JP2014182323A - Interference filter, optical filter device, optical module, and electronic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an interference filter capable of reducing an influence of external static electricity, and to provide an optical filter device, an optical module, and electronic equipment.SOLUTION: A variable wavelength interference filter 5 includes; a fixed reflective film 54 which reflects a part of incident light and transmits a part thereof; a movable reflective film 55 which is arranged oppositely to the fixed reflective film 54, reflects a part of the incident light, and transmits a part thereof; a first transparent electrode 515 which is disposed on a side of the fixed reflective film 54 opposite to the movable reflective film 55; and a second transparent electrode 525 which is disposed on a side of the movable reflective film 55 opposite to the fixed reflective film 54. The first transparent electrode 515 is disposed in an area which is coincident with an area of the fixed reflective film 54 and the second transparent electrode 525 is disposed in an area which is coincident with an area of the movable reflective film 55, in a plan view, and the first transparent electrode 515 and the second transparent electrode 525 have the same electrical potential.

Description

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

  Conventionally, a spectral filter that acquires light of a specific wavelength from incident light by reflecting light between a pair of reflection mirrors, transmitting light of a specific wavelength, and canceling light of other wavelengths by interference is known. ing. As such a spectral filter, there is known an interference filter capable of selecting light to be emitted by adjusting a distance between mirrors (see, for example, Patent Document 1).

  The interference filter described in Patent Document 1 includes a fixed mirror structure having a fixed mirror, and a movable mirror structure having a movable mirror disposed on the fixed mirror structure via a support member. The part that bridges the air gap of the movable mirror structure is a displaceable membrane, and a voltage is applied between the electrode provided on the fixed mirror structure and the electrode provided on the movable mirror structure. Then, the membrane is bent by applying the electrostatic attractive force. As a result, the facing distance of the mirror changes, and light having a wavelength corresponding to the facing distance can be transmitted.

JP 2012-112777 A

  By the way, in the interference filter as described above, when static electricity is applied from the outside or when the interference filter is disposed in the electric field, charges may be accumulated in the reflective film (fixed mirror and movable mirror). Since the reflecting film is electrically floating, there is no escape space for the accumulated charges, and the gap size (opposite distance) between the reflecting films may fluctuate due to electrostatic force. There is a problem that it affects the accuracy when changing the dimensions.

  An object of the present invention is to provide an interference filter, an optical filter device, an optical module, and an electronic apparatus that can reduce the influence of external static electricity and an electric field.

The interference filter of the present invention reflects a part of incident light and reflects at least part of the first reflective film, and faces the first reflective film, reflects part of incident light and transmits at least part of it. A second transparent film, a first transparent electrode provided at a distance from a surface of the first reflective film opposite to the surface facing the second reflective film, and the second reflective film; A second transparent electrode provided at a distance from a surface opposite to the surface facing the first reflective film; and in a plan view as viewed from the film thickness direction of the first reflective film The first transparent electrode is provided in a region at least coincident with the region of the first reflective film, and the second transparent electrode is the second reflective film in a plan view as viewed from the film thickness direction of the second reflective film. Provided in a region at least coincident with the first transparent electrode and the second transparent electrode. Transparent electrode is characterized in that it is at the same potential.
Here, a connection portion for connecting the first transparent electrode and the second transparent electrode may be provided in the interference filter, and a circuit connected to the first transparent electrode and the second transparent electrode is provided outside the interference filter. By providing it, the same potential may be used.

In the present invention, the first transparent electrode and the second transparent electrode are provided at positions overlapping at least the first reflective film and the second reflective film in plan view. The first transparent electrode and the second transparent electrode are at the same potential. For this reason, even when static electricity is applied, static electricity does not reach from the first transparent electrode and the second transparent electrode to the first reflective film and the second reflective film, and the first reflective film and the second reflective film are charged. Can be suppressed. Moreover, even when an electric field is applied, such as when an interference filter is disposed in an electric field, the transparent electrode functions as an electric field shield, and the electric polarization of the reflective film due to the influence of the electric field can be suppressed. Therefore, charging to the first reflective film and the second reflective film can be suppressed.
Furthermore, since the first transparent electrode and the second transparent electrode are maintained at the same potential, even if static electricity is applied to the first transparent electrode and the second transparent electrode, for example, electrostatic force due to static electricity is generated between these transparent electrodes. It does not act, and the fluctuation of the gap dimension between the reflective films can be suppressed.

In the interference filter according to the aspect of the invention, it is preferable that the first transparent electrode and the second transparent electrode have a ground potential.
In the present invention, the first transparent electrode and the second transparent electrode are maintained at the ground potential. That is, the first transparent electrode and the second transparent electrode are grounded, and even if static electricity is input, they can be immediately released, and charging of the first reflective film and the second reflective film due to static electricity can be suppressed more reliably.

  The interference filter of the present invention comprises a first substrate provided with the first reflective film and a second substrate provided with the second reflective film, wherein the first transparent electrode is formed on the first substrate. The second transparent electrode is provided on a surface opposite to the surface on which the second reflective film is provided on the second substrate. It is preferable that

In the present invention, the first transparent electrode is provided on the surface of the first substrate opposite to the surface on which the first reflective film is provided, and the surface on the opposite side of the surface of the second substrate on which the second reflective film is provided. A second transparent electrode is provided. Here, in this invention, the 1st board | substrate and the 2nd board | substrate are formed with glass etc., and have insulation.
In the present invention, the first transparent electrode and the second transparent electrode are configured to be provided on the outer peripheral surface of the interference filter, so that static electricity applied from the outside can flow more reliably to the transparent electrode. Can be more reliably suppressed. In addition, even when an electric field is applied to the interference filter, the first transparent electrode and the second transparent electrode function as a shield, so that the influence of the electric field on the reflective film is reduced.
Furthermore, an insulating substrate (first substrate, second substrate) is provided between each reflective film (first reflective film, second reflective film) and each transparent electrode (first transparent electrode, second transparent electrode). Thus, the reflective film can be used as an electrode. As described above, since the influence of static electricity and electric field can be suppressed, voltage control of the reflective film (for example, when the reflective film is used as a capacitance detection electrode, capacitive detection control, and when used as a drive electrode, drive control) is easy. It becomes.

In the interference filter of the present invention, the first reflective film is provided on the first transparent electrode via a first insulating member, and the second reflective film is provided on the second transparent electrode via a second insulating member. It is preferable to be provided.
In the present invention, the first reflective film is provided on the first transparent electrode via the first insulating member, and the second reflective film is provided on the second transparent electrode via the second insulating member. Even in such a configuration, similarly to the above-described invention, when the interference filter is disposed in the electric field, the electric polarization of the reflective film can be suppressed by causing the transparent electrode to function as an electric field shield.
Moreover, between each reflective film (1st reflective film, 2nd reflective film) and each transparent electrode (1st transparent electrode, 2nd transparent electrode), it is an insulating member (1st insulating member, 2nd insulating property). Member), the reflective film can also be used as an electrode. As described above, since the influence of static electricity and electric field can be suppressed, voltage control of the reflective film (for example, when the reflective film is used as a capacitance detection electrode, capacitive detection control, and when used as a drive electrode, drive control) is easy. It becomes.
Further, when the first reflective film and the second reflective film are conductive films, the first reflective film and the second reflective film, the first transparent electrode and the first reflective film, and the second transparent electrode and the second reflective film Each membrane will be configured as a capacitor. Therefore, even when static electricity that causes a potential difference between the first transparent electrode and the second transparent electrode is applied, the first transparent electrode and the second transparent electrode have the same potential, and the potential difference between the reflective films Generation | occurrence | production can be suppressed and the problem that an electrostatic force acts between reflection films can be suppressed.

