JP2014106269A - Wavelength variable interference filter, optical filter device, optical module, and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wavelength variable interference filter in which contact between reflection films can be suppressed even when a gap dimension between the reflection films is decreased, and to provide an optical filter device, an optical module, and an electronic apparatus.SOLUTION: A wavelength variable interference filter 5 includes a fixed substrate 51, a movable substrate 52, a fixed reflection film 54 disposed on the fixed substrate 51, and a movable reflection film 55 disposed on the movable substrate 52 and opposing to the fixed reflection film 54. The fixed substrate 51 includes a reflection film setting surface 512A and an electrode setting groove 511 enclosing an outer circumference of the reflection film setting surface 512A. The fixed reflection film 54 is disposed from the reflection film setting surface 512A to the electrode setting groove 511.

Description

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

2. Description of the Related Art Conventionally, a wavelength variable interference filter is known in which a reflective film is disposed opposite to each other on a pair of substrates facing each other (see, for example, Patent Document 1).
The wavelength tunable interference filter described in Patent Document 1 is a wavelength tunable interference filter in which a fixed substrate and a movable substrate are joined. A fixed reflective film is provided on a surface of the fixed substrate facing the movable substrate, and the fixed substrate of the movable substrate. A movable reflective film facing the fixed reflective film is provided on the surface facing the surface.
In addition, the variable wavelength interference filter is provided with an electrostatic actuator, and by applying a voltage to the electrostatic actuator, it is possible to change the dimension between the fixed reflective film and the movable reflective film.

JP 2010-204457 A

By the way, in order to cover a wide wavelength range including, for example, the visible light range by the wavelength variable interference filter as described above, it is necessary to use a material having appropriate reflection characteristics and transmission characteristics for the wavelength range as the reflection film. There is. As such a material, for example, a metal film such as Ag or a metal alloy film such as AgC is preferably used.
In order to form such a reflective film on a substrate, after forming the reflective film on the substrate by sputtering or the like, a resist having a pattern corresponding to the shape of the reflective film is formed and etched. Thereafter, the resist is removed with a resist removing liquid (for example, an alkaline solution), whereby a reflective film having a predetermined shape is formed.

However, when removing the resist, the resist is removed only from the upper surface of the resist by the resist removing liquid at the central portion of the reflective film. However, the resist is also removed from the side surface in addition to the upper surface of the resist at the peripheral edge portion of the reflective film. The resist is removed by the removing solution. For this reason, the outer peripheral portion of the reflective film has a higher resist removal rate than the central portion, and the resist removal solution is exposed to the reflective film for a long time, and a rough film portion whose optical characteristics have changed due to film deterioration is formed. End up.
Here, when the wavelength tunable interference filter is used as a device for surface spectroscopy, the reflection film has the same optical characteristics and is set as an effective region that can transmit light with uniform resolution. At this time, if the rough film portion is included in the effective region, the optical characteristics of the tunable interference filter are deteriorated. Therefore, it is necessary to set the effective region so that the rough film portion is not included, and the effective region becomes narrow. There is a problem.

  An object of the present invention is to provide a variable wavelength interference filter, an optical filter device, an optical module, and an electronic apparatus that can set a wide effective region.

  The wavelength tunable interference filter of the present invention is provided on the first substrate, the second substrate disposed to face the first substrate, and the first substrate, and reflects a part of incident light and transmits a part thereof. A first reflective film, and a second reflective film provided on the second substrate, facing the first reflective film, reflecting a part of incident light and transmitting a part thereof. Includes a first flat portion facing the second substrate, and a groove portion that surrounds an outer periphery of the first flat portion in a plan view of the first substrate and the second substrate viewed from the substrate thickness direction. The one reflective film is provided continuously in the first flat portion and at least a partial region of the groove.

  In the present invention, the first reflective film is continuously provided from the first plane portion to at least a part of the groove portion on the outer periphery of the first plane portion. That is, the first reflective film is provided from the first flat surface portion to a part of the groove portion, and the outer peripheral edge thereof is located in the groove portion. In such a configuration, since the outer peripheral portion of the first reflective film is located in the groove portion surrounding the outer periphery of the first flat surface portion, when the rough film portion due to film deterioration is formed on the outer peripheral portion when the first reflective film is formed. However, the rough film portion is located in the groove portion. Accordingly, the central portion of the first reflective film that is unlikely to cause film deterioration is provided in a wide region of the first plane portion, and this region can be set as an effective region. That is, in the present invention, a wide effective area can be set.

In the wavelength tunable interference filter according to the aspect of the invention, it is preferable that a distance from the groove portion to the second substrate is longer than a distance from the first flat portion to the second substrate.
In the present invention, the distance from the groove part to the second substrate is longer than the distance from the first flat part to the second substrate. In addition, when a rough film portion is formed on the reflective film, unevenness may occur due to a shape change. In this case, if the convex portion of the rough film portion protrudes toward the second substrate, there is a risk that the first reflective film and the second reflective film come into contact with each other if the gap dimension between the reflective films is narrowed. On the other hand, in the present invention, since the rough film portion is formed in the groove portion having a longer distance from the second substrate than the first flat portion, the convex portion of the rough film portion is formed on the second substrate than the first flat portion. It does not protrude to the side, and the contact between the reflection films as described above can be suppressed.

  In the wavelength tunable interference filter according to the aspect of the invention, the groove portion may include a flat portion facing the second substrate, and a curved surface portion provided between the flat portion and the first plane portion, and the first reflection. It is preferable that the outer peripheral edge of the film is located at the boundary between the curved surface portion and the flat portion or outside the boundary.

  In the present invention, the groove part includes a flat part parallel to the second substrate and the first flat part, and a curved part connecting the flat part to the first flat part, and the first reflective film includes at least the first reflective film. One flat surface portion and a curved surface portion are covered. In such a configuration, the possibility that the rough film portion of the first reflective film is generated on the first flat surface portion becomes lower. Therefore, the possibility that the rough film portion is formed on the first plane portion can be reduced, and the effective area can be expanded.

