JP2012220912A - Interference filter, optical module and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an interference filter capable of suppressing a reduction in resolution, and further to provide an optical module and an electronic apparatus.SOLUTION: A wavelength variable interference filter 5 comprises: a fixed substrate 51 having a reflecting film fixing surface 512A provided with a fixed reflecting film 54 and a fixing side initial gap forming surface 513A that is parallel to the reflecting film fixing surface 512A and is provided with a fixing side initial gap forming electrode portion 561B; and a movable substrate 52 having a movable surface 520A provided with a movable reflecting film 55 opposite to the fixed reflecting film 54 through a gap G1 between the fixed reflecting film 54 and the movable reflecting film 55 and a movable side initial gap forming surface 520B that is disposed on the same plane as that of the movable surface 520A and is sequentially laminated with a movable side initial gap forming electrode portion 562B and an insulating layer 57. The insulating layer 57 is opposite to a fixing side driving electrode portion 561A through a minute gap G3, and the minute gap G3 is formed so as to be smaller than the gap G1 between the fixed reflecting film 54 and the movable reflecting film 55.

Description

  The present invention relates to an interference filter, an optical module including the interference filter, and an electronic apparatus including the optical module.

  2. Description of the Related Art Conventionally, an interference filter is known in which a reflective film is disposed on a surface of a pair of substrates facing each other via a predetermined air gap (see, for example, Patent Document 1).

  In the Fabry-Perot filter (interference filter) described in Patent Document 1, a fixed substrate provided with a fixed mirror and a movable substrate provided with a movable mirror are joined via a spacer. In this interference filter, the movable substrate is provided with a conductive diaphragm, and the movable mirror can be displaced toward the fixed substrate by deforming the diaphragm. The fixed substrate is provided with a fixed electrode. When a voltage is applied between the drive electrode and the diaphragm, the diaphragm is bent by electrostatic attraction, and the air gap between the movable mirror and the fixed mirror. The structure which can change is taken.

JP 2003-215473 A

  By the way, in the interference filter, it is necessary that the pair of reflection films be maintained in parallel, and when the parallel relationship between these reflection films is broken, the wavelength of the extracted light varies depending on the position where the multiple interference of the light occurs. There is a problem that the resolution of the interference filter is significantly reduced. In particular, as in Patent Document 1, in the configuration in which electrodes are provided on each of the substrates facing each other and the air gap is changed by electrostatic attraction, the magnitude of the electrostatic attraction increases in inverse proportion to the square of the distance between the electrodes. . For this reason, even if the inclination of the reflective film is about an error in the initial state, the inclination of the reflective film becomes large if the gap between the air gaps is reduced by voltage application.

  Here, in the interference filter described in Patent Document 1, the initial gap (the size of the air gap in the initial state) is set to a predetermined value by the spacer, but in reality, the spacer is bonded to the fixed substrate or the movable substrate. There is a need to. In such bonding, bonding with a bonding film containing siloxane, an adhesive, or the like is performed. Usually, in order to obtain bonding strength at the bonded portion, the bonded portion is bonded in a pressurized state. When such pressure bonding is performed, the bonding strength can be obtained, but the movable substrate may be inclined and bonded to the fixed substrate. As described above, when the movable substrates are joined in an inclined state, the reflective films are not parallel to each other, and there is a problem that the resolution of the interference filter is lowered as described above.

  In view of the above-described problems, an object of the present invention is to provide an interference filter, an optical module, and an electronic device that can suppress a decrease in resolution.

The interference filter of the present invention includes a first substrate, a second substrate facing the first substrate, a first reflective film provided on a surface of the first substrate facing the second substrate, and the second substrate A second reflection film provided on a surface of the substrate facing the first substrate and facing the first reflection film with a gap between the reflection films having a predetermined size; An initial gap forming portion set to the first substrate, wherein the first substrate has a flat first reflecting film fixing surface on which the first reflecting film is provided, and is parallel to and flat with the first reflecting film fixing surface. The first initial gap forming surface, and the second substrate is a flat second reflecting film fixing surface on which the second reflecting film is provided, and is opposed to the first initial gap forming surface, and the second substrate A second initial gap forming surface parallel to and flat with the reflecting film fixing surface, The distance between the initial gap forming surface and the second initial gap forming surface is smaller than the distance between the gaps between the front reflection films, and the initial gap forming portion connects the first initial gap forming surface and the second initial gap forming surface to each other. It is characterized in that it is biased in the approaching direction and kept parallel.
Here, in the present invention, the first initial gap forming surface of the first substrate is parallel to the first reflecting film fixing surface. The first initial gap forming surface and the first reflecting film fixing surface are on the same plane. The structure to be formed is also included. In this case, the second reflection film of the second substrate is set such that the distance between the first reflection film fixing surface and the second reflection film fixing surface is larger than the distance between the first initial gap formation surface and the second initial gap formation surface. The fixed surface and the second initial gap forming surface may be provided at different plane positions.
Similarly, the second initial gap forming surface of the second substrate is parallel to the second reflecting film fixing surface, and the second initial gap forming surface and the second reflecting film fixing surface are formed on the same plane. The structure to be included is also included. In this case, the first reflective film of the first substrate is such that the distance between the first reflective film fixing surface and the second reflective film fixed surface is larger than the distance between the first initial gap forming surface and the second initial gap forming surface. The fixed surface and the first initial gap forming surface may be provided at different plane positions.
Further, in the present invention, the initial gap forming portion means that “the first initial gap forming surface and the second initial gap forming surface are urged in a direction close to each other and maintained in parallel” means the first initial gap forming surface. And the second initial gap forming surfaces are in contact with each other to be parallel. Here, the contact of the first initial gap forming surface and the second initial gap forming surface refers to, for example, a first initial gap other than a configuration in which the first initial gap forming surface and the second initial gap forming surface are in direct surface contact. Another structure having a uniform thickness, such as a film member or a spacer, is sandwiched between the formation surface and the second initial gap formation surface so that no gap is generated between the first initial gap formation surface and the second initial gap formation surface. Is included.

According to the present invention, the first substrate has a first initial gap forming surface parallel to the first reflecting film fixing surface, and the second substrate has a second initial gap forming surface parallel to the second reflecting film fixing surface. Have. Then, the initial gap forming portion urges the first initial gap forming surface and the second initial gap forming surface in directions close to each other.
Thereby, a 1st initial gap formation surface and a 2nd initial gap formation surface become the same plane because a 1st initial gap formation surface and a 2nd initial gap formation surface contact surface. Alternatively, the first initial gap forming surface and the second initial gap forming surface are brought into contact with each other via a spacer or the like, so that the first initial gap forming surface and the second initial gap forming surface are parallel to each other. Thus, when the first initial gap forming surface and the second initial gap forming surface are the same plane or parallel, the first reflecting film fixing surface parallel to the first initial gap forming surface and the second Since the second reflecting film fixing surface parallel to the initial gap forming surface is also parallel, the first reflecting film and the second reflecting film provided on these reflecting film fixing surfaces are also parallel. In the interference filter of the present invention, the gap between the reflection films in this state is set as the initial gap, and the initial state is set. Thereby, for example, even if the second substrate is bonded to the first substrate in a slightly inclined state, in the initial state, the first reflective film and the second reflective film can be made parallel, and the interference filter Of the resolution can be suppressed.

In the interference filter according to the aspect of the invention, the initial gap forming portion includes a first electrode provided on the first initial gap forming surface and a second electrode provided on the second initial gap forming surface and facing the first electrode. At least one of the electrode, the surface of the first electrode facing the second electrode, and the surface of the second electrode facing the first electrode, with a small gap smaller than the gap between the reflective films And an insulating layer facing the other electrode.
Here, in the case where an insulating layer is provided on only one of the first electrode and the second electrode, it is only necessary to provide a minute gap between the electrode provided with the insulating layer and the other electrode. In the case where an insulating layer is provided on both the first electrode and the second electrode, it is sufficient that a minute gap is provided between the insulating layers of each electrode.

  According to the present invention, the initial gap forming portion applies a voltage between the first electrode provided on the first initial gap forming surface and the second electrode provided on the second initial gap forming surface. The first initial gap forming surface and the second initial gap forming surface are biased in a direction approaching each other by electrostatic attraction. In such an interference filter, since an insulating layer is provided between the first electrode and the second electrode by electrostatic attraction, the first electrode and the second electrode are not in direct contact with each other while the voltage is applied. The biasing force due to electrostatic attraction can be always applied between the first electrode and the second electrode, and an accurate initial gap can be set.

  In the interference filter according to the aspect of the invention, in the plan view of the first substrate and the second substrate viewed from the substrate thickness direction, the first reflection film fixing surface and the second reflection film fixing surface are the first substrate and the second substrate. Provided in a substrate central region of a second substrate, wherein the first initial gap forming surface and the second initial gap forming surface are outside the substrate central region of the first substrate and the second substrate; It is preferable to be provided in an annular region that surrounds.