In the interference filter of the present invention, the first reflection film and the second reflection film have conductivity, and the interference filter includes a first mirror electrode connected to the first reflection film, and the second reflection film. And a second mirror electrode connected to the first electrode.
In the present invention, by connecting mirror electrodes (first mirror electrode, second mirror electrode) to the reflection film, each reflection film is detected between, for example, a capacitance detection electrode for detecting the capacitance between the reflection films, or between the reflection films. By applying a voltage, it can function as a drive electrode or the like that is driven by applying an electrostatic attractive force. At this time, as described above, the insulating member is interposed between the reflective film and the transparent electrode, and the first transparent electrode and the second transparent electrode have the same potential. Therefore, when instantaneous static electricity is applied, the reflective film functions to have the same potential, and generation of electrostatic force between the reflective films can be suppressed. Furthermore, when the first reflective film and the second reflective film function as electrodes, a rapid current change can be suppressed, noise components can be removed, and the reflective film can appropriately function as an electrode.

In the interference filter according to the aspect of the invention, a gap changing unit that changes a gap size between the first reflecting film and the second reflecting film is provided.
In the present invention, since a gap changing unit that changes the gap size between the reflective films is provided, light of a desired wavelength can be emitted from the interference filter by controlling the gap size. In addition, when the gap between the reflection films is controlled, if the reflection film is charged, the accuracy of the gap control at the gap changing unit is reduced by the electrostatic force generated between the reflection films. On the other hand, in the present invention, as described above, charging and electrical polarization of each reflective film are suppressed by each transparent electrode, so that the accuracy of gap control can be improved.

The optical filter device of the present invention is arranged so as to reflect a part of incident light and to transmit at least part of the first reflection film, facing the first reflection film, and reflects part of incident light and reflects at least part of it. A second transparent film that transmits the first transparent electrode, a first transparent electrode that is spaced from a surface of the first reflective film opposite to the surface facing the second reflective film, and the second reflective film An interference filter having a second transparent electrode spaced from a surface opposite to the surface facing the first reflective film in the film; and a housing for storing the interference filter. In the plan view as seen from the film thickness direction of the first reflective film, the first transparent electrode is provided in an area at least coincident with the area of the first reflective film, and seen from the film thickness direction of the second reflective film. In the plan view, the second transparent electrode is Provided in a region at least matches the area of the membrane, the first transparent electrode and the second transparent electrode, characterized in that it is at the same potential.
In the present invention, as described above, the influence of static electricity or electric field can be suppressed in the interference filter. In addition, by housing such an interference filter in the housing, it is possible to prevent intrusion of a charged substance or the like and further suppress charging to the reflective film.

  The optical module of the present invention is arranged to face the first reflective film, a first reflective film that reflects part of incident light and transmits at least part, and reflects at least part of incident light. A second transparent film that transmits, a first transparent electrode that is spaced from a surface of the first reflective film opposite to the surface facing the second reflective film, and the second reflective film An interference filter having a second transparent electrode provided at a distance from a surface opposite to the surface facing the first reflective film, and a light receiving unit for receiving light emitted from the interference filter The first transparent electrode is provided in a region at least coincident with the region of the first reflective film in a plan view as viewed from the film thickness direction of the first reflective film, and the film of the second reflective film In the plan view seen from the thickness direction, the second transparent electrode is Serial provided in a region with at least a matching area of the second reflecting film, the first transparent electrode and the second transparent electrode, characterized in that it is at the same potential.

  In the present invention, as described above, the influence of static electricity or electric field can be suppressed in the interference filter. Accordingly, there is no change in the gap size between the reflecting films due to these influences, and the drive control of the interference filter is not hindered, so that light having a desired wavelength can be detected with high accuracy by the light receiving unit.

In the optical module according to the aspect of the invention, it is preferable that the optical module includes a potential control unit that makes the first transparent electrode and the second transparent electrode have the same potential.
In the present invention, since the potentials of the first transparent electrode and the second transparent electrode are set to the same potential by the potential control unit, no electrostatic force is generated between the transparent electrodes. Therefore, the gap dimension between the reflective films can be appropriately set, and light having a desired wavelength can be received by the light receiving unit.

In the optical module according to the aspect of the invention, it is preferable that the potential control unit sets the first transparent electrode and the second transparent electrode to a ground potential.
In the present invention, the transparent electrode is at ground potential, and even when static electricity is applied, it can be released immediately. Therefore, charging of the first reflective film and the second reflective film can be prevented.

  In the optical module of the present invention, the first reflective film is provided on the first transparent electrode via a first insulating member, and the second reflective film is provided on the second transparent electrode via a second insulating member. A first mirror electrode connected to the first reflective film and insulated from the first transparent electrode; and connected to the second reflective film; and the first transparent electrode. It is preferable that a second mirror electrode insulated from the second mirror electrode is provided, and the optical module includes a mirror control unit that controls the first mirror electrode and the second mirror electrode.

  In the present invention, even if there is a sudden current change in the mirror control unit, the first reflective film and the first transparent electrode, the second reflective film and the second transparent electrode act as a capacitor, respectively, and the influence of the current change is affected. Can be suppressed. Therefore, it is possible to reduce noise generated by a sudden large current flowing through the first reflective film and the second reflective film. As a result, the drive by the reflective film can be controlled with high accuracy. For example, when the reflective film functions as an electrode for electrostatic capacitance detection, accurate capacitance detection with reduced influence of noise components can be performed. When the reflective film functions as a drive electrode, the gap size between the reflective films due to the noise component High-accuracy drive control that suppresses fluctuations of the above becomes possible.

The electronic device of the present invention is arranged to face the first reflective film, a first reflective film that reflects part of incident light and transmits at least part, and reflects at least part of incident light. A second transparent film that transmits, a first transparent electrode that is spaced from a surface of the first reflective film opposite to the surface facing the second reflective film, and the second reflective film An interference filter having a second transparent electrode provided at a distance from a surface opposite to the surface facing the first reflective film, and a control unit for controlling the interference filter. In a plan view seen from the film thickness direction of the first reflective film, the first transparent electrode is provided in an area at least coincident with the area of the first reflective film, and seen from the film thickness direction of the second reflective film. In plan view, the second transparent electrode has a region of the second reflective film. Provided in a region that matches even without, the first transparent electrode and the second transparent electrode, characterized in that it is at the same potential.
In the present invention, as described above, the influence of static electricity or electric field can be suppressed in the interference filter. Accordingly, there is no change in the gap size between the reflecting films due to these effects, and the interference filter drive control is not hindered, so that light of a desired wavelength can be emitted from the interference filter with high accuracy.