The wavelength tunable interference filter of the present invention comprises a first electrode provided on the first substrate, and a second electrode provided on the second substrate and facing the first electrode, wherein the first electrode is It is preferable that the flat portion is provided.
In the present invention, by applying a voltage between the first electrode provided on the first substrate and the second electrode provided on the second substrate, the gap dimension between the first reflective film and the second reflective film. Can be changed. Here, by providing the first electrode on the flat portion of the groove, the balance of the electrostatic attractive force acting between the first electrode and the second electrode is improved, and the parallelism of the first reflective film and the second reflective film is improved. The gap dimension can be accurately changed without being damaged.
In addition, since the first electrode is provided on the flat portion, the gap between the first reflective film and the second reflective film (interreflection film gap) is smaller than the gap between the first electrode and the second electrode (interelectrode gap). . In such a configuration, the variable region of the gap between the reflective films can be increased, and the electrostatic attraction between the first electrode and the second electrode can be easily controlled. It can be set to a desired value.
By providing the first electrode in the groove, it is not necessary to separately form a groove for arranging the first electrode, and the configuration can be simplified. That is, in this invention, a groove part can be functioned as both a groove | channel for escaping the groove | channel for 1st electrode arrangement | positioning, and the rough film part of the outer peripheral part of a 1st reflective film.

In the variable wavelength interference filter according to the aspect of the invention, it is preferable that the groove portion is provided in an annular shape surrounding the first flat surface portion in the plan view.
In the present invention, the groove portion is annular and surrounds the first flat surface portion. In such a configuration, in the first reflective film, the entire outer peripheral part where the rough film part may be formed is located in the groove part. Therefore, it is possible to avoid the inconvenience that the rough film portion is formed on the first plane portion and the effective area is narrowed, and the inconvenience that the convex portion of the rough film portion contacts the second reflective film can be more reliably suppressed.

In the wavelength tunable interference filter according to the aspect of the invention, the second reflective film may have a first plane portion facing region that faces the first plane portion of the second substrate and a groove portion facing at least the groove portion in the plan view. It is preferable to be provided continuously in a part of the region.
In the present invention, the outer peripheral edge of the second reflective film is located in the groove facing region. For this reason, in the second reflective film, an outer peripheral portion where a rough film portion may be formed at the time of film formation is located in the groove facing region. Therefore, when the entire first plane portion is used as the effective region, there is a low possibility that the rough film portion of the second reflective film is generated in the effective region, and the deterioration of the optical characteristics of the wavelength variable interference filter can be suppressed.
In addition, even when a rough film portion having irregularities is formed on the outer peripheral portion of the second reflective film, the contact between the first reflective film and the second reflective film is suppressed because the rough film portion is in a position facing the groove portion. can do.

In the wavelength tunable interference filter according to the aspect of the invention, the groove portion may include a flat portion facing the second substrate, and a curved surface portion provided between the flat portion and the first flat surface portion, and the groove portion facing region. Comprises a flat portion facing region facing the flat portion and a curved portion facing region facing the curved portion, and the outer peripheral edge of the second reflective film has the flat portion facing region and the curved portion facing region. It is preferable to be located outside the boundary or outside the boundary.
In the present invention, further, the outer peripheral edge of the second reflective film is located at the boundary between the flat portion facing region and the curved surface facing region, or outside the boundary, so that the rough film portion of the second reflective film becomes the first plane portion. It is less likely to occur in opposing areas. That is, in the wavelength tunable interference filter, even when the entire region overlapping the first plane portion is the effective region, the possibility that the rough film portion of the second reflective film is generated in the effective region is low. A decrease in optical characteristics can be suppressed. The inconvenience that the reflective films come into contact with each other due to the convex portions of the rough film portion can be more reliably suppressed.

  An optical filter device of the present invention is provided on a first substrate, a second substrate disposed opposite to the first substrate, and the first substrate, and reflects a part of incident light and transmits a part thereof. A wavelength tunable interference filter provided with a reflective film, a second reflective film provided on the second substrate, and facing the first reflective film, reflecting a part of incident light and transmitting a part thereof, and the wavelength tunable filter A housing for storing an interference filter, and the first substrate is a first flat portion facing the second substrate, and the first substrate and the second substrate in a plan view when viewed from the substrate thickness direction. It has a groove part which encloses the perimeter of the 1st plane part, and the 1st reflective film is continuously provided in the 1st plane part and at least a partial field of the groove part.

  In the present invention, as in the case of the above-described invention, the effective area can be set wide, and contact between the first reflective film and the second reflective film can also be suppressed. In addition, since the variable wavelength interference filter is housed in the casing, it is possible to suppress deterioration of the reflective film due to gas contained in the atmosphere and adhesion of foreign substances.

  An optical module of the present invention is provided on a first substrate, a second substrate disposed to face the first substrate, and the first substrate, and reflects a part of incident light and transmits a part thereof. A second reflection film provided on the second substrate, facing the first reflection film, reflecting a part of incident light and transmitting a part thereof; the first reflection film; and the second reflection film. A detection unit that detects light having a wavelength selected by interference of light incident between the reflection film and the first substrate, the first plane unit facing the second substrate, and the first substrate A planar view of the first substrate and the second substrate as viewed from the thickness direction of the substrate, the groove surrounding the outer periphery of the first planar portion; and the first reflective film includes at least one of the first planar portion and the groove portion. It is characterized by being provided continuously in the region of the part.

  In the present invention, as in the case of the above-described invention, since the central portion of the first reflective film that is unlikely to deteriorate is provided in a wide area of the first flat surface portion, the effective area in the tunable interference filter can be increased, The amount of light to be detected can be increased.

  The electronic device according to the present invention includes a first substrate, a second substrate disposed opposite to the first substrate, and a first reflection that is provided on the first substrate and reflects part of incident light and transmits part of the incident light. A wavelength tunable interference filter provided with a second reflective film that is provided on the second substrate and faces the first reflective film and reflects part of incident light and transmits part of the incident light; and the wavelength tunable interference A control unit that controls the filter, wherein the first substrate is a first planar portion that faces the second substrate, and the first substrate and the second substrate in a plan view when viewed from the substrate thickness direction. It has a groove part which encloses the perimeter of the 1st plane part, and the 1st above-mentioned reflective film is continuously provided in the 1st plane part and a partial field of the above-mentioned groove part.

  In the present invention, as in the case of the above-described invention, the central portion of the first reflective film, which is unlikely to deteriorate, is provided in a wide area of the first flat surface portion. Light having a wavelength selected by multiple interference between the film and the second reflective film can be extracted with high accuracy. Therefore, highly accurate processing can be realized in various processing using the extracted light in the electronic device.

