JP2016031295A - Optical module, measuring device, and electronic equipment - Google Patents

Abstract

An optical module, a measuring device, and an electronic device capable of improving the light use efficiency are provided. An optical module includes a pair of reflective films facing each other, and a wavelength variable interference filter that emits light having a wavelength corresponding to a gap dimension between the pair of reflective films. ) And the wavelength tunable interference filter 5 is fixed, and light is applied to a region overlapping the pair of reflection films 54 and 55 in a plan view as viewed from the optical axis L1 direction which is the normal direction of the pair of reflection films 54 and 55. A housing 610 (fixed portion) having a light incident port 611 (light passage region) to be transmitted, and light of the wavelength variable interference filter 5 fixed to the housing 610 at a position facing the light incident port 611 in the plan view. And a radial type refractive index distribution lens 7 having an optical axis along the direction of the axis L1 and having a refractive index that changes in accordance with the distance from the optical axis. [Selection] Figure 2

Description

  The present invention relates to an optical module, a measuring device, and an electronic apparatus.

  Conventionally, a Fabry-Perot interference filter (interference filter) is known in which a pair of reflective films are opposed to each other, and light having a predetermined wavelength that has been strengthened by multiple interference between the pair of reflective films is transmitted from incident light. Such an interference filter and a spectroscopic camera that captures light transmitted through the interference filter with an imaging unit are known (see, for example, Patent Document 1).

  The interference filter preferably makes light incident on each reflective film perpendicularly. If the light incident angle is not vertical, light is not extracted at a desired wavelength, resulting in a decrease in resolution. To deal with such a problem, in the spectroscopic camera described in Patent Document 1, a telecentric optical system is arranged on the light incident side of the interference filter. This telecentric optical system is an optical system with an exit pupil at infinity, and the light emitted from this telecentric optical system has a principal ray parallel to the central optical axis, which reduces the resolution of the interference filter. Can be suppressed.

JP 2013-170867 A

  However, a telecentric optical system is usually configured by combining a plurality of optical elements (such as lenses). For this reason, a plurality of interfaces (for example, a boundary surface between quartz glass and air) whose refractive index changes greatly are arranged on the optical path of the light traveling toward the interference filter. When light passes through this interface, part of the light is reflected, which may reduce the light utilization efficiency.

  An object of the present invention is to provide an optical module, a measuring apparatus, and an electronic apparatus that can improve the light utilization efficiency.

  An optical module according to an application example of the present invention has a pair of reflective films facing each other, an interference filter that emits light having a wavelength according to a gap dimension of the pair of reflective films, and the interference filter is fixed. A fixed portion having a light passage region that allows light to pass through a region overlapping with the pair of reflection films in a plan view as viewed from the optical axis direction of the interference filter that is a normal direction of the pair of reflection films; In view, a radial that is fixed to the fixing portion at a position facing the light passage region, has an optical axis along the optical axis direction of the interference filter, and the refractive index changes according to the distance from the optical axis. And a refractive index distribution lens.

Here, as a radial type gradient index lens, for example, a lens whose refractive index decreases as the distance from the optical axis can be exemplified. Hereinafter, the radial type gradient index lens is also simply referred to as a gradient index lens.
The light passage region is, for example, an opening provided in the fixed portion or a light-transmitting region formed of a light-transmitting material.
In this application example, the gradient index lens is fixed to the fixed portion at a position facing the light passage region of the fixed portion to which the interference filter is fixed. In such a gradient index lens, as in the telecentric optical system, the principal ray of the emitted light is parallel to the optical axis direction of the interference filter, and a reduction in resolution in the interference filter can be suppressed.
In addition, the number of interfaces can be reduced and light reflection at the interfaces can be suppressed as compared with the case of using a telecentric optical system. Therefore, the amount of light emitted from the interference filter relative to the amount of light incident on the optical module can be increased, and the light utilization efficiency can be improved.

In the optical module of this application example, the fixing portion has an opening in the light passage region,
It is preferable that a translucent member that is joined to the fixing portion and covers the opening is provided, and the radial type gradient index lens is joined to the translucent member with a translucent adhesive.
In this application example, the refractive index distribution lens covers the opening of the fixing portion and is fixed to the light transmitting member disposed at a position overlapping the light passage region via a light-transmitting adhesive.
In such a configuration, the relative position of the interference filter and the refractive index distribution lens can be determined by fixing the refractive index distribution lens to the light transmissive member fixed to the fixing portion. For example, the refractive index distribution lens can be fixed so that the optical axis of the refractive index distribution lens is orthogonal to the reflective film. Therefore, it is possible to suppress a reduction in resolution due to a position shift and a wavelength shift of interference light due to a change in angle of incident light.
Further, by fixing the gradient index lens with a translucent adhesive, no space is formed between the refractive index distribution lens and the translucent member, and the translucent adhesive can be filled. Reflection by the interface between the gradient index lens and the translucent member can be suppressed.

In the optical module of this application example, it is preferable that the refractive index of the adhesive is not less than the refractive index of the translucent member and not more than the maximum value of the refractive index of the radial type gradient index lens.
In this application example, the refractive index of the adhesive is not less than the refractive index of the translucent member and not more than the maximum value of the refractive index of the refractive index distribution lens, and between the refractive index distribution lens and the adhesive, and The difference in refractive index at each interface between the adhesive and the translucent member can be reduced, and reflection at the interface can be more reliably suppressed.

In the optical module of this application example, it is preferable that the fixed portion has an opening in the light passage region, and the radial type gradient index lens is bonded to the fixed portion and covers the opening.
In this application example, the gradient index lens is directly bonded to the fixing member at a position covering the opening.
In such a configuration, the structure can be simplified and the size can be reduced as compared with the case where a translucent member covering the opening of the fixed portion is provided. In addition, light loss at the interface of the translucent member can be suppressed, and the light utilization efficiency can be improved.

In the optical module of the application example, an optical axis along the optical axis direction of the interference filter is provided on the opposite side of the radial refractive index distribution lens with respect to the interference filter in the optical axis direction of the interference filter. And having a second radial type refractive index distribution lens whose refractive index changes according to the distance from the optical axis, and the imaging position of the radial type refractive index distribution lens is in the arrangement region of the interference filter It is preferable.
In this application example, a pair of refractive index distribution lenses are arranged with the interference filter interposed therebetween, and the imaging position of the refractive index distribution lens arranged on the light incident side of the interference filter is located in the arrangement area of the interference filter. Further, the light emitted from the interference filter is imaged at a predetermined position by the second radial type refractive index transmission lens disposed on the light emission side of the interference filter.
In such a configuration, in the vicinity of the imaging position of the gradient index lens arranged on the light incident side, the light beam diameter of the light emitted from the gradient index lens becomes small, and accordingly, a pair of reflections of the interference filter It is possible to reduce the area of the region facing the film (area of each reflective film). Accordingly, it is possible to reduce the size of the optical module.

In the optical module of this application example, it is preferable that the optical module includes an imaging element that is disposed at an imaging position of the radial type gradient index lens and receives light emitted from the interference filter.
In this application example, the imaging element is disposed at the imaging position of the refractive index distribution lens on the opposite side of the refractive index distribution lens with the interference filter interposed therebetween.
In such a configuration, even if a coupling optical system is not disposed between the interference filter and the image sensor, the light transmitted through the refractive index distribution lens and dispersed by the interference filter can be imaged by the image sensor. Therefore, by disposing an imaging optical system including a lens or the like, it is possible to suppress the problem that the interface increases and the light use efficiency decreases, and the optical module can be miniaturized.

A measuring apparatus according to an application example of the present invention includes the optical module according to the application example described above, a light source, and a pair of reflective films facing each other, and a gap size between the pair of reflective films from light emitted from the light source. And a light guide member for guiding the light emitted from the second interference filter to the radial gradient index lens. To do.
In this application example, the light emitted from the light source and dispersed by the interference filter is guided to the radial type gradient index lens provided in the optical module by the light guide member.
In such a configuration, the target is irradiated with light emitted from the light source and dispersed by the interference filter, and reflected light corresponding to the wavelength of the irradiated light is incident on the optical module. By appropriately adjusting the wavelength of the interference light of the two interference filters, for example, fluorescence corresponding to the excitation light can be detected with high resolution.
In addition, by reflecting light emitted from the light source and dispersed by the interference filter with the light guide member, the light is reflected at the interface as compared with the case where the light is reflected or refracted by an optical element such as a plurality of lenses or mirrors. Can be suppressed, and the light utilization efficiency can be improved. Furthermore, similarly to the case of the optical module of the above application example, it is possible to suppress the reflection of light at the interface and improve the light utilization efficiency as compared with the case of using the telecentric optical system.