The block diagram which shows schematic structure of the spectrometer of 1st embodiment which concerns on this invention. The top view which shows schematic structure of the wavelength variable interference filter of 1st embodiment. Sectional drawing when the wavelength variable interference filter of FIG. 2 is sectioned along the line AA ′. Sectional drawing which shows schematic structure of the wavelength variable interference filter in the modification of 1st embodiment. Sectional drawing which shows schematic structure of the wavelength variable interference filter of 2nd embodiment. Sectional drawing which shows schematic structure of the optical filter device of 3rd embodiment. 1 is a diagram illustrating a schematic configuration of a color measurement device that is an example of an electronic apparatus according to the invention. The figure which shows schematic structure of the gas detection apparatus which is an example of the electronic device 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 analyzer which is an example of the electronic device of this invention. Schematic diagram showing a schematic configuration of a spectroscopic camera which is an example of the electronic apparatus of the present 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 the spectrometer according to the first embodiment of the present invention.
The spectroscopic measurement device 1 is an example of the electronic apparatus of the present invention, and is a device that analyzes the light intensity of each wavelength in the measurement target light reflected by the measurement target X and measures the spectral spectrum. In this embodiment, an example of measuring the measurement target light reflected by the measurement target X is shown. However, when a light emitter such as a liquid crystal panel is used as the measurement target X, the light emitted from the light emitter is measured. The target light may be used.
As shown in FIG. 1, the 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 detector 11, an IV converter 12, an amplifier 13, an A / D converter 14, and a filter drive circuit 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 detector 11. . The detection signal output from the detector 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]
The wavelength variable interference filter 5 of the optical module 10 will be described below. FIG. 2 is a plan view showing a schematic configuration of the variable wavelength interference filter 5. FIG. 3 is a cross-sectional view of the tunable interference filter of FIG. 2 taken along line AA ′.
As shown in FIGS. 2 and 3, the variable wavelength interference filter 5 is a rectangular plate-like optical member, for example, and includes a fixed substrate 51 (first substrate) and a movable substrate 52 (second substrate). Each of the fixed substrate 51 and the movable substrate 52 is formed of an insulating material such as various types of glass or quartz, and is bonded by a bonding film 53 (see FIG. 3) formed of, for example, a plasma polymerization film mainly containing siloxane. By doing so, it is configured integrally. That is, in this embodiment, the fixed substrate 51 constitutes the first insulating member in the present invention, and the movable substrate 52 constitutes the second insulating member in the present invention.

The fixed substrate 51 is provided with a fixed reflective film 54 constituting the first reflective film of the present invention, and the movable substrate 52 is provided with a movable reflective film 55 constituting the second reflective film of the present invention. The fixed reflection film 54 and the movable reflection film 55 are arranged to face each other via a gap G1 (see FIG. 3).
The fixed substrate 51 is provided with a fixed electrode 561, and the movable substrate 52 is provided with a movable electrode 562. The fixed electrode 561 and the movable electrode 562 are arranged to face each other with a predetermined gap. These fixed electrode 561 and movable electrode 562 constitute an electrostatic actuator 56 which is an example of a gap changing unit of the present invention.
In the following description, the wavelength tunable interference filter 5 was seen from a plan view seen from the thickness direction of the fixed substrate 51 or the movable substrate 52, that is, from the stacking direction of the fixed substrate 51, the bonding film 53, and the movable substrate 52. The plan view is referred to as a filter 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 has a thickness dimension larger than that of the movable substrate 52, and the electrostatic attraction by the electrostatic actuator 56 and 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 FIG. 3, the fixed substrate 51 includes an electrode arrangement groove 511 and a reflection film installation part 512 formed by, for example, etching. Moreover, one end side (side C1-C2 in FIG. 2) of the fixed substrate 51 protrudes outward from the substrate edge (side C5-C6 in FIG. 2) of the movable substrate 52, and the first terminal extraction portion 514 is formed. It is composed.

The electrode arrangement groove 511 is formed in an annular shape centering on the filter center point O of the fixed substrate 51 in the filter plan view. The reflection film installation part 512 is formed so as to protrude from the center part of the electrode arrangement groove 511 toward the movable substrate 52 in the filter plan view. The groove bottom surface of the electrode arrangement groove 511 serves as an electrode installation surface 511A on which the fixed electrode 561 of the electrostatic actuator 56 is arranged. In addition, the protruding front end surface of the reflection film installation portion 512 is a reflection film installation surface 512A.
The fixed substrate 51 is provided with an electrode lead groove (not shown) extending from the electrode placement groove 511 toward the outer peripheral edge of the fixed substrate 51.

A fixed electrode 561 constituting the electrostatic actuator 56 is provided on the electrode installation surface 511 </ b> A of the electrode arrangement groove 511. The fixed electrode 561 is provided in a region of the electrode installation surface 511 </ b> A that faces a movable portion 521 described later. The fixed electrode 561 is formed, for example, in an arc shape (substantially C shape), and as shown in FIG. 2, 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 movable electrode 562 and the fixed electrode 561 may be stacked.
The fixed electrode 561 includes a fixed extraction electrode 561A extending to the first terminal extraction portion 514 along the electrode extraction groove. The extended leading end portion of the fixed extraction electrode 561A is connected to the filter drive circuit 15 by, for example, an FPC (Flexible printed circuits) or a lead wire.

  The fixed reflective film 54 is installed on the reflective film installation surface 512A of the reflective film installation unit 512 as described above. As the fixed reflection film 54, a conductive reflection film material such as a metal film such as Ag or an Ag alloy can be used, for example, and deterioration due to oxidation or the like can be suppressed, and from the visible light region to the near infrared region. It is more preferable to use an Ag alloy film having high reflection characteristics with respect to a wide wavelength band over the light region.

As the fixed reflective film 54, for example, a dielectric multilayer film in which the high refractive layer is TiO ₂ and the low refractive layer is SiO ₂ may be used. In the case where a dielectric multilayer film is used as the fixed reflective film 54, conductivity can be imparted by laminating a conductive film on the lowermost layer or the uppermost layer (surface layer) of the dielectric multilayer film.
In addition, you may use reflective films, such as Ag alloy which has a high reflectance characteristic with respect to a wide wavelength range, for example as a conductive film. In this case, the conductive film can widen the wavelength range to be measured of the wavelength tunable interference filter 5, it is possible to take out a desired target wavelength with respect to a wide wavelength band, and the dielectric multilayer film increases the wavelength. It becomes possible to extract light of a target wavelength with resolution. In this case, a transparent adhesive layer may be further interposed between the conductive film and the reflective film installation portion 512 and between the conductive film and the dielectric multilayer film in order to improve adhesion.