  According to the present invention, the first initial gap forming surface and the second initial gap forming surface are formed outside the diameter of the substrate central region on which the first reflective film and the second reflective film are provided, in the annular region surrounding the substrate central region. Is provided. For this reason, the first initial gap forming surface and the second initial gap forming surface can be accurately maintained in parallel over the circumferential direction of the substrate center region, and the first reflective film and the second reflective film can be more reliably secured. Can be kept parallel.

  In the interference filter according to the aspect of the invention, the second substrate may include the annular region and the substrate central region of the second substrate outside the annular region in a plan view of the second substrate viewed from the substrate thickness direction. It is preferable to include an outer holding portion that is movably held on the first substrate side, and a bonding portion that is provided further on the outer side than the outer holding portion and is bonded to the first substrate.

  According to the present invention, the outer holding portion is provided between the annular region and the joint portion. For this reason, when the first gap forming surface and the second initial gap forming surface are applied with an urging force close to each other, the outer holding portion is bent to form the initial gap of the second substrate. The annular region provided with the surface can be easily displaced toward the first substrate.

The interference filter of the present invention includes: a first drive electrode provided on a surface facing the second substrate in the substrate central region of the first substrate; and the substrate central region of the second substrate, And a second drive electrode facing the first substrate via an interelectrode gap.
According to the present invention, the size of the gap between the reflective films can be changed by electrostatic attraction by applying a voltage between the first drive electrode and the second drive electrode provided in the central region of the substrate. At this time, as described above, since the first initial gap forming surface and the second initial gap forming surface are brought into contact with each other, the initial gap size of the gap between the reflective films is uniform. Even when it becomes smaller, the parallelism of the first reflective film and the second reflective film can be maintained well, and a reduction in the resolution of the interference filter can be suppressed.

In the interference filter according to the aspect of the invention, it is preferable that the gap between the electrodes is larger than the gap between the reflection films.
According to the present invention, the range that can be set as the gap between the reflective films can be increased, and the wavelength range of light that can be extracted by the interference filter can be broadened.
That is, in the wavelength tunable interference filter, the wavelength extracted through transmission or reflection is determined by the gap between the first reflection film and the second reflection film. Therefore, in order to acquire the transmission or reflection wavelength corresponding to a wider wavelength range in the wavelength tunable interference filter, it is necessary to increase the fluctuation range of the gap between the reflection films. Here, when a voltage is applied between the first drive electrode and the second drive electrode and the gap between the reflection films is changed by electrostatic attraction, if the gap between the electrodes is smaller than the gap between the reflection films, the gap between the electrodes The gap between the reflective films can be changed only between the gaps. In such a configuration, the fluctuation range of the gap between the reflection films is reduced, and the wavelength range that can be extracted by the wavelength variable interference filter is reduced.
On the other hand, in the present invention, the gap between the electrodes is formed larger than the gap between the reflective films, so that the gap between the reflective films can be changed in a larger fluctuation range and can be taken out by the variable wavelength interference filter. The possible wavelength range can be broadened.
In general, the electrostatic attractive force acting between the electrodes is inversely proportional to the square of the distance. Therefore, if the gap between the electrodes becomes small, it becomes difficult to control the electrostatic attractive force, and it is difficult to adjust the gap between the reflective films. On the other hand, in the present invention, the gap between the electrodes is formed larger than the gap between the reflective films, so that the electrostatic attractive force can be easily controlled, and the gap between the reflective films can be accurately set to a desired value. it can.

  In the interference filter according to the aspect of the invention, the initial gap forming portion includes a first electrode provided on the first initial gap forming surface and a second electrode provided on the second initial gap forming surface and facing the first electrode. At least one of the electrode, the surface of the first electrode facing the second electrode, and the surface of the second electrode facing the first electrode, with a small gap smaller than the gap between the reflective films An insulating layer facing the other electrode, wherein the first electrode and the first drive electrode are electrically connected, and the second electrode and the second drive electrode are electrically connected. Is preferred.

The first electrode and the first drive electrode may be independent electrodes capable of setting different potentials, and the second electrode and the second drive electrode may be independent electrodes capable of setting different potentials. In this case, it is necessary to provide a lead line for each electrode, and the configuration may be complicated. On the other hand, in the present invention, it is only necessary to provide an extraction electrode for the first electrode and the first drive electrode, and an extraction electrode for the second electrode and the second drive electrode, and the configuration can be simplified.
In order to facilitate the displacement of the second reflective film toward the first substrate, a diaphragm is provided between the substrate central region where the second reflective film and the second drive electrode are provided and the annular region where the second electrode is provided. It is good also as a structure to provide. In such a configuration, when a voltage is applied between the first drive electrode and the second drive electrode to adjust the gap between the reflection films, the diaphragm stabilizes after repeating vibration based on the natural frequency, and between the reflection films. The gap is set to a predetermined value. Here, in the present invention, since the second electrode and the second drive electrode are connected, the diaphragm is provided with a connection portion for connecting the second electrode and the second drive electrode, and the rigidity of the diaphragm Will improve. Therefore, when the driving voltage is applied between the first driving electrode and the second driving electrode to displace the diaphragm, the time until the vibration of the diaphragm is stabilized is shortened, and the processing speed can be increased.

An optical module according to the present invention includes the above-described variable wavelength interference filter and a detection unit that detects light extracted by the variable wavelength interference filter.
According to the present invention, the optical module includes the variable wavelength interference filter as described above. Here, the wavelength tunable interference filter exhibits the above-described effects, can suppress a decrease in resolution, and can extract light having a desired wavelength that is transmitted or reflected with high accuracy. Therefore, in an optical module equipped with such a tunable interference filter, the amount of light of the desired wavelength extracted by the tunable interference filter is detected by the detection unit, so that the amount of light of the desired wavelength is accurately detected. can do.

An electronic apparatus according to the present invention includes the above-described optical module.
According to the present invention, since the electronic device includes the optical module having the wavelength variable interference filter described above, various electronic processes in the electronic device are performed based on the light amount of the light having the desired wavelength detected with high accuracy. Can do.

1 is a block diagram showing a schematic configuration of a color measuring device according to a first embodiment of the present invention. The top view of the wavelength variable interference filter of 1st embodiment. Sectional drawing in the state before a drive of the wavelength variable interference filter of 1st embodiment. Sectional drawing in the initial state of the wavelength variable interference filter of 1st embodiment. The top view which shows schematic structure of the wavelength variable interference filter of 2nd embodiment. Sectional drawing which shows schematic structure of the wavelength variable interference filter of 2nd embodiment. Sectional drawing which shows schematic structure of the wavelength variable interference filter of other embodiment. Schematic of the gas detection apparatus which is the other example of the electronic device of this invention. The block diagram of the gas detection apparatus of FIG. The block diagram which shows the structure of the food analyzer which is another example of the electronic device of this invention. Schematic of the spectroscopic camera which is the other 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.
[1. (Schematic configuration of the color measuring device)
FIG. 1 is a block diagram illustrating a schematic configuration of a color measurement device 1 (electronic device) according to the present embodiment.
As shown in FIG. 1, the color measurement device 1 includes a light source device 2 that emits light to the inspection target A, a color measurement sensor 3 (optical module), and a control device 4 that controls the overall operation of the color measurement device 1. Is provided. The colorimetric device 1 reflects the light emitted from the light source device 2 by the inspection object A, receives the reflected inspection light by the colorimetric sensor 3, and outputs the light from the colorimetric sensor 3. This is an apparatus that analyzes and measures the chromaticity of the inspection target light, that is, the color of the inspection target A, based on the detection signal.

[2. Configuration of light source device]
The light source device 2 includes a light source 21 and a plurality of lenses 22 (only one is shown in FIG. 1), and emits white light to the inspection target A. The plurality of lenses 22 may include a collimator lens. In this case, the light source device 2 converts the white light emitted from the light source 21 into parallel light by the collimator lens and inspects from a projection lens (not shown). Inject toward the subject A. In the present embodiment, the colorimetric device 1 including the light source device 2 is illustrated. However, for example, when the inspection target A is a light emitting member such as a liquid crystal panel, the light source device 2 may not be provided.