An electronic apparatus according to an application example of the invention includes a pair of reflective films facing each other, an interference filter that emits light having a wavelength according to a gap size of the pair of reflective films, and the interference filter is fixed. A fixed portion having a light passage region that allows light to pass through a region overlapping with the pair of reflection films in a plan view as viewed from the optical axis direction of the interference filter that is a normal direction of the pair of reflection films; In view, a radial that is fixed to the fixing portion at a position facing the light passage region, has an optical axis along the optical axis direction of the interference filter, and the refractive index changes according to the distance from the optical axis. And a processing unit that performs processing based on light emitted from the interference filter.
In this application example, similarly to the application example related to the optical module, it is possible to improve the light use efficiency. For this reason, it is possible to increase the light amount of the interference light with respect to the incident light amount. Therefore, it is possible to provide an electronic device that can suppress a decrease in processing system due to a decrease in the amount of interference light and improve the processing accuracy.

1 is a block diagram showing a schematic configuration of a spectrometer according to a first embodiment. The figure which shows schematic structure of the optical filter device and image pick-up element in the optical module of 1st embodiment. The top view which shows schematic structure of the wavelength variable interference filter of 1st embodiment. Sectional drawing in the IV-IV line in FIG. The figure which shows schematic structure of the optical filter device and image pick-up element in the optical module of the modification of 1st embodiment. The figure which shows schematic structure of the optical filter device and image pick-up element in the optical module of 2nd embodiment. The figure which shows schematic structure of the optical filter device and image pick-up element in the optical module of 3rd embodiment. The figure which shows schematic structure of the optical filter device and image pick-up element in the optical module of the modification of 3rd embodiment. The figure which shows schematic structure of the optical filter device and image pick-up element in the optical module of the other modification of 3rd embodiment. The figure which shows schematic structure of the measuring apparatus of 4th embodiment. The figure which shows typically the example of arrangement | positioning of the optical filter device in the optical module of one modification. The top view which shows typically the example of arrangement | positioning of the optical filter device in the optical module of one modification. FIG. 6 is a block diagram illustrating a schematic configuration of a color measurement device that is another example of the electronic apparatus of the invention. Schematic of the gas detection apparatus which is another example of the electronic device of this invention. The block diagram which shows the control system of the gas detection apparatus of FIG. The block diagram which shows schematic structure of the food analyzer which is another example of the electronic device of this invention. The schematic diagram which shows schematic structure of the spectroscopic camera which is another example of the electronic device of this invention.

[First embodiment]
Hereinafter, a first embodiment according to the present invention will be described with reference to the drawings.
[Configuration of Spectrometer]
FIG. 1 is a block diagram showing a schematic configuration of a spectrometer according to the present invention.
The spectroscopic measurement device 1 is an example of the electronic apparatus of the present invention, and is a device that analyzes the light intensity of each wavelength in the measurement target light reflected by the measurement target X and measures the spectral spectrum. In this embodiment, an example of measuring the measurement target light reflected by the measurement target X is shown. However, when a light emitter such as a liquid crystal panel is used as the measurement target X, the light emitted from the light emitter is measured. The target light may be used.
As shown in FIG. 1, the spectroscopic measurement apparatus 1 includes an optical module 10 and a control unit 20 corresponding to a processing unit of the present invention that processes a signal output from the optical module 10.

[Configuration of optical module]
The optical module 10 includes an optical filter device 600, an image sensor 11, an IV converter 12, an amplifier 13, an A / D converter 14, and a drive control unit 15.
The optical module 10 guides the measurement target light reflected by the measurement target X to the wavelength variable interference filter 5 through an incident optical system (not shown), and transmits the light transmitted through the wavelength variable interference filter 5 to the image sensor 11 (light reception). To receive light. The detection signal output from the image sensor 11 is output to the control unit 20 via the IV converter 12, the amplifier 13, and the A / D converter 14.

[Configuration of optical filter device]
FIG. 2 is a diagram illustrating a schematic configuration of the optical filter device 600 and the imaging element 11 in the optical module 10.
The optical filter device 600 is a device that extracts light having a predetermined target wavelength from incident light to be inspected and forms an image of the light on the image sensor 11. The optical filter device 600 is housed in the housing 610 and the housing 610. The variable wavelength interference filter 5, the first radial type refractive index distribution lens 7 disposed on the light incident side of the optical filter device 600, and the second radial type refractive index disposed on the light emitting side of the optical filter device 600. A rate distribution lens 8. Such an optical filter device 600 can be incorporated into an optical module such as a colorimetric sensor, or an electronic device such as a colorimetric device or a gas analyzer. Note that the configuration of an optical module or electronic device including the optical filter device 600 will be described in detail later.

[Configuration of wavelength tunable interference filter]
FIG. 3 is a plan view showing a schematic configuration of the variable wavelength interference filter. 4 is a cross-sectional view of the variable wavelength interference filter taken along the line IV-IV in FIG.
The wavelength variable interference filter 5 corresponds to the spectral filter of the present invention, and is a wavelength variable type Fabry-Perot etalon. The wavelength variable interference filter 5 is, for example, a rectangular plate-like optical member, and includes a fixed substrate 51 having a thickness dimension of, for example, about 500 μm and a movable substrate 52 having a thickness dimension of, for example, about 200 μm. . The fixed substrate 51 and the movable substrate 52 are each formed of, for example, various types of glass such as soda glass, crystalline glass, quartz glass, lead glass, potassium glass, borosilicate glass, and non-alkali glass, or crystal. . The fixed substrate 51 and the movable substrate 52 are bonded such that the first bonding portion 513 of the fixed substrate 51 and the second bonding portion 523 of the movable substrate 52 are made of, for example, a plasma polymerization film mainly containing siloxane. By being bonded by the film 53 (the first bonding film 531 and the second bonding film 532), they are integrally formed.

The fixed substrate 51 is provided with a fixed reflective film 54, and the movable substrate 52 is provided with a movable reflective film 55. The fixed reflection film 54 and the movable reflection film 55 are disposed to face each other with a gap G1 interposed therebetween. The wavelength variable interference filter 5 is provided with an electrostatic actuator 56 used to adjust (change) the size of the gap G1.
Further, in the optical axis L1 (see FIG. 4) direction of the wavelength tunable interference filter 5, the fixed substrate 51 in the plan view as shown in FIG. The plane center point O of the movable substrate 52 coincides with the center points of the fixed reflection film 54 and the movable reflection film 55 and coincides with the center point of the movable portion 521 described later. Here, the optical axis L1 direction of the wavelength tunable interference filter 5 coincides with the normal direction of each of the reflection films 54 and 55.

(Configuration of fixed substrate)
In the fixed substrate 51, an electrode arrangement groove 511 and a reflection film installation part 512 are formed by etching. The fixed substrate 51 is formed to have a thickness larger than that of the movable substrate 52, and the fixed substrate is caused by electrostatic attraction when a voltage is applied between the fixed electrode 561 and the movable electrode 562 or internal stress of the fixed electrode 561. There is no 51 deflection.
Further, a notch 514 is formed at the apex C1 of the fixed substrate 51, and a movable electrode pad 564P described later is exposed on the fixed substrate 51 side of the wavelength variable interference filter 5.

The electrode arrangement groove 511 is formed in an annular shape centering on the plane center point O of the fixed substrate 51 in the filter plan view. The reflection film installation part 512 is formed so as to protrude from the center part of the electrode arrangement groove 511 toward the movable substrate 52 in the plan view. The groove bottom surface of the electrode arrangement groove 511 is an electrode installation surface 511A on which the fixed electrode 561 is arranged. In addition, the protruding front end surface of the reflection film installation portion 512 is a reflection film installation surface 512A.
In addition, the fixed substrate 51 is provided with electrode extraction grooves 511B extending from the electrode arrangement grooves 511 toward the vertexes C1 and C2 of the outer peripheral edge of the fixed substrate 51.

A fixed electrode 561 is provided on the electrode installation surface 511 </ b> A of the electrode arrangement groove 511. More specifically, the fixed electrode 561 is provided in a region of the electrode installation surface 511 </ b> A that faces a movable electrode 562 of the movable portion 521 described later. In addition, an insulating film for ensuring insulation between the fixed electrode 561 and the movable electrode 562 may be stacked over the fixed electrode 561.
The fixed substrate 51 is provided with a fixed extraction electrode 563 extending from the outer peripheral edge of the fixed electrode 561 in the direction of the vertex C2. The extended leading end portion of the fixed extraction electrode 563 (portion located at the vertex C2 of the fixed substrate 51) constitutes a fixed electrode pad 563P connected to the drive control unit 15.
In the present embodiment, a configuration in which one fixed electrode 561 is provided on the electrode installation surface 511A is shown. For example, a configuration in which two concentric circles centered on the plane center point O are provided (double electrode configuration). ) Etc.