1 is a block diagram showing a schematic configuration of a spectrometer according to an embodiment of the present invention. The top view which shows schematic structure of the wavelength variable interference filter of this embodiment. Sectional drawing of the wavelength variable interference filter which cut the III-III line in FIG. The top view which looked at the stationary substrate from the movable substrate side in this embodiment. The top view which looked at the movable substrate from the fixed substrate side in this embodiment. The flowchart which shows the manufacturing process of the wavelength variable interference filter of this embodiment. The figure which shows the state of the 1st glass substrate in the fixed substrate formation process of FIG. The figure which shows the state of the 2nd glass substrate in the movable substrate formation process of FIG. The figure which shows the board | substrate joining process of FIG. Sectional drawing which shows schematic structure of the optical filter device of 2nd embodiment which concerns on this invention. Sectional drawing of the wavelength variable interference filter which shows an example of other embodiment of this invention. FIG. 3 is a block diagram illustrating an example of a color measurement device that is an electronic apparatus according to the invention. Schematic which shows an example of the gas detection apparatus which is an 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 electronic device of this invention. The schematic diagram which shows schematic structure of the spectroscopic camera which is an electronic device of this invention.

[First embodiment]
Hereinafter, a first embodiment according to the present invention will be described with reference to the drawings.
[Configuration of Spectrometer]
FIG. 1 is a block diagram showing a schematic configuration of a spectrometer according to an embodiment of the present invention.
The spectroscopic measurement device 1 is an electronic apparatus according to the present invention, and is a device that measures the spectrum of the measurement target light based on the measurement target light reflected by the measurement target X. 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.

[Configuration of optical module]
Next, the configuration of the optical module 10 will be described below.
As shown in FIG. 1, 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 voltage control unit 15. Configured.

The detector 11 receives the light transmitted through the wavelength variable interference filter 5 of the optical module 10 and outputs a detection signal (current) corresponding to the light intensity of the received light.
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 wavelength variable interference filter)
FIG. 2 is a plan view showing a schematic configuration of the variable wavelength interference filter 5. 3 is a cross-sectional view of the wavelength tunable interference filter 5 taken along the line III-III in FIG.
The variable wavelength interference filter 5 of the present embodiment is a so-called Fabry-Perot etalon. As shown in FIG. 2, the variable wavelength interference filter 5 includes a fixed substrate 51 and a movable substrate 52. The fixed substrate 51 and the movable substrate 52 are each formed of, for example, various types of glass, crystal, silicon, or the like. The fixed substrate 51 and the movable substrate 52 are bonded such that the first bonding portion 513 of the fixed substrate 51 and the second bonding portion 523 of the movable substrate 52 are made of, for example, a plasma polymerization film mainly containing siloxane. By being joined by the film 53, it is configured integrally.

  The fixed substrate 51 is provided with a fixed reflective film 54 (first reflective film), and the movable substrate 52 is provided with a movable reflective film 55 (second reflective film). The reflection film 55 is disposed so as to face the gap G1 between the reflection films. The wavelength variable interference filter 5 is provided with an electrostatic actuator 56 that is used to adjust the size (gap size) of the gap G1 between the reflection films. The electrostatic actuator 56 includes a fixed electrode 561 (first electrode) provided on the fixed substrate 51 and a movable electrode 562 (second electrode) provided on the movable substrate 52. Here, the fixed electrode 561 and the movable electrode 562 may be provided directly on the surface of the fixed substrate 51 and the movable substrate 52, respectively, or may be provided via other film members. Good.

(Configuration of fixed substrate)
FIG. 4 is a plan view of the fixed substrate 51 as viewed from the movable substrate 52 side.
The fixed substrate 51 is formed to have a larger thickness dimension than the movable substrate 52, and the electrostatic attraction by the electrostatic actuator 56 or the inside of a film member (for example, the fixed reflection film 54) formed on the fixed substrate 51. There is no bending of the fixed substrate 51 due to stress.
As shown in FIGS. 3 and 4, the fixed substrate 51 includes an electrode arrangement groove 511 (groove portion of the present invention) and a reflective film installation portion 512 (first flat portion of the present invention) formed by etching, for example. Further, as shown in FIGS. 2 and 4, a part of the outer peripheral edge (vertex C2) of the fixed substrate 51 is provided with a notch part 514, and a movable electrode pad 564P described later is provided with a wavelength from the notch part 514. The configuration is such that the surface of the variable interference filter 5 is exposed.

The reflective film installation part 512 has a reflective film installation surface 512 </ b> A that faces the movable substrate 52. This reflection film installation surface 512A is a circular plane having a radius R1 centered on the filter center point O of the fixed substrate 51 in the filter plan view, and is a surface facing the fixed substrate 51 of the movable substrate 52 (movable surface 521A). ) And parallel to the surface. In the present embodiment, the circular reflection film installation surface 512A is illustrated, but is not limited thereto, and may be, for example, a polygonal shape such as an octagonal shape or a hexagonal shape, or an elliptical shape.
The electrode placement groove 511 is provided outside the reflection film installation portion 512 in the filter plan view, and is formed in an annular shape centering on the filter center point O. In addition, the surface of the electrode placement groove 511 that faces the movable substrate 52 is longer than the reflective film installation surface 512 </ b> A from the movable substrate 52. The electrode arrangement groove 511 includes an electrode installation surface 511A (flat portion of the present invention) parallel to the movable substrate 52 and the reflection film installation surface 512A, and a curved surface that is curved from the electrode installation surface 511A toward the reflection film installation surface 512A. Part 511B. Here, in the filter plan view, the dimension (radius of the boundary L) from the filter center point O to the boundary L of the electrode installation surface 511A and the curved surface portion 511B is R2.
Further, the fixed substrate 51 is provided with electrode lead grooves 511C (see FIG. 4) extending from the electrode arrangement grooves 511 toward the apexes C1 and C2 of the fixed substrate 51.