[3. (Configuration of colorimetric sensor)
As shown in FIG. 1, the colorimetric sensor 3 has a variable wavelength interference filter 5, a detection unit 31 that receives light transmitted through the variable wavelength interference filter 5, and a variable wavelength of light transmitted through the variable wavelength interference filter 5. Voltage control unit 32. Further, the colorimetric sensor 3 includes an incident optical lens (not shown) that guides the reflected light (inspection light) reflected by the inspection object A at a position facing the variable wavelength interference filter 5. In the colorimetric sensor 3, the wavelength variable interference filter 5 separates the light having a predetermined wavelength from the inspection target light incident from the incident optical lens, and the detected light is received by the detection unit 31.
The detection unit 31 includes a plurality of photoelectric exchange elements, and generates an electrical signal corresponding to the amount of received light. And the detection part 31 is connected to the control apparatus 4, and outputs the produced | generated electric signal to the control apparatus 4 as a light reception signal.

(3-1. Configuration of wavelength tunable interference filter)
FIG. 2 is a plan view showing a schematic configuration of the variable wavelength interference filter 5, and FIG. 3 is a cross-sectional view showing a schematic configuration of the variable wavelength interference filter 5.
As shown in FIG. 2, the wavelength variable interference filter 5 is a planar square plate-like optical member. As shown in FIG. 3, the variable wavelength interference filter 5 includes a fixed substrate 51 that is a first substrate of the present invention and a movable substrate 52 that is a second substrate of the present invention. 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. . Then, as shown in FIG. 3, the fixed substrate 51 and the movable substrate 52 have a fixed-side bonding surface 513B and a movable-side bonding surface 520C formed along the outer periphery of the substrate, for example, plasma containing siloxane as a main component. By being joined by a joining film 53 made of a polymer film or the like, it is integrally constructed.

The fixed substrate 51 is provided with a fixed reflective film 54 constituting the first reflective film of the present invention, and the movable substrate 52 is provided with a movable reflective film 55 constituting the second reflective film of the present invention. Here, the fixed reflective film 54 is fixed to the surface of the fixed substrate 51 facing the movable substrate 52, and the movable reflective film 55 is fixed to the surface of the movable substrate 52 facing the fixed substrate 51. Further, the fixed reflection film 54 and the movable reflection film 55 are disposed to face each other via the inter-reflection film gap G1.
Furthermore, the wavelength variable interference filter 5 is provided with an electrostatic actuator 56 that is used to adjust the dimension of the inter-reflective film gap G1 between the fixed reflective film 54 and the movable reflective film 55. The electrostatic actuator 56 includes a fixed electrode 561 constituting the first electrode and the first drive electrode of the present invention provided on the fixed substrate 51 side, and a second electrode and a second electrode of the present invention provided on the movable substrate 52 side. And a movable electrode 562 constituting a drive electrode. The fixed side electrode 561 and the movable side electrode 562 may be provided directly on the substrate surfaces of the fixed substrate 51 and the movable substrate 52, respectively, or may be provided via other film members. .
Further, when the wavelength variable interference filter 5 is viewed from the thickness direction of the fixed substrate 51 (movable substrate 52) in a plan view as shown in FIG. 2 (hereinafter referred to as filter plan view), the fixed substrate 51 and the movable substrate 52 The plane center point O coincides with the center point 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.

(3-1-1. Configuration of Fixed Substrate)
The fixed substrate 51 is formed by processing a glass base material having a thickness of, for example, 500 μm. The fixed substrate 51 is formed to have a thickness larger than that of the movable substrate 52, and electrostatic attraction when a voltage is applied between the fixed side electrode 561 and the movable side electrode 562, and internal stress of the fixed side electrode 561. There is no bending of the fixed substrate 51 due to the above.

As shown in FIG. 3, the fixed substrate 51 is provided with an electrode formation groove 511 and a reflection film fixing portion 512 formed by etching. The electrode forming groove 511 and the reflective film fixing portion 512 are provided in the substrate center region Ar1 that is a circular region centered on the plane center point O of the fixed substrate 51 in the filter plan view.
Further, the fixed substrate 51 is provided with a fixed outer peripheral surface 513 formed on a flat optical surface by, for example, cutting, polishing, or the like in a region outside the boundary of the substrate center region Ar1 in the filter plan view ( However, the part where the electrode lead-out groove described later is formed is excluded).
The fixed-side outer peripheral surface 513 constitutes the first initial gap forming surface of the present invention and the above-described fixed-side joining surface 513B. That is, of the fixed outer peripheral surface 513, the annular region Ar2 located on the substrate center region Ar1 side becomes the fixed initial gap forming surface 513A that is the first initial gap forming surface of the present invention. An outer peripheral area Ar3 formed along the outer peripheral edge of the fixed substrate 51 serves as a fixed-side bonding surface 513B.

The electrode forming groove 511 is formed in a ring shape centered on the plane center point O of the fixed substrate 51 in the filter plan view. The reflection film fixing portion 512 is formed so as to protrude from the center portion of the electrode forming groove 511 toward the movable substrate 52 in the filter plan view. Here, the protruding front end surface of the reflection film fixing portion 512 is a reflection film fixing surface 512A which is the first reflection film fixing surface of the present invention.
Further, in the fixed substrate 51, two electrodes extending from the electrode forming groove 511 toward at least the vertex C1 and the vertex C3 among the vertexes C1, C2, C3, and C4 of the outer peripheral edge of the fixed substrate 51. A drawing groove (not shown) is provided.

  In a region from the electrode fixing surface 511A which is the groove bottom portion of the electrode forming groove 511 of the fixed substrate 51 to the fixed side initial gap forming surface 513A of the fixed side outer peripheral surface 513, a fixed side electrode having a uniform thickness and a ring shape in plan view 561 is formed. Specifically, the fixed-side electrode 561 is formed on the fixed-side drive electrode portion 561A (which constitutes the first drive electrode of the present invention) formed on the electrode fixing surface 511A and the fixed-side initial gap forming surface 513A. The fixed-side gap forming electrode portion 561B (which constitutes the first electrode of the present invention). Further, since the electrode forming groove 511 is formed by etching (wet etching) one surface side of the fixed substrate 51, the inner peripheral side surface 511B of the electrode forming groove 511 is a surface parallel to the substrate thickness direction of the fixed substrate 51. In other words, the curved surface shape gradually curves from the fixed outer peripheral surface 513 toward the electrode fixing surface 511A. The fixed side electrode 561 is provided across the electrode fixing surface 511A, the inner peripheral side surface 511B, and the fixed side initial gap forming surface 513A, so that the fixed side drive electrode portion 561A and the fixed side gap forming electrode portion 561B are electrically connected. Connected.

  Further, a fixed extraction electrode 563 extending from the outer peripheral edge of the fixed side electrode 561 is formed on the fixed substrate 51. Specifically, the fixed extraction electrode 563 is formed from the position closest to the vertex C1 on the outer peripheral edge of the fixed side electrode 561 to the vertex C1 along the electrode formation groove extending in the direction toward the vertex C1. Has been. The distal end portion of the fixed extraction electrode 563 (portion located at the vertex C1 of the fixed substrate 51) constitutes a fixed electrode pad 563P connected to the voltage control unit 32.

  The fixed substrate 51 is provided with a first counter electrode 581 in an electrode extraction groove formed in a direction from the electrode forming groove 511 toward the vertex C3 of the fixed substrate 51. The first counter electrode 581 is insulated from the fixed side electrode 561. The tip portions of the first counter electrode 581 and the second counter electrode 582 (portions located at the vertex C3 of the fixed substrate 51) constitute a first counter electrode pad 581P connected to the voltage control unit 32.

As described above, the reflective film fixing portion 512 is formed in a substantially cylindrical shape that is coaxial with the electrode forming groove 511 and has a smaller diameter than the electrode forming groove 511, and is formed on the movable substrate 52 of the reflective film fixing portion 512. The opposing surface (protruding tip surface) is the reflective film fixing surface 512A of the present invention.
Here, the reflection film fixing portion 512 is formed to protrude from the electrode fixing surface 511A of the electrode forming groove 511 to the movable substrate 52 side, and the reflection film fixing surface 512A which is a protruding tip surface is formed on the fixed side outer peripheral surface 513. It is formed to be lower. That is, the distance between the reflecting film fixing surface 512A and the movable substrate 52 is smaller than the distance between the electrode fixing surface 511A and the movable substrate 52, and larger than the distance between the fixed-side outer peripheral surface 513 and the movable substrate 52.
A fixed reflection film 54 is provided on the reflection film fixing surface 512A. The fixed reflective film 54 may be formed of a metal single layer film, a dielectric multilayer film, or an Ag alloy on the dielectric multilayer film. It may be configured to be formed. As the metal single layer film, for example, a single layer film of an Ag alloy can be used. In the case of a dielectric multilayer film, for example, a dielectric multilayer film in which the high refractive layer is TiO ₂ and the low refractive layer is SiO ₂ is used. be able to.

