JP2014013339A - Wavelength variable interference filter, optical filter device, optical module, and electronic equipment - Google Patents

Abstract

The present invention provides a variable wavelength interference filter, an optical filter device, an optical module, and an electronic apparatus that can adjust a gap with high accuracy and can greatly change the gap.
The variable wavelength interference filter includes a first substrate on which a first reflective film is provided, a second substrate on which a second reflective film is provided, and a first electrode provided on the first substrate. 561, a second electrode 562 provided on the second substrate and facing the first electrode through a predetermined gap, and a dielectric provided on a part of at least one surface of the first electrode and the second electrode Of the actuator region where the first electrode and the second electrode overlap in the plan view, the first region where the dielectric film is provided is the actuator. It is provided on the side away from the optical interference region Ar ₀ of regions.
[Selection] Figure 5

Description

  The present invention relates to a wavelength tunable interference filter, an optical filter device, an optical module, and an electronic apparatus.

  2. Description of the Related Art Conventionally, a wavelength variable interference filter that has a pair of reflective films facing each other and extracts light of a predetermined wavelength from light to be measured by changing the distance between the reflective films is known (for example, Patent Documents). 1).

  The wavelength variable interference filter (optical resonator) described in Patent Document 1 includes a first substrate and a second substrate that face each other, a reflective film that is disposed on each substrate and faces each other via a gap between the reflective films, Electrodes disposed on each substrate and facing each other are provided. In such a wavelength variable interference filter, by applying a voltage between the electrodes, the second substrate can be deformed and the gap between the reflective films can be adjusted.

Japanese Patent Laid-Open No. 7-243963

  By the way, the wavelength variable interference filter of Patent Document 1 is configured to control the gap between the reflection films by one electrostatic actuator constituted by a pair of electrodes. Therefore, the second substrate is warped during the gap control between the reflection films. As a result, the parallelism of the reflective film deteriorates, resulting in a problem that the resolution deteriorates.

  An object of the present invention is to provide a variable wavelength interference filter, an optical filter device, an optical module, and an electronic apparatus having high resolution.

  The wavelength tunable interference filter of the present invention is provided on the first substrate, the second substrate facing the first substrate, the first reflective film provided on the first substrate, and the second substrate, The second reflective film facing the first reflective film with a gap, and the first reflective film and the second reflective film in a plan view of the first substrate and the second substrate viewed from the substrate thickness direction. An electrostatic actuator provided outside the overlapping optical interference region and changing the gap, wherein the electrostatic actuator is provided on the first substrate and on the second substrate. A second electrode facing the first electrode via a predetermined gap, and a dielectric film provided on a part of at least one surface of the first electrode and the second electrode. In the plan view, the first electric And among the actuators region where the second electrode overlap each other, the first region where the dielectric layer is provided, characterized in that provided on the side away from the optical interference region of the actuator region.

  In the present invention, the first region where the dielectric film is formed is formed on the side away from the optical interference region in plan view. In such a configuration, since a high electrostatic attraction acts on the dielectric film, the electrostatic attraction of the first area where the dielectric film exists is large in the actuator area, and the dielectric film is provided in the actuator area. The electrostatic attraction in the inner area that is not is smaller than in the first area. The first region located on the side away from the optical interference region is a region having a large electrostatic attraction, and the other second region is a region having a small electrostatic attraction. A distribution having regions is formed. When the gap is controlled by such an electrostatic actuator, even when the second substrate is bent, a strong electrostatic attractive force acts on the first region, and the inner bending can be suppressed, and the second reflecting film can be bent. Can also be suppressed. Therefore, it is possible to change the gap between the reflection films while maintaining the parallelism of each reflection film, and it is possible to extract light with high resolution, that is, a narrow half-value width.

In the wavelength tunable interference filter according to the aspect of the invention, it is preferable that the first region and the second region where the dielectric film is not provided are formed with an interval therebetween.
In the present invention, the first region and the second region where the dielectric film is not provided are formed with a space therebetween. In such a configuration, compared to the case where the first region and the second region are formed without a gap therebetween, the two substrates have a larger difference in deflection amount on the outside than the two regions. A stronger electrostatic attraction can be applied to a certain first region than the second region located inside. In other words, the first region acts as a force point, the second region acts as a fulcrum, and the region including the light interference region located inside the second region acts as a point of action, as if it acts like the lever principle. The influence of warpage can be further reduced.

  In the wavelength tunable interference filter according to the aspect of the invention, the electrostatic actuator is provided outside the optical interference region in the plan view, and the first electrostatic actuator that changes the gap and the first actuator in the plan view. A second electrostatic actuator provided outside the electrostatic actuator and driven independently of the first electrostatic actuator to change the gap, wherein the first electrostatic actuator comprises the first electrostatic actuator A first inner electrode provided on the substrate side, and a second inner electrode provided on the second substrate side and facing the first inner electrode with a predetermined gap therebetween, the second electrostatic actuator Is a first outer electrode provided on the first substrate side and a second outer electrode provided on the second substrate side and facing the first outer electrode with a predetermined gap. And poles, it is preferable provided with a dielectric film provided on a part of at least one surface of the first outer electrode and the second outer electrode.

In the present invention, the first electrostatic actuator and the second electrostatic actuator that can be driven independently from each other are provided on the outer peripheral side of the optical interference region where the first reflective film and the second reflective film overlap. In such a configuration, the first electrostatic actuator and the second electrostatic actuator can be independently driven. Therefore, it is possible to control the gap with higher accuracy than when the gap is controlled by one electrostatic actuator.
In addition, since the electrostatic actuators are independent of each other, warpage can be suppressed by increasing the electrostatic attraction force outside by the second electrostatic actuator, and the second electrostatic actuator has a dielectric film. Power saving can be achieved without increasing the voltage.

In the wavelength tunable interference filter of the present invention, a protective film is formed on the surfaces of the first reflective film and the second reflective film, and the dielectric film and the protective film have the same material and the same thickness. It is preferable that Here, the “same thickness” described in the present invention includes a slight error as long as the configuration is maintained.
In the present invention, the dielectric film and the protective film are made of the same material and the same thickness. In such a configuration, since the dielectric film and the protective film can be formed by the same process, the manufacturing cost can be reduced.

In the wavelength tunable interference filter according to the aspect of the invention, the first reflective film and the second reflective film are formed of a dielectric-containing film having the dielectric film, and the dielectric film and the dielectric film of the dielectric-containing film; Are preferably made of the same material and the same thickness.
In the present invention, the dielectric film and the dielectric film of the reflective film (dielectric-containing film) are made of the same material and the same thickness. In such a configuration, the dielectric film and the dielectric film of the reflective film (dielectric-containing film) can be formed by the same process, so that the manufacturing cost can be reduced.

  The optical filter device of the present invention includes a first substrate, a second substrate facing the first substrate, a first reflective film provided on the first substrate, and a first reflective film provided on the second substrate. The second reflection film facing the film with a gap, and the optical interference of the first reflection film and the second reflection film overlapping in a plan view of the first substrate and the second substrate viewed from the substrate thickness direction. A tunable interference filter provided outside the region and provided with an electrostatic actuator that changes the gap; and a housing that houses the tunable interference filter, wherein the electrostatic actuator includes the first substrate. A first electrode provided on the second substrate; a second electrode provided on the second substrate and facing the first electrode with a predetermined gap; at least one of the first electrode and the second electrode One on the surface A first region where the dielectric film is provided in the actuator region where the first electrode and the second electrode overlap in the plan view, It is provided in the actuator area | region in the side away from the said light interference area | region.