A fixed electrode 561 constituting the electrostatic actuator 56 is provided on the electrode installation surface 511A. The fixed electrode 561 is preferably formed in a substantially annular shape centering on the filter center point O, and more preferably formed in an annular shape. In addition, the ring shape described here includes a configuration in which a part is notched and becomes, for example, a C shape.
The fixed substrate 51 is provided with a fixed extraction electrode 563 extending from the outer peripheral edge of the fixed electrode 561 to the vertex C1 along the electrode extraction groove 511C toward the vertex C1. The extended leading end portion of the fixed extraction electrode 563 (the portion located at the vertex C1 of the fixed substrate 51) constitutes a fixed electrode pad 563P connected to the voltage control unit 15.
The fixed electrode 561 may be made of any material as long as it has conductivity. Specifically, the fixed electrode 561 is made of a metal oxide having good adhesion to a metal film or an alloy film. For example, an ITO (Indium Tin Oxide) film or a laminate of a Cr layer and an Au layer Etc.
In addition, an insulating film for ensuring insulation between the fixed electrode 561 and the movable electrode 562 may be stacked over the fixed electrode 561.
In the present embodiment, a configuration in which one fixed electrode 561 is provided on the electrode installation surface 511A is shown. For example, a configuration in which two concentric circles centering on the filter center point O are provided (double electrode configuration). ) Etc.

The reflective film installation part 512 is provided with a fixed reflective film 54. The fixed reflective film 54 is continuously provided from the reflective film installation surface 512A to the curved surface portion 511B of the electrode arrangement groove 511. Specifically, in the filter plan view, the fixed reflective film 54 is provided so as to cover the region having the radius R2 from the filter center point O, that is, the reflective film installation surface 512A and the curved surface portion 511B inside the boundary L. .
The fixed reflection film 54 is preferably a film having reflection characteristics and transmission characteristics over a wide wavelength range including the visible wavelength range. For example, a metal film such as Ag, an alloy film such as an AgC alloy, or the like is preferably used as the fixed reflective film 54. In this embodiment, an AgC alloy film is used.

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

  Of the surfaces of the fixed substrate 51 that face the movable substrate 52, the surfaces on which the electrode arrangement groove 511, the reflective film installation portion 512, and the extraction electrode arrangement groove are not formed constitute the first bonding portion 513. The first bonding portion 513 is bonded to the second bonding portion 523 of the movable substrate 52 by the bonding film 53.

(Configuration of movable substrate)
FIG. 5 is a plan view of the movable substrate 52 as viewed from the fixed substrate 51 side.
As shown in FIGS. 2, 3, and 5, the movable substrate 52 has a circular movable portion 521 centered on the filter center point O, and is coaxial with the movable portion 521 and has the movable portion 521 in the filter plan view. A holding portion 522 that holds the substrate and a substrate outer peripheral portion 525 provided outside the holding portion 522 are provided.
Further, as shown in FIGS. 2 and 5, the movable substrate 52 is provided with a notch 524 at the vertex C <b> 1, and the tip of the fixed electrode pad 563 </ b> P is exposed from the notch 524.
Similar to the fixed substrate 51, an antireflection film may be formed on the surface of the movable portion 521 opposite to the fixed substrate 51.

  The movable part 521 has a thickness dimension larger than that of the holding part 522. For example, in this embodiment, the movable part 521 has the same dimension as the thickness dimension of the movable substrate 52 (substrate outer peripheral part 525). The movable portion 521 is formed to have a diameter larger than at least the diameter of the outer peripheral edge of the reflection film installation surface 512A in the filter plan view.

  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. Here, in the filter plan view, a region facing the reflective film installation surface 512A of the movable surface 521A is a first facing region 521B (first planar portion facing region), and a region facing the curved surface portion 511B is a second facing region 521C ( The curved surface portion opposing region) and the region facing the electrode installation surface 511A are defined as a third facing region 521D (flat portion facing region). Therefore, the groove facing region of the present invention is constituted by the second facing region 521C and the third facing region 521D.

As shown in FIGS. 2, 3, and 5, the movable electrode 562 is provided in a region facing the fixed electrode 561, that is, the third facing region 521 </ b> D outside the movable reflective film 55 in the filter plan view. .
Further, the movable electrode 562 is provided with a movable extraction electrode 564 that is arranged to face the electrode extraction groove 511 </ b> C extending in the direction of the vertex C <b> 2 toward the vertex C <b> 2 of the fixed substrate 51. An extending tip portion of the movable extraction electrode 564 (portion located at the vertex C1 of the movable substrate 52) constitutes a movable electrode pad 564P connected to the voltage control unit 15. As the movable electrode 562, like the fixed electrode 561, it only needs to have conductivity. For example, an ITO film or a laminate in which an Au layer is laminated on a Cr layer can be used.

The movable reflective film 55 is made of the same material as the fixed reflective film 54 (AgC alloy film in this embodiment).
Similarly to the fixed substrate 51, the movable reflective film 55 is provided in a region having a radius R2 from the filter center point O in the filter plan view. That is, the movable reflective film 55 is provided so as to cover the first opposing region 521B and the second opposing region 521C.

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.
In this embodiment, the diaphragm-like holding part 522 is illustrated, but the present invention is not limited to this. For example, a configuration in which beam-like holding parts arranged at equiangular intervals around the filter center point O are provided. And so on.

  As described above, the substrate outer peripheral portion 525 is provided outside the holding portion 522 in the filter plan view. A second bonding portion 523 facing the first bonding portion 513 is provided on the surface of the substrate outer peripheral portion 525 facing the fixed substrate 51, and is bonded to the first bonding portion 513 through the bonding film 53.

(Configuration of voltage controller)
The voltage control unit 15 is connected to the fixed extraction electrode 563 (fixed electrode pad 563P) and the movable extraction electrode 564 (movable electrode pad 564P) of the variable wavelength interference filter 5.
When the voltage control unit 15 receives a voltage command signal corresponding to the wavelength to be measured from the control unit 20, the voltage control unit 15 applies a corresponding voltage between the fixed extraction electrode 563 and the movable extraction electrode 564. Thereby, an electrostatic attractive force based on the applied voltage is generated in the electrostatic actuator 56 (between the fixed electrode 561 and the movable electrode 562) of the wavelength variable interference filter 5, and the movable portion 521 is displaced toward the fixed substrate 51, The size of the gap G1 between the reflection films changes.