As described above, the reflective film installation portion 512 is formed in a substantially cylindrical shape that is coaxial with the electrode arrangement groove 511 and has a smaller diameter than the electrode arrangement groove 511, and is formed on the movable substrate 52 of the reflection film installation portion 512. An opposing reflection film installation surface 512A is provided.
As shown in FIGS. 3 and 4, a fixed reflective film 54 is installed in the reflective film installation part 512. As the fixed reflective film 54, for example, a metal film such as Ag or an alloy film such as an Ag alloy can be used. For example, a dielectric multilayer film in which the high refractive layer is TiO ₂ and the low refractive layer is SiO ₂ may be used. Further, a reflective film in which a metal film (or alloy film) is laminated on a dielectric multilayer film, a reflective film in which a dielectric multilayer film is laminated on a metal film (or alloy film), a single refractive layer (TiO ₂ or SiO ₂₎ and a metal film (or alloy film) and the like may be used reflective film formed by laminating a.

  Of the surface of the fixed substrate 51 that faces the movable substrate 52, the surface on which the electrode placement groove 511, the reflective film installation portion 512, and the electrode extraction groove 511B are not formed by etching constitutes the first joint portion 513. The first bonding portion 513 is bonded to the movable substrate 52 by the bonding film 53.

(Configuration of movable substrate)
The movable substrate 52 includes a circular movable portion 521 centered on the plane center point O in the filter plan view as shown in FIG. 3, a holding portion 522 that is coaxial with the movable portion 521 and holds the movable portion 521, A substrate outer peripheral portion 525 provided outside the holding portion 522.
Further, as shown in FIG. 3, the movable substrate 52 is formed with a notch 524 corresponding to the vertex C2, and when the wavelength variable interference filter 5 is viewed from the movable substrate 52 side, the fixed electrode pad is formed. 563P is exposed.

  The movable part 521 is formed to have a thickness dimension larger than that of the holding part 522. For example, in this embodiment, the movable part 521 is formed to have the same dimension as the thickness dimension of the movable substrate 52. The movable portion 521 is formed to have a diameter larger than at least the diameter of the outer peripheral edge of the reflection film installation surface 512A in the filter plan view. The movable part 521 is provided with a movable electrode 562 and a movable reflective film 55.

The movable electrode 562 faces the fixed electrode 561 through the gap G2, and is formed in an annular shape having the same shape as the fixed electrode 561. The movable electrode 562 forms an electrostatic actuator 56 together with the fixed electrode 561. In addition, the movable substrate 52 includes a movable extraction electrode 564 that extends from the outer peripheral edge of the movable electrode 562 toward the vertex C <b> 1 of the movable substrate 52. An extending tip portion of the movable extraction electrode 564 (portion located at the vertex C1 of the movable substrate 52) constitutes a movable electrode pad 564P connected to the drive control unit 15.
The movable reflective film 55 is provided in the central part of the movable surface 521A of the movable part 521 so as to face the fixed reflective film 54 via the gap G1. As the movable reflective film 55, a reflective film having the same configuration as that of the fixed reflective film 54 described above is used.
In the present embodiment, as described above, an example in which the dimension of the gap G2 is larger than the dimension of the gap G1 is shown, but the present invention is not limited to this. For example, when infrared rays or far infrared rays are used as the measurement target light, the gap G1 may be larger than the gap G2 depending on the wavelength range of the measurement target light.

The holding part 522 is a diaphragm that surrounds the periphery of the movable part 521, and has a thickness dimension smaller than that of the movable part 521. Such a holding part 522 is easier to bend than the movable part 521, and the movable part 521 can be displaced toward the fixed substrate 51 by a slight electrostatic attraction. At this time, since the movable portion 521 has a thickness dimension larger than that of the holding portion 522 and becomes rigid, even when the holding portion 522 is pulled toward the fixed substrate 51 by electrostatic attraction, the shape of the movable portion 521 changes. Absent. Therefore, the movable reflective film 55 provided on the movable portion 521 is not bent, and the fixed reflective film 54 and the movable reflective film 55 can be always maintained in a parallel state.
In this embodiment, the diaphragm-like holding part 522 is illustrated, but the present invention is not limited to this. For example, a configuration in which beam-like holding parts arranged at equiangular intervals around the plane center point O are provided. And so on.

  As described above, the substrate outer peripheral portion 525 is provided outside the holding portion 522 in the filter plan view. The surface of the substrate outer peripheral portion 525 that faces the fixed substrate 51 faces the first bonding portion 513 and is bonded to the fixed substrate 51 by the bonding film 53.

[Case, Configuration of First and Second Radial Type Gradient Index Lens]
The housing 610 corresponds to a fixing portion of the present invention, and the wavelength variable interference filter 5 is fixed and accommodated therein as shown in FIG. The housing 610 has, for example, a substantially rectangular parallelepiped outer shape, and can accommodate the wavelength variable interference filter 5 in a state where the inside is maintained in a vacuum or a reduced pressure state, thereby improving the response speed of the wavelength variable interference filter 5. be able to.
In the present embodiment, the fixed substrate 51 of the variable wavelength interference filter 5 is fixed to the inner surface of the housing 610 with various adhesives such as epoxy and silicone. Then, light enters from the surface 52A of the movable substrate 52 of the variable wavelength interference filter 5 opposite to the fixed substrate 51 (hereinafter, the surface 52A is referred to as a light incident surface 52A).

The housing 610 is formed with a light incident port 611 that forms a light passage region that allows light incident on the wavelength variable interference filter 5 to pass therethrough, and a light passage region that allows light emitted from the wavelength variable interference filter 5 to pass therethrough. And a light exit port 612 to be provided. The light incident port 611 and the light emitting port 612 are openings provided in the reflection film overlapping region overlapping with the reflection films 54 and 55 in the filter plan view when viewed from the optical axis L1 of the wavelength variable interference filter 5. In the present embodiment, the outer diameters of the light incident port 611 and the light emitting port 612 are larger than the reflective film overlapping region in the filter plan view. Thereby, interference light can be emitted in the entire region where the reflective films 54 and 55 face each other.
Note that the outer diameters of the light incident port 611 and the light emitting port 612 may be smaller than the reflective film overlapping region. In this case, the light incident port 611 limits the range in which light is incident in the reflective film overlapping region. Can function as an aperture.

A translucent member 613 is bonded to the light incident port 611 by a bonding agent (not shown) such as low melting point glass. The translucent member 613 is a plate-like member having translucency, and is formed of quartz glass (a refractive index in the visible light region is about 1.4) or the like.
A first radial type gradient index lens 7 (hereinafter also referred to as the first lens 7) is fixed to the surface of the translucent member 613 opposite to the inside of the housing 610.

The first lens 7 is a columnar optical element whose refractive index changes according to the distance from the optical axis. The first lens 7 is arranged so that the optical axis coincides with the optical axis L1 of the wavelength variable interference filter, and emits the light incident from the light incident surface 7A from the light emitting surface 7B. Further, the imaging position P1 of the first lens 7 is located between the reflective films 54 and 55 of the wavelength variable interference filter 5. Here, in this embodiment, the length in the optical axis direction is set so as to form an inverted image.
In the present embodiment, the refractive index of the first lens 7 decreases as the distance from the optical axis increases. For example, the refractive index changes within a range of 1.7 or less. As such an optical element, for example, SELFOC (registered trademark) can be used.

  In the present embodiment, in the first lens 7, the width of the emitted light beam in the direction orthogonal to the optical axis L <b> 1 is smaller than that of each of the reflection films 54 and 55 when passing through each of the reflection films 54 and 55. In addition, a refractive index, a width dimension in a direction orthogonal to the optical axis L1, and the like are set. As a result, a part of the light emitted from the first lens 7 is not incident on each of the reflection films 54 and 55, thereby suppressing the use efficiency and the range of the field angle that can be imaged from being reduced. it can.

  In the present embodiment, the dimension (area) of the first lens 7 in the direction orthogonal to the optical axis L1 is formed to be approximately the same as that of the light incident port 611, but may be a different dimension. However, if the width dimension of the light incident port 611 is smaller than the width of the light beam emitted from the first lens 7, a part of the light emitted from the first lens 7 may be shielded by the housing 610. is there. Therefore, the dimension of the light incident port 611 is set so that the light beam emitted from the first lens 7 passes through without being partially shielded.

The light exit surface 7B of the first lens 7 is bonded to the light transmissive member 613 with an optical adhesive 614 having translucency. The optical adhesive 614 is filled between the light emitting surface 7B and the translucent member 613 without any gap. Therefore, the first lens 7 and the translucent member 613 are joined by the optical adhesive 614 without interposing a gas layer. The refractive index of the optical adhesive 614 is not less than the refractive index of the translucent member 613 and not more than the maximum value of the refractive index of the first lens 7, for example, in the range of not less than 1.4 and not more than 1.7. .
Thereby, the change of the refractive index in the light emission surface 7B of the 1st lens 7 and the surface of the translucent member 613, ie, an interface, can be made small, and reflection of the light in the said interface can be suppressed.

Further, similarly to the light incident port 611, a light transmitting member 615 is joined to the light emitting port 612, and the second radial type is formed on the surface of the light transmitting member 615 opposite to the inside of the housing 610. A refractive index distribution lens 8 (hereinafter also referred to as a second lens 8) is fixed by an optical adhesive 616.
Similar to the optical adhesive 614, the optical adhesive 616 has a refractive index that is greater than or equal to the refractive index of the translucent member 615 and less than or equal to the maximum value of the refractive index of the second lens 8.

