surface and an attachment portion 71b. The attachment portion 71b is formed in a cylindrical shape that is slightly smaller than the main body 71a. The attachment portion 71b detachably engages with the attachment portion 21c of the filter device 2 described above.

[0069] An imaging element 72 is disposed within the main body 71a of the housing 71. The imaging element 72 is, for example, an InGaAs image sensor. The imaging element 72 has a light receiving surface 72a disposed on the imaging plane of the light L formed by the second lens unit 26, and captures an image of the light L emitted from the emission unit 21b. Also disposed within the main body 71a are a control circuit for controlling the imaging element 72, an image processing circuit for processing images acquired by the imaging element 72, a cooling mechanism for cooling the imaging element 72, and the like. In FIG. 1, these components are indicated by the reference numeral 73.

[0070] In the hyperspectral camera 1, light L incident from the incident portion 21a is collected by the first lens portion 25 and travels along the optical axis A toward the FPI filter 10. The light L traveling toward the FPI filter 10 passes through or transmits through the aperture 34a of the aperture member 34, the light passing portion 45 of the support 31, the aperture P1 of the FPI filter 10, the mirror portions 14 and 15, and the bandpass filter 33, in this order. The light L is dispersed according to wavelength when passing through the FPI filter 10 (mirror portions 14 and 15). The light L emitted from the FPI filter 10 (bandpass filter 33) is imaged on the light receiving surface 72a of the image sensor 72 by the second lens portion 26, and is captured by the image sensor 72.

[0071] As shown in FIG. 11, the hyperspectral camera 1 (filter device 2) may constitute a filter system 100. The filter system 100 includes a housing 21 and a plurality of filter units 22. The plurality of filter units 22 have different transmission wavelength characteristics of the FPI filters 10. One of the plurality of filter units 22 is selectively fixed to the housing 21. That is, in this filter system 100, the plurality of filter units 22 are replaceably attached to the housing 21. This allows the filter units 22 (FPI filters 10) to be used differently depending on the desired transmission wavelength characteristics. [Action and effect]

[0072] In the filter device 2, an insertion section 24 is formed on the side surface 21d of the housing 21. The support 31 has a first section 41 in which a light transmitting section 45 is formed and an FPI filter 10 is disposed, and a second section 42 extending to intersect with the first section 41. The first section 41 is inserted into the insertion section 24 of the housing 21 so that the light transmission region 10a of the FPI filter 10 is positioned on the optical axis A, and the second section 42 faces the side surface 21d of the housing 21. The filter unit 22 is detachably fixed to the side surface 21d of the housing 21 at the second section 42. This structure allows the filter unit 22 to be easily replaced by inserting and removing it from the insertion section 24 of the housing 21. This improves convenience compared to, for example, a case in which the filter unit 22 is permanently disposed within the housing 21. For example, in the filter device 2, the filter unit 22 can be easily replaced with another filter unit 22 having different transmission wavelength characteristics. In this way, the filter device 2 improves convenience.

[0073] A positioning pin 21f is provided on the housing 21, and an insertion hole 48 into which the positioning pin 21f is inserted is provided on the second part 42. As a result, by inserting the positioning pin 21f into the insertion hole 48, the filter unit 22 can be positioned relative to the housing 21, and the FPI filter 10 can be positioned with high precision.

[0074] A plurality of positioning pins 21f are provided, and a plurality of insertion holes 48 are provided in the same number as the plurality of positioning pins 21f. This makes it possible to suppress deviation in the arrangement angle of the filter unit 22 (FPI filter 10) with respect to the optical axis A. Since deviation in the arrangement angle of the FPI filter 10 with respect to the optical axis A significantly affects the transmission wavelength characteristics of the FPI filter 10, it is important to suppress such deviation.

[0075] A cover member 29 that covers the second portion 42 is provided on the side surface 21d of the housing 21 so that the second portion 42 is not exposed to the outside of the housing 21. This makes it possible to suppress the influence of external factors (for example, physical impact, stray light from outside the housing 21, etc.) on the filter unit 22.