As shown in FIG. 2, the fixed substrate 51 is connected to the outer peripheral edge of the fixed reflection film 54, passes through the C-shaped opening of the fixed electrode 561, and extends toward the first terminal extraction portion 514. One mirror electrode 541 is provided. The first mirror electrode 541 is formed by being formed simultaneously with the formation of the fixed reflective film 54.
The first mirror electrode 541 is connected to the filter drive circuit 15 on the first terminal extraction portion 514.

  In the fixed substrate 51, the electrode placement groove 511, the reflection film installation portion 512, and the region where the electrode lead-out groove is not formed constitutes 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.

A first transparent electrode 515 is provided on the surface of the fixed substrate 51 that does not face the movable substrate 52. The first transparent electrode 515 is formed of a material having translucency with respect to light having a wavelength to be measured in the spectrometer 1 of the present embodiment. For example, a near infrared light region is measured from visible light. In the case of the target wavelength, ITO (Indium Tin Oxide) or the like can be used.
The first transparent electrode 515 is connected to the filter drive circuit 15 and is set to the ground potential by the filter drive circuit 15.

(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, And a second joint portion 523 provided outside the holding portion 522.
Further, as shown in FIG. 2, one end side (side C <b> 7-C <b> 8 in FIG. 2) of the movable substrate 52 projects outward from the substrate edge (side C <b> 3-C <b> 4 in FIG. 2) of the fixed substrate 51. The second terminal extraction part 524 is configured.

  The movable part 521 is formed to have a thickness dimension larger than that of the holding part 522. For example, in this embodiment, the movable part 521 is formed to have the same dimension as the thickness dimension of the movable substrate 52. The movable portion 521 is formed to have a diameter larger than at least the diameter of the outer peripheral edge of the reflection film installation surface 512A in the filter plan view. A movable reflective film 55 and a movable electrode 562 are provided on the movable surface 521A of the movable portion 521 facing the fixed substrate 51.

The movable electrode 562 is provided on the outer peripheral side of the movable reflective film 55 in the plan view of the filter, and is disposed to face the fixed electrode 561 with a gap. The movable electrode 562 is formed in an arc shape (substantially C shape), and as shown in FIG. 2, a C-shaped opening is provided in a part near the sides C7-C8. Similarly to the fixed electrode 561, an insulating film may be stacked over the movable electrode 562.
Here, as shown in FIG. 2, in the filter plan view, the electrostatic actuator 56 is configured by an arc region where the movable electrode 562 and the fixed electrode 561 overlap (region indicated by a hatched portion rising to the right in FIG. 2). Yes. As shown in FIG. 2, the electrostatic actuator 56 has a shape and an arrangement that are symmetrical with respect to the filter center point O in the plan view of the filter. Therefore, the electrostatic attractive force generated when a voltage is applied to the electrostatic actuator 56 also acts on a position that is point-symmetric with respect to the filter center point O, and displaces the movable portion 521 toward the fixed substrate 51 in a balanced manner. Is possible.

  As shown in FIG. 2, the movable electrode 562 is provided with a movable extraction electrode 562 </ b> A that extends toward the second terminal extraction portion 524. The movable extraction electrode 562A is disposed along a position facing an electrode extraction groove provided on the fixed substrate 51. Further, the extending tip of the movable extraction electrode 562A is connected to the filter drive circuit 15 by, for example, an FPC or a lead wire.

The movable reflective film 55 is provided at the center of the movable surface 521A of the movable part 521 so as to face the fixed reflective film 54 with the gap G1 between the reflective films. As the movable reflective film 55, a reflective film having the same configuration as that of the fixed reflective film 54 described above is used. In the present embodiment, the fixed electrode 561 is provided on the electrode installation surface 511A, and the fixed reflection film 54 is provided on the reflection film installation surface 512A located on the movable substrate 52 side with respect to the electrode installation surface 511A. G1 is smaller than the gap between the electrodes 561 and 562.
As shown in FIG. 2, the movable substrate 52 is connected to the outer peripheral edge of the movable reflective film 55, passes through the C-shaped opening of the movable electrode 562, and extends toward the second terminal extraction portion 524. Two mirror electrodes 551 are provided.
In the case where the movable reflective film 55 is composed of a laminate of a dielectric multilayer film and a conductive film, the second mirror electrode 551 is formed at the same time as the conductive film and is connected to the conductive film.
The second mirror electrode 551 is connected to the filter driving circuit 15 on the second terminal extraction portion 524 by, for example, an FPC or a lead wire.

  In the present embodiment, as shown in FIG. 3, an example in which the gap between the electrodes 561 and 562 is larger than the gap G1 is shown, but the present invention is not limited to this. For example, the gap G1 may be configured to be larger than the gap between the electrodes 561 and 562 depending on the measurement target wavelength range, such as when infrared light is used as the measurement target light.

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

  As described above, the second bonding portion 523 is provided outside the holding portion 522 in the filter plan view. A region facing the fixed substrate 51 of the second bonding portion 523 and a region facing the first bonding portion 513 are bonded to the first bonding portion 513 through the bonding film 53.

A second transparent electrode 525 is provided on the surface of the movable substrate 52 that does not face the fixed substrate 51. The second transparent electrode 525 is formed of a material having translucency with respect to the light having the wavelength to be measured in the spectroscopic measurement apparatus 1, similarly to the first transparent electrode 515. For example, ITO or the like is used. it can.
The second transparent electrode 525 is connected to the filter drive circuit 15 and is grounded by the filter drive circuit 15 in the same manner as the first transparent electrode 515. That is, the first transparent electrode 515 and the second transparent electrode 525 are both at ground potential (same potential).

[Configuration of optical module detector, IV converter, amplifier, A / D converter]
Next, returning to FIG. 1, the optical module 10 will be described.
The detector 11 receives (detects) the light transmitted through the wavelength variable interference filter 5 and outputs a detection signal based on the amount of received light to the IV converter 12.
The IV converter 12 converts the detection signal input from the detector 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.

[Configuration of filter drive circuit]
As shown in FIG. 1, the filter drive circuit 15 includes a voltage control unit 151, a capacitance detection unit 152, and a ground electrode 153.
The voltage control unit 151 is connected to the fixed extraction electrode 561 </ b> A and the movable extraction electrode 562 </ b> A, and applies a drive voltage to the electrostatic actuator 56 under the control of the control unit 20.
The capacitance detection unit 152 corresponds to the mirror control unit of the present invention, is connected to the first mirror electrode 541 and the second mirror electrode 551, and detects the capacitance between the reflection films 54 and 55, that is, the dimension of the gap G1. Is detected.
The ground electrode 153 is connected to the first transparent electrode 515 and the second transparent electrode 525, and grounds the transparent electrodes 515 and 525.