  Similar to the first lens 7, the second lens 8 is a columnar optical element whose refractive index changes according to the distance from the optical axis so that the optical axis coincides with the optical axis L1 of the wavelength variable interference filter. The length in the optical axis direction is set so that an inverted image is formed. Further, the second lens 8 emits the light emitted from the wavelength variable interference filter 5 and incident from the light incident surface 8 </ b> A from the light emitting surface 8 </ b> B and forms an image on the image sensor 11. Here, the second lens 8 passes the light from the object arranged on the light incident surface 7 </ b> A side of the first lens 7 through the first lens 7 and the second lens 8, so that an erect image is captured by the image sensor 11. Can be imaged.

  Although not shown in FIG. 2, an internal terminal is provided inside the housing 610, and the internal terminal is connected to the electrode pads 563 </ b> P and 564 </ b> P (see FIG. 3) of the wavelength variable interference filter 5. In addition, an external terminal connected to the internal terminal is provided outside the housing 610. The wavelength variable interference filter 5 is connected to the drive control unit 15 via an external terminal.

[Configurations of Image Sensor, IV Converter, Amplifier, A / D Converter, and Drive Control Unit]
Next, returning to FIG. 1, the optical module 10 will be described.
The image sensor 11 receives (detects) the light transmitted through the wavelength variable interference filter 5 and outputs a detection signal based on the amount of received light to the IV converter 12.
The IV converter 12 converts the detection signal input from the image sensor 11 into a voltage value and outputs the voltage value to the amplifier 13.
The amplifier 13 amplifies a voltage (detection voltage) corresponding to the detection signal input from the IV converter 12.
The A / D converter 14 converts the detection voltage (analog signal) input from the amplifier 13 into a digital signal and outputs it to the control unit 20.

  The drive control unit 15 applies a drive voltage to the electrostatic actuator 56 of the wavelength variable interference filter 5 based on the control of the control unit 20. As a result, an electrostatic attractive force is generated between the fixed electrode 561 and the movable electrode 562 of the electrostatic actuator 56, and the movable portion 521 is displaced toward the fixed substrate 51 side.

[Configuration of control unit]
Next, the control unit 20 of the spectrometer 1 will be described.
The control unit 20 is configured by combining a CPU, a memory, and the like, for example, and controls the overall operation of the spectroscopic measurement apparatus 1. As illustrated in FIG. 1, the control unit 20 includes a wavelength setting unit 21, a light amount acquisition unit 22, and a spectroscopic measurement unit 23. The memory of the control unit 20 stores V-λ data indicating the relationship between the wavelength of light transmitted through the wavelength variable interference filter 5 and the drive voltage applied to the electrostatic actuator 56 corresponding to the wavelength. ing.

The wavelength setting unit 21 sets a target wavelength of light extracted by the variable wavelength interference filter 5 and instructs the electrostatic actuator 56 to apply a drive voltage corresponding to the set target wavelength based on the V-λ data. Is output to the drive control unit 15.
The light amount acquisition unit 22 acquires the light amount of the light having the target wavelength that has passed through the wavelength variable interference filter 5 based on the light amount acquired by the imaging element 11.
The spectroscopic measurement unit 23 measures the spectral characteristics of the light to be measured based on the light amount acquired by the light amount acquisition unit 22.

[Operational effects of the first embodiment]
In the present embodiment, the first lens 7 is fixed to the casing 610 at a position facing the light incident port 611 that forms the light passage region of the casing 610 to which the wavelength variable interference filter 5 is fixed.
In such a configuration, for example, compared to a case where light is guided to the wavelength variable interference filter 5 using a telecentric optical system including optical elements such as a plurality of lenses, the surface of the optical element crossing the optical path ( The number of interfaces) can be reduced, and reflection of light at the interface can be suppressed. Therefore, the amount of light emitted from the wavelength variable interference filter 5 with respect to the amount of light incident on the optical module 10 can be increased, and the light utilization efficiency can be improved.
Further, when the amount of light decreases, the amount of light received by the image sensor 11 decreases, and depending on the sensitivity of the image sensor 11, there is a possibility that sufficient amount of data cannot be acquired. On the other hand, in the present embodiment, a decrease in the amount of received light due to a decrease in the amount of light can be suppressed, and a decrease in the accuracy of spectroscopic measurement can be suppressed.

In the present embodiment, the first lens 7 is bonded with an optical adhesive 614 at a position overlapping the light incident port 611 of the light transmitting member 613 disposed so as to cover the light incident port 611 forming the light passage region. ing.
In such a configuration, the relative position between the wavelength variable interference filter 5 and the first lens 7 is determined by fixing the first lens 7 to the translucent member 613 fixed to the housing 610. Can do. Accordingly, it is possible to suppress a decrease in resolution due to the position shift of the first lens 7 and a wavelength shift of the interference light due to an angle change of incident light.

Further, by fixing the first lens 7 to the translucent member 613 with the optical adhesive 614, no space is formed between the first lens 7 and the translucent member 613, and the optical adhesive 614 is filled. The reflection by the interface between the first lens 7 and the translucent member 613 can be suppressed.
In addition, also about the 2nd lens 8, by fixing to the translucent member 615 with the optical adhesive 616, a space is not formed between the 2nd lens 8 and the translucent member 615, and the reflection by an interface can be suppressed.

In the present embodiment, the refractive index of the optical adhesive 614 is set to be equal to or higher than the refractive index of the translucent member 613 and equal to or lower than the maximum value of the refractive index of the first lens 7. And the refractive index difference at each interface between the optical adhesive 614 and the translucent member 613 can be reduced, and reflection at the interface can be more reliably suppressed.
Similarly, the refractive index difference of the optical adhesive 616 can be reduced by setting the refractive index to be equal to or higher than the refractive index of the translucent member 615 and equal to or lower than the maximum value of the refractive index of the second lens 8. , Reflection at the interface can be more reliably suppressed.

In the present embodiment, the lenses 7 and 8 are disposed with the wavelength variable interference filter 5 interposed therebetween, and the imaging position P1 of the first lens 7 disposed on the light incident surface 52A side of the wavelength variable interference filter 5 is the wavelength variable. It is located in the arrangement area of the interference filter 5 (for example, the position between a pair of reflective films).
In such a configuration, the light from the first lens 7 is imaged in the arrangement region of the wavelength variable interference filter 5. For this reason, the light beam diameter of the light emitted from the first lens 7 is reduced in the vicinity of the imaging position, so that the size of the region where the pair of reflective films 54 and 55 face each other can be reduced. The module 10 can be miniaturized.

[Modification of First Embodiment]
In the optical filter device 600 of the optical module 10 of the first embodiment, the tunable interference filter 5 is housed in the housing 610 that is an example of the fixing unit of the present invention, and the translucent member provided in the housing 610. Although it is fixed to 613, the present invention is not limited to this. For example, a glass cap may be bonded to the wavelength variable interference filter 5 at a position covering the movable substrate 52, and the first lens 7 may be fixed to the glass cap.

FIG. 5 is a diagram illustrating a schematic configuration of an optical filter device and an image sensor in an optical module according to a modification. In addition, about the structure similar to the optical module 10 of 1st embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted or simplified.
As shown in FIG. 5, in the optical module 10A of the present modification, the optical filter device 600A is fixed to the light incident surface 52A side of the movable substrate 52 of the wavelength variable interference filter 5, and covers the light incident surface 52A. 620.
The glass cap 620 includes a wall portion 620A that is fixed to the outer peripheral portion of the movable substrate 52, and a facing portion 620B that faces the light incident surface 52A. The wall portion 620A and the outer peripheral portion of the movable substrate 52 are bonded by a bonding agent (not shown) such as low-melting glass. The glass cap 620 is formed of a light-transmitting material such as quartz glass, and the reflection film overlapping region of the facing portion 620B in the filter plan view is a light passage region.

The first lens 7 is in a position overlapping the reflective films 54 and 55 on the surface opposite to the wavelength variable interference filter 5 of the glass cap 620 in a plan view as viewed along the optical axis L1 of the wavelength variable interference filter 5. It is fixed by an optical adhesive 621. Similar to the optical adhesive 614, the refractive index of the optical adhesive 621 is not less than the refractive index of the glass cap 620 and not more than the maximum value of the refractive index of the first lens 7.
Further, the second lens 8 is fixed by an optical adhesive 622 at a position overlapping the reflective films 54 and 55 on the surface of the fixed substrate 51 opposite to the movable substrate 52 in the filter plan view. Similar to the optical adhesive 614, the refractive index of the optical adhesive 622 is not less than the refractive index of the fixed substrate 51 and not more than the maximum value of the refractive index of the second lens 8.