[0076] The cover member 29 has an extraction hole 29a formed therein for extracting the wiring W2 electrically connected to the second terminal 53 to the outside of the housing 21. This allows the wiring W2 to be easily extracted to the outside of the housing 21.

[0077] The first terminal 52 and the second terminal 53 are disposed on the first portion 41, and the distance from the second terminal 53 to the second portion 42 is shorter than the distance from the first terminal 52 to the second portion 42. As a result, the second terminal 53 is disposed relatively close to the second portion 42, and therefore the second terminal 53 can be easily electrically connected to the outside of the housing 21 via, for example, the wiring W2.

[0078] A convex portion 46 is formed on the second surface 41b of the first portion 41 (the surface on which the FPI filter 10 is disposed), and the bandpass filter 33 is disposed on the convex portion 46. As a result, by disposing the bandpass filter 33 on the convex portion 46, the bandpass filter 33 can be disposed so as to overlap with the FPI filter 10 when viewed from the optical axis direction D, which makes it easier to align the FPI filter 10 and the bandpass filter 33.

[0079] The aperture member 34 is disposed in the first portion 41 so that the aperture 34a overlaps the light-transmitting region 10a and so that light L incident from the incident portion 21a toward the FPI filter 10 passes through the aperture 34a. This allows the aperture member 34 to be disposed on the light incident side of the FPI filter 10. The aperture member 34 also prevents the light L from entering the FPI filter 10 at an angle.

[0080] The aperture member 34 is absorptive of the light L. This allows the light L reflected by, for example, the FPI filter 10 (light-shielding layer 135) to be absorbed by the aperture member 34, and prevents the light L reflected by the FPI filter 10 from becoming stray light within the housing 21. This configuration is particularly effective when the aperture P1 is formed of a reflective layer (light-shielding layer 135), as in the FPI filter 10.

[0081] When viewed from the optical axis direction D, the aperture 34a is smaller than the light transmission region 10a of the FPI filter 10. This makes it possible to further prevent, for example, light L reflected by the FPI filter 10 from becoming stray light within the housing 21. In addition, the aperture member 34 can further prevent the light L from being incident on the FPI filter 10 at an angle.

[0082] The aperture member 34 is disposed on the first surface 41a (surface on one side in the optical axis direction D) of the first portion 41, and the FPI filter 10 is disposed on the second surface 41b (surface on the other side in the optical axis direction D) of the first portion 41. This allows the FPI filter 10 and the aperture member 34 to be suitably disposed on the support body 31. Furthermore, because the FPI filter 10 and the aperture member 34 are disposed to face each other across the first portion 41, the aperture member 34 can further prevent light L from being incident on the FPI filter 10 at an angle.

[0083] The filter device 2 includes a first lens unit 25 that focuses light L traveling from the incident unit 21a toward the FPI filter 10, and a second lens unit 26 that forms an image of the light L that has passed through the FPI filter 10, and the first lens unit 25 and the second lens unit 26 are arranged inside the housing 21. This makes it possible to configure a filter device 2 that includes the first lens unit 25 and the second lens unit 26. Furthermore, the filter device 2 can be made smaller than when the first lens unit 25 and the second lens unit 26 are arranged outside the housing 21, for example.

[0084] The present invention is not limited to the above-described embodiment and modifications. For example, the materials and shapes of each component are not limited to those described above, and various materials and shapes can be used. In the above-described embodiment, the FPI filter 10 is disposed on the second surface 41b side of the first portion 41, but the FPI filter 10 may be disposed on the first surface 41a side of the first portion 41. In the above-described embodiment, the light transmitting portion 45 is a through hole, but the light transmitting portion 45 may be a notch formed in the first portion 41. The side surface 21d of the housing 21 does not need to have the flat portion 21e and may be formed, for example, by only a cylindrical portion.

[0085] In the above embodiment, the imaging element 72 is arranged outside the housing 21 (inside the housing 71 of the imaging device 7), but the imaging element 72 may be arranged inside the housing 21. In this case, the emission unit 21b is not provided in the housing 21, and the imaging device 7 is not attached to the housing 21. In other words, the hyperspectral camera 1 may include the filter device 2 and the imaging element 72 arranged inside the housing 21 of the filter device 2.