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

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

[Operational effects of the first embodiment]
In this embodiment, in the variable wavelength interference filter 5, the first transparent electrode 515 is provided on the surface of the fixed substrate 51 that does not face the movable substrate 52, and the first transparent electrode 515 is provided on the surface of the movable substrate 52 that does not face the fixed substrate 51. Two transparent electrodes 525 are provided. For this reason, even when an electric field is applied to the wavelength tunable interference filter 5 from the outside, the electric field shielding effect of the first transparent electrode 515 and the second transparent electrode 525 suppresses the electric field from flowing to the reflection films 54 and 55, thereby reflecting Charging in the films 54 and 55 can be suppressed.
In the present embodiment, the first transparent electrode 515 and the second transparent electrode 525 are connected to the ground electrode 153 and have a ground potential. Therefore, even when static electricity is applied from the outside, it can immediately flow to the ground electrode 153, and the inconvenience of static electricity flowing around the reflection films 54 and 55 can be suppressed.
As described above, charging of the reflection films 54 and 55 can be suppressed by static electricity or an electric field, and generation of electrostatic force between the reflection films 54 and 55 can be suppressed. As a result, when the drive voltage is applied to the electrostatic actuator 56 by the voltage controller 151, the gap G1 can be accurately set to a dimension corresponding to the desired target wavelength, and the amount of light corresponding to the target wavelength is appropriately measured. it can. Thereby, the spectrum with respect to the measuring object X can be measured with high accuracy.

In the present embodiment, the first mirror electrode 541 is connected to the fixed reflective film 54, the second mirror electrode 551 is connected to the movable reflective film 55, and the first mirror electrode 541 and the second mirror electrode 551 are connected to the capacitance detection unit. 152 is connected.
When the first mirror electrode 541 and the second mirror electrode 551 are grounded in order to prevent the reflection films 54 and 55 from being charged, an additional capacitance detection electrode is required to detect the dimension of the gap G1. It becomes. In this case, since the capacitance detection amount electrode is disposed at a position away from the reflection films 54 and 55, there is a possibility that the accurate dimension of the gap G1 cannot be detected. On the other hand, in this embodiment, since the dimension of the gap G1 between the reflective films 54 and 55 can be directly detected, and charging can be prevented in each of the reflective films 54 and 55 as described above, the gap detection accuracy can be improved. Can be improved.

In the present embodiment, the dimension of the gap G1 can be set to a desired value by the electrostatic actuator 56. For this reason, by sequentially changing the size of the gap G1, it is possible to sequentially detect the amount of light for a plurality of target wavelengths in the measurement wavelength range, and the spectral spectrum can be easily measured by the single wavelength variable interference filter 5. it can.
Further, when the size of the gap G1 is changed by the electrostatic actuator 56, if the reflection films 54 and 55 are charged, the accuracy of the gap control is lowered by the electrostatic force. Since the charging of the reflection films 54 and 55 can be suppressed, the accuracy of gap control can be improved.

[Modification of First Embodiment]
In the first embodiment described above, the first transparent electrode 515 is provided on the entire surface of the fixed substrate 51 not facing the movable substrate 52, and the second transparent electrode 525 is opposed to the fixed substrate 51 of the movable substrate 52. The example provided on the entire surface that is not present is shown.
On the other hand, it is good also as a structure as shown in FIG. FIG. 4 is a cross-sectional view showing a schematic configuration of a variable wavelength interference filter according to a modification of the first embodiment.
That is, the first transparent electrode 515 is provided in a region of the fixed substrate 51 that overlaps with the fixed reflective film 54 (light interference region Ar1) in the filter plan view, and the second transparent electrode 525 is included in the movable substrate 52. The filter is provided in a region (light interference region Ar1) overlapping with the movable reflective film 55 in plan view.

Even in such a configuration, similarly to the first embodiment, static electricity applied from the outside of the wavelength tunable interference filter 5 can be immediately released to the ground electrode 153, so that the static electricity is transmitted to the reflection films 54 and 55. The inconvenience of wrapping around and charging can be suppressed, and electrostatic force due to static electricity is not generated between the reflective films 54 and 55. Therefore, when controlling the gap G1, the gap G1 can be accurately set to a desired dimension with respect to the drive voltage applied to the electrostatic actuator 56.
Even when the wavelength tunable interference filter 5 is disposed in the electric field, the first transparent electrode 515 and the second transparent electrode 525 function as a shield, and the reflection films 54 and 55 are electrically polarized by the influence of the electric field. Can also be suppressed.
Further, since the second transparent electrode 525 is not disposed in the holding portion 522 that is most easily bent in the movable substrate 52, the bending of the holding portion 522 due to film stress can be reduced.

[Second Embodiment]
Next, a second embodiment according to the present invention will be described with reference to the drawings.
In the first embodiment described above, the first transparent electrode 515 is provided on the surface of the fixed substrate 51 not facing the movable substrate 52, and the second transparent electrode 525 is the surface of the movable substrate 52 not facing the fixed substrate 51. The example provided in is shown. On the other hand, in the present embodiment, the first transparent electrode 515 is provided on the surface of the fixed substrate 51 facing the movable substrate 52, and the second transparent electrode 525 is provided on the surface of the movable substrate 52 facing the fixed substrate 51. This is different from the first embodiment.

FIG. 5 is a cross-sectional view illustrating a schematic configuration of a wavelength tunable interference filter according to the second embodiment. In addition, about the structure similar to said 1st embodiment, while attaching | subjecting a same sign, the description is abbreviate | omitted or simplified.
As shown in FIG. 5, in the variable wavelength interference filter 5A of the present embodiment, a first transparent electrode 515A is provided on the reflective film installation surface 512A of the fixed substrate 51, and the first insulating member is provided on the first transparent electrode 515A. A fixed reflective film 54 is disposed via 516.
Similarly, a second transparent electrode 525A is provided on the movable substrate 52, and the movable reflective film 55 is disposed on the second transparent electrode 525A via a second insulating member 526.
The first transparent electrode 515A and the second transparent electrode 525A may be arranged on the substrates 51 and 52 via other layers.
In addition, an extraction electrode (not shown) is connected to the first transparent electrode 515 </ b> A, and this extraction electrode is extracted to the first terminal extraction portion 514 at a position where it does not contact the first mirror electrode 541. For example, it is arranged in parallel with the first mirror electrode, and is drawn out to the first terminal extraction portion 514 through the C-shaped opening of the fixed electrode 561.
Similarly, an extraction electrode (not shown) is also connected to the second transparent electrode 525 </ b> A, and this extraction electrode is extracted to the second terminal extraction portion 524 at a position where it does not contact the second mirror electrode 551.
These transparent electrodes 515A and 525A are connected to the ground electrode 153 and have a ground potential, as in the first embodiment.