  In the present invention, similarly to the above-described invention, in the wavelength tunable interference filter, it is possible to reduce the warp generated in the second substrate and extract light with a high resolution and a narrow half-value width. In addition, since the wavelength tunable interference filter is housed in the housing, the wavelength tunable interference filter can be protected from an external impact. In addition, the housing can suppress the entry of charged particles from the outside, and each electrode that constitutes the electrostatic actuator and each reflective film can be prevented from being charged by charged particles. Control can be implemented.

  The optical module of the present invention includes a first substrate, a second substrate facing the first substrate, a first reflective film provided on the first substrate, and the second substrate. The second reflection film facing the one reflection film through a gap, and the overlapping light of the first reflection film and the second reflection film in a plan view of the first substrate and the second substrate viewed from the substrate thickness direction An electrostatic actuator that is provided outside an interference region and that changes the gap; and a detection unit that detects light extracted by the first reflective film and the second reflective film. A first electrode provided on the first substrate; a second electrode provided on the second substrate and facing the first electrode with a predetermined gap; the first electrode and the second electrode; Provided on a part of at least one surface of A first region where the dielectric film is provided in the actuator region in which the first electrode and the second electrode overlap in the plan view. It is provided in the side away from the said optical interference area | region.

  In the present invention, similarly to the above-described invention, in the wavelength tunable interference filter, it is possible to suppress light generated in the second substrate and to extract light with high resolution and narrow half-value width. Therefore, by detecting the light extracted from the variable wavelength interference filter by the detection unit, it is possible to accurately detect the amount of light having a desired specific wavelength.

  The electronic device of the present invention is provided on the first substrate, the second substrate facing the first substrate, the first reflective film provided on the first substrate, and the second substrate, The second reflection film facing the one reflection film through a gap, and the overlapping light of the first reflection film and the second reflection film in a plan view of the first substrate and the second substrate viewed from the substrate thickness direction A variable wavelength interference filter provided outside the interference region and including the electrostatic actuator that changes the gap; and a control unit that controls the variable wavelength interference filter, wherein the electrostatic actuator includes the first A first electrode provided on one substrate; a second electrode provided on the second substrate and facing the first electrode with a predetermined gap; at least one of the first electrode and the second electrode Provided on a part of one surface Of the actuator region in which the first electrode and the second electrode overlap in the plan view, the first region where the dielectric film is provided is the actuator region. It is provided in the side away from the said optical interference area | region among these.

  In the present invention, light having a high resolution and a narrow half-value width can be extracted from the light interference region, and the electronic apparatus can perform accurate processing based on the light.

1 is a block diagram showing a schematic configuration of a spectrometer according to a first embodiment of the present invention. The top view which shows schematic structure of the wavelength variable interference filter of 1st embodiment. The top view which looked at the fixed substrate of 1st embodiment from the movable substrate side. The top view which looked at the movable substrate of a first embodiment from the fixed substrate side. Sectional drawing when the wavelength variable interference filter of FIG. 2 is sectioned along the line AA ′. Sectional drawing which shows the relationship between the protective film and dielectric film which were formed in the fixed board | substrate. Sectional drawing which shows the relationship between the fixed reflection film (dielectric multilayer film) formed on the fixed substrate, and the dielectric film. Sectional drawing at the time of changing the gap of the wavelength variable interference filter of FIG. Sectional drawing at the time of changing the gap of the wavelength variable interference filter of a conventional structure. The top view which looked at the fixed board | substrate of the wavelength variable interference filter of 2nd embodiment from the movable board | substrate side. The top view which shows schematic structure of the wavelength variable interference filter of 3rd embodiment. Sectional drawing which shows schematic structure of the optical filter device of 4th embodiment. Schematic which shows the colorimetry apparatus (electronic device) provided with the wavelength variable interference filter of this invention. Schematic which shows the gas detection apparatus (electronic device) provided with the wavelength variable interference filter of this invention. The block diagram which shows the structure of the control system of the gas detection apparatus of FIG. The figure which shows schematic structure of the food-analysis apparatus (electronic device) provided with the wavelength variable interference filter of this invention. The figure which shows schematic structure of the spectroscopic camera (electronic device) provided with the wavelength variable interference filter of this invention.

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

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

[Configuration of wavelength tunable interference filter]
Next, the wavelength variable interference filter 5 incorporated in the optical module 10 will be described.
FIG. 2 is a plan view showing a schematic configuration of the variable wavelength interference filter 5. FIG. 3 is a plan view of the fixed substrate 51 as viewed from the movable substrate 52 side. FIG. 4 is a plan view of the movable substrate 52 as viewed from the fixed substrate 51 side. FIG. 5 is a cross-sectional view of the tunable interference filter 5 of FIG. 2 taken along line AA ′.
As shown in FIG. 2, the wavelength variable interference filter 5 is, for example, a rectangular plate-shaped optical member, and includes a fixed substrate 51 that constitutes a first substrate and a movable substrate 52 that constitutes a second substrate. The fixed substrate 51 and the movable substrate 52 are each formed of, for example, various glasses such as soda glass, crystalline glass, quartz glass, lead glass, potassium glass, borosilicate glass, and alkali-free glass, crystal, and the like. . Then, the first bonding portion 513 of the fixed substrate 51 and the second bonding portion 523 of the movable substrate 52 are bonded together by a bonding film 53 made of, for example, a plasma polymerized film containing siloxane as a main component. It is configured.

A fixed reflective film 54 constituting the first reflective film of the present invention is provided on a surface of the fixed substrate 51 facing the movable substrate 52, and a surface of the movable substrate 52 facing the fixed substrate 51 is provided with a first reflective film 54 of the present invention. A movable reflecting film 55 constituting a two reflecting film is provided. The fixed reflection film 54 and the movable reflection film 55 are disposed to face each other with a gap G1 interposed therebetween. A gap is the distance between the surfaces of each reflective film. Then, in a plan view of the fixed substrate 51 and the movable substrate 52 as viewed from the thickness direction, the light interference region Ar ₀ of the present invention is configured by the region where the fixed reflective film 54 and the movable reflective film 55 overlap.
The variable wavelength interference filter 5 is provided with an electrostatic actuator 56 used to adjust (change) the gap amount of the gap G1. Such an electrostatic actuator can easily change the gap G1 by electrostatic attraction by applying a predetermined voltage between the opposing electrodes, and can simplify the configuration. The electrostatic actuator 56 can be driven under the control of the voltage control unit 15.
In the following description, the planar view seen from the substrate thickness direction of the fixed substrate 51 or the movable substrate 52, that is, the planar view seen from the stacking direction of the fixed substrate 51 and the movable substrate 52, This is referred to as a plan view. In the present embodiment, the center point of the fixed reflection film 54 and the center point of the movable reflection film 55 coincide with each other in the filter plan view, and the center point of these reflection films in the plan view is referred to as a filter center point O. A straight line passing through the center point of these reflective films is referred to as a central axis.

(Configuration of fixed substrate)
The fixed substrate 51 is formed to have a larger thickness dimension than the movable substrate 52, and the electrostatic attraction by the electrostatic actuator 56 or the inside of a film member (for example, the fixed reflection film 54) formed on the fixed substrate 51. There is no bending of the fixed substrate 51 due to stress.
As shown in FIGS. 3 and 5, the fixed substrate 51 includes an electrode arrangement groove 511 and a reflective film installation portion 512 formed by, for example, etching. Further, as shown in FIGS. 2 and 3, notches 514 are provided at the apexes C <b> 2 and C <b> 4 of the fixed substrate 51.