[0086] In the above embodiment, FPI filter 10 is configured as a membrane type in which first laminate 122 and second laminate 124 (thin film laminates) that constitute mirror sections 14 and 15 are stacked on one substrate 11. However, FPI filter 10 may also be configured as a substrate-bonded type. In this case, for example, a first substrate on which a reflective film that constitutes one mirror section is formed and a second substrate on which a reflective film that constitutes the other mirror section are formed may be bonded so that the pair of mirror sections face each other.

[0087] In the above embodiment, the wiring portion 32 is configured by the wiring board 51, but the wiring portion 32 may be formed directly on the support body 31 or may include a portion embedded in the support body 31. For example, the wiring board 51 may not be provided, and a wiring portion including the first terminal 52, the second terminal 53, and a portion electrically connecting the first terminal 52 and the second terminal 53 may be formed in the proximal portion 43 of the first portion 41 of the support body 31. At least a portion of the wiring portion 32 may be disposed in the distal portion 44 of the first portion 41.

[0088] In the above embodiment, the first portion 41 and the second portion 42 are perpendicular to each other, but the first portion 41 and the second portion 42 may intersect at an angle other than perpendicular as long as they intersect. In the above embodiment, the positioning pin 21f is provided on the housing 21, and the insertion hole 48 into which the positioning pin 21f is inserted is provided on the second portion 42. However, conversely, the positioning pin may be provided on the second portion 42, and the insertion hole into which the positioning pin is inserted may be provided on the housing 21. However, from the viewpoint of stability when inserting the positioning pin into the insertion hole, a configuration in which the positioning pin 21f is provided on the housing 21 and the insertion hole 48 is provided on the second portion 42, as in the above embodiment, is preferable.

[0089] The multiple positioning pins 21f do not necessarily have to be aligned along a direction perpendicular to the optical axis direction D, but may be aligned along a direction intersecting the optical axis direction D. Alternatively, the multiple positioning pins 21f may be aligned along a direction parallel to the optical axis direction D. The cover member 29 may be omitted. The cover member 29 does not have to be provided with the extraction hole 29a, and the wiring W2 may be drawn out to the outside of the housing 21 at a position other than the cover member 29, for example.

[0090] At least one of the first terminal 52 and the second terminal 53 may be located on the second portion 42. The distance from the second terminal 53 to the second portion 42 may be equal to or longer than the distance from the first terminal 52 to the second portion 42. The convex portion 46 may not be formed on the first portion 41; for example, the second surface 41b of the first portion 41 may be a flat surface. The bandpass filter 33 may be omitted. The aperture member 34 may not be absorbing light L. When viewed from the optical axis direction D, the aperture 34a may have the same shape as the light-transmitting region 10a of the FPI filter 10, or may be larger than the light-transmitting region 10a. The aperture member 34 may be omitted. The aperture member 34 may be located on the second surface 41b side of the first portion 41.

[0091] The first lens unit 25 may be configured as an optical system that collimates the light L traveling from the incident unit 21a toward the FPI filter 10 (reducing the angle of incidence on the Fabry-Perot interference filter 10, i.e., the angle with respect to the optical axis direction D). The filter device 2 may not include at least one of the first lens unit 25 and the second lens unit 26.

[0092] In the above embodiment, the support body 31 has the first portion 41 and the second portion 42, but the support body 31 may have only the first portion 41 without the second portion 42. In this case, too, the filter unit 22 can be easily replaced by inserting and removing the filter unit 22 (first portion 41) into and from the insertion portion 24 of the housing 21, which improves convenience compared to, for example, a case in which the filter unit 22 is arranged in the housing 21 in a non-removable state. [Explanation of symbols]

[0093] 1... hyperspectral camera, 2... filter device, 10... Fabry-Perot interference filter, 10a... light transmission region, 10a... light transmission region, 14, 15... mirror portion, 21... housing, 21a... incident portion (light incident portion), 21d... side surface, 21f... positioning pin, 22... filter unit, 24... insertion portion, 25... first lens portion, 26... second lens portion, 29... cover member, 29a... extraction hole, 31... support body, 32... arrangement Line portion, 33...bandpass filter, 34...aperture member, 34a...aperture, 41...first portion, 41a...first surface (surface on one side in the optical axis direction), 41b...second surface (surface on the other side in the optical axis direction), 42...second portion, 45...light passing portion, 46...convex portion, 48...insertion hole, 52...first terminal, 53...second terminal, 72...imaging element, 100...filter system, W2...wiring, A...optical axis, D...optical axis direction, L...light.