  In such a configuration, the optical module 10 </ b> A is configured by bonding the first lens 7 to the glass cap 620 and the second lens 8 to the fixed substrate 51 without providing the housing 610 for housing the wavelength variable interference filter 5. Simplification and downsizing are possible.

[Second Embodiment]
In the optical module 10 of the first embodiment, the first lens 7 is fixed to the translucent member 613 and the second lens 8 is fixed to the translucent member 615, respectively. On the other hand, the second embodiment is different in that the first lens 7 and the second lens 8 are directly fixed to the housing 610.
In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified.

FIG. 6 is a diagram illustrating a schematic configuration of an optical filter device and an image sensor in the optical module of the second embodiment.
As shown in FIG. 6, in the optical filter device 600 </ b> B of the optical module 10 </ b> B, the first lens 7 is directly bonded to the housing 610 at a position that covers the light incident port 611 by the bonding member 617.
Further, the second lens 8 is directly bonded to the housing 610 at a position covering the light emission port 612 by the bonding member 618.
Also in this embodiment, the optical axes of the wavelength variable interference filter 5, the first lens 7, and the second lens 8 are the same. Further, the imaging position P1 of the first lens 7 is located between the pair of reflective films 54 and 55 of the wavelength variable interference filter 5.

  Also in the present embodiment, the width of the light beam emitted from the first lens 7 in the direction perpendicular to the optical axis L1 is smaller than that of each of the reflection films 54 and 55 when passing through each of the reflection films 54 and 55. In addition, the refractive index of the first lens 7, the width dimension in the direction orthogonal to the optical axis L1, and the like are set. As a result, it is possible to suppress a decrease in the light utilization efficiency and a reduction in the field angle range in which an image can be formed.

  In the present embodiment, the dimension (area) of the first lens 7 in the direction perpendicular to the optical axis L <b> 1 is larger than that of the light incident port 611. Even in such a configuration, if the width of the light incident port 611 is smaller than the width of the light beam emitted from the first lens 7, a part of the light emitted from the first lens 7 is received by the housing 610. The angle of view and the refractive index of the first lens 7 and the dimensions of the light entrance 611 are set so that the light beam emitted from the first lens 7 passes through without being partially shielded so as not to be shielded. To do.

[Operational effects of the second embodiment]
In the present embodiment, the first lens 7 is directly bonded to the housing 610 by the bonding member 617 at a position covering the light incident port 611.
In such a configuration, the structure of the optical module 10B can be simplified and downsized as compared with the case where the translucent members 613 and 615 (see FIG. 2) are provided as in the first embodiment. In addition, light loss at the interface between the translucent members 613 and 615 can be suppressed, and light utilization efficiency can be improved.
In the present embodiment, the second lens 8 is also directly joined to the housing 610 by the joining member 617 at a position covering the light incident port 611, and similarly, the structure of the optical module 10B is simplified. And downsizing.

[Third embodiment]
The optical module 10 of the first embodiment includes two radial type gradient index lenses 7 and 8. On the other hand, the third embodiment is different in that a radial type gradient index lens is provided only on the light incident side of the wavelength variable interference filter 5.
In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified.

FIG. 7 is a diagram illustrating a schematic configuration of an optical filter device and an image sensor in the optical module of the third embodiment.
As shown in FIG. 7, the optical filter device 600 </ b> C of the optical module 10 </ b> C is bonded so as to cover the housing 610, the translucent member 613 bonded so as to cover the light incident port 611, and the light emitting port 612. A translucent member 615 and a radial type gradient index lens 9 (hereinafter also referred to as a lens 9) are provided. The imaging element 11 is bonded to the light transmitting member 615 of the optical filter device 600C by an optical adhesive 616A.

Similarly to the first lens 7, the lens 9 is bonded to the translucent member 613 with an optical adhesive 614. The refractive index of the optical adhesive 614 is not less than the refractive index of the translucent member 613 and not more than the maximum value of the refractive index of the lens 9.
The imaging position P2 of the lens 9 is located on the imaging surface of the imaging device 11 and forms an inverted image on the imaging device 11.

[Operational effects of the third embodiment]
In the present embodiment, the lens 9 is disposed on the light incident surface 52A side of the wavelength variable interference filter 5, and the imaging element 11 is disposed on the opposite side of the light incident surface 52A and at the imaging position P2 of the lens 9.
In such a configuration, even if the coupling optical system is not disposed between the wavelength variable interference filter 5 and the image sensor 11, the light transmitted through the lens 9 and dispersed by the wavelength variable interference filter 5 is transmitted by the image sensor 11. An image can be formed. Therefore, an increase in the interface due to the arrangement of the imaging optical system including the lens or the like can be suppressed, and a decrease in light use efficiency due to the increase in the interface can be suppressed. Further, since no coupling optical system or the like is disposed, the optical module 10C can be reduced in size.

[Modification of Third Embodiment]
In the optical filter device 600C of the third embodiment, the variable wavelength interference filter 5 is housed in a housing 610 that is an example of a fixing portion of the present invention, and is fixed to a light transmitting member 613 provided in the housing 610. However, the present invention is not limited to this.
FIG. 8 is a diagram illustrating a schematic configuration of an optical filter device and an imaging element in an optical module according to a modification of the third embodiment.
As shown in FIG. 8, in the optical filter device 600D of the optical module 10D, similarly to the optical filter device 600A according to the modification of the first embodiment shown in FIG. The glass cap 620 fixed to 5 is provided. Then, the lens 9 is fixed to the glass cap 620 with the optical adhesive 621. In addition, the image pickup device 11 is bonded by an optical adhesive 622A at a position overlapping the reflective films 54 and 55 on the surface of the fixed substrate 51 opposite to the movable substrate 52 in plan view of the filter.
In such a configuration, similarly to the optical filter device 600A according to the modified example of the first embodiment, the housing 610 for housing the wavelength variable interference filter 5 is not provided, the first lens 7 is mounted on the glass cap 620, and the fixed substrate. By joining the second lens 8 to 51, the configuration can be simplified or downsized.

FIG. 9 is a diagram illustrating a schematic configuration of an optical filter device and an imaging element in an optical module according to another modification of the third embodiment.
As shown in FIG. 9, in the optical filter device 600 </ b> E of the optical module 10 </ b> E, the lens 9 covers the light incident port 611 with the bonding member 617, as in the optical filter device 600 </ b> B according to the second embodiment shown in FIG. 6. In this way, it is directly joined to the housing 610.
In such a configuration, similarly to the second embodiment, the configuration of the optical module 10E is simplified and miniaturized as compared with the case where the translucent member 613 (see FIG. 2) is provided as in the first embodiment. Is possible.

[Fourth embodiment]
Hereinafter, an embodiment according to a measuring apparatus of the present invention will be described based on the drawings.
[Configuration of Spectrometer]
FIG. 10 is a diagram showing a schematic configuration of a measuring apparatus according to the fourth embodiment of the present invention.
A measuring apparatus 1A shown in FIG. 10 irradiates a measurement target with light of a predetermined first wavelength (for example, excitation light), and reflects light from the illuminated measurement target (second wavelength corresponding to the predetermined first wavelength). For example, fluorescence) to obtain a spectral image.
As illustrated in FIG. 10, the measurement apparatus 1 </ b> A includes an optical filter device 600 (see FIG. 2) according to the first embodiment, the image sensor 11, and the illumination unit 30. In the present embodiment, the configuration including the optical filter device 600 of the first embodiment is illustrated, but the configurations of the optical filter devices of the second and third embodiments may be employed.

The illumination unit 30 emits light having a predetermined first wavelength.
The illumination unit 30 includes a light source 31, a second variable wavelength interference filter 5 </ b> A housed in a housing 610, a fiber connector 32, an optical fiber 33, and a third radial refractive index distribution lens 34 (hereinafter referred to as a first refractive index distribution lens 34). 3 lens 34). The second variable wavelength interference filter 5A is configured in the same manner as the variable wavelength interference filter 5 included in the optical filter device 600.

  The light source 31 is provided with a position facing the light incident port 611 (see FIG. 2) of the housing 610, and irradiates light in a direction toward the second wavelength variable interference filter 5A. The light emitted from the light source 31 includes light having a predetermined first wavelength (for example, excitation light for emitting fluorescence). For example, the light source 31 is a white light source such as an LED that outputs white light including near infrared light from visible light of 380 nm to 700 nm.

The fiber connector 32 is provided at a position facing the light emission port 612 (see FIG. 2) of the housing 610, and guides the first wavelength light emitted from the wavelength variable interference filter 5 to the optical fiber 33.
The optical fiber 33 is bonded to the light incident surface 7 </ b> A of the first lens 7 with an optical adhesive 35, and guides light having a first wavelength to the first lens 7 of the optical filter device 600. The light guide unit of the present invention includes a fiber connector 32 and an optical fiber 33.
The third lens 34 is bonded to the light incident surface 7A with an optical adhesive 35 so that the optical axis thereof coincides with that of the first lens 7, and forms an image of light of the first wavelength on the measurement target. The distance from the measurement target side end surface 34A of the third lens 34 to the imaging position can be set as appropriate depending on the refractive index distribution of the third lens 34 and the length in the optical axis direction. For example, the third lens 34 can be brought into close contact with the measurement target by forming an image at the position of the end face 34A. Therefore, it is possible to prevent the light reflected by the measurement target from entering the third lens 34 and reducing the light use efficiency.