The electrode placement groove 511 is formed in an annular shape having a radius R1 with the filter center point O of the fixed substrate 51 as the center in the filter plan view. The reflection film installation part 512 is formed so as to protrude from the center part of the electrode arrangement groove 511 toward the movable substrate 52 in the filter plan view. The groove bottom surface of the electrode arrangement groove 511 serves as an electrode installation surface 511A on which the electrodes constituting the electrostatic actuator 56 are arranged. Further, the protruding front end surface of the reflection film installation portion 512 is a reflection film installation surface 512A on which the fixed reflection film 54 is disposed.
The fixed substrate 51 is provided with an electrode extraction groove 511 </ b> B extending from the electrode arrangement groove 511 toward the outer peripheral edge of the fixed substrate 51. Specifically, the fixed substrate 51 is provided with three electrode extraction grooves 511 </ b> B extending toward the apexes C <b> 1, C <b> 2, C <b> 4 of the fixed substrate 51.

  A first electrode 561 constituting the electrostatic actuator 56 is provided on the electrode placement surface 511A and the electrode lead-out groove 511B of the electrode placement groove 511. The first electrode 561 may be provided directly on the electrode installation surface 511A and the electrode extraction groove 511B, or another thin film (layer) is provided on the electrode installation surface 511A and the electrode extraction groove 511B, and the first electrode 561 is installed thereon. Also good. In FIG. 2, the first electrode 561 provided on the fixed substrate 51 is indicated by a broken line, and the second electrode 562 provided on the movable substrate 52 is indicated by a solid line for easy understanding of the electrode configuration of each of the substrates 51 and 52. Is displayed.

The first electrode 561 is formed in an annular shape having an inner periphery with a radius R2 and an outer periphery with a radius R3 with the filter center point O as the center. Examples of a material for forming the first electrode 561 include ITO (Indium Tin Oxide).
A dielectric film 57 is formed on a part of the surface of the first electrode 561. As a result, the surface of the first electrode 561 includes a first region 57A where the dielectric film 57 is formed and a second region 57B where the dielectric film 57 is not formed. The first region 57A, in plan view, and is formed on the side away from the optical interference region Ar _0. The dielectric film 57 of the present embodiment is formed in an annular shape having an inner circumference with a radius R4 and an outer circumference with a radius R3 with the filter center point O as the center.
Examples of the material for forming the dielectric film 57 include Al ₂ O ₃ , SiO ₂ , HfO ₂ , and TiO ₂ . The dielectric film 57 may be formed by alternately stacking films made of the above materials. Note that the film thickness of the dielectric film 57 may be appropriately adjusted according to the relative dielectric constant of the dielectric film, the rigidity (ease of bending) of the movable substrate, and the like.

  Further, the first region 57A may be formed by a plurality of regions that are point-symmetric with respect to the filter center point O. In this case, for example, a configuration in which a plurality of dielectric films 57 are formed in an arc shape with the filter center point O as the center, and these dielectric films 57 are arranged at symmetrical positions with respect to the filter center point O is exemplified. it can. Even in this case, the electrostatic attractive force can be applied to the filter center point O in a well-balanced manner, and the tilt of the reflective film during driving can be suppressed.

  The first electrode 561 includes a first extraction electrode 561A that extends along the electrode extraction groove 511B to the vertex C1. The front end portion of the first extraction electrode 561A is exposed from a notch 524 described later provided on the movable substrate 52 when the variable wavelength interference filter 5 is viewed from the movable substrate 52 side. And the front-end | tip part of 561 A of 1st extraction electrodes is connected to the voltage control part 15 by FPC (Flexible printed circuits), a lead wire, etc., for example.

As described above, the reflective film installation portion 512 is formed in a substantially cylindrical shape that is coaxial with the electrode arrangement groove 511 and has a smaller diameter than the electrode arrangement groove 511, and is formed on the movable substrate 52 of the reflection film installation portion 512. An opposing reflection film installation surface 512A is provided.
As shown in FIGS. 3 and 5, a fixed reflective film 54 is installed in the reflective film installation part 512. The fixed reflective film 54 may be provided directly on the reflective film installation part 512, or another thin film (layer) may be provided on the reflective film installation part 512 and may be installed thereon. As the fixed reflective film 54, for example, a metal film such as Ag or a conductive alloy film such as an Ag alloy can be used. In the case of using a metal film such as Ag, it is preferable to form the protective film 54A in order to suppress the deterioration of Ag. In this case, it is preferable to form the protective film 54A and the dielectric film 57 with the same material and the same thickness t as shown in FIG. In this case, the protective film 54A of the fixed reflective film 54 and the dielectric film 57 can be simultaneously formed by the same process.
Further, for example, a dielectric multilayer film formed by alternately stacking a high refractive index layer and a low refractive index layer using TiO _{2 as} a high refractive index layer and SiO ₂ as a low refractive index layer may be used. A reflective film in which a multilayer film and a metal film are laminated, a reflective film in which a dielectric single layer film and an alloy film are laminated, or the like may be used. In this case, as shown in FIG. 7, it is preferable that the layer 54B on the surface of the dielectric multilayer film and the dielectric film 57 are made of the same material and the same thickness t. In this case, the layer 54B on the surface of the dielectric multilayer film and the dielectric film 57 can be formed simultaneously in the same process.

  Further, an antireflection film may be formed at a position corresponding to the fixed reflection film 54 on the light incident surface of the fixed substrate 51 (the surface on which the fixed reflection film 54 is not provided). This antireflection film can be formed by alternately laminating a low refractive index film and a high refractive index film, and reduces the reflectance of visible light on the surface of the fixed substrate 51 and increases the transmittance.

  Of the surfaces of the fixed substrate 51 facing the movable substrate 52, the surfaces on which the electrode placement groove 511, the reflective film installation portion 512, and the electrode extraction groove 511 </ b> B are not formed constitute the first joint portion 513. The first bonding portion 513 is bonded to the second bonding portion 523 of the movable substrate 52 by the bonding film 53.

(Configuration of movable substrate)
The movable substrate 52 includes a circular movable portion 521 centering on the filter center point O in the filter plan view as shown in FIG. 2, a holding portion 522 that is coaxial with the movable portion 521 and holds the movable portion 521, A substrate outer peripheral portion 525 provided outside the holding portion 522.
Further, as shown in FIGS. 2 and 4, the movable substrate 52 is provided with a notch 524 at the vertex C1.

  The movable part 521 has a thickness dimension larger than that of the holding part 522. For example, in this embodiment, the movable part 521 has the same dimension as the thickness dimension of the movable substrate 52 (substrate outer peripheral part 525). The movable portion 521 is formed to have a diameter larger than at least the diameter of the outer peripheral edge of the reflection film installation surface 512A in the filter plan view. The movable portion 521 is provided with a movable reflective film 55 and a second electrode 562 that constitutes the electrostatic actuator 56. The movable reflective film 55 and the second electrode 562 may be provided directly on the movable surface 521A, or another thin film (layer) may be provided on the movable surface 521A and may be installed thereon.

The holding part 522 is a diaphragm that surrounds the periphery of the movable part 521, and has a thickness dimension smaller than that of the movable part 521. Such a holding part 522 is easier to bend than the movable part 521, and the movable part 521 can be displaced toward the fixed substrate 51 by a slight electrostatic attraction. At this time, since the movable portion 521 has a thickness dimension larger than that of the holding portion 522 and becomes rigid, even if the movable portion 521 is pulled to the fixed substrate 51 side by electrostatic attraction, the shape change of the movable portion 521 is caused to some extent. Can be suppressed.
In this embodiment, the diaphragm-like holding part 522 is illustrated, but the present invention is not limited to this. For example, a configuration in which beam-like holding parts arranged at equiangular intervals around the filter center point O are provided. And so on.

As described above, the substrate outer peripheral portion 525 is provided outside the holding portion 522 in the filter plan view.
Similar to the fixed substrate 51, an antireflection film may be formed on the surface of the movable portion 521 opposite to the fixed substrate 51.

  The second electrode 562 is formed in an annular shape having an inner circumference with a radius R2 and an outer circumference with a radius R3 with the filter center point O as the center. Further, the second electrode 562 is provided at a position overlapping the first electrode 561 as shown in FIG. 2 in the filter plan view.