(Configuration of control unit)
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 shown in FIG. 1, the control unit 20 includes a filter drive unit 21, a light amount acquisition unit 22, and a spectroscopic measurement unit 23.
The control unit 20 includes a storage unit (not shown) that stores various data, and V-λ data for controlling the electrostatic actuator 56 is stored in the storage unit.
In this V-λ data, the peak wavelength of light transmitted through the wavelength variable interference filter 5 with respect to the voltage applied to the electrostatic actuator 56 is recorded.

The filter driving unit 21 sets a target wavelength of light extracted by the wavelength variable interference filter 5 and reads a target voltage value corresponding to the target wavelength set from the V-λ data stored in the storage unit. Then, the filter drive unit 21 outputs a control signal for applying the read target voltage value to the voltage control unit 15. Thereby, the voltage of the target voltage value is applied from the voltage control unit 15 to the electrostatic actuator 56.
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.
As a spectroscopic measurement method in the spectroscopic measurement unit 23, for example, a method of measuring a spectroscopic spectrum using a light amount detected by the detector 11 with respect to a measurement target wavelength as a light amount of the measurement target wavelength, or a light amount of a plurality of measurement target wavelengths. And a method for estimating a spectral spectrum based on the above.
As a method of estimating a spectral spectrum, for example, by generating a measurement spectrum matrix having matrix elements as light amounts for a plurality of measurement target wavelengths, a predetermined conversion matrix is applied to this measurement spectrum matrix, Estimate the spectrum of the light to be measured. In this case, a plurality of sample lights whose spectral spectra are known are measured by the spectroscopic measurement apparatus 1, and a matrix obtained by applying a conversion matrix to a measurement spectrum matrix generated based on the amount of light obtained by the measurement, and a known The transformation matrix is set so that the deviation from the spectral spectrum is minimized.

[Manufacturing method of tunable interference filter]
Next, a method for manufacturing the wavelength variable interference filter 5 as described above will be described with reference to the drawings.
FIG. 6 is a flowchart showing a manufacturing process of the wavelength variable interference filter 5.
In the manufacture of the variable wavelength interference filter 5, first, a first glass substrate M1 for forming the fixed substrate 51 and a second glass substrate M2 for forming the movable substrate 52 are prepared, and the fixed substrate forming step S1 and the movable substrate are prepared. The forming step S2 is performed. Thereafter, the substrate bonding step S3 is performed, and the first glass substrate M1 processed in the fixed substrate forming step S1 and the second glass substrate M2 processed in the movable substrate forming step S2 are bonded, and the wavelength is changed in units of chips. The variable interference filter 5 is cut out.
Hereinafter, each process S1-S3 is demonstrated based on drawing.

(Fixed substrate formation process)
FIG. 7 is a diagram showing a state of the first glass substrate M1 in the fixed substrate forming step S1.
In the fixed substrate forming step S1, first, as shown in FIG. 7A, both surfaces of the first glass substrate M1 (for example, the thickness dimension is 1 mm), which is a manufacturing material of the fixed substrate 51, have a surface roughness Ra of 1 nm or less. Polish both sides until it becomes.

Next, the substrate surface of the first glass substrate M1 is processed by etching.
Specifically, a resist is applied to the substrate surface of the first glass substrate M1, and the applied resist is exposed and developed by a photolithography method, whereby the electrode installation surface 511A and the reflective film installation surface 512A are formed. Patterning to open. Here, in the present embodiment, a plurality of fixed substrates 51 are formed from one first glass substrate M1. Therefore, in this step, a resist pattern is formed on the first glass substrate M1 so that the plurality of fixed substrates 51 are manufactured in a state of being arranged in parallel in an array.
Then, wet etching using, for example, hydrofluoric acid (BHF or the like) is performed on both surfaces of the first glass substrate M1. At this time, etching is performed up to the depth of the reflection film installation surface 512A.

  Thereafter, the resist pattern is removed, and a resist RE1 is applied again to the substrate surface of the first glass substrate M1. Then, the applied resist is exposed and developed by a photolithography method, so that patterning is performed so that regions corresponding to the electrode installation surface 511A and the electrode extraction groove 511C are opened. Here, as shown in FIG. 7B, the resist RE1 is patterned so that the inner periphery of the opening pattern is located at a radius R2 from the filter center point O.

Thereafter, wet etching is performed on the first glass substrate M1. Thereby, the electrode installation surface 511A on which the fixed electrode 561 is installed becomes flat, and the curved surface portion 511B is formed by the side etching from the boundary L of the electrode installation surface 511A to the reflection film installation surface 512A being curved. That is, as shown in FIG. 7C, the first glass substrate M1 in which the substrate shape of the fixed substrate 51 is determined is formed.
In the filter plan view, the width (radius R2−radius R1) of the region where the curved surface portion 511B is formed is substantially the same as the difference in depth between the reflective film installation surface 512A and the electrode installation surface 511A. Therefore, when removing the resist of the fixed reflective film 54 (described later), the electrodes are arranged so that a region (outer peripheral part) where a rough film part may be formed on the fixed reflective film 54 is in the curved surface part 511B. The difference in the depth dimension of the surface 511A is determined. In the present embodiment, the difference in depth dimension between the reflective film installation surface 512A and the electrode installation surface 511A is about 100 μm.
Thereafter, the resist RE1 is removed.

Next, an electrode material (for example, ITO) for forming the fixed electrode 561 and the fixed extraction electrode 563 is formed on the first glass substrate M1 using a vapor deposition method, a sputtering method, or the like. And a resist is apply | coated to the 1st glass substrate M1, and a resist is patterned according to the shape of the fixed electrode 561 and the fixed extraction electrode 563 using the photolithographic method. Then, after performing etching with an ITO etching solution (for example, a mixed solution of hydrochloric acid, nitric acid, and water), the resist is removed. Thus, as shown in FIG. 7D, a fixed electrode 561 and a fixed extraction electrode 563 are formed. In FIG. 7, the fixed extraction electrode 563 is not shown.
Further, when an insulating layer is formed on the fixed electrode 561, SiO ₂ having a thickness of, for example, about 100 nm is formed on the entire surface of the fixed substrate 51 facing the movable substrate 52 by, for example, plasma CVD after the formation of the fixed electrode 561. Form a film. Then, the SiO ₂ on the fixed electrode pad 563P is removed by, for example, dry etching.