The image sensor 11 is bonded to the light exit surface 8B of the second lens 8 of the optical filter device 600 with an optical adhesive 619. The second lens 8 of the optical filter device 600 is designed so that the light emitted from the variable wavelength interference filter 5 forms an image on the imaging surface of the imaging element 11.
10, the wavelength variable interference filters 5 and 5A are driven and controlled by the drive control unit 15 based on commands from the control unit 20.

[Operation of measuring device]
In the measuring apparatus 1A configured as described above, the light emitted from the light source 31 enters the second variable wavelength interference filter 5A. In the second variable wavelength interference filter 5A, the size of the gap G1 is controlled so as to transmit light of the first wavelength. Therefore, the first wavelength light is emitted from the second variable wavelength interference filter 5 </ b> A, guided by the fiber connector 32 and the optical fiber 33, and incident on the light incident surface 7 </ b> A of the first lens 7.

  Thereafter, the light of the first wavelength is condensed on the wavelength variable interference filter 5 by the first lens 7. In the wavelength tunable interference filter 5, the size of the gap G <b> 1 is controlled so as to transmit light of the second wavelength corresponding to the first wavelength. For this reason, the light of the 1st wavelength condensed on the 2nd wavelength variable interference filter 5A is reflected. The reflected light of the first wavelength is transmitted through the first lens 7 and the third lens 34, is emitted from the end face 34A, and is irradiated onto the measurement target. And the light containing the light of the 2nd wavelength corresponding to the 1st wavelength is reflected from the measuring object irradiated with the light of the 1st wavelength.

The reflected light is incident on the third lens 34 again, passes through the third lens 34 and the first lens 7, and is collected on the wavelength variable interference filter 5. Of the collected light, light of the second wavelength is emitted from the wavelength variable interference filter 5 and imaged on the image sensor 11 by the second lens 8. In this way, a spectral image of fluorescence corresponding to excitation light having a second wavelength corresponding to the first wavelength, for example, a predetermined wavelength, is acquired.
A spectral image can be acquired at each of a plurality of second wavelengths by appropriately setting the size of the gap G1 of each of the wavelength variable interference filters 5 and 5A.

[Effects of Fourth Embodiment]
In the present embodiment, the optical filter device 600 of the optical module 10 is provided with the fiber connector 32 and the optical fiber 33, which are light guide members, of the light emitted from the light source 31 and dispersed by the second variable wavelength interference filter 5A. 1 lead to the lens 7.
In such a configuration, as described above, the second wavelength corresponding to the first wavelength is adjusted by appropriately adjusting the wavelengths of the interference light (first wavelength and second wavelength) of the two wavelength variable interference filters 5 and 5A. (For example, fluorescence corresponding to excitation light) can be detected with high resolution.

  In the present embodiment, the light emitted from the light source 31 and dispersed by the second variable wavelength interference filter 5A is guided by the fiber connector 32 and the optical fiber 33 (light guide member), thereby a plurality of lenses and mirrors. Compared with the case where light is reflected or refracted by an optical element or the like, the reflection of light at the interface can be suppressed, and the light utilization efficiency can be improved.

  In the present embodiment, the second lens 8 is bonded to the image sensor 11 by the optical adhesive 616, and the image forming position of the second lens 8 is located on the image pickup surface of the image sensor 11. In such a configuration, the optical adhesive 616 is filled between the second lens 8 and the imaging element 11, reflection at the interface can be suppressed, and light utilization efficiency can be improved.

[Modification of Embodiment]
In addition, this invention is not limited to the above-mentioned embodiment, The deformation | transformation in the range which can achieve the objective of this invention, improvement, etc. are included in this invention.
In each of the above embodiments, the optical module has been illustrated with a configuration including one optical filter device and an image sensor, but the present invention is not limited to this and employs a configuration including a plurality of optical filter devices and image sensors. May be.
FIG. 11 is a diagram showing a schematic configuration of a main part of an optical module according to a modification of the present invention.
As illustrated in FIG. 11, the optical module 10 </ b> F includes a plurality of optical filter devices 600 and the image sensor 11 disposed at the imaging position of the second lens 8 of each optical filter device 600. Each optical filter device 600 has a housing 610 fixed to the support substrate 16 in a state of being inserted into an opening 16 </ b> A provided in the support substrate 16.

FIG. 12 is a plan view showing a schematic configuration when the optical module 10F according to a modification shown in FIG. 11 is viewed from the first lens 7 side in the optical axis direction.
As shown in FIG. 12, a plurality of optical filter devices 600 are arranged in the X direction, and a plurality of such columns are arranged in parallel to each other in the Y direction orthogonal to the X direction (in FIG. 12, 2 rows). Further, the plurality of columns are arranged offset in X. Specifically, the optical filter device 600 is disposed between two adjacent optical filter devices 600 included in adjacent rows in the X direction.

  In addition, the imageable range R1 (imageable range on the imaging surface S1 in FIG. 11) of each first lens 7 indicated by a one-dot chain line in FIG. 12 overlaps with the adjacent optical filter device 600 in plan view in the optical axis direction. . Thereby, a spectral image covering a wide range can be acquired at once.

  In the first embodiment, the refractive index of the optical adhesive that joins the radial type refractive index distribution lens and the translucent member is equal to or higher than the refractive index of the translucent member and the refractive index of the radial type refractive index distribution lens. Although the structure which is below the maximum value is illustrated, the present invention is not limited to this, and a refractive index other than the above range may be used as long as it is a translucent adhesive.

  In each of the above embodiments, the configuration in which the movable substrate 52 of the wavelength tunable interference filter 5 is fixed to the housing 610 is illustrated, but the present invention is not limited to this, and the fixed substrate 51 may be fixed.

In each of the above-described embodiments, the gap change unit includes the electrostatic actuator 56 that changes the size of the gap G1 between the reflection films by applying electrostatic voltage to the fixed electrode 561 and the movable electrode 562. Although illustrated, it is not limited to this.
For example, an induction actuator may be used as the gap changing unit. In this case, a configuration in which the first induction coil is arranged instead of the fixed electrode 561 and the second induction coil or permanent magnet is arranged instead of the movable electrode 562 can be exemplified.
Furthermore, a piezoelectric actuator may be used as the gap changing unit. In this case, the lower electrode layer, the piezoelectric film, and the upper electrode layer are stacked on the holding unit 522, and the voltage applied between the lower electrode layer and the upper electrode layer is varied as an input value, so that the piezoelectric film can be expanded and contracted. A configuration in which the holding portion 522 is bent can be exemplified.
Moreover, in each said embodiment, although the structure which provided the electrostatic actuator 56 as a gap change part only in one side of a pair of board | substrate was illustrated, this invention is not limited to this, A gap change part is provided in both board | substrates. It may be provided.

In each of the above embodiments, the wavelength variable interference filter 5 configured to be able to change the inter-reflective film gap G1 is exemplified, but the present invention is not limited to this, and the interference filter is an interference filter in which the size of the inter-reflective film gap G1 is fixed. May be.
In each of the above-described embodiments, the wavelength variable interference filter 5 includes a pair of substrates 51 and 52 and a pair of reflective films 54 and 55 provided on the substrates 51 and 52, respectively. It is not limited to. For example, the movable substrate 52 may not be provided, and the fixed substrate 51 may be fixed to the housing 610. In this case, for example, the first reflective film, the gap spacer, and the second reflective film are stacked on one surface of the substrate (fixed substrate), and the first reflective film and the second reflective film are opposed to each other through the gap. To do. In this configuration, a single substrate is used, and the spectral element can be made thinner.

  In each of the above embodiments, the spectroscopic measurement apparatus 1 is exemplified as the electronic apparatus of the present invention. However, the optical module and the electronic apparatus of the present invention can be applied in various other fields. In addition, although the following modification of an electronic device illustrates the structure provided with the optical filter device 600 of 1st embodiment, this invention is not limited to this, The optical filter device of 2nd and 3rd embodiment is used. You can also.

For example, as shown in FIG. 13, the electronic apparatus of the present invention can be applied to a color measuring device for measuring color.
FIG. 13 is a block diagram illustrating an example of a colorimetric device 400 including a wavelength variable interference filter.
As shown in FIG. 13, the color measurement device 400 includes a light source device 410 that emits light to the measurement target X, a color measurement sensor 420 (optical module), and a control device 430 that controls the overall operation of the color measurement device 400. And comprising. The colorimetric device 400 reflects light emitted from the light source device 410 by the measurement target X, receives the reflected inspection target light by the colorimetric sensor 420, and outputs the light from the colorimetric sensor 420. It is an apparatus that analyzes and measures the chromaticity of the inspection target light, that is, the color of the measurement target X, based on the detection signal.