In the present embodiment, the first insulating member 516 and the second insulating member 526 are made of a film material, and the fixed reflective film 54 and the first transparent electrode 515A, and the movable reflective film 55 and the second transparent electrode 525A. Both function as a large-capacity capacitor. At this time, in order to increase the capacity of the capacitor, it is preferable to use a material having a relative dielectric constant higher than that of SiO ₂ which is a material of the substrates 51 and 52 for the first insulating member 516 and the second insulating member 526. As such a material, for example, a high-k film material such as Al ₂ O ₃ or HfO ₂ can be used.
In such a configuration, the fixed reflective film 54 and the first transparent electrode 515A, the movable reflective film 55 and the second transparent electrode 525A each function as a capacitor, and the capacity detection accuracy in the capacity detection unit 152 can be improved. . In the present embodiment, the total capacity of each capacitor constituted by the fixed reflective film 54 and the movable reflective film 55, the fixed reflective film 54 and the first transparent electrode 515A, and the movable reflective film 55 and the second transparent electrode 525A, respectively. Detected. Therefore, when detecting the size of the gap G1, the capacitor of the fixed value composed of the fixed reflective film 54 and the first transparent electrode 515A, the movable reflective film 55 and the second transparent electrode 525A is calculated from the total capacity. Subtract capacity.

[Operational effects of the second embodiment]
In the present embodiment, similarly to the above-described invention, it is possible to reduce the inconvenience that the reflecting films 54 and 55 are charged by the electric field shielding effect by the first transparent electrode 515A and the second transparent electrode 525A.

In the present embodiment, the fixed reflection film 54 and the movable reflection film 55 are caused to function as capacitance detection electrodes. At this time, the fixed reflective film 54, the first transparent electrode 515A, the movable reflective film 55, and the second transparent electrode 525A constitute capacitors, respectively, and the first transparent electrode 515A and the second transparent electrode 525A are connected to the filter drive circuit 15. The same potential is connected to the ground electrode 153. Therefore, for example, even when momentary static electricity is applied to the mirror electrodes 541 and 551, the reflective films 54 and 55 function to have the same potential, and generation of electrostatic force between the reflective films can be suppressed.
Furthermore, since it is possible to avoid the inconvenience that a large current flows from the capacitance detection unit 152 to the reflection films 54 and 55, the capacitance detection unit 152 can exclude noise components and accurately detect the capacitance (dimension of the gap G1). can do.
Further, since the high-k material having a high relative dielectric constant is used as the insulating members 516 and 526, the capacity of the capacitor can be further increased. Thereby, a noise component can be removed more suitably and static electricity tolerance can be improved more.

[Third embodiment]
Next, an optical filter device according to a third embodiment of the present invention will be described below.
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 particularly for a miniaturized optical module. In the present embodiment, an optical filter device that enables the wavelength variable interference filter 5 to be easily installed even for such an optical module will be described below.
As shown in FIG. 6, the optical filter device 600 includes a wavelength variable interference filter 5 and a casing 601 that houses the wavelength variable 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 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. In addition, a light passage hole 611 is formed in the base substrate 610 in a region facing a light interference region (a region where the reflection films 54 and 55 are opposed). 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.

The base inner surface 612 of the base substrate 610 facing the lid 620 corresponds to each of the extraction electrodes 561A and 562A, the mirror electrodes 541 and 551, and the transparent electrodes 515 and 525 of the wavelength variable interference filter 5. An inner terminal portion 615 is provided. For example, the FPC 615A can be used for the connection between the extraction electrodes 561A and 562A, the mirror electrodes 541 and 551, the transparent electrodes 515 and 525, and the inner terminal portion 615, for example, Ag paste, ACF (Anisotropic Conductive). Film), ACP (Anisotropic Conductive Paste), etc. 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. For example, wiring connection by wire bonding or the like may be performed, and wire bonding and FPC connection may be used in combination.
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. 6, the lid 620 includes a lid bonding portion 624 bonded to the base bonding portion 617 of the base substrate 610, a side wall portion 625 that continues from the lid bonding 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 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.

[Operational effects of the third embodiment]
In such an optical filter device 600, 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 matter, gas contained in the atmosphere, etc. It is possible to prevent damage to the wavelength tunable interference filter 5 due to factors. In addition, since charged particles can be prevented from entering, the electrodes 561 and 562 can be prevented from being charged. Therefore, generation of electrostatic 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.
For example, in the first embodiment, the fixed substrate 51 that is the first substrate and the movable substrate 52 that is the second substrate are not provided, and the first reflective film and the second reflective film may face each other. In this case, for example, the fixed electrode is formed on one surface of the parallel plate-shaped sacrificial layer, and the first reflective film is formed so as to cover them. A movable electrode is formed on the other surface of the sacrificial layer, and a second reflective film is formed so as to cover them. Then, after forming a first insulating member (film material) on the first reflective film, a first transparent electrode is formed on the first insulating member. Similarly, after forming a second insulating member (film material) on the second reflective film, a second transparent electrode is formed on the second insulating member. Thereafter, the sacrificial layer is removed. Thus, the interference filter in which the first reflective film provided with the first drive electrode and the first control electrode and the second reflective film provided with the second drive electrode and the second control electrode are opposed to each other through a space. Can be formed.

In the first embodiment, the example in which the first transparent electrode 515 and the second transparent electrode 525 are set to the ground potential has been described, but the present invention is not limited to this.
In the present invention, the transparent electrodes 515 and 525 may be set to the same potential. Even in this case, generation of electrostatic force between the transparent electrodes 515 and 525 and between the reflective films 54 and 55 can be suppressed by the shielding effect. As a configuration for setting the transparent electrodes 515 and 525 to the same potential, for example, the voltage control unit 15 may short-circuit the transparent electrodes 515 and 525, and the transparent electrodes 515 and 525 are connected to a reference potential electrode set to a reference potential. It is good also as composition to do. Further, for example, an electrode for short-circuiting the transparent electrodes 515 and 525 may be formed on the surfaces of the fixed substrate 54 and the movable substrate 55 of the wavelength variable interference filter 5 so as to have the same potential.

Moreover, in each embodiment mentioned above, the electrostatic actuator 56 was illustrated as a gap change part, and the structure which changes the dimension of the gap G1 between the fixed reflective film 54 and the movable reflective film 55 by the electrostatic actuator 56 was illustrated. However, it is not limited to this.
For example, the gap changing unit may be configured to use a dielectric actuator including a first dielectric coil provided on the fixed substrate 51 and a second dielectric coil or permanent magnet provided on the movable substrate 52.
Further, a piezoelectric actuator may be used instead of the electrostatic actuator 56. In this case, for example, the lower electrode layer, the piezoelectric film, and the upper electrode layer are stacked on the holding unit 522, and the voltage applied between the lower electrode layer and the upper electrode layer is varied as an input value, thereby expanding and contracting the piezoelectric film. Thus, the holding portion 522 can be bent.
Furthermore, the configuration is not limited to the configuration in which the size of the gap G1 between the reflection films is changed by applying a voltage. For example, the size of the gap G1 between the reflection films can be changed by changing the air pressure between the fixed substrate 51 and the movable substrate 52. A configuration to be adjusted can also be exemplified.