  Further, the fixed substrate 51 may have an antireflection film (not shown) formed at a position corresponding to the fixed reflection film 54 on the surface opposite to the movable substrate 52. Such an antireflection film can be formed by alternately laminating a low refractive index film and a high refractive index film, reducing the reflectance of visible light on the surface of the fixed substrate 51 and increasing the transmittance. Let

(3-1-2. Configuration of movable substrate)
The movable substrate 52 is formed by processing a glass substrate having a thickness of, for example, 200 μm by etching.
Specifically, the movable substrate 52 is coaxial with the movable portion 521 in the substrate central region Ar1 and the movable portion 521 formed in a circular shape in the substrate central region Ar1 in the filter plan view as shown in FIG. And an inner holding portion 522 that holds the movable portion 521. Further, the movable substrate 52 includes an outer holding portion 523 formed in a ring shape with the plane center point O as a center between the annular region Ar2 and the outer peripheral region Ar3 in the filter plan view. The region sandwiched between the inner holding portion 522 and the outer holding portion 523 of the movable substrate 52 constitutes an outer movable portion 524 that is moved when the reflection film gap G1 is set as the initial gap.
Further, as shown in FIG. 2, the movable substrate 52 is provided with a notch 525 corresponding to each of the apexes C1 and C3 of the fixed substrate 51, so that the wavelength variable interference filter 5 can be viewed from the movable substrate 52 side. The fixed electrode pad 563P and the first counter electrode pad 581P are exposed on the exposed surface.
The surface of the movable substrate 52 facing the fixed substrate 51 (movable side facing surface 520) is formed on a flat optical surface by, for example, cutting or polishing. And the area | region corresponding to the movable part 521 among this movable side opposing surface 520 comprises the movable surface 520A which is a 2nd reflective film fixed surface of this invention, and cyclic | annular area | region Ar2 of the movable side opposing surface 520 is the 1st of this invention. A movable initial gap forming surface 520B, which is a two initial gap forming surface, is configured, and an outer peripheral area Ar3 of the movable opposing surface 520 configures a movable joint surface 520C.

The movable part 521 is formed to have a thickness dimension larger than that of the inner holding part 522. For example, in this embodiment, the movable part 521 is formed to be 200 μm, which is the same dimension as the thickness dimension of the movable substrate 52. In addition, the movable portion 521 is formed in a circular shape having a diameter larger than that of the reflective film fixing portion 512 in the filter plan view. A movable reflective film 55 and a movable electrode 562 are provided on the movable surface 520 </ b> A facing the fixed substrate 51 of the movable portion 521.
The movable reflective film 55 is provided in a region of the movable surface 520A of the movable portion 521 facing the reflective film fixed surface 512A so as to face the fixed reflective film 54 via the inter-reflective film 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.

The movable-side electrode 562 has a uniform film thickness in a region extending from the movable surface 520A to the movable-side initial gap forming surface 520B in the movable-side facing surface 520, in a region overlapping the fixed-side electrode 561 in the filter plan view. Is provided. Here, a portion of the fixed side electrode 561 located on the movable surface 520A constitutes a movable side drive electrode portion 562A that is the second drive electrode of the present invention. Further, a portion of the fixed side electrode 561 located on the movable side initial gap forming surface 520B constitutes a movable side gap forming electrode portion 562B which is the second electrode of the present invention. That is, in this embodiment, the movable side drive electrode portion 562A and the movable side gap forming electrode portion 562B are electrically connected.
Here, the movable side drive electrode portion 562A is opposed to the fixed side drive electrode portion 561A provided on the electrode fixing surface 511A via the inter-electrode gap G2.
On the other hand, an insulating layer 57 having a uniform thickness is laminated on the surface of the movable side gap forming electrode portion 562B facing the fixed side gap forming electrode portion 561B. The insulating layer 57 faces the fixed-side gap forming electrode portion 561B through the minute gap G3. Here, the movable side drive electrode portion 562A, the movable side gap forming electrode portion 562B, and the insulating layer 57 constitute the initial gap forming portion of the present invention.

  The movable substrate 52 has a movable extraction electrode 564 extending from the outer peripheral edge of the movable electrode 562. The movable extraction electrode 564 extends from the position closest to the vertex C3 of the movable electrode 562 toward the vertex C3. The movable extraction electrode 564 is a first counter electrode 581 (first electrode) formed at the position of the vertex C3 of the fixed substrate 51 by a conductive member 58 such as Ag paste in the vicinity of the outer peripheral edge of the movable substrate 52. It is electrically connected to the counter electrode pad 581P).

  Further, the movable portion 521 may be provided with an antireflection film (not shown) on the surface opposite to the fixed substrate 51. Similar to the antireflection film formed on the fixed substrate 51, the antireflection film can be formed by alternately laminating low refractive index films and high refractive index films.

The inner holding part 522 is a diaphragm that surrounds the periphery of the movable part 521, and is formed to have a thickness dimension of, for example, 50 μm and smaller in rigidity in the thickness direction than the movable part 521.
For this reason, the inner holding part 522 can be bent more easily than the movable part 521 and can be bent toward the fixed substrate 51 by electrostatic attraction. At this time, since the movable portion 521 has a thickness dimension larger than that of the inner holding portion 522 and becomes rigid, even when a force that deflects the movable substrate 52 due to electrostatic attraction acts, the movable portion 521 is hardly bent. Further, the bending of the movable reflective film 55 formed on the movable portion 521 can be prevented.
In the present embodiment, the diaphragm-shaped inner holding portion 522 is illustrated, but the present invention is not limited thereto. For example, beam-shaped holding portions arranged at equiangular intervals around the plane center point O are provided. It is good also as a structure.

The outer holding portion 523 is provided between the annular region Ar2 where the movable-side gap forming electrode portion 562B of the movable substrate 52 is provided and the movable-side bonding surface 520C bonded to the fixed substrate 51 by the bonding film 53, and is movable outside. The part 524 is movably held on the fixed substrate 51 side. Similar to the inner holding portion 522, the outer holding portion 523 is formed to have a thickness of, for example, 50 μm, and is formed simultaneously with the inner holding portion 522 by etching when the movable substrate 52 is formed.
In the present embodiment, an example of a diaphragm shape is shown as the outer holding portion 523. However, like the inner holding portion 522 described above, for example, the outer holding portions 523 are arranged at equiangular intervals with the plane center point O as the center. A configuration in which a beam-shaped holding portion is provided may be employed.

(3-1-3. Operation of wavelength variable interference filter)
In the wavelength variable interference filter 5 as described above, the dimension of the interelectrode gap G2 is formed larger than the dimension of the inter-reflection film gap G1, and the dimension of the inter-reflection film gap G1 is formed larger than the dimension of the minute gap G3. Has been.
In such a wavelength variable interference filter 5, when a voltage is applied to the electrostatic actuator 56 and an electrostatic attractive force is applied between the fixed side electrode 561 and the movable side electrode 562, the electrostatic force acting between 561B and 562B is applied. The initial gap of G2 is set by the attractive force, and the size of G2 can be set to a desired value by the electrostatic attractive force acting between 561A and 562A.
That is, when an electrostatic attractive force acts between the fixed-side gap forming electrode portion 561B and the movable-side gap forming electrode portion 562B, the insulating layer 57 on the movable-side gap forming electrode portion 562B comes into surface contact with the fixed-side gap forming electrode portion 561B. . Here, the fixed-side initial gap forming surface 513A provided with the fixed-side gap forming electrode portion 561B is a flat surface parallel to the reflecting film fixing surface 512A provided with the fixed reflecting film 54, and the movable-side gap forming electrode portion. The movable-side joint surface 520C provided with 562B is flush with the movable surface 520A provided with the movable reflective film 55, and the fixed-side gap forming electrode portion 561B, the movable-side gap forming electrode portion 562B, and the insulating layer 57 are It is a film formed with a uniform thickness. Therefore, when the insulating layer 57 and the fixed-side gap forming electrode portion 561B are in surface contact as described above, the fixed-side initial gap forming surface 513A and the movable surface 520A become parallel, and the fixed reflective film 54 and the movable reflective film 55 are parallel. Can be maintained.