  The second electrode 562 includes a second extraction electrode 562A that extends to the vertices C2 and C4, respectively. The tip of the second extraction electrode 562A is exposed from a notch 514 provided in the fixed substrate 51 when the wavelength variable interference filter 5 is viewed from the fixed substrate 51 side. The distal end portion of the second extraction electrode 562A is connected to the voltage control unit 15 by, for example, an FPC or a lead wire.

In the present embodiment, as shown in FIGS. 2 and 5, the electrostatic actuator 56 is configured by a region where the first electrode 561 and the second electrode 562 overlap each other.
As a result, the electrostatic actuator 56 can generate the same electrostatic attraction force in a region that is point-symmetric with respect to the filter center point O. Therefore, the movable portion 521 is well balanced with the inclination of the movable portion 521 suppressed. Can be displaced toward the fixed substrate 51 side.

The movable reflective film 55 is provided in the central part of the movable surface 521A of the movable part 521 so as to face the fixed reflective film 54 via the gap G1. As the movable reflective film 55, a reflective film having the same configuration as that of the fixed reflective film 54 described above is used.
In this embodiment, an example in which the gap between the electrodes is larger than the gap G1 is shown, but the present invention is not limited to this. For example, when infrared rays or far infrared rays are used as the measurement target light, the gap G1 may be larger than the gap between the electrodes depending on the wavelength range of the measurement target light.

[Configuration of Optical Module Detection Unit, IV Converter, Amplifier, A / D Converter, and Voltage Control Unit]
Next, returning to FIG. 1, the optical module 10 will be described.
The detector 11 receives (detects) the light that has passed through the optical interference region Ar ₀ of the wavelength variable interference filter 5 and outputs a detection signal based on the amount of received light to the IV converter 12.
The IV converter 12 converts the detection signal input from the detection unit 11 into a voltage value and outputs the voltage value to the amplifier 13.
The amplifier 13 amplifies a voltage (detection voltage) corresponding to the detection signal input from the IV converter 12.

The A / D converter 14 converts the detection voltage (analog signal) input from the amplifier 13 into a digital signal and outputs it to the control unit 20.
The voltage control unit 15 applies a voltage to the electrostatic actuator 56 of the wavelength variable interference filter 5 based on the control of the control unit 20. As a result, an electrostatic attractive force is generated between the first electrode 561 and the second electrode 562 of the electrostatic actuator 56, the movable portion 521 is displaced toward the fixed substrate 51, and the gap amount of the gap G1 is set to a predetermined value. The

[Configuration of control unit]
Next, the control unit 20 of the spectrometer 1 will be described.
The control unit 20 corresponds to a processing unit of the present invention, and is configured by combining, for example, a CPU and a memory, and controls the overall operation of the spectroscopic measurement apparatus 1. As illustrated in FIG. 1, the control unit 20 includes a wavelength setting unit 21, a light amount acquisition unit 22, and a spectroscopic measurement unit 23.

The wavelength setting unit 21 sets a target wavelength of light extracted by the wavelength variable interference filter 5, and outputs a control signal to the voltage control unit 15 to extract the set target wavelength from the wavelength variable interference filter 5.
The light quantity acquisition unit 22 acquires the light quantity of light having a target wavelength that has passed through the wavelength variable interference filter 5 based on the light quantity acquired by the detection unit 11.
The spectroscopic measurement unit 23 measures the spectral characteristics of the light to be measured based on the light amount acquired by the light amount acquisition unit 22.

[Optical characteristics of tunable interference filter]
Next, optical characteristics of the wavelength variable interference filter 5 in the spectroscopic measurement apparatus 1 as described above will be described with reference to the drawings.
FIG. 8 is a cross-sectional view showing a state in which the gap G1 of the tunable interference filter 5 of the present invention is changed, and FIG. 9 is a cross-section showing a state in which the gap G2 of the tunable interference filter 905 having the conventional configuration is changed. FIG.
In general, in the wavelength tunable interference filter 905 having the conventional configuration as shown in FIG. 9, the gap G2 between the fixed reflection film 953 provided on the fixed substrate 951 and the movable reflection film 954 provided on the movable substrate 952 is set. A voltage is applied between the first electrode 955 and the second electrode 956. Thereby, the movable substrate 952 is bent toward the fixed substrate 951 by the electrostatic attractive force F. That is, the movable substrate 952 is bent in the direction of narrowing the gap G2.
At this time, since the thickness of the movable portion 921 is larger than the holding portion 922, when a voltage is applied between the first electrode 955 and the second electrode 956, the holding portion 922 is greatly bent, and the bending of the movable portion 921 is suppressed to some extent. However, actually, the stress due to the bending is transmitted to the movable portion 921 of the movable substrate 952, and slightly warps the movable portion 921. Then, the movable reflective film 954 installed on the movable substrate 952 side of the movable part 921 also warps following the warp of the movable part 921, and the parallelism of the movable reflective film 954 deteriorates. Therefore, there is a problem that the resolution is deteriorated.

In contrast, in the wavelength tunable interference filter 5 of the present embodiment, of the surface of the fixed electrode 561, the dielectric film 57 is provided on the side away from the optical interference region Ar _0. Accordingly, among the electrostatic actuator 56, the electrostatic attractive force F1 acting on the first region 57A provided with the dielectric film 57 and the electrostatic attractive force acting on the second region 57B provided inside the first region 57A. F2 has different values as shown in the following formulas (1) and (2).

The formula (1), in (2), F1 is the electrostatic attraction of the first region, F2 is the electrostatic attraction of the second region, epsilon is the dielectric constant of the dielectric, epsilon ₀ is the vacuum dielectric constant, G is The interelectrode gap, t, indicates the thickness of the dielectric film.
Here, the dielectric constant of the dielectric film 57 is greater than 1. Therefore, as shown in equations (1) and (2), the electrostatic attractive force F1 acting on the first region 57A is larger than the electrostatic attractive force F2 acting on the second region 57B.
By deflecting the movable substrate 52 to the fixed substrate 51 side with such electrostatic attraction distribution, the outside of the movable portion 521 corresponding to the first region 57A is displaced to the fixed substrate 51 side more than before. Therefore, the gap amount in the first region 57A can be brought close to the gap amount in the second region 57B, and the movable portion 521 becomes flat. Thereby, the curvature of the movable reflection film | membrane 55 in the movable part 521 can be suppressed, and the fall of resolution can be suppressed.

[Operational effects of the first embodiment]
In the present embodiment, in plan view, the first region 57A of the dielectric film 57 is formed is formed on the side away from the optical interference region Ar _0. For this reason, since a high electrostatic attraction is exerted on the dielectric film 57, the electrostatic attraction F1 of the first area 57A where the dielectric film 57 exists is large in the actuator area, and the dielectric film 57 in the actuator area is large. The electrostatic attractive force F2 of the inner second region 57B that is not provided is smaller than that of the first region 57A. Since the electrostatic attractive force in the first region 57A is located on the side away from the optical interference region Ar ₀ becomes large area, the other second region area electrostatic attraction is small in 57B, 1 single electrostatic actuator 56 A distribution having different electrostatic attraction areas is formed.
When the gap G1 is controlled by such an electrostatic actuator, even when the second substrate is bent, a strong electrostatic attraction acts on the first region, and the inner bending can be suppressed. Deflection can also be suppressed.
Therefore, it is possible to change the gap G1 while maintaining the parallelism of the reflecting films 54 and 55, and it is possible to extract light with high resolution, that is, a narrow half-value width.

  The dielectric film 57 and the protective film 54A of the fixed reflective film 54 may be made of the same material and the same thickness. In such a configuration, since the dielectric film 57 and the protective film 54A can be formed at the same time, the manufacturing cost can be reduced.