Claims

1. A filter unit; a housing having a light incident portion into which light is incident, the light incident from the light incident portion traveling inside along an optical axis; The filter unit comprises: a support body on which a light passing portion is formed; a Fabry-Perot interference filter having a pair of mirror portions facing each other in an optical axis direction parallel to the optical axis and having a variable distance therebetween, the Fabry-Perot interference filter being disposed on the support body so as to overlap with the light passing portion when viewed from the optical axis direction; a wiring portion having a first terminal electrically connected to the Fabry-Perot interference filter and a second terminal for electrical connection to the outside of the housing, the wiring portion being disposed on the support body so as not to overlap with a light transmission region of the Fabry-Perot interference filter when viewed from the optical axis direction; An insertion portion is formed on a side surface of the housing, the support body has a first portion in which the light passing portion is formed and in which the Fabry-Perot interference filter is disposed, and a second portion extending so as to intersect with the first portion, the first portion is inserted into the insertion portion of the housing so that the light transmission region of the Fabry-Perot interference filter is positioned on the optical axis, the second portion faces the side surface of the housing; The filter unit is detachably fixed to the side surface of the housing at the second portion.

2. The filter device according to claim 1 , wherein one of the second portion and the housing is provided with a positioning pin, and the other of the second portion and the housing is provided with an insertion hole into which the positioning pin is inserted.

3. The filter device according to claim 2 , wherein a plurality of the positioning pins are provided, and the number of the insertion holes is the same as the number of the positioning pins.

4. The filter device according to claim 1 , further comprising a cover member provided on the side surface of the housing to cover the second portion so as to prevent the second portion from being exposed to the outside of the housing.

5. The filter device according to claim 4 , wherein the cover member has an extraction hole formed therein for extracting a wire electrically connected to the second terminal to the outside of the housing.

6. the first terminal and the second terminal are disposed on the first portion, The filter device according to claim 1 , wherein a distance from the second terminal to the second portion is shorter than a distance from the first terminal to the second portion.

7. the filter unit further comprises a band-pass filter; a protrusion protruding from a surface on which the Fabry-Perot interference filter is disposed is formed in the first portion; The filter device according to claim 1 , wherein the band-pass filter is disposed on the convex portion.

8. The filter unit further includes an aperture member having an aperture formed therein, 3. The filter device according to claim 1, wherein the aperture member is arranged in the first portion so that the aperture overlaps with the light-transmitting region and the light incident from the light incident portion toward the Fabry-Perot interference filter passes through the aperture.

9. The filter device according to claim 8 , wherein the aperture member is absorptive of the light.

10. 9. The filter device of claim 8, wherein the aperture is smaller than the light-transmitting area of ​​the Fabry-Perot interference filter when viewed in the optical axis direction.

11. 9. The filter device according to claim 8, wherein the aperture member is disposed on a surface on one side of the first portion in the optical axis direction, and the Fabry-Perot interference filter is disposed on a surface on the other side of the first portion in the optical axis direction.

12. a first lens unit that condenses or collimates the light traveling from the light incident unit toward the Fabry-Perot interference filter; a second lens unit that forms an image of the light that has passed through the Fabry-Perot interference filter, The filter device according to claim 1 , wherein the first lens portion and the second lens portion are disposed within the housing.

13. The filter device according to claim 1 or 2; an image sensor that captures the light that has passed through the Fabry-Perot interference filter.

14. A filter system using the filter device according to claim 1 or 2, a plurality of the filter units, each having a different transmission wavelength characteristic of the Fabry-Perot interference filter, and the housing; A filter system, wherein one of the plurality of filter units is fixed to the housing.

Images