Next, the fixed reflective film 54 is formed on the reflective film installation surface 512A. Specifically, the film layer of the fixed reflective film 54 is formed on the surface of the first glass substrate M1 on which the electrode placement groove 511 and the reflective film installation part 512 are formed by vacuum deposition or sputtering.
Thereafter, a resist RE2 is applied and patterned using a photolithography method so that the resist RE2 remains only in a region having a radius R2 from the filter center point O in a plan view of the filter. The applied resist RE2 is about 1 μm. Thereafter, unnecessary portions of the film material are removed by etching, whereby the fixed reflective film 54 is formed as shown in FIG.

Thereafter, the resist RE2 on the fixed reflective film 54 is removed.
Here, as indicated by an arrow in FIG. 7E, the resist RE2 is removed from the upper surface at the central portion of the fixed reflective film 54, whereas the resist from the upper surface and side surfaces is removed from the outer peripheral portion of the fixed reflective film 54. RE2 is removed. Therefore, the resist RE2 in the outer peripheral portion of the fixed reflective film 54 is removed earlier, and the outer peripheral portion is exposed to the resist removing solution until the central resist RE2 is removed. Further, the end surface of the outer peripheral edge of the fixed reflective film 54 is directly exposed to the resist removing solution. Since the resist removing liquid for removing the resist RE2 is an alkaline solution, when the fixed reflective film 54 is in contact with the resist removing liquid for a long time, the film is deteriorated and a rough film portion (unevenness) is generated. Here, since the thickness dimension of the resist RE2 is about 1 μm as described above, when the resist RE2 is removed, the fixed reflective film 54 can have a rough film portion formed in a range of about 1 μm from the outer periphery. There is sex.
In the present embodiment, as described above, since the width of the curved surface portion 511B is about 100 μm, the region where the rough film portion may be formed is within the curved surface portion 511B. Therefore, even when a rough film portion is formed in the resist removal process and unevenness is generated on the outer peripheral portion of the fixed reflective film 54, the unevenness protrudes above the reflective film installation surface 512A (movable substrate 52 side). There is no.
As a result, as shown in FIG. 7F, the first glass substrate M1 in which the fixed substrates 51 are arranged in an array is formed.

(Movable substrate formation process)
Next, the movable substrate forming step S2 will be described. FIG. 8 is a diagram illustrating a state of the second glass substrate M2 in the movable substrate forming step S2.
In the movable substrate forming step S2, first, as shown in FIG. 8A, both surfaces are precisely polished until the surface roughness Ra of the second glass substrate M2 (for example, the thickness dimension is 0.5 mm) is 1 nm or less.
Then, a Cr / Au layer is formed on the surface of the second glass substrate M2, and using this Cr / Au layer as an etching mask, a region corresponding to the holding portion 522 is etched using, for example, a hydrofluoric acid system (BHF or the like). . Thereafter, by removing the Cr / Au layer used as the etching mask, as shown in FIG. 8B, the second glass substrate M2 in which the substrate shape of the movable substrate 52 is determined is manufactured.

  Next, as shown in FIG. 8C, a movable electrode 562 and a movable extraction electrode 564 are formed. In forming the movable electrode 562 and the movable extraction electrode 564, a method similar to the formation of the fixed electrode 561 in the fixed substrate 51 can be used.

Thereafter, as shown in FIG. 8D, a movable reflective film 55 is formed on the movable surface 521A. The movable reflective film 55 can also be formed by the same method as the fixed reflective film 54.
At this time, like the fixed reflective film 54, the movable reflective film 55 is formed in a region having a radius R2 from the filter center point O, that is, in the first opposing region 521B and the second opposing region 521C. Thereby, when the resist on the movable reflective film 55 is removed, a rough film portion is not formed on the first facing region 521B facing the reflective film installation surface 512A.
Thus, the second glass substrate M2 in which the movable substrates 52 are arranged in a plurality of arrays is manufactured.

(Board bonding process)
Next, the substrate bonding step S3 will be described. FIG. 9 is a diagram illustrating a state of the first glass substrate M1 and the second glass substrate M2 in the substrate bonding step S3.
In this substrate bonding step S3, first, a plasma polymerized film (bonding film) mainly composed of polyorganosiloxane is formed on the first bonding portion 513 of the first glass substrate M1 and the second bonding portion 523 of the second glass substrate M2. 53) is formed by, for example, a plasma CVD method or the like. The thickness of the bonding film 53 may be, for example, 10 nm to 1000 nm.

Then, in order to providing the activation energy to the plasma-polymerized film of the first glass substrate M1 and the second glass substrate M2, performing the O ₂ plasma treatment or UV treatment. In the case of O ₂ plasma treatment, the treatment is performed for 30 seconds under conditions of an O ₂ flow rate of 1.8 × 10 ⁻³ (m ³ / h), a pressure of 27 Pa, and an RF power of 200 W. In the case of UV treatment, the treatment is performed for 3 minutes using excimer UV (wavelength 172 nm) as a UV light source.
After applying activation energy to the plasma polymerized film, the alignment of the first glass substrate M1 and the second glass substrate M2 is adjusted, and the first glass substrate M1 and the second glass substrate M2 are stacked via the plasma polymerized film. In addition, a load of 98 (N), for example, is applied to the joint portion for 10 minutes. Thereby, the 1st glass substrate M1 and the 2nd glass substrate M2 are joined.

  Thereafter, a cutting step of taking out each wavelength variable interference filter 5 in units of chips is performed. Specifically, the joined body of the first glass substrate M1 and the second glass substrate M2 is cut along the line B1 shown in FIG. For the cutting, for example, laser cutting or the like can be used. As described above, the variable wavelength interference filter 5 for each chip is manufactured.