  Further, the dielectric film 57 and the dielectric film 54B of the reflective film (dielectric-containing film) 54 may be made of the same material and the same thickness. In such a configuration, the dielectric film 57 and the dielectric film 54B of the reflective film (dielectric-containing film) 54 can be formed at the same time, so that the manufacturing cost can be reduced.

[Second Embodiment]
Next, the variable wavelength interference filter according to the second embodiment of the present invention will be described.
In the first embodiment, the configuration formed without leaving the gap between the first region 57A and the second region 57B has been exemplified.
On the other hand, in the second embodiment, the first region 57A and the second region 57B are different from the first embodiment in that they are formed at intervals.
FIG. 10 is a plan view of the fixed substrate 51 of the variable wavelength interference filter 5A according to the second embodiment as viewed from the movable substrate 52 side. In the following description of the embodiments, the same components are denoted by the same reference numerals and description thereof is omitted.
As shown in FIG. 10, in the variable wavelength interference filter 5A of the second embodiment, the shape of the first electrode 561 provided on the fixed substrate 51 is such that the inner ring 561B and the inner ring 561B are arranged outside the inner ring 561B. Is composed of an outer ring 561C provided at intervals. That is, the shape of the first electrode 561 is configured as a double ring of an inner ring 561B and an outer ring 561C. The inner ring 561B is formed in an annular shape having a radius R2 at the inner periphery and a radius R5 at the filter center point O as the center. Further, the outer ring 561C is formed in an annular shape having an inner circumference with a radius R6 and an outer circumference with a radius R3 with the filter center point O as the center. The inner ring 561B and the outer ring 561C of the first electrode 561 are connected to each other by the first extraction electrode 561A.
The shape of the second electrode 562 provided on the movable substrate 52 is also composed of an inner ring and an outer ring, similarly to the shape of the first electrode 561.

Then, a dielectric film 57 is formed on the surface of the outer ring 561C of the fixed substrate 51 constituting the first substrate. Here, in this embodiment, the dielectric film 57 is formed so as to cover the entire surface of the outer ring 561C, and the entire surface of the outer ring 561C is the first region 57A. A part of the first region 57 </ b> A may be formed by partially covering the part. In this case, a configuration in which a plurality of dielectric films 57 are formed in an arc shape with the filter center point O as the center, and these dielectric films 57 are disposed at symmetrical positions with respect to the filter center point O can be exemplified. Even in this case, the electrostatic attractive force can be applied to the filter center point O in a well-balanced manner, and the tilt of the reflective film during driving can be suppressed.
Although the dielectric film 57 is formed on the surface of the outer ring 561C of the fixed substrate 51 constituting the first substrate, it may be formed on the outer ring of the movable substrate 52 constituting the second substrate.

[Operational effects of the second embodiment]
In the present embodiment, the first region 57A and the second region 57B are formed at intervals. Therefore, also in the present embodiment, as in the first embodiment, when the electrostatic actuator 56 is driven, the warp generated in the movable portion 521 of the movable substrate 52 can be suppressed to a small level. The movable portion 521 can be displaced toward the fixed substrate 51 while maintaining the parallelism of the movable reflective film 55. Thereby, the gap adjustment of the gap G1 can be performed with higher accuracy.
In addition, in the first embodiment, compared to the case where the first region 57A and the second region 57B are formed without being spaced, the two regions in which the difference in the amount of deflection in the movable portion 521 becomes larger are provided. On the other hand, an electrostatic attractive force stronger than that of the second region 57B on the inner side can be applied to the first region 57A on the outer side. In other words, the first region acts as a force point, the second region serves as a fulcrum, and the region including the light interference region located inside the second region acts as a lever, as if it acts like a lever. The influence can be made smaller.

[Third embodiment]
Next, a variable wavelength interference filter according to a third embodiment of the present invention will be described.
In the first embodiment and the second embodiment, the configuration in which the electrostatic attraction force is applied by one electrostatic actuator 56 to perform the gap control of the gap G1 is illustrated.
In contrast, in the third embodiment, on the outer peripheral side of the optical interference region Ar ₀ where the movable reflective layer 55 constituting the fixed reflective film 54 and the second reflecting film of the first reflection film overlap, independently of each other The point which the driveable 1st electrostatic actuator 56A and the 2nd electrostatic actuator 56B are provided differs from the said 1st embodiment and said 2nd embodiment.
FIG. 11 is a plan view showing a schematic configuration of a wavelength tunable interference filter 5B according to the third embodiment. In FIG. 11, the films (fixed reflective film 54, first inner electrode 561D, first outer electrode 561E, first inner extraction electrode 561F, first outer extraction electrode 561G) provided on the fixed substrate 51 are indicated by solid lines, Films (movable reflection film 55, second inner electrode 562D, second outer electrode 562E, second inner extraction electrode 562F, second outer extraction electrode 562G) provided on movable substrate 52 are indicated by broken lines.

As shown in FIG. 11, the variable wavelength interference filter 5B of the third embodiment, an electrostatic actuator, in plan view, provided outside the optical interference region Ar _0, the first electrostatic actuator 56A to change the gap G1 And a second electrostatic actuator 56B that is provided outside the first electrostatic actuator 56A in a plan view and is driven independently of the first electrostatic actuator 56A to change the gap G1. Yes.

In this configuration, as shown in FIG. 11, one end side (side C1-C2 in FIG. 11) of the fixed substrate 51 projects outward from the substrate edge (side C5-C6 in FIG. 11) of the movable substrate 52. And constitutes a fixed-side terminal extraction portion 514A. The fixed substrate 51 is provided with a first inner electrode 561D constituting the first electrostatic actuator 56A and a first outer electrode 561E constituting the second electrostatic actuator 56B.
The first inner electrode 561D is provided on the outer peripheral side of the reflective film installation portion on the inner peripheral side of the first outer electrode 561E, and the first outer electrode 561E is provided on the outer peripheral side of the first inner electrode 561D. The first inner electrode 561D and the first outer electrode 561E are each formed in an arc shape (substantially C shape), and a C-shaped opening is provided in a part close to the side C1-C2. In addition, an insulating film for ensuring insulation between the second inner electrode 562D and the second outer electrode 562E may be stacked on the first inner electrode 561D and the first outer electrode 561E.
The fixed substrate 51 is provided with a first inner extraction electrode 561F extending from one end of the first inner electrode 561D toward the vertex C2, and extending from one end of the first outer electrode 561E toward the vertex C1. A first outer extraction electrode 561G is provided. The first inner extraction electrode 561F is disposed along an electrode extraction groove (not shown) extending toward the vertex C2, and extends to the vertex C2 on the fixed-side terminal extraction portion 514A. The first outer extraction electrode 561G is disposed along an electrode extraction groove (not shown) extending toward the vertex C1, and extends to the vertex C1 on the fixed terminal extraction portion 514A. And the extended front-end | tip part of these 1st inner side extraction electrodes 561F and 1st outer side extraction electrodes 561G is connected to the voltage control part 15 by FPC (Flexible printed circuits), a lead wire, etc., for example.