  The light source device 410, the light source 411, and a plurality of lenses 412 (only one is shown in FIG. 13) are provided, and for example, reference light (for example, white light) is emitted to the measurement target X. Further, the plurality of lenses 412 may include a collimator lens. In this case, the light source device 410 converts the reference light emitted from the light source 411 into parallel light by the collimator lens and measures it from a projection lens (not shown). Inject toward the target X. In the present embodiment, the color measurement device 400 including the light source device 410 is illustrated. However, for example, when the measurement target X is a light emitting member such as a liquid crystal panel, the light source device 410 may not be provided.

  The colorimetric sensor 420 is an optical module according to the present invention. As shown in FIG. 13, the colorimetric sensor 420 transmits light through the optical filter device 600, the image sensor 11 that receives light transmitted through the optical filter device 600, and the optical filter device 600. And a drive control unit 15 that varies the wavelength of light. Then, the colorimetric sensor 420 splits light having a predetermined wavelength out of the inspection target light by the variable wavelength interference filter 5 (see FIG. 2) of the optical filter device 600, and the image sensor 11 receives the split light. .

The control device 430 controls the overall operation of the color measurement device 400.
As the control device 430, for example, a general-purpose personal computer, a portable information terminal, a color measurement dedicated computer, or the like can be used. As shown in FIG. 13, the control device 430 includes a light source control unit 431, a colorimetric sensor control unit 432, a colorimetric processing unit 433, and the like.
The light source control unit 431 is connected to the light source device 410 and outputs a predetermined control signal to the light source device 410 based on, for example, a user's setting input to emit white light with a predetermined brightness.
The colorimetric sensor control unit 432 is connected to the colorimetric sensor 420, sets the wavelength of light received by the colorimetric sensor 420 based on, for example, a user's setting input, and detects the amount of light received at this wavelength. A control signal to this effect is output to the colorimetric sensor 420. Accordingly, the drive control unit 15 of the colorimetric sensor 420 applies a voltage to the electrostatic actuator 56 based on the control signal, and drives the wavelength variable interference filter 5.
The colorimetric processing unit 433 analyzes the chromaticity of the measurement target X from the amount of received light detected by the image sensor 11.

Another example of the electronic device of the present invention is a light-based system for detecting the presence of a specific substance. As such a system, for example, an in-vehicle gas leak detector that detects a specific gas with high sensitivity by adopting a spectroscopic measurement method using the optical module of the present invention, a photoacoustic rare gas detector for a breath test, etc. Examples of the gas detection device can be exemplified.
An example of such a gas detection device will be described below with reference to the drawings.

FIG. 14 is a schematic view showing an example of a gas detection apparatus provided with the optical module of the present invention.
FIG. 15 is a block diagram showing a configuration of a control system of the gas detection device of FIG.
As shown in FIG. 14, the gas detection device 100 includes a sensor chip 110, a flow path 120 including a suction port 120A, a suction flow path 120B, a discharge flow path 120C, and a discharge port 120D, a main body 130, It is configured with.
The main body unit 130 includes a sensor unit cover 131 having an opening through which the flow channel 120 can be attached, a discharge unit 133, a housing 134, an optical unit 135, a filter 136, an optical filter device 600, a light receiving element 137 (light receiving unit), and the like. Including a detection device (optical module), a control unit 138 (processing unit) that performs processing of a signal output according to light received by the light receiving element 137 and control of the detection device and the light source unit, and power for supplying power It comprises a supply unit 139 and the like. The optical unit 135 emits light, and a beam splitter 135B that reflects light incident from the light source 135A toward the sensor chip 110 and transmits light incident from the sensor chip toward the light receiving element 137. And lenses 135C, 135D, and 135E.
As shown in FIG. 14, an operation panel 140, a display unit 141, a connection unit 142 for interface with the outside, and a power supply unit 139 are provided on the surface of the gas detection device 100. When the power supply unit 139 is a secondary battery, a connection unit 143 for charging may be provided.
Further, as shown in FIG. 15, the control unit 138 of the gas detection apparatus 100 controls a signal processing unit 144 configured by a CPU or the like, a light source driver circuit 145 for controlling the light source 135A, and the variable wavelength interference filter 5. Drive control unit 15, a light receiving circuit 147 that receives a signal from the light receiving element 137, a sensor chip detection that reads a code from the sensor chip 110 and receives a signal from a sensor chip detector 148 that detects the presence or absence of the sensor chip 110. A circuit 149, a discharge driver circuit 150 for controlling the discharge means 133, and the like are provided.

Next, operation | movement of the above gas detection apparatuses 100 is demonstrated below.
A sensor chip detector 148 is provided inside the sensor unit cover 131 at the upper part of the main body unit 130, and the sensor chip detector 148 detects the presence or absence of the sensor chip 110. When the signal processing unit 144 detects the detection signal from the sensor chip detector 148, the signal processing unit 144 determines that the sensor chip 110 is attached, and displays a display signal for displaying on the display unit 141 that the detection operation can be performed. put out.

  For example, when the operation panel 140 is operated by the user and an instruction signal to start the detection process is output from the operation panel 140 to the signal processing unit 144, the signal processing unit 144 first sends the signal processing unit 144 to the light source driver circuit 145. A light source activation signal is output to activate the light source 135A. When the light source 135A is driven, laser light having a single wavelength and stable linear polarization is emitted from the light source 135A. The light source 135A includes a temperature sensor and a light amount sensor, and the information is output to the signal processing unit 144. When the signal processing unit 144 determines that the light source 135A is stably operating based on the temperature and light quantity input from the light source 135A, the signal processing unit 144 controls the discharge driver circuit 150 to operate the discharge unit 133. Thereby, the gas sample containing the target substance (gas molecule) to be detected is guided from the suction port 120A to the suction channel 120B, the sensor chip 110, the discharge channel 120C, and the discharge port 120D. The suction port 120A is provided with a dust removal filter 120A1 to remove relatively large dust, some water vapor, and the like.

The sensor chip 110 is a sensor that incorporates a plurality of metal nanostructures and uses localized surface plasmon resonance. In such a sensor chip 110, an enhanced electric field is formed between the metal nanostructures by the laser light, and when gas molecules enter the enhanced electric field, Raman scattered light and Rayleigh scattered light including information on molecular vibrations are generated. Occur.
These Rayleigh scattered light and Raman scattered light enter the filter 136 through the optical unit 135, and the Rayleigh scattered light is separated by the filter 136, and the Raman scattered light enters the optical filter device 600. Then, the signal processing unit 144 outputs a control signal to the drive control unit 15. Accordingly, the drive control unit 15 drives the electrostatic actuator 56 of the wavelength tunable interference filter 5 in the same manner as in the first embodiment, so that the Raman scattered light corresponding to the gas molecule to be detected becomes the wavelength tunable interference filter 5. Spectate with. Thereafter, when the dispersed light is received by the light receiving element 137, a light reception signal corresponding to the amount of received light is output to the signal processing unit 144 via the light receiving circuit 147. In this case, target Raman scattered light can be extracted from the wavelength variable interference filter 5 with high accuracy.
The signal processing unit 144 compares the spectrum data of the Raman scattered light corresponding to the gas molecule to be detected obtained as described above and the data stored in the ROM, and determines whether or not the target gas molecule is the target gas molecule. To determine the substance. Further, the signal processing unit 144 displays the result information on the display unit 141 or outputs the result information from the connection unit 142 to the outside.

  14 and 15 exemplify the gas detection device 100 that performs gas detection from the Raman scattered light obtained by spectrally dividing the Raman scattered light by the wavelength variable interference filter 5. You may use as a gas detection apparatus which specifies gas classification by detecting the light absorbency of. In this case, a gas sensor that allows gas to flow into the sensor and detects light absorbed by the gas in the incident light is used as the optical module of the present invention. A gas detection device that analyzes and discriminates the gas flowing into the sensor by such a gas sensor is an electronic apparatus of the present invention. Even in such a configuration, it is possible to detect a gas component using the wavelength variable interference filter.

In addition, the system for detecting the presence of a specific substance is not limited to the detection of the gas as described above, but a non-invasive measuring device for saccharides by near-infrared spectroscopy, and non-invasive information on food, living body, minerals, etc. A substance component analyzer such as a measuring device can be exemplified.
Hereinafter, a food analyzer will be described as an example of the substance component analyzer.

FIG. 16 is a diagram showing a schematic configuration of a food analysis apparatus which is an example of an electronic apparatus using the optical module of the present invention.
As shown in FIG. 16, the food analysis device 200 includes a detector 210 (optical module), a control unit 220, and a display unit 230. The detector 210 includes a light source 211 that emits light, an optical filter device 600 (see FIG. 2) that includes a wavelength tunable interference filter 5 that splits light from a measurement object, and an imaging unit 212 that detects the split light. And.
The control unit 220 also controls the light source control unit 221 that controls the turning on / off of the light source 211 and the brightness control at the time of lighting, the drive control unit 15 that controls the variable wavelength interference filter 5, and the imaging unit 212. A detection control unit 223 that acquires a spectral image captured by the imaging unit 212, a signal processing unit 224, and a storage unit 225.