[Operational effects of the first embodiment]
In the wavelength tunable interference filter 5 of the present embodiment, the fixed reflective film 54 is provided from the reflective film installation surface 512 </ b> A to the electrode arrangement groove 511. Therefore, the outer peripheral portion of the fixed reflective film 54 is positioned in the electrode placement groove 511 that is longer than the reflective film installation surface 512A from the movable substrate 52.
In general, when the fixed reflective film 54 and the movable reflective film 55 are provided in a region overlapping with the reflective film installation surface 512A in plan view of the filter, the region where the rough film portion is formed deteriorates the film characteristics. The effective diameter (effective area) through which the variable interference filter 5 can accurately transmit light of the target wavelength is smaller than the radius R1. On the other hand, in this embodiment, since the rough film portion is not formed in the region overlapping with the reflective film installation surface 512A in the filter plan view, the effective diameter is set to the entire region of the reflective film installation surface 512A (region of radius R1). The amount of light transmitted through the wavelength variable interference filter 5 can be increased. Therefore, the amount of light detected by the detector 11 is also increased, and the spectroscopic measurement apparatus 1 can perform highly accurate spectroscopic measurement processing.

  Further, when forming the fixed reflective film 54, even if a rough film portion having irregularities is formed on the outer peripheral portion of the fixed reflective film 54, the irregularities of the rough film portion are closer to the movable substrate 52 side than the reflective film installation surface 512 </ b> A. Does not protrude. Therefore, even when a voltage is applied to the electrostatic actuator 56 to reduce the gap dimension of the gap G1 between the reflection films, the contact between the fixed reflection film 54 and the movable reflection film 55 can be suppressed.

The same applies to the movable reflective film 55, from the first facing area 521B facing the reflective film installation surface 512A to the groove facing area facing the electrode placement groove 511 (area including the second facing area 521C and the third facing area 521D). It is formed over.
Therefore, even when the effective diameter is set to the entire area of the reflection film installation surface 512A (region of radius R1) as described above, the possibility that a rough film portion is generated within the effective diameter is low. A decrease in optical characteristics can be suppressed.
In addition, since the outer peripheral portion of the movable reflective film 55 is located in the groove facing region with respect to the dimension between the fixed substrate 51 and the movable substrate 52 rather than the gap G1 between the reflective films, the fixed reflective film 54 and the movable reflective film. Contact with 55 can be more reliably suppressed.

In the present embodiment, the outer peripheral edge of the fixed reflective film 54 is located on the boundary L between the electrode installation surface 511A and the curved surface portion 511B. In such a configuration, the possibility that a rough film portion is formed on the fixed reflective film 54 on the reflective film installation surface 512A is lower, and the contact between the reflective films can be more reliably suppressed.
The same applies to the movable reflective film 55, and the outer peripheral edge of the movable reflective film 55 is located at the boundary L between the second opposing region 521C and the third opposing region 521D. A possibility that a rough film part will be formed becomes lower, and contact between reflective films can be controlled more certainly.

In the present embodiment, the groove portion of the present invention is an electrode arrangement groove 511. By adopting such a configuration, for example, a groove for preventing a rough film portion from being formed on the fixed reflective film 54 on the reflective film installation surface 512A and a groove for installing the fixed electrode 561 are respectively provided. The configuration can be simplified as compared with the provided configuration, and the tunable interference filter 5 can be reduced in size.
Further, by providing the fixed electrode 561 on the flat electrode installation surface 511A, the gap between the fixed electrode 561 and the movable electrode 562 can be made uniform, and the inconvenience of non-uniform electrostatic attraction can be suppressed.

  In the present embodiment, the electrode arrangement groove 511 is formed in an annular shape surrounding the reflection film installation surface 512A. Accordingly, the entire outer peripheral portion of the fixed reflective film 54 where the rough film portion may be formed is located in the electrode arrangement groove 511, and the contact between the reflective films can be more reliably suppressed. it can.

[Second Embodiment]
Next, a second embodiment of the present invention will be described based on the drawings.
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.
FIG. 10 is a sectional view showing a schematic configuration of the optical filter device according to the second embodiment of the present invention.

As shown in FIG. 10, the optical filter device 600 includes a wavelength tunable interference filter 5 and a housing 601 that houses the wavelength tunable interference filter 5.
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 this base substrate 610, the fixed substrate 51 of the wavelength variable interference filter 5 is installed. As the installation of the fixed substrate 51 to the base substrate 610, for example, it may be arranged through an adhesive layer or the like, and is arranged 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. And the base side glass substrate 630 is joined so that this light passage hole 611 may be covered. As a method for joining the base side glass substrate 630, for example, glass frit joining using a glass frit that is a piece of glass that has been melted at a high temperature and rapidly cooled, adhesion by an epoxy resin, or the like can be used.

On the base inner surface 612 of the base substrate 610 facing the lid 620, inner terminal portions 615 are provided corresponding to the respective extraction electrodes 563 and 564 of the wavelength variable interference filter 5. For example, FPC 615A can be used for connection between each extraction electrode 563, 564 and the inner terminal portion 615. For example, Ag paste, ACF (Anisotropic Conductive Film), ACP (Anisotropic Conductive Paste), or the like is joined. Further, the connection is not limited to the connection by the FPC 615A, and wiring connection by wire bonding or the like may be performed, for example.
In addition, the base substrate 610 has through holes 614 corresponding to positions where the respective inner terminal portions 615 are provided, and the respective inner terminal portions 615 are interposed via conductive members filled in the through holes 614. The base substrate 610 is connected to an outer terminal portion 616 provided on the base outer surface 613 opposite to the base inner surface 612.
A base joint 617 that is joined to the lid 620 is provided on the outer periphery of the base substrate 610.

As shown in FIG. 10, the lid 620 includes a lid joint 624 joined to the base joint 617 of the base substrate 610, a side wall 625 that continues from the lid joint 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 movable substrate 52 side of the wavelength variable 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. 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.

  In the optical filter device 600 according to the present embodiment as described above, the wavelength tunable interference filter 5 is protected by the casing 601, so that the wavelength tunable interference filter 5 can be prevented from being damaged by an external factor. Further, since the inside of the optical filter device 600 is hermetically sealed, entry of foreign matter such as water droplets and charged substances can be suppressed, and inconvenience that these foreign matters adhere to the fixed reflective film 54 and the movable reflective film 55 is also suppressed. be able to.