Further, the end side (side C7-C8 in FIG. 11) of the movable substrate 52 projects outward from the substrate end edge (side C3-C4 in FIG. 11) of the fixed substrate 51, and the movable side terminal take-out portion 524A is configured. The movable substrate 52 is provided with a second inner electrode 562D constituting the first electrostatic actuator 56A and a second outer electrode 562E constituting the second electrostatic actuator 56B.
The second inner electrode 562D is provided on the outer peripheral side of the reflection film installation portion on the inner peripheral side of the second outer electrode 562E, and the second outer electrode 562E is provided on the outer peripheral side of the second inner electrode 562D. The second inner electrode 562D and the second outer electrode 562E are each formed in an arc shape (substantially C shape), and a C-shaped opening is provided in a part close to the side C7-C8. Here, in the filter plan view, the second inner electrode 562D includes an arc region that overlaps the first inner electrode 561D, and the first electrostatic actuator 56A is configured by the arc region. Similarly, the second outer electrode 562E includes an arc region that overlaps the first outer electrode 561E, and the second electrostatic actuator 56B is configured by this arc region. Note that, similarly to the first inner electrode 561D and the first outer electrode 561E, an insulating film for ensuring insulation may be stacked on the second inner electrode 562D and the second outer electrode 562E.

  The movable substrate 52 is provided with a second inner lead electrode 562F extending from one end of the second inner electrode 562D toward the vertex C8, and extending from one end of the second outer electrode 562E toward the vertex C7. A second outer extraction electrode 562G is provided. The second inner lead electrode 562F is disposed at a position facing an electrode lead groove (not shown) extending toward the vertex C4 provided on the fixed substrate 51, and extends to the vertex C8 on the movable terminal lead portion 524A. To do. Further, the second outer lead electrode 562G is disposed at a position facing an electrode lead groove (not shown) extending toward the vertex C3, and extends to the vertex C7 on the movable side terminal lead portion 524A. And the extended front-end | tip part of these 2nd inner extraction electrodes 562F and the 2nd outer extraction electrode 562G is connected to the voltage control part 15 by FPC, a lead wire, etc., for example.

Here, the dielectric film 57 is formed so as to cover the entire surface of the first outer electrode 561E, and the entire surface of the first outer electrode 561E serves as the first region 57A. A part of the first region 57 </ b> A may be formed by partially covering the part.
In this case, a configuration in which a plurality of dielectric films 57 are formed in an arc shape with the filter center point O as the center, and these dielectric films 57 are disposed at symmetrical positions with respect to the filter center point O can be exemplified. Even in this case, the electrostatic attractive force can be applied to the filter center point O in a well-balanced manner, and the tilt of the reflective film during driving can be suppressed.
The first electrostatic actuator 56A is provided on the first inner electrode 561D provided on the fixed substrate 51 side constituting the first substrate and the movable substrate 52 side constituting the second substrate, and is provided on the first inner electrode 561D. And a second inner electrode 562D facing each other through the gap. The second electrostatic actuator 56B is provided on the first outer electrode 561E provided on the fixed substrate 51 side constituting the first substrate and on the movable substrate 52 side constituting the second substrate, and the first outer electrode 561E. And a dielectric film 57 provided so as to cover the surface of the first outer electrode 561E. The dielectric film 57 may be configured to cover the surface of the second outer electrode 562E. The dielectric film 57 is formed on the surface of at least one of the first outer electrode 561E and the second outer electrode 562E, whereby the first region 57A is formed, and the other dielectric film 57 is formed. The second region 57B is configured by the non-region.

[Operational effects of the third embodiment]
In the present embodiment, the first electrostatic actuator 56A and the second electrostatic actuator 56B can be driven independently. Therefore, compared with the case where the gap is controlled by one electrostatic actuator, fine voltage setting can be performed, and control with a higher degree of freedom is possible.
Further, the first region 57A is formed by forming the dielectric film 57 on the first outer electrode 561E constituting the second electrostatic actuator 56B located on the outer peripheral side of the first electrostatic actuator 56A. In such a configuration, since the electrostatic attractive force of the second electrostatic actuator 56B can be further improved, the gap G1 can be changed more greatly.

[Fourth embodiment]
Next, 4th embodiment of this invention is described based on drawing.
In the spectroscopic measurement device 1 of the first embodiment, the wavelength variable interference filter 5 is directly provided to the optical module 10. However, some optical modules have a complicated configuration, and it may be difficult to directly provide the variable wavelength interference filter 5 for a particularly small optical module. In the present embodiment, the tunable interference filter 5, the tunable interference filter 5A of the second embodiment, and the tunable interference filter 5B of the third embodiment can be easily installed even for such an optical module. The optical filter device will be described below.
FIG. 12 is a cross-sectional view showing a schematic configuration of an optical filter device according to the fourth embodiment of the present invention.

As shown in FIG. 12, the optical filter device 600 includes a wavelength tunable interference filter 5 and a housing 601 that houses the wavelength tunable interference filter 5. In the present embodiment, the wavelength variable interference filter 5 is illustrated as an example, but the wavelength variable interference filter 5A of the second embodiment and the wavelength variable interference filter 5B of the third embodiment may be used.
The housing 601 includes a base substrate 610, a lid 620, a base side glass substrate 630, and a lid side glass substrate 640.

The base substrate 610 is configured by, for example, a single layer ceramic substrate. On the base substrate 610, the movable substrate 52 of the variable wavelength interference filter 5 is installed. As the installation of the movable substrate 52 on the base substrate 610, for example, it may be disposed via an adhesive layer or the like, and is disposed by being fitted to another fixing member or the like. Also good. Moreover, the base substrate 610, in a region facing the light interference region Ar _0, the light passing hole 611 is formed open. And the base side glass substrate 630 is joined so that this light passage hole 611 may be covered. As a method for joining the base side glass substrate 630, for example, glass frit joining using a glass frit that is a piece of glass that has been melted at a high temperature and rapidly cooled, adhesion by an epoxy resin, or the like can be used.

On the base inner surface 612 of the base substrate 610 facing the lid 620, inner terminal portions 615 are provided corresponding to the extraction electrodes 561A and 562A of the wavelength variable interference filter 5, respectively. For example, FPC 615A can be used for connection between each extraction electrode 561A, 562A and the inner terminal portion 615. For example, Ag paste, ACF (Anisotropic Conductive Film), ACP (Anisotropic Conductive Paste), or the like is used. In addition, when maintaining the internal space 650 in a vacuum state, it is preferable to use Ag paste with little outgas. Further, the connection is not limited to the connection by the FPC 615A, and wiring connection by wire bonding or the like may be performed, for example.
In addition, the base substrate 610 has through holes 614 corresponding to positions where the respective inner terminal portions 615 are provided, and the respective inner terminal portions 615 are interposed via conductive members filled in the through holes 614. The base substrate 610 is connected to an outer terminal portion 616 provided on the base outer surface 613 opposite to the base inner surface 612.
A base joint 617 that is joined to the lid 620 is provided on the outer periphery of the base substrate 610.

As shown in FIG. 12, the lid 620 includes a lid joint portion 624 joined to the base joint portion 617 of the base substrate 610, a side wall portion 625 that continues from the lid joint portion 624 and rises in a direction away from the base substrate 610, A top surface portion 626 that is continuous from the side wall portion 625 and covers the fixed substrate 51 side of the variable wavelength interference filter 5 is provided. The lid 620 can be formed of an alloy such as Kovar or a metal, for example.
The lid 620 is tightly bonded to the base substrate 610 by bonding the lid bonding portion 624 and the base bonding portion 617 of the base substrate 610.
As this joining method, for example, in addition to laser welding, soldering using silver brazing, sealing using a eutectic alloy layer, welding using low melting glass, glass adhesion, glass frit bonding, epoxy resin Adhesion etc. are mentioned. These bonding methods can be appropriately selected depending on the materials of the base substrate 610 and the lid 620, the bonding environment, and the like.

The top surface portion 626 of the lid 620 is parallel to the base substrate 610. A light passage hole 621 is formed in the top surface portion 626 in a region facing the light interference region Ar ₀ of the wavelength variable interference filter 5. And the lid side glass substrate 640 is joined so that this light passage hole 621 may be covered. As a method for bonding the lid-side glass substrate 640, for example, glass frit bonding, adhesion using an epoxy resin, or the like can be used as in the case of bonding the base-side glass substrate 630.