At this time, since the electrostatic attractive force acting between the electrodes is inversely proportional to the square of the distance between the electrodes, the electrostatic attractive force acting on the interelectrode gap G2 is compared with the electrostatic attractive force acting on the minute gap G3. A larger electrostatic attraction acts between the small gaps G3 having a small gap size. Therefore, in the initial state where the minimum voltage (initial setting voltage) for bringing the insulating layer 57 and the fixed-side gap forming electrode portion 561B into surface contact is applied to the electrostatic actuator 56, the amount of deflection of the inner holding portion 522 is substantially “0”. And the inconvenience that the wave region measurable by the colorimetric device 1 is narrowed can be suppressed. That is, in the pre-drive state as shown in FIG. 3 the voltage to the electrostatic actuator 56 is not applied, the size of the reflective film gap G1 g _10, the size of the electrode gap G2 g _20, the minute gap G3 dimensions When g _30, in the initial state as shown in FIG. 4, the gap G1 between the reflective films of the dimensions (the initial gap dimension) _{g 1 is,} g 10 _{-g 30,} and the dimension _{g 2} of the inter-electrode gap G2 _{is, g 20} -G ₃₀ .
The initial setting voltage is such that when the variable wavelength interference filter 5 is manufactured, the voltage applied to the electrostatic actuator 56 is gradually increased from “0” so that the insulating layer 57 and the fixed-side gap forming electrode portion 561B are first used. It can be obtained by measuring the voltage at the time of surface contact. For example, an initial setting voltage is stored in a storage unit (not shown) of the control device 4 or a storage unit provided in the voltage control unit 32, and the initial setting voltage is stored from the storage unit when the variable wavelength interference filter 5 is driven. Is read and applied to the electrostatic actuator 56, the wavelength variable interference filter 5 can be easily set to the initial state.

Further, in the wavelength tunable interference filter 5 of the present embodiment, by further increasing the voltage applied to the electrostatic actuator 56 from the initial state, the movable part 521 is displaced to the fixed substrate 51 side, and the dimension of the gap G1 between the reflection films is measured. And the wavelength of light transmitted through the wavelength tunable interference filter 5 can be changed.
Here, as described above, the gap G2 between the electrodes is formed to have a size larger than the gap G1 between the reflection films. For this reason, the changeable amount of the gap G1 between the reflection films is not restricted by the gap G2 between the electrodes. That is, in the case where the dimension of the interelectrode gap G2 is smaller than the dimension of the interreflection film gap G1, the variable range g of the interreflection film gap G1 is (g ₁ −g ₂ ) <g ≦ g ₁ . In contrast, in the case where the size of the inter-electrode gap G2 is greater than the dimension of the gap G1 between the reflective film, the variation range g of the reflection film gap G1 is, 0 <g ≦ g _1, and the reflective film gap The range of the set value of G1 can be expanded.

In the variable wavelength interference filter 5 of the present embodiment, the movable side electrode 562 is provided on the surface of the inner holding portion 522 that faces the fixed substrate 51. In such a configuration, the rigidity of the inner holding portion 522 can be increased. Thereby, when setting the wavelength variable interference filter 5 to the initial state, the bending of the inner holding portion 522 can be further reduced in a state where the initial setting voltage is applied. Further, when the movable portion 521 is displaced from the initial state, when a voltage is applied to the electrostatic actuator 56, the inner holding portion 522 repeats vibration based on the natural frequency due to the application of electrostatic attraction, and the vibration gradually decreases. Then, the movable part 521 is stopped at a predetermined position. At this time, in the configuration in which the movable-side electrode 562 is provided on the surface of the inner holding portion 522 facing the fixed substrate 51, the rigidity of the inner holding portion 522 is increased. Therefore, the time until the vibration of the inner holding portion 522 stops is reduced. This can be shortened, and quick chromaticity measurement in the colorimetric device 1 can be performed.
Here, when increasing the rigidity of the inner holding part 522, it is conceivable to increase the thickness dimension of the inner holding part 522. In this case, however, the rigidity of the inner holding part 522 is greater than that of the outer holding part 523 as described above. In order to increase the thickness, it is necessary to set the thickness dimensions of the inner holding part 522 and the outer holding part 523 to different dimensions. In such a configuration, when the inner holding portion 522 and the outer holding portion 523 are formed on the movable substrate 52 by etching, the etching time of the inner holding portion 522 and the outer holding portion 523 is made different, or the inner holding portion is held in a separate process. It is necessary to form the part 522 and the outer holding part 523, and there is a problem that the manufacturing process becomes complicated. On the other hand, in this embodiment, since the inner side holding part 522 and the outer side holding part 523 are formed in the same thickness, a manufacturing process can be simplified and the above-mentioned effect can be acquired.

(3-2. Configuration of voltage control means)
The voltage control unit 32 is connected to the fixed electrode pad 563P and the first counter electrode pad 581P, and the fixed electrode pad 563P and the first counter electrode pad 581P are connected based on the control signal input from the control device 4. A predetermined potential is set and a voltage is applied to the electrostatic actuator 56 to drive it.

[4. Configuration of control device]
The control device 4 controls the overall operation of the color measurement device 1.
As the control device 4, for example, a general-purpose personal computer, a portable information terminal, other color measurement dedicated computer, or the like can be used.
As shown in FIG. 1, the control device 4 includes a light source control unit 41, a colorimetric sensor control unit 42, a colorimetric processing unit 43 that constitutes an analysis processing unit of the present invention, and the like.
The light source control unit 41 is connected to the light source device 2. Then, the light source control unit 41 outputs a predetermined control signal to the light source device 2 based on, for example, a user setting input, and causes the light source device 2 to emit white light with a predetermined brightness.
The colorimetric sensor control unit 42 is connected to the colorimetric sensor 3. The colorimetric sensor control unit 42 sets a wavelength of light received by the colorimetric sensor 3 based on, for example, a user's setting input, and outputs a control signal for detecting the amount of light received at this wavelength. Output to the colorimetric sensor 3. Thereby, the voltage control unit 32 of the colorimetric sensor 3 sets the voltage applied to the electrostatic actuator 56 so as to transmit only the wavelength of light desired by the user based on the control signal.
The colorimetric processing unit 43 analyzes the chromaticity of the inspection object A from the amount of received light detected by the detection unit 31.

[5. (Effects of Embodiment)
As described above, in the wavelength tunable interference filter 5 of the first embodiment, the fixed substrate 51 is parallel to the flat reflective film fixing surface 512A on which the fixed reflective film 54 is provided and the reflective film fixed surface 512A, and the fixed side gap. A fixed-side initial gap forming surface 513A on which the forming electrode portion 561B is provided is provided. Further, the movable substrate 52 includes a movable surface 520A provided with the movable reflective film 55 and a movable side bonding surface 520C provided with the movable side gap forming electrode portion 562B in a flat movable side facing surface 520 facing the fixed substrate 51. In addition, an insulating layer 57 facing the fixed-side gap forming electrode portion 561B is provided on the surface facing the fixed-side gap forming electrode portion 561B of the movable-side gap forming electrode portion 562B via the minute gap G3. Therefore, by applying a voltage between the fixed-side gap forming electrode portion 561B and the movable-side gap forming electrode portion 562B, the outer movable portion 524 is displaced toward the fixed substrate 51 by electrostatic attraction, and the insulating layer 57 is fixed on the fixed side. It is in surface contact with the gap forming electrode portion 561B. As a result, the movable-side facing surface 520 and the fixed-side initial gap forming surface 513A are parallel to each other, so that the reflective film fixing surface 512A parallel to the fixed-side initial gap forming surface 513A is also parallel to the movable-side facing surface 520. Therefore, for example, in the manufacturing process of the variable wavelength interference filter 5, when the fixed substrate 51 and the movable substrate 52 are pressure-bonded, the movable substrate 52 is inclined with respect to the fixed substrate 51. Even when the film fixing surface 512A and the movable-side facing surface 520 are not parallel, in the initial state, the inclination of the movable substrate 52 is corrected, and the fixed reflection film 54 on the reflection film fixing surface 512A and the movable surface 520A are corrected. It is possible to form an initial gap in which the movable reflective film 55 is maintained in parallel. For this reason, the resolution of the wavelength variable interference filter 5 can be maintained high. Further, since the electrostatic actuator 56 includes the fixed drive electrode portion 561A and the movable drive electrode portion 562A, the size of the inter-reflective film gap G1 can be adjusted by further applying a voltage from the initial state. And can transmit light of a desired wavelength.
Therefore, the colorimetric sensor 3 having such a wavelength tunable interference filter 5 can accurately measure the amount of light having a desired wavelength to be measured that has passed through the wavelength tunable interference filter 5. The colorimetric device 1 including the sensor 3 can perform accurate chromaticity measurement.

  The reflection film fixed surface 512A and the movable surface 520A on which the fixed reflection film 54 and the movable reflection film 55 are provided are arranged in the substrate center region Ar1, and the fixed side gap forming electrode portion is arranged in the annular region Ar2 surrounding the outer periphery of the substrate center region Ar1. 561B, a movable side gap forming electrode portion 562B, and an insulating layer 57 are provided. Therefore, as compared with the case where the fixed gap forming electrode portion 561B, the movable gap forming electrode portion 562B, and the initial gap forming portion constituted by the insulating layer 57 are provided only on a part of the outer peripheral side of the substrate center region Ar1. Thus, the parallelism of the reflecting film fixed surface 512A and the movable surface 520A can be maintained more reliably.