Furthermore, the present invention can also be applied to an interference filter on the fixed wavelength side where no gap changing section is provided.
In the fixed wavelength interference filter, the movable portion 521 and the holding portion 522 as in the above embodiment are not provided, and the distance between the first substrate (fixed substrate 51) and the second substrate (movable substrate 52) (the reflective film 54). , 55 is kept constant. However, even in such a fixed wavelength type interference filter, when static electricity is applied from the outside or when it is placed in an electric field, each reflective film is charged, so that the gap dimension between the reflective films is caused by electrostatic force. May vary. In contrast, for example, as in the first embodiment, the first transparent electrode and the second transparent electrode are provided on the outer peripheral surface of each of the substrates 51 and 52, or as in the second embodiment, the first transparent electrode and the second transparent electrode are provided. By forming the first reflective film via the one insulating member and forming the second reflective film via the second transparent electrode and the second insulating member, charging to the reflective film can be suppressed, and electrostatic force is applied. Gap fluctuation can be suppressed.

In the above embodiment, the first mirror electrode 541 and the second mirror electrode 551 are connected to the capacitance detection unit 152, and the reflection films 54 and 55 function as capacitance detection electrodes. However, the present invention is not limited to this. Not. For example, the reflective films 54 and 55 may function as driving electrodes. In this case, the voltage control unit 151 corresponds to the mirror control unit of the present invention, and controls the drive voltage applied to the first mirror electrode 541 and the second mirror electrode 551.
At this time, as in the second embodiment, each of the first transparent electrode 515, the fixed reflective film 54, the second transparent electrode 525, and the movable reflective film 55 may function as a capacitor. In this case, the driving accuracy can be improved when a driving voltage is applied between the reflective films 54 and 55.

  In the said embodiment, although the example in which the 1st transparent electrode 515 and the 2nd transparent electrode 525 become a grounding potential was shown, it is not limited to this. For example, the reference potential Vcom (≈0 V) may be set in advance.

  Moreover, although the spectroscopic measurement apparatus 1 has been exemplified as the electronic apparatus of the present invention in each of the above embodiments, the optical module and the electronic apparatus of the present invention can be applied in various other fields.

For example, as shown in FIG. 7, the electronic apparatus of the present invention can also be applied to a color measuring device for measuring color.
FIG. 7 is a block diagram showing an example of a colorimetric device 400 provided with a variable wavelength interference filter.
As shown in FIG. 7, the color measuring device 400 includes a light source device 410 that emits light to the inspection target A, a color measuring sensor 420 (optical module), and a control device 430 that controls the overall operation of the color measuring 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 that analyzes and measures the chromaticity of the inspection target light, that is, the color of the inspection target A, based on the detection signal.

  A light source device 410, a light source 411, and a plurality of lenses 412 (only one is shown in FIG. 7) 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.

  The colorimetric sensor 420 is an optical module of the present invention. As shown in FIG. 7, the colorimetric sensor 420 includes a wavelength variable interference filter 5, a detector 11 that receives light transmitted through the wavelength variable interference filter 5, and the wavelength variable interference filter 5. And a filter driving circuit 15 that varies the wavelength of light to be transmitted. 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 the light having a predetermined wavelength from the inspection target light incident from the incident optical lens, and the detected light is received by the detector 11. Instead of the tunable interference filter 5, the above-described tunable interference filter 5A 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. 7, 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 filter drive circuit 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 detector 11.

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

FIG. 8 is a schematic view showing a gas detection device which is an example of the electronic apparatus of the present invention.
FIG. 9 is a block diagram showing a configuration of a control system of the gas detection device of FIG.
As shown in FIG. 8, the gas detection device 100 includes a sensor chip 110, a flow path 120 including a suction port 120A, a suction flow path 120B, a discharge flow path 120C, and a discharge port 120D, a main body 130, It is configured with.
The main body unit 130 includes a sensor unit cover 131 having an opening through which the flow channel 120 can be attached, a discharge unit 133, a housing 134, an optical unit 135, a filter 136, a wavelength variable interference filter 5, a light receiving element 137 (detection unit), and the like. , 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 tunable interference filter 5, the above-described tunable interference filter 5A 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. 9, an operation panel 140, a display unit 141, a connection unit 142 for interface with the outside, and a power supply unit 139 are provided on the surface of the gas detection device 100. When the power supply unit 139 is a secondary battery, a connection unit 143 for charging may be provided.
Further, as shown in FIG. 9, the control unit 138 of the gas detection device 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. Filter driving circuit 15, a light receiving circuit 147 that receives a signal from the light receiving element 137, a sensor chip detection that receives a signal from a sensor chip detector 148 that reads the code of the sensor chip 110 and 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 filter driving circuit 15. Thereby, the filter drive circuit 15 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.

  8 and 9, the gas detection device 100 that performs gas detection from the Raman scattered light obtained by spectrally dividing the Raman scattered light with the variable wavelength interference filter 5 is illustrated. You may use as a gas detection apparatus which specifies gas classification by detecting the light absorbency of. In this case, a gas sensor that allows gas to flow into the sensor and detects light absorbed by the gas in the incident light is used as the optical module of the present invention. A gas detection device that analyzes and discriminates the gas flowing into the sensor by such a gas sensor is an electronic apparatus of the present invention. Even in such a configuration, 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. 10 is a diagram showing a schematic configuration of a food analyzer which is an example of the electronic apparatus of the present invention.
As shown in FIG. 10, the food analysis device 200 includes a detector 210 (optical module), a control unit 220, and a display unit 230. The detector 210 includes a light source 211 that emits light, an imaging lens 212 into which light from the measurement target is introduced, a wavelength variable interference filter 5 that splits the light introduced from the imaging lens 212, and the dispersed light. And an imaging unit 213 (detection unit) for detecting. Instead of the tunable interference filter 5, the above-described tunable interference filter 5A 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 filter driving circuit 15 that controls the wavelength variable interference filter 5, and the imaging unit 213. , A detection control unit 223 that acquires a spectral image captured by the imaging unit 213, a signal processing unit 224, and a storage unit 225.

  In the food analyzer 200, when the system is driven, the light source 211 is controlled by the light source control unit 221, and light is irradiated from the light source 211 to the measurement object. Then, the light reflected by the measurement object enters the wavelength variable interference filter 5 through the imaging lens 212. The variable wavelength interference filter 5 is driven by the driving method as shown in the first embodiment under the control of the filter driving circuit 15. 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 filter driving circuit 15 to change the voltage value applied to the wavelength variable interference filter 5 and acquires a spectral image for each wavelength.

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

FIG. 10 shows an example of the food analysis apparatus 200, but it can also be used as a non-invasive measurement apparatus for other information as described above with a substantially similar configuration. For example, it can be used as a biological analyzer for analyzing biological components such as measurement and analysis of body fluid components such as blood. As such a bioanalytical device, for example, a device that detects ethyl alcohol as a device that measures a body fluid component such as blood, it can be used as a drunk driving prevention device that detects the drunk state of the driver. Further, it can also be used as an electronic endoscope system provided with such a biological analyzer.
Furthermore, it can also be used as a mineral analyzer for performing component analysis of minerals.