[Effects of Fourth Embodiment]
In the optical filter device 600 of the present embodiment, since the wavelength tunable interference filter 5 is protected by the housing 601, it is possible to prevent changes in the characteristics of the wavelength tunable interference filter 5 due to foreign matters, gases contained in the atmosphere, and the like. It is possible to prevent the wavelength tunable interference filter 5 from being damaged due to mechanical factors. In addition, since charged particles can be prevented from entering, the electrodes 561 and 562 can be prevented from being charged. Therefore, the generation of Coulomb force due to charging can be suppressed, and the parallelism of the reflection films 54 and 55 can be more reliably maintained.

For example, when the wavelength tunable interference filter 5 manufactured in a factory is transported to an assembly line for assembling an optical module or an electronic device, the wavelength tunable interference filter 5 protected by the optical filter device 600 is transported safely. It becomes possible.
In addition, since the optical filter device 600 is provided with the outer terminal portion 616 exposed on the outer peripheral surface of the housing 601, wiring can be easily performed even when the optical filter device 600 is incorporated into an optical module or an electronic device. Become.

[Other Embodiments]
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.
In the first to third embodiments, the dielectric film 57 is formed on the first electrode 561 on the fixed substrate 51 side, but may be formed on the second electrode 562 on the movable substrate 52 side.
Further, although the dielectric film 57 is formed on either the first electrode 561 or the second electrode 562, the dielectric film 57 may be formed on both the first electrode 561 and the second electrode 562.
In the first embodiment, an example in which the dielectric film 57 is formed in an annular shape having the inner periphery with the radius R4 and the outer periphery with the radius R3 centering on the filter center point O is shown. For example, you may form in circular arc shape. In that case, a plurality of arc-shaped dielectric films are formed so as to have a target shape as the filter center point O. Thereby, the inclination of the reflective film during driving can be suppressed.
In the third embodiment, the first inner electrode 561D and the first outer electrode 561E are each formed in an arc shape (substantially C shape), and a C-shaped opening is provided in a part close to the side C1-C2. The first inner electrode 561D has an annular shape, the first outer electrode 561E has an arc shape (C-shape) with a slit in part, and the first inner extraction electrode 561F of the first inner electrode 561D has a first shape. It is good also as a structure arrange | positioned at the slit of the one outer side electrode 561E.

  Moreover, although the spectroscopic measurement apparatus 1 has been exemplified as the electronic apparatus of the present invention in each of the above-described embodiments, the wavelength variable interference filter driving method, the optical module, and the electronic apparatus of the present invention are applied to various other fields. be able to.

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

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

  As shown in FIG. 13, the colorimetric sensor 420 has a variable wavelength interference filter 5, a detection unit 11 that receives light that passes through the variable wavelength interference filter 5, and a wavelength of light that is transmitted through the variable wavelength interference filter 5. And a voltage control unit 15 to perform. Further, the colorimetric sensor 420 includes an incident optical lens (not shown) that guides the reflected light (inspection target light) reflected by the inspection target A to a position facing the wavelength variable interference filter 5. In the colorimetric sensor 420, the wavelength variable interference filter 5 separates 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 11. Instead of the wavelength variable interference filter 5, the wavelength variable interference filters 5A and 5B described above and the optical filter device 600 may be provided.

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

Another example of the electronic device of the present invention is a light-based system for detecting the presence of a specific substance. As such a system, for example, an in-vehicle gas leak detector that detects a specific gas with high sensitivity by adopting a spectroscopic measurement method using the 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. 14 is a schematic diagram illustrating an example of a gas detection device including a wavelength variable interference filter.
FIG. 15 is a block diagram showing a configuration of a control system of the gas detection device of FIG.
As shown in FIG. 14, the gas detection device 100 includes a sensor chip 110, a flow path 120 including a suction port 120A, a suction flow path 120B, a discharge flow path 120C, and a discharge port 120D, a main body 130, It is configured with.
The main body unit 130 includes a sensor unit cover 131 having an opening through which the flow channel 120 can be attached, a discharge unit 133, a housing 134, an optical unit 135, a filter 136, a wavelength variable interference filter 5, a light receiving element 137 (detection unit), and the like. , A control unit 138 (processing unit) that processes a detected signal and controls the detection unit, a power supply unit 139 that supplies power, and the like. Instead of the wavelength variable interference filter 5, the wavelength variable interference filters 5A and 5B described above and the optical filter device 600 may be provided. The optical unit 135 emits light, and a beam splitter 135B that reflects light incident from the light source 135A toward the sensor chip 110 and transmits light incident from the sensor chip toward the light receiving element 137. And lenses 135C, 135D, and 135E.
Further, as shown in FIG. 15, an operation panel 140, a display unit 141, a connection unit 142 for interface with the outside, and a power supply unit 139 are provided on the surface of the gas detection device 100. When the power supply unit 139 is a secondary battery, a connection unit 143 for charging may be provided.
Further, as shown in FIG. 15, the control unit 138 of the gas detection apparatus 100 controls a signal processing unit 144 configured by a CPU or the like, a light source driver circuit 145 for controlling the light source 135A, and the variable wavelength interference filter 5. 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, laser light having a single wavelength and stable linear polarization is emitted from the light source 135A. The light source 135A includes a temperature sensor and a light amount sensor, and the information is output to the signal processing unit 144. When the signal processing unit 144 determines that the light source 135A is stably operating based on the temperature and light quantity input from the light source 135A, the signal processing unit 144 controls the discharge driver circuit 150 to operate the discharge unit 133. Thereby, the gas sample containing the target substance (gas molecule) to be detected is guided from the suction port 120A to the suction channel 120B, the sensor chip 110, the discharge channel 120C, and the discharge port 120D. The suction port 120A is provided with a dust removal filter 120A1 to remove relatively large dust, some water vapor, and the like.

The sensor chip 110 is a sensor that incorporates a plurality of metal nanostructures and uses localized surface plasmon resonance. In such a sensor chip 110, an enhanced electric field is formed between the metal nanostructures by the laser light, and when gas molecules enter the enhanced electric field, Raman scattered light and Rayleigh scattered light including information on molecular vibrations are generated. Occur.
These Rayleigh scattered light and Raman scattered light enter the filter 136 through the optical unit 135, and the Rayleigh scattered light is separated by the filter 136, and the Raman scattered light enters the wavelength variable interference filter 5. Then, the signal processing unit 144 outputs a control signal to the voltage control unit 146. Thereby, the voltage control unit 146 drives the electrostatic actuator 56 of the wavelength variable interference filter 5 in the same manner as in the first embodiment, and the Raman scattered light corresponding to the gas molecule to be detected is transmitted to the wavelength variable interference filter 5. Spectate with. Thereafter, when the dispersed light is received by the light receiving element 137, a light reception signal corresponding to the amount of received light is output to the signal processing unit 144 via the light receiving circuit 147. In this case, target Raman scattered light can be extracted from the wavelength variable interference filter 5 with high accuracy.
The signal processing unit 144 compares the spectrum data of the Raman scattered light corresponding to the gas molecule to be detected obtained as described above and the data stored in the ROM, and determines whether or not the target gas molecule is the target gas molecule. To determine the substance. Further, the signal processing unit 144 displays the result information on the display unit 141 or outputs the result information from the connection unit 142 to the outside.