The movable substrate 52 includes an outer holding portion 523 between the annular region Ar2 and the outer peripheral region Ar3. The outer holding portion 523 holds the outer movable portion 524 movably toward the fixed substrate 51. For this reason, when the voltage is applied to the electrostatic actuator 56, the outer holding portion 523 is bent, so that the outer movable portion 524 is easily displaced, and the initial setting for setting the wavelength variable interference filter 5 to the initial state. The voltage can be reduced and power can be saved.
In the configuration in which the outer holding unit 523 is not provided, it is necessary to increase the initial setting voltage for setting the wavelength variable interference filter 5 to the initial state. In this case, since the electrostatic attractive force acting between the fixed drive electrode portion 561A and the movable drive electrode portion 562A is also increased, the inner holding portion 522 is bent in the initial state, and the initial gap dimension of the inter-reflective film gap G1 is small. Become. On the other hand, in the present embodiment, as described above, since the initial setting voltage can be reduced, the deflection of the inner holding portion 522 in the initial state can be suppressed, and the initial gap size of the inter-reflection film gap G1 can be increased. can do. Therefore, since the wavelength range of light that can be extracted by the wavelength variable interference filter 5 can be broadened, the wavelength range that can be measured by the colorimetric device 1 is also widened, so that more accurate chromaticity measurement can be performed. Can be implemented.
Furthermore, the inner holding part 522 and the outer holding part 523 have the same thickness dimension. Such an inner holding part 522 and an outer holding part 523 can be formed at the same time by performing the etching process once on the movable substrate 52, and the manufacturing process can be simplified.

  The movable side electrode 562 is formed in a ring shape from the movable surface 520A to the movable side initial gap forming surface 520B. That is, the movable side electrode 562 is also formed on the movable side facing surface 520 of the inner holding portion 522 that faces the fixed substrate 51. For this reason, the rigidity of the inner side holding part 522 can be strengthened by the movable side electrode 562 provided on the inner side holding part 522. Therefore, when the initial setting voltage is applied between the fixed side electrode 561 and the movable side electrode 562, the inner holding portion 522 is less likely to bend than the outer holding portion 523, and the initial gap size of the inter-reflection film gap G1 is reduced. Can be suppressed. In addition, when the voltage is further applied to the electrostatic actuator 56 from the initial state to change the gap G1 between the reflection films, the vibration of the inner holding portion 522 can be stopped more quickly, and quick measurement can be performed. it can.

In the pre-driving state, the size of the minute gap G3 is smaller than the size of the inter-reflection film gap G1, and the size of the inter-reflection film gap G1 is smaller than the size of the inter-electrode gap G2.
For this reason, when a voltage is applied to the electrostatic actuator 56, the electrostatic attractive force acting on the minute gap G3 can be made larger than the electrostatic attractive force acting on the inter-electrode gap G2, and the inner holding portion 522 is bent in the initial state. Can be further reduced.
Further, since the inter-electrode gap G2 is larger than the inter-reflective film gap G1, it is possible to increase the variable amount of the dimension of the inter-reflective film gap G1. Therefore, the measurable wavelength range of the color measuring device 1 can be widened. In addition, the electrostatic attraction between the fixed drive electrode portion 561A and the movable drive electrode portion 562A can be easily controlled, and the dimension of the gap G1 between the reflection films can be set to a desired target value with higher accuracy.

  Further, the fixed-side drive electrode portion 561A and the fixed-side gap forming electrode portion 561B are configured by one fixed-side electrode 561 and are in an electrically connected state. Similarly, the movable side drive electrode portion 562A and the movable side gap forming electrode portion 562B are configured by one movable side electrode 562 and are in an electrically connected state. Therefore, by applying a voltage to the fixed electrode pad 563P connected to the fixed side electrode 561 and the first counter electrode pad 581P connected to the movable side electrode 562, the fixed side drive electrode portion 561A and the movable side drive electrode portion A voltage can be applied between 562A and between the movable drive electrode portion 562A and the movable gap forming electrode portion 562B. That is, electrostatic attraction can be applied to each of the gap G2 between the electrodes and the minute gap G3 with a simple configuration.

[Second Embodiment]
Next, 2nd embodiment which concerns on this invention is described based on drawing.
In the first embodiment, the fixed-side drive electrode portion 561A that is the first drive electrode and the fixed-side gap forming electrode portion 561B that is the first electrode are electrically connected, and the movable-side drive electrode that is the second drive electrode. The part 562A and the movable side gap forming electrode part 562B which is the second electrode are electrically connected. In contrast, the variable wavelength interference filter according to the second embodiment is such that the first drive electrode and the first electrode are electrically insulated, and the second drive electrode and the second electrode are electrically insulated. This is different from the wavelength variable interference filter 5 of the first embodiment.

FIG. 5 is a plan view showing a schematic configuration of the variable wavelength interference filter according to the second embodiment. FIG. 6 is a cross-sectional view illustrating a schematic configuration of a wavelength tunable interference filter according to the second embodiment. In the following description of the embodiments, the same reference numerals are given to the same configurations as those in the above embodiments, and the description thereof is omitted or simplified.
In the wavelength tunable interference filter 5A of the present embodiment, the fixed drive electrode 561C constituting the first drive electrode of the present invention is provided on the electrode fixed surface 511A of the fixed substrate 51, and on the fixed initial gap forming surface 513A. A fixed-side gap forming electrode 561D constituting the first electrode of the present invention is provided. Further, a movable drive electrode 562C constituting the second drive electrode of the present invention is provided on the movable surface 520A of the movable substrate 52, and the second electrode of the present invention is configured on the movable side initial gap forming surface 520B. A movable side gap forming electrode 562D is provided.

The fixed drive electrode 561C is formed in a ring shape centered on the plane center point O on the electrode fixing surface 511A in the substrate center region Ar1 of the fixed substrate 51 in the filter plan view. A fixed extraction electrode 563 extending toward the vertex C1 is provided from a position closest to the vertex C1 of the fixed drive electrode 561C, and the tip of the fixed extraction electrode 563 is connected to the voltage control unit 32. A fixed electrode pad 563P is provided.
The fixed-side gap forming electrode 561D is an electrode that is electrically insulated from the fixed-side drive electrode 561C. In the filter plan view, the fixed-side gap forming electrode 561D is a C centered on the plane center point O in the annular region Ar2 of the fixed substrate 51. It is formed in a letter shape. The fixed-side gap forming electrode 561D is provided with a C-shaped opening at a position close to the vertex C1, and a fixed extraction electrode 563 connected to the fixed-side driving electrode 561C is provided at the C-shaped opening. Further, a fixed-side gap forming lead electrode 565 extending toward the vertex C4 is provided from a position closest to the vertex C4 of the fixed-side gap forming electrode 561D. A gap forming electrode pad 565 </ b> P connected to the voltage control unit 32 is provided at the distal end portion.

  The fixed substrate 51 is provided with a first counter electrode 581 and a second counter electrode 582 at positions corresponding to the vertex C3 and the vertex C2, respectively. The first counter electrode 581 and the second counter electrode 582 are electrically insulated from the fixed drive electrode 561C and the fixed gap forming electrode 561D, respectively. Further, a first counter electrode pad 581P and a second counter electrode pad 582P connected to the voltage control unit 32 are provided at the distal ends of the first counter electrode 581 and the second counter electrode 582.

The movable drive electrode 562C is formed in a ring shape centered on the plane center point O on the movable surface 520A in the substrate center region Ar1 of the movable substrate 52 in the filter plan view. A movable extraction electrode 564 extending toward the vertex C3 is provided from the position closest to the vertex C3 of the movable drive electrode 562C. The tip of the movable extraction electrode 564 is connected to the first counter electrode 581 provided at the vertex C3 of the fixed substrate 51 via the conductive member 58.
The movable-side gap forming electrode 562D is an electrode that is electrically insulated from the movable-side drive electrode 562C. In the filter plan view, the movable-side gap forming electrode 562D is a C centered on the plane center point O in the annular region Ar2 of the movable substrate 52. It is formed in a letter shape. The movable side gap forming electrode 562D is provided with a C-shaped opening at a position close to the vertex C3, and a movable extraction electrode 564 connected to the movable driving electrode 562C is provided at the C-shaped opening. A movable-side gap forming lead electrode 566 extending toward the vertex C2 is provided from the position closest to the vertex C2 of the movable-side gap forming electrode 562D. The leading end of the fixed-side gap forming extraction electrode 565 is connected to the second counter electrode 582 provided at the vertex C <b> 2 of the fixed substrate 51 via the conductive member 58.
In addition, an insulating layer 57 is stacked on the movable-side gap forming electrode 562D on the surface facing the fixed-side gap forming electrode 561D.