  In the food analyzer 200, when the system is driven, the light source 211 is controlled by the light source control unit 221, and light is irradiated from the light source 211 to the measurement object. Then, the light reflected by the measurement object enters the wavelength variable interference filter 5 of the optical filter device 600. The variable wavelength interference filter 5 is driven by the driving method as described in the first embodiment under the control of the drive control unit 15. Thereby, the light of the target wavelength can be extracted from the variable wavelength interference filter 5 with high accuracy. The extracted light is imaged by an imaging unit 212 configured by, for example, a CCD camera or the like. The captured light is accumulated in the storage unit 225 as a spectral image. In addition, the signal processing unit 224 controls the drive control unit 15 to change the voltage value applied to the wavelength variable interference filter 5 and acquires a spectral image for each wavelength.

Then, the signal processing unit 224 performs arithmetic processing on the data of each pixel in each image accumulated in the storage unit 225, and obtains a spectrum at each pixel. In addition, the storage unit 225 stores, for example, information related to food components with respect to the spectrum, and the signal processing unit 224 analyzes the obtained spectrum data based on the information related to food stored in the storage unit 225. The food component contained in the detection target and its content are obtained. Moreover, a food calorie, a freshness, etc. are computable from the obtained food component and content. Furthermore, by analyzing the spectral distribution in the image, it is possible to extract a portion of the food to be inspected that has reduced freshness, and to detect foreign substances contained in the food. Can also be implemented.
Then, the signal processing unit 224 performs processing for causing the display unit 230 to display information such as the components and contents of the food to be examined, the calories, and the freshness obtained as described above.

FIG. 16 shows an example of the food analysis apparatus 200, but it can also be used as a non-invasive measurement apparatus for other information as described above with a substantially similar configuration. For example, it can be used as a biological analyzer for analyzing biological components such as measurement and analysis of body fluid components such as blood. As such a bioanalytical device, for example, a device that detects ethyl alcohol as a device that measures a body fluid component such as blood, it can be used as a drunk driving prevention device that detects the drunk state of the driver. Further, it can also be used as an electronic endoscope system provided with such a biological analyzer.
Furthermore, it can also be used as a mineral analyzer for performing component analysis of minerals.

Furthermore, the optical module and electronic apparatus of the present invention can be applied to the following apparatuses.
For example, it is possible to transmit data using light of each wavelength by changing the intensity of light of each wavelength over time. In this case, light of a specific wavelength is transmitted by a wavelength variable interference filter provided in the optical module. The data transmitted by the light of the specific wavelength can be extracted by separating the light and receiving the light at the light receiving unit, and the electronic data having such a data extraction optical module can be used to extract the light data of each wavelength. By processing, optical communication can be performed.

Further, the electronic device can be applied to a spectroscopic camera, a spectroscopic analyzer, or the like that captures a spectroscopic image by dispersing light with the optical module of the present invention. An example of such a spectroscopic camera is an infrared camera incorporating a wavelength variable interference filter.
FIG. 17 is a schematic diagram showing a schematic configuration of the spectroscopic camera. As shown in FIG. 17, the spectroscopic camera 300 includes a camera body 310, an optical filter device 600, and an imaging unit 320.
The camera body 310 is a part that is gripped and operated by a user.
The optical filter device 600 is provided in the camera body 310 and guides incident image light to the imaging unit 320.
The imaging unit 320 includes a light receiving element and captures image light guided by the optical filter device 600.
In such a spectroscopic camera 300, a spectral image of light having a desired wavelength can be captured by transmitting light having a wavelength to be imaged by the variable wavelength interference filter 5 (see FIG. 2) of the optical filter device 600. .

Furthermore, the optical module of the present invention may be used as a bandpass filter. For example, among the light in a predetermined wavelength range emitted from the light emitting element, only the light in the narrow band centered on the predetermined wavelength is used as the variable wavelength interference filter. It can also be used as an optical laser device for spectrally transmitting through.
Further, the optical module of the present invention may be used as a biometric authentication device. For example, the optical module can be applied to authentication devices such as blood vessels, fingerprints, retinas, and irises using light in the near infrared region and visible region.

  Furthermore, an optical module and an electronic device can be used as a concentration detection device. In this case, the infrared energy (infrared light) emitted from the substance is spectrally analyzed by the variable wavelength interference filter, and the analyte concentration in the sample is measured.

  As described above, the optical module and the electronic apparatus of the present invention can be applied to any device that splits predetermined light from incident light. And since the optical module of this invention can disperse | distribute a some wavelength with one device as mentioned above, the measurement of the spectrum of a some wavelength and the detection with respect to a some component can be implemented accurately. Therefore, compared with the conventional apparatus which takes out a desired wavelength with a plurality of devices, it is possible to promote downsizing of the optical module and the electronic apparatus, and for example, it can be suitably used as a portable or in-vehicle optical device.

  In addition, the specific structure for carrying out the present invention may be configured by appropriately combining the above-described embodiments and modification examples within the scope in which the object of the present invention can be achieved, and may be appropriately changed to other structures and the like. May be.

  DESCRIPTION OF SYMBOLS 1 ... Spectrometer (electronic device), 5 ... Wavelength variable interference filter (interference filter), 5A ... 2nd wavelength variable interference filter (2nd interference filter), 7 ... 1st radial type refractive index distribution lens, DESCRIPTION OF SYMBOLS 8 ... 2nd radial type gradient index lens, 10 ... Optical module, 11 ... Image sensor, 20 ... Control part (processing part), 31 ... Light source, 32 ... Fiber connector (light guide member), Optical fiber (light guide member) ), 51... Fixed substrate (substrate), 54. Fixed reflective film (first reflective film), 55. Movable reflective film (second reflective film), 100... Gas detector, 137. DESCRIPTION OF SYMBOLS 200 ... Food analyzer 210 ... Detector 220 ... Control part 300 ... Spectroscopic camera 320 ... Imaging part 400 ... Color measuring device 420 ... Color measuring sensor 430 ... Control device (processing part), 600 ... Optical I Luther device 610 ... housing (fixed portion), 611 ... light inlet (opening), 613 ... light transmitting member, 614,621 ... optical adhesive.

Claims (8)

An interference filter having a pair of reflective films opposed to each other, and emitting light having a wavelength corresponding to a gap dimension of the pair of reflective films;
In the plan view seen from the optical axis direction of the interference filter, which is the normal direction of the pair of reflection films, the interference filter is fixed, a light passage region that allows light to pass through the region overlapping the pair of reflection films A fixing part having,
In the plan view, the optical filter is fixed to the fixed portion at a position facing the light passage region, has an optical axis along the optical axis direction of the interference filter, and the refractive index changes according to the distance from the optical axis. An optical module comprising a radial type gradient index lens. The optical module according to claim 1,
The fixed part has an opening in the light passage region,
A translucent member joined to the fixed portion and covering the opening;
The radial type gradient index lens is bonded to the light transmissive member with a light transmissive adhesive. The optical module according to claim 2, wherein
The optical module, wherein the refractive index of the adhesive is not less than the refractive index of the translucent member and not more than the maximum value of the refractive index of the radial type gradient index lens. The optical module according to claim 1,
The fixed part has an opening in the light passage region,
The radial type gradient index lens is bonded to the fixed portion and covers the opening. The optical module according to any one of claims 1 to 4,
In the optical axis direction of the interference filter, the optical filter has an optical axis along the optical axis direction of the interference filter on the side opposite to the radial refractive index distribution lens with respect to the interference filter. A second radial type gradient index lens whose refractive index changes according to the distance;
An optical module, wherein an imaging position of the radial type gradient index lens is in an arrangement region of the interference filter. The optical module according to any one of claims 1 to 4,
An optical module, comprising: an imaging element that is disposed at an image forming position of the radial type gradient index lens and receives light emitted from the interference filter. The optical module according to any one of claims 1 to 6,
A light source;
A second interference filter that has a pair of reflective films opposed to each other, and emits light having a wavelength according to a gap size of the pair of reflective films from the light emitted from the light source;
And a light guide member for guiding the light emitted from the second interference filter to the radial type gradient index lens. An interference filter having a pair of reflective films opposed to each other, and emitting light having a wavelength corresponding to a gap dimension of the pair of reflective films;
In the plan view seen from the optical axis direction of the interference filter, which is the normal direction of the pair of reflection films, the interference filter is fixed, a light passage region that allows light to pass through the region overlapping the pair of reflection films A fixing part having,
In the plan view, the optical filter is fixed to the fixed portion at a position facing the light passage region, has an optical axis along the optical axis direction of the interference filter, and the refractive index changes according to the distance from the optical axis. A radial type gradient index lens,
And a processing unit that performs processing based on the light emitted from the interference filter.

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