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

Further, the electronic device can be applied to a spectroscopic camera, a spectroscopic analyzer, or the like that captures a spectroscopic image by dispersing light with the optical module of the present invention. An example of such a spectroscopic camera is an infrared camera incorporating a wavelength variable interference filter.
FIG. 11 is a schematic diagram showing a schematic configuration of the spectroscopic camera. As shown in FIG. 11, the spectroscopic camera 300 includes a camera body 310, an imaging lens unit 320, and an imaging unit 330.
The camera body 310 is a part that is gripped and operated by a user.
The imaging lens unit 320 is provided in the camera body 310 and guides incident image light to the imaging unit 330. Further, as shown in FIG. 11, the imaging lens unit 320 includes an objective lens 321, an imaging lens 322, and a variable wavelength interference filter 5 provided between these lenses. Instead of the tunable interference filter 5, the above-described tunable interference filter 5A 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, with respect to each wavelength, the drive control unit (not shown) drives the wavelength variable interference filter 5 by the driving method of the present invention as shown in the first embodiment or the third embodiment, so that the accuracy is improved. The image light of the spectral image of the target wavelength can be taken out.

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

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

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

  In addition, the specific structure for carrying out the present invention 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, 5, 5A ... Variable wavelength interference filter, 10 ... Optical module, 15 ... Filter drive circuit, 20 ... Control part, 51 ... Fixed substrate, 52 ... Movable substrate, 54 ... Fixed reflection film, 55 ... Movable Reflective film 56 ... Electrostatic actuator 100 ... Gas detector 151 ... Voltage controller 152 ... Capacitance detector 153 ... Ground electrode 200 ... Food analyzer 300 ... Spectroscopic camera 400 ... Color measuring device 515 , 515A ... first transparent electrode, 525,525A ... second transparent electrode, 516 ... first insulating member, 526 ... second insulating member, 541 ... first mirror electrode, 551 ... second mirror electrode, 561 ... fixed electrode, 562 ... movable electrode.

Claims (12)

A first reflective film that reflects a portion of incident light and transmits at least a portion thereof;
A second reflective film facing the first reflective film, reflecting a part of incident light and transmitting at least a part thereof;
A first transparent electrode provided at a distance from a surface opposite to the surface facing the second reflective film in the first reflective film;
A second transparent electrode provided at a distance from the surface opposite to the surface facing the first reflective film in the second reflective film;
With
In a plan view seen from the film thickness direction of the first reflective film, the first transparent electrode is provided in an area at least coincident with the area of the first reflective film,
In a plan view seen from the film thickness direction of the second reflective film, the second transparent electrode is provided in an area at least coincident with the area of the second reflective film,
The interference filter, wherein the first transparent electrode and the second transparent electrode have the same potential. The interference filter according to claim 1,
The interference filter, wherein the first transparent electrode and the second transparent electrode are at ground potential. The interference filter according to claim 1 or 2,
A first substrate provided with the first reflective film;
A second substrate provided with the second reflective film,
The first transparent electrode is provided on the surface of the first substrate opposite to the surface on which the first reflective film is provided,
Said 2nd transparent electrode was provided in the surface on the opposite side to the surface in which said 2nd reflective film of said 2nd board | substrate was provided. The interference filter characterized by the above-mentioned. The interference filter according to any one of claims 1 to 3,
The first reflective film is provided on the first transparent electrode via a first insulating member,
The interference filter, wherein the second reflective film is provided on the second transparent electrode through a second insulating member. The interference filter according to any one of claims 1 to 4,
The first reflective film and the second reflective film have conductivity,
The interference filter includes a first mirror electrode connected to the first reflective film and a second mirror electrode connected to the second reflective film. The interference filter according to any one of claims 1 to 5,
An interference filter comprising a gap changing unit that changes a gap dimension between the first reflective film and the second reflective film. A first reflective film that reflects a part of incident light and transmits at least a part thereof, a second reflective film that is arranged opposite to the first reflective film and reflects a part of incident light and transmits at least a part thereof; A first transparent electrode provided at a distance from a surface of the first reflective film opposite to the surface facing the second reflective film; and the first reflective film of the second reflective film; An interference filter having a second transparent electrode spaced from a surface opposite to the opposing surface;
A housing for housing the interference filter;
With
In a plan view seen from the film thickness direction of the first reflective film, the first transparent electrode is provided in an area at least coincident with the area of the first reflective film,
In a plan view seen from the film thickness direction of the second reflective film, the second transparent electrode is provided in an area at least coincident with the area of the second reflective film,
Said 1st transparent electrode and said 2nd transparent electrode are the same electric potential. The optical filter device characterized by the above-mentioned. A first reflective film that reflects a part of incident light and transmits at least a part thereof, a second reflective film that is arranged opposite to the first reflective film and reflects a part of incident light and transmits at least a part thereof; A first transparent electrode provided at a distance from a surface of the first reflective film opposite to the surface facing the second reflective film; and the first reflective film of the second reflective film; An interference filter having a second transparent electrode spaced from a surface opposite to the opposing surface;
A light receiving unit that receives light emitted from the interference filter,
In a plan view seen from the film thickness direction of the first reflective film, the first transparent electrode is provided in an area at least coincident with the area of the first reflective film,
In a plan view seen from the film thickness direction of the second reflective film, the second transparent electrode is provided in an area at least coincident with the area of the second reflective film,
The optical module, wherein the first transparent electrode and the second transparent electrode are at the same potential. The optical module according to claim 8, wherein
An optical module comprising: a potential control unit configured to make the first transparent electrode and the second transparent electrode have the same potential. The optical module according to claim 9, wherein
The optical module, wherein the potential control unit sets the first transparent electrode and the second transparent electrode to a ground potential. The optical module according to any one of claims 8 to 10,
The first reflective film is provided on the first transparent electrode via a first insulating member,
The second reflective film is provided on the second transparent electrode via a second insulating member,
The interference filter includes a first mirror electrode connected to the first reflective film and insulated from the first transparent electrode, and connected to the second reflective film and insulated from the first transparent electrode. A second mirror electrode is provided,
The optical module includes a mirror control unit that controls the first mirror electrode and the second mirror electrode. A first reflective film that reflects a part of incident light and transmits at least a part thereof, a second reflective film that is arranged opposite to the first reflective film and reflects a part of incident light and transmits at least a part thereof; A first transparent electrode provided at a distance from a surface of the first reflective film opposite to the surface facing the second reflective film; and the first reflective film of the second reflective film; An interference filter having a second transparent electrode spaced from a surface opposite to the opposing surface;
A control unit for controlling the interference filter,
In a plan view seen from the film thickness direction of the first reflective film, the first transparent electrode is provided in an area at least coincident with the area of the first reflective film,
In a plan view seen from the film thickness direction of the second reflective film, the second transparent electrode is provided in an area at least coincident with the area of the second reflective film,
The electronic device, wherein the first transparent electrode and the second transparent electrode are at the same potential.

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