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

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

FIG. 16 is a diagram illustrating a schematic configuration of a food analyzer that is an example of an electronic apparatus using the wavelength variable interference filter 5.
As shown in FIG. 16, the food analysis device 200 includes a detector 210 (optical module), a control unit 220, and a display unit 230. The detector 210 includes a light source 211 that emits light, an 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. Instead of the wavelength variable interference filter 5, the wavelength variable interference filters 5A and 5B described above and the optical filter device 600 may be provided.
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 wavelength variable interference filter 5 is driven by the driving method as shown in the first embodiment under the control of the voltage control unit 222. Thereby, the light of the target wavelength can be extracted from the variable wavelength interference filter 5 with high accuracy. Then, the extracted 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 its content are obtained. Moreover, a food calorie, a freshness, etc. are computable from the obtained food component and content. Furthermore, by analyzing the spectral distribution in the image, it is possible to extract a portion of the food to be inspected that has reduced freshness, and to detect foreign substances contained in the food. Can also be implemented.
Then, the signal processing unit 224 performs processing for causing the display unit 230 to display information such as the components and contents of the food to be examined, the calories, and the freshness obtained as described above.

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

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

Further, the electronic 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. 17 is a schematic diagram showing a schematic configuration of the spectroscopic camera. As shown in FIG. 17, the spectroscopic camera 300 includes a camera body 310, an 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. As shown in FIG. 17, the imaging lens unit 320 includes an objective lens 321, an imaging lens 322, and a wavelength variable interference filter 5 provided between these lenses. Instead of the wavelength variable interference filter 5, the wavelength variable interference filters 5A and 5B described above and the optical filter device 600 may be provided.
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. At this time, for each wavelength, a voltage controller (not shown) drives the wavelength variable interference filter 5 by the driving method of the present invention as shown in the first embodiment, so that a spectral image of the target wavelength can be accurately obtained. Image light can be extracted.

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 is tunable out of light in a predetermined wavelength range emitted from a light emitting element. 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 a plurality of devices, it is possible to promote downsizing of the optical module and the electronic apparatus, and for example, it can be suitably used as a portable or in-vehicle optical device.

  In addition, the specific structure for carrying out the present invention can be appropriately changed to other structures and the like within a range in which the object of the present invention can be achieved.

DESCRIPTION OF SYMBOLS 1 ... Spectrometer (electronic device) 5, 5A, 5B ... Wavelength variable interference filter, 10 ... Optical module, 15 ... Voltage control part, 20 ... Control part, 51 ... Fixed board | substrate (1st board | substrate), 52 ... Movable Substrate (second substrate), 54 ... fixed reflective film (first reflective film), 55 ... movable reflective film (second reflective film), 56 ... electrostatic actuator, 56A ... first electrostatic actuator, 56B ... second static Electric actuator, 57 ... dielectric film, 57A ... first region, 57B ... second region, 100 ... gas detection device (electronic device), 137 ... light receiving element (detection unit), 200 ... food analysis device (electronic device), 213 ... Imaging unit (detection unit), 300 ... Spectral camera (electronic device), 330 ... Imaging unit (detection unit), 400 ... Colorimetry device (electronic device), 430 ... Control unit, 561 ... First electrode, 561D ... First inner electrode, 561 ... first outer electrode, 562 ... second electrode, 562d ... second inner electrode, 562e ... second outer electrode, G1 ... gap, Ar 0 _... optical interference region.

Claims (8)

A first substrate;
A second substrate facing the first substrate;
A first reflective film provided on the first substrate;
A second reflective film provided on the second substrate and facing the first reflective film via a gap;
An electrostatic actuator that is provided outside the light interference region where the first reflective film and the second reflective film overlap in a plan view of the first substrate and the second substrate viewed from the thickness direction of the substrate, and changes the gap. And comprising
The electrostatic actuator includes a first electrode provided on the first substrate, a second electrode provided on the second substrate and opposed to the first electrode through a predetermined gap, and the first electrode A dielectric film provided on a part of the surface of at least one of the electrode and the second electrode, and
In the plan view, among the actuator regions where the first electrode and the second electrode overlap, the first region provided with the dielectric film is provided on the side of the actuator region away from the light interference region. A tunable interference filter characterized by The tunable interference filter according to claim 1,
The wavelength tunable interference filter, wherein the first region and the second region where the dielectric film is not provided are formed with an interval between each other. In the wavelength tunable interference filter according to claim 1 or 2,
The electrostatic actuator is
A first electrostatic actuator that is provided outside the optical interference region and changes the gap in the plan view;
A second electrostatic actuator that is provided outside the first electrostatic actuator in the plan view and is driven independently of the first electrostatic actuator to change the gap;
The first electrostatic actuator includes a first inner electrode provided on the first substrate side and a second inner electrode provided on the second substrate side and facing the first inner electrode with a predetermined gap therebetween. And comprising
The second electrostatic actuator includes a first outer electrode provided on the first substrate side and a second outer electrode provided on the second substrate side and facing the first outer electrode with a predetermined gap therebetween. And a dielectric film provided on a part of the surface of at least one of the first outer electrode and the second outer electrode. A variable wavelength interference filter, comprising: In the wavelength variable interference filter according to any one of claims 1 to 3,
A protective film is formed on the surfaces of the first reflective film and the second reflective film,
The wavelength variable interference filter, wherein the dielectric film and the protective film are made of the same material and the same thickness. In the wavelength variable interference filter according to any one of claims 1 to 4,
The first reflective film and the second reflective film are composed of a dielectric-containing film having the dielectric film,
The variable wavelength interference filter, wherein the dielectric film and the dielectric film of the dielectric-containing film are made of the same material and the same thickness. A first substrate, a second substrate facing the first substrate, a first reflective film provided on the first substrate, provided on the second substrate, and opposed to the first reflective film via a gap In a plan view of the second reflective film and the first substrate and the second substrate viewed from the substrate thickness direction, the second reflective film is provided outside the light interference region where the first reflective film and the second reflective film overlap, A tunable interference filter with an electrostatic actuator to change the gap;
A housing that houses the wavelength tunable interference filter;
The electrostatic actuator includes a first electrode provided on the first substrate, a second electrode provided on the second substrate and opposed to the first electrode through a predetermined gap, and the first electrode A dielectric film provided on a part of the surface of at least one of the electrode and the second electrode, and
In the plan view, among the actuator regions where the first electrode and the second electrode overlap, the first region provided with the dielectric film is provided on the side of the actuator region away from the light interference region. An optical filter device characterized by comprising: A first substrate;
A second substrate facing the first substrate;
A first reflective film provided on the first substrate;
A second reflective film provided on the second substrate and facing the first reflective film via a gap;
An electrostatic actuator that is provided outside the light interference region where the first reflective film and the second reflective film overlap in a plan view of the first substrate and the second substrate viewed from the thickness direction of the substrate, and changes the gap. When,
A detector that detects light extracted by the first reflective film and the second reflective film;
The electrostatic actuator includes a first electrode provided on the first substrate, a second electrode provided on the second substrate and opposed to the first electrode through a predetermined gap, and the first electrode A dielectric film provided on a part of the surface of at least one of the electrode and the second electrode, and
In the plan view, among the actuator regions where the first electrode and the second electrode overlap, the first region provided with the dielectric film is provided on the side of the actuator region away from the light interference region. An optical module characterized by that. A first substrate;
A second substrate facing the first substrate;
A first reflective film provided on the first substrate;
A second reflective film provided on the second substrate and facing the first reflective film via a gap;
An electrostatic actuator that is provided outside the light interference region where the first reflective film and the second reflective film overlap in a plan view of the first substrate and the second substrate viewed from the thickness direction of the substrate, and changes the gap. A tunable interference filter comprising:
A control unit for controlling the wavelength variable interference filter,
The electrostatic actuator includes a first electrode provided on the first substrate, a second electrode provided on the second substrate and opposed to the first electrode through a predetermined gap, and the first electrode A dielectric film provided on a part of the surface of at least one of the electrode and the second electrode, and
In the plan view, among the actuator regions where the first electrode and the second electrode overlap, the first region provided with the dielectric film is provided on the side of the actuator region away from the light interference region. An electronic device characterized by