In such a wavelength tunable interference filter 5A, the transition operation from the pre-driving state to the initial state and the dimension adjusting operation of the inter-reflective film gap G1 are performed by separate electrodes.
The transition operation from the pre-driving state to the initial state is performed by the voltage controller 32 from the gap forming electrode pad 565P and the second counter electrode pad 582P to the initial set voltage to the fixed side gap forming electrode 561D and the movable side gap forming electrode 562D. Is applied. As a result, an electrostatic attractive force is generated between the fixed-side gap forming electrode 561D and the movable-side gap forming electrode 562D, and the insulating layer 57 on the movable-side gap forming electrode 562D is in surface contact with the fixed-side gap forming electrode 561D. The inter-reflective film gap G1 is set to the initial gap dimension and is in the initial state.
In this initial state, the voltage control unit 32 applies a drive voltage from the fixed electrode pad 563P and the first counter electrode pad 581P to the fixed drive electrode 561C and the movable drive electrode 562C, so that the interelectrode gap G2 is applied. It is possible to set the gap G1 between the reflection films to a desired dimension by applying an electrostatic attractive force.

(Effect of embodiment)
In the wavelength variable interference filter 5A as described above, the fixed-side drive electrode 561C and the fixed-side gap forming electrode 561D are provided independently, and signals can be individually input from the fixed electrode pad 563P and the gap forming electrode pad 565P. It has become. Similarly, the movable-side drive electrode 562C and the movable-side gap forming electrode 562D are provided independently, and signals can be individually input from the first counter electrode pad 581P and the second counter electrode pad 582P. Therefore, the electrostatic attractive force acting on the gap G2 between the electrodes and the electrostatic attractive force acting on the minute gap G3 can be set individually. Accordingly, it is possible to set the wavelength variable interference filter 5A to the initial state by applying a voltage only between the fixed side gap forming electrode 561D and the movable side gap forming electrode 562D. In the initial state, the movable surface 520A and the movable side The initial gap forming surface 520B can be the same plane. Therefore, the displaceable amount of the gap G1 between the reflection films can be increased, and the wavelength range of light that can be extracted by the wavelength variable interference filter 5A can be expanded.

[Modification of Embodiment]
It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, in the above-described embodiment, the initial gap forming portion of the present invention includes the fixed side gap forming electrode portion 561B, the movable side gap forming electrode portion 562B, and the insulating layer 57 provided between the fixed substrate 51 and the movable substrate 52. Although an example or an example constituted by the fixed side gap forming electrode 561D and the movable side gap forming electrodes 562D and 57 has been shown, the present invention is not limited to this. For example, it is good also as a structure as shown in FIG.
FIG. 7 is a cross-sectional view showing a schematic configuration of a wavelength tunable interference filter 5B according to another embodiment of the present invention.
The variable wavelength interference filter 5B includes a case 6 that holds a fixed substrate 51 and a movable substrate 52. In the case 6, the initial gap of the present invention is located at a position facing the outer movable portion 524 of the movable substrate 52. An urging member 61 that is a forming portion is provided.
In the variable wavelength interference filter 5B, the fixed side initial gap forming surface 513A of the fixed substrate 51 and the movable side initial gap forming surface 520B of the movable substrate 52 are not provided with electrodes. The outer movable portion 524 is biased toward the fixed substrate 51 by the biasing force, and the fixed initial gap forming surface 513A and the movable initial gap forming surface 520B are in direct surface contact. Here, as the biasing means, for example, a coil spring, a piezoelectric element, an elastic resin, or the like can be used.
Even in the variable wavelength interference filter 5B having such a configuration, the fixed initial gap forming surface 513A and the movable initial gap forming surface 520B are in surface contact with each other, so that the reflective film fixed surface 512A and the movable surface 520A are parallel to each other. The fixed reflective film 54 and the movable reflective film 55 can be set in an initial state where they are maintained in parallel.

In the first embodiment, the configuration in which the insulating layer 57 is formed on the movable side gap forming electrode portion 562B is exemplified, but the insulating layer 57 covers the entire surface of the movable side electrode 562 that faces the fixed side electrode 561. Also good. In this case, leakage due to discharge or the like between the fixed side electrode 561 and the movable side electrode 562 can be prevented, and the dimension adjustment of the gap G1 between the reflection films can be performed with high accuracy. Similarly, in the second embodiment, the configuration in which the insulating layer 57 is formed on the movable side gap forming electrode 562D is exemplified, but the insulating layer 57 may be formed on the movable side driving electrode 562C.
Furthermore, the configuration is not limited to the configuration in which the insulating layer 57 is provided on the movable side gap forming electrode portion 562B. For example, the insulating layer 57 may be provided on the fixed side gap forming electrode portion 561B. The insulating layer 57 may be provided on both of the gap forming electrode portions 562B. The same applies to the second embodiment, such that the insulating layer 57 is provided on the fixed gap forming electrode 561D, the insulating layer 57 is provided on both the fixed gap forming electrode 561D and the movable gap forming electrode 562D, and the like. It is good. Furthermore, a configuration in which the insulating layer 57 is provided on the entire surface of the fixed side electrode 561 facing the movable side electrode 562, and a configuration in which the insulating layer 57 is provided on the entire surface of the fixed side electrode 561 and the movable side electrode 562 facing each other. And so on.

  In the above embodiment, the configuration in which the inter-electrode gap G2 is formed larger than the inter-reflective film gap G1 is exemplified, but the present invention is not limited to this. For example, a configuration in which the electrode fixing surface 511A and the reflecting film fixing surface 512A are formed on the same surface, or a reflecting film fixing groove on a cylindrical concave groove is formed at the center of the electrode fixing surface 511A. A configuration in which the reflective film fixing surface 512A is formed on the bottom surface may be employed. Such a configuration is suitable, for example, when analyzing light having a relatively large wavelength, such as infrared light or far infrared light, as measurement target light.

  In the above embodiment, as the interference filter of the present invention, the dimension of the inter-reflective film gap G1 is varied by the fixed drive electrode unit 561A and the movable drive electrode unit 562A, or the fixed drive electrode 561C and the movable drive electrode 562C. The tunable interference filter 5, the tunable interference filter 5 </ b> A, and the tunable interference filter 5 </ b> B that can be used are exemplified, but the present invention is not limited thereto. For example, the fixed drive electrode unit 561A and the movable drive electrode unit 562A, the fixed drive electrode 561C and the movable drive electrode 562C are not provided, and the dimension of the inter-reflection film gap G1 is a fixed value set in advance. The present invention can also be applied to an interference filter that extracts only light having a predetermined wavelength according to the gap G1 between the reflection films. Even in this case, since the fixed reflection film 54 and the movable reflection film 55 can be maintained in parallel, the light of the predetermined wavelength can be transmitted with high accuracy, and the resolution in the interference filter can be improved.

  In the above-described embodiment, the movable surface 520 and the movable initial gap forming surface 520B are provided in the movable-side facing surface 520 of the movable substrate 52 facing the fixed substrate 51, that is, the movable surface 520A and the movable-side initial surface. Although the gap forming surface 520B is a surface provided in the same plane, the present invention is not limited to this. For example, the annular region Ar2 of the movable side facing surface 520 or the annular region Ar2 and the outer peripheral region Ar3 are formed so as to protrude toward the fixed substrate 51, and the movable surface 520A and the movable side initial gap forming surface 520B are different planes. Good.

Although the colorimetric device 1 is exemplified as the electronic apparatus of the present invention, the wavelength variable interference filter, optical module, and electronic apparatus of the present invention can be used in various other fields.
For example, it can be used as 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 variable wavelength interference filter of the present invention, or a photoacoustic rare gas detection for a breath test. A gas detection device such as a vessel can be exemplified.
An example of such a gas detection device will be described below with reference to the drawings.

FIG. 8 is a schematic diagram illustrating an example of a gas detection apparatus including a wavelength variable interference filter.
FIG. 9 is a block diagram showing a configuration of a control system of the gas detection device of FIG.
As shown in FIG. 8, 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, a wavelength variable interference filter 5, a light receiving element 137 (detection unit), and the like. And a control unit 138 for processing a detected signal and controlling the detection unit, a power supply unit 139 for supplying power, and the like. The optical unit 135 emits light, and a beam splitter that reflects light incident from the light source 135A toward the sensor chip 110 and transmits light incident from the sensor chip 110 toward the light receiving element 137. 135B, a lens 135C, a lens 135D, and a lens 135E. In addition, although the structure which uses the wavelength variable interference filter 5 is illustrated, it is good also as a structure which uses the wavelength variable interference filter 5A and the wavelength variable interference filter 5B which were mentioned above.
Further, as shown in FIG. 9, 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. 9, 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. Voltage control unit 146, a light receiving circuit 147 that receives a signal from the light receiving element 137, a sensor chip detection that reads a code of 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, a linearly polarized laser beam having a single wavelength 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 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 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 wavelength variable interference filter 5. Then, the signal processing unit 144 controls the voltage control unit 146 to adjust the voltage applied to the wavelength variable interference filter 5, and causes the wavelength variable interference filter 5 to split the Raman scattered light corresponding to the gas molecule to be detected. . 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.
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.

  8 and 9, the gas detection device 100 that performs gas detection from the Raman scattered light obtained by spectrally dividing the Raman scattered light with the variable wavelength interference filter 5 is illustrated. 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, the gas component can be detected by using the variable wavelength interference filter of the present invention.

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. 10 is a diagram illustrating a schematic configuration of a food analyzer that is an example of an electronic apparatus using the wavelength tunable interference filter 5. Although the wavelength variable interference filter 5 is used here, a configuration using the wavelength variable interference filter 5A and the wavelength variable interference filter 5B may be used.
As shown in FIG. 10, 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 imaging lens 212 into which light from the measurement target is introduced, a wavelength variable interference filter 5 that splits the light introduced from the imaging lens 212, and the dispersed light. And an imaging unit 213 (detection unit) for detecting.
In addition, the control unit 220 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 voltage control unit 222 that controls the wavelength variable interference filter 5, and the imaging unit 213. , A detection control unit 223 that acquires a spectral image captured by the imaging unit 213, 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 through the imaging lens 212. The variable wavelength interference filter 5 is applied with a voltage capable of dispersing a desired wavelength under the control of the voltage control unit 222, and the dispersed light is imaged by an imaging unit 213 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 voltage control unit 222 to change the voltage value applied to the wavelength tunable 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 the content thereof 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 component and content of the food to be inspected and the calories and freshness obtained as described above.

FIG. 10 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, as a device for measuring a body fluid component such as blood, a device for detecting ethyl alcohol can be used as a drunk driving prevention device for detecting a driver's drinking state. 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 wavelength variable interference filter, optical module, and electronic device of the present invention can be applied to the following devices.
For example, by changing the intensity of light of each wavelength over time, it is also possible to transmit data using light of each wavelength. 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 device equipped with such an optical module for data extraction can be used to extract the light data of each wavelength. By processing, optical communication can be performed.

Further, the electronic apparatus can be applied to a spectroscopic camera, a spectroscopic analyzer, or the like that captures a spectroscopic image by dispersing light with the variable wavelength interference filter of the present invention. An example of such a spectroscopic camera is an infrared camera incorporating a wavelength variable interference filter.
FIG. 11 is a schematic diagram showing a schematic configuration of the spectroscopic camera. As shown in FIG. 11, the spectroscopic camera 300 includes a camera body 310, an imaging lens unit 320, and an imaging unit 330 (detection unit).
The camera body 310 is a part that is gripped and operated by a user.
The imaging lens unit 320 is provided in the camera body 310 and guides incident image light to the imaging unit 330. Further, as shown in FIG. 11, the imaging lens unit 320 includes an objective lens 321, an imaging lens 322, and a variable wavelength interference filter 5 provided between these lenses.
The imaging unit 330 includes a light receiving element, and images the image light guided by the imaging lens unit 320.
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.

Furthermore, the wavelength tunable interference filter of the present invention may be used as a bandpass filter. For example, only light in a narrow band centered on a predetermined wavelength out of light in a predetermined wavelength range emitted from the light emitting element can be wavelength-variable. It can also be used as an optical laser device that spectrally transmits through an interference filter.
In addition, the tunable interference filter of the present invention may be used as a biometric authentication device, and 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 tunable interference filter, the optical module, and the electronic device of the present invention can be applied to any device that splits predetermined light from incident light. Since the wavelength tunable interference filter according to the present invention can split a plurality of wavelengths with one device as described above, it is possible to accurately measure a spectrum of a plurality of wavelengths and detect a plurality of components. it can. Therefore, compared with the conventional apparatus which takes out a desired wavelength with multiple devices, size reduction of an optical module or an electronic device can be promoted, and for example, it can be suitably used as a portable or vehicle-mounted optical device.

  In addition, the specific structure for carrying out the present invention can be appropriately changed to another structure or the like as long as the object of the present invention can be achieved.

  DESCRIPTION OF SYMBOLS 1 ... Color measuring apparatus (electronic device), 3 ... Color measuring sensor (optical module), 5, 5A, 5B ... Wavelength variable interference filter, 31 ... Detection part, 51 ... Fixed board | substrate (1st board | substrate), 52 ... Movable board | substrate (Second substrate), 54 ... fixed reflective film (first reflective film), 55 ... movable reflective film (second reflective film), 57 ... insulating layer, 61 ... biasing member (initial gap forming portion), 512A ... reflective Film fixing surface (first reflecting film fixing surface), 513A ... Fixed side initial gap forming surface (first initial gap forming surface), 520A ... Movable surface (second reflecting film fixing surface), 520B ... Movable side initial gap forming surface (Second initial gap forming surface) 520C ... movable side joining surface (joining portion), 523 ... outside holding portion, 561A ... fixed side driving electrode portion (first driving electrode), 561B ... fixed side gap forming electrode portion (first) One electrode), 561C... Fixed side drive electrode (first electrode) Drive electrode), 561D ... fixed side gap forming electrode (first electrode), 562A ... movable side drive electrode portion (second drive electrode), 562B ... movable side gap forming electrode portion (second electrode), 562C ... movable side drive. Electrode (second drive electrode), 562D ... movable side gap forming electrode (second electrode), Ar1 ... substrate center region, Ar2 ... annular region, G1 ... reflective film gap, G2 ... electrode gap, G3 ... minute gap, O: Plane center point.

Claims (9)

A first substrate;
A second substrate facing the first substrate;
A first reflective film provided on a surface of the first substrate facing the second substrate;
A second reflective film provided on a surface of the second substrate facing the first substrate and facing the first reflective film via a gap between the reflective films of a predetermined size;
An initial gap forming part that sets the dimension of the gap between the reflective films to an initial dimension, and
The first substrate includes a flat first reflecting film fixing surface on which the first reflecting film is provided, and a first initial gap forming surface that is parallel to the first reflecting film fixing surface and flat.
The second substrate has a flat second reflection film fixing surface on which the second reflection film is provided, and a first flat surface opposite to the first initial gap forming surface, parallel to the second reflection film fixing surface, and flat. Two initial gap forming surfaces,
The distance between the first initial gap forming surface and the second initial gap forming surface is smaller than the distance between the front reflective film gaps,
The said initial gap formation part urges | biases said 1st initial gap formation surface and said 2nd initial gap formation surface to the mutually adjacent direction, and maintains it in parallel. The interference filter characterized by the above-mentioned. The interference filter according to claim 1,
The initial gap forming part is
A first electrode provided on the first initial gap forming surface;
A second electrode provided on the second initial gap forming surface and facing the first electrode;
At least one of the surface of the first electrode that faces the second electrode and the surface of the second electrode that faces the first electrode, the other electrode via a small gap that is smaller than the gap between the reflective films An interference filter, comprising: an insulating layer facing the surface. The interference filter according to claim 1 or 2,
In a plan view of the first substrate and the second substrate viewed from the substrate thickness direction, the first reflective film fixing surface and the second reflective film fixing surface are substrate center regions of the first substrate and the second substrate, respectively. The first initial gap formation surface and the second initial gap formation surface are provided in an annular region surrounding the substrate center region outside the substrate center region of the first substrate and the second substrate. An interference filter characterized by The interference filter according to claim 3.
The second substrate has the annular region and the substrate central region of the second substrate on the first substrate side outside the annular region in a plan view of the second substrate viewed from the substrate thickness direction. An interference filter comprising: an outer holding portion that is movably held; and a bonding portion that is provided further outside than the outer holding portion and is bonded to the first substrate. The interference filter according to claim 3 or 4,
A first drive electrode provided on a surface facing the second substrate in the substrate central region of the first substrate;
A second drive electrode facing the first substrate via an inter-electrode gap in the substrate central region of the second substrate;
An interference filter characterized by comprising: The interference filter according to claim 5,
The interference filter is characterized in that the gap between the electrodes is larger than the gap between the reflection films. The interference filter according to claim 5 or 6,
The initial gap forming part is
A first electrode provided on the first initial gap forming surface;
A second electrode provided on the second initial gap forming surface and facing the first electrode;
At least one of the surface of the first electrode that faces the second electrode and the surface of the second electrode that faces the first electrode, the other electrode via a small gap that is smaller than the gap between the reflective films And an insulating layer opposite to
The first electrode and the first drive electrode are electrically connected,
The interference filter, wherein the second electrode and the second drive electrode are electrically connected. The wavelength variable interference filter according to any one of claims 1 to 7,
A detection unit for detecting light extracted by the variable wavelength interference filter;
An optical module comprising: An electronic apparatus comprising the optical module according to claim 8.

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