[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 first substrate of the present invention is the fixed substrate 51, and the fixed substrate 51 is closer to the reflective film installation surface 512A, which is the first flat portion, and the movable substrate 52 than the reflective film installation surface 512A. However, the present invention is not limited to this. However, the present invention is not limited to this. For example, as shown in FIG. 11, in the movable substrate 52, the second opposing region 521C and the third opposing region 521D surrounding the first opposing region 521B may be configured as groove portions. By adopting such a configuration, the outer peripheral portion in which the rough film portion in the movable reflective film 55 may be formed does not protrude toward the fixed substrate 51 from the first facing region 521B. Therefore, as in the above embodiment, the area overlapping the reflective film installation surface 512A, which is the first plane portion (area having a radius R1 from the filter center point O) can be set as the effective diameter, and the fixed reflective film 54 In addition, the contact of the movable reflective film 55 can be suppressed.
11 shows an example in which the fixed substrate 51 is provided with the electrode arrangement groove 511 and the reflection film installation portion 512, and the reflection film installation surface 512A and the electrode installation surface 511A have different height dimensions. The film installation surface 512A and the electrode installation surface 511A may be the same surface.

In the above-described embodiment, the configuration in which the dimension of the inter-reflective film gap G1 is changed by the electrostatic actuator 56 including the fixed electrode 561 and the movable electrode 562 is exemplified, but the present invention is not limited to this.
For example, a configuration may be used in which 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 is used.
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 voltage application. For example, the air pressure between the fixed substrate 51 and the movable substrate 52 with respect to the air pressure outside the wavelength variable interference filter 5 is changed. Thus, a configuration for adjusting the size of the gap G1 between the reflection films can be exemplified.

  In the said embodiment, although the outer periphery of the fixed reflection film 54 showed the example located in the boundary L, it is not limited to this. In the present invention, the region in which the rough film portion may be formed only needs to be configured in the electrode arrangement groove 511 outside the reflection film installation surface 512A. For example, the thickness dimension of the resist when forming the reflection film, etc. Depending on the case, the outer peripheral edge of the fixed reflective film 54 may be located in the middle part of the curved surface part 511B. Further, the outer peripheral edge of the fixed reflective film 54 may be located outside the boundary L, and in this case, the inconvenience that the unevenness of the rough film portion contacts the movable reflective film 55 can be suppressed more reliably. The same applies to the movable reflective film 55.

In this embodiment, although the groove part of this invention was the electrode arrangement | positioning groove | channel 511, and the example provided in the cyclic | annular form surrounding the reflective film installation part 512 was shown, it is not limited to this. For example, the electrode arrangement groove 511 may have an arc shape, and may be provided outside the reflection film installation portion 512 so as to be rotationally symmetric (equally spaced) with respect to the filter center point O. Even in this case, since the rough film portion is not formed in the region overlapping the reflection film installation surface 512A, the region overlapping the reflection film installation surface 512A (the region having the radius R1 from the filter center point O) is set as the effective region in the filter plan view. can do. In addition, the risk that the reflective films come into contact with each other increases as compared with the above embodiment, but the risk can be reduced as compared with the configuration in which the entire fixed reflective film 54 is provided on the same plane.
Alternatively, the movable reflective film 55 may be provided in the first facing region 521B. In this case, the unevenness of the rough film portion formed on the movable reflective film 55 may come into contact with the fixed reflective film 54, but the rough film portion of the fixed reflective film 54 is formed in a region facing the rough film portion. Is less likely to be Therefore, the convex portions of the rough film portion protruding to the opposite substrate side among the reflective films 54 and 55 are provided at different positions, and the contact between the reflective films can be suppressed.

  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 wavelength variable interference filter 5, the optical module, and the electronic apparatus of the present invention can be applied in various other fields. it can.

For example, as shown in FIG. 12, the electronic apparatus of the present invention can also be applied to a color measuring device for measuring color.
FIG. 12 is a block diagram illustrating an example of a color measurement device 400 including the wavelength variable interference filter 5.
As shown in FIG. 12, the color measurement device 400 includes a light source device 410 that emits light to the inspection target A, a color measurement sensor 420 (optical module), and a control device 430 that controls the overall operation of the color measurement device 400. (Control part). The color measuring device 400 reflects light emitted from the light source device 410 by the inspection target A, receives the reflected inspection target light by the color measuring sensor 420, and outputs the light from the color measuring sensor 420. This is an apparatus for analyzing and measuring the chromaticity of the inspection target light, that is, the color of the inspection target A based on the detection signal.

  The light source device 410 includes a light source 411 and a plurality of lenses 412 (only one is shown in FIG. 12), and emits, for example, reference light (for example, white light) to the inspection target A. The plurality of lenses 412 may include a collimator lens. In this case, the light source device 410 converts the reference light emitted from the light source 411 into parallel light by the collimator lens and inspects from a projection lens (not shown). Inject toward the subject A. In the present embodiment, the color measuring device 400 including the light source device 410 is illustrated, but the light source device 410 may not be provided when the inspection target A is a light emitting member such as a liquid crystal panel.

  As shown in FIG. 12, the colorimetric sensor 420 includes a tunable interference filter 5, a detector 11 that receives light transmitted through the tunable interference filter 5, and a voltage applied to the electrostatic actuator 56 of the tunable interference filter 5. And a voltage control unit 15 for controlling. Note that an optical filter device 600 may be used instead of the variable wavelength interference filter 5. 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.

The control device 430 is a control unit of the present invention and 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. 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 as illustrated in FIG.
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 command signal to that effect is output to the colorimetric sensor 420. Thereby, the voltage control unit 15 of the colorimetric sensor 420 applies a voltage to the electrostatic actuator 56 based on the control signal, and drives the wavelength variable interference filter 5.
The colorimetric processing unit 433 analyzes the chromaticity of the inspection target A from the amount of received light detected by the detector 11. Similarly to the first, the colorimetric processing unit 433 analyzes the chromaticity of the inspection target A by estimating the spectral spectrum S using the estimation matrix Ms with the light amount obtained by the detector 11 as the measurement spectrum D. May be.

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 wavelength tunable interference filter 5 of the present invention, or a photoacoustic noble gas for a breath test. A gas detection device such as a detector can be exemplified.
An example of such a gas detection device will be described below with reference to the drawings.

FIG. 13 is a schematic diagram illustrating an example of a gas detection apparatus including the wavelength variable interference filter 5.
FIG. 14 is a block diagram showing a configuration of a control system of the gas detection device of FIG.
As shown in FIG. 13, the gas detection device 100 includes a sensor chip 110, a flow path 120 including a suction port 120A, a suction flow path 120B, a discharge flow path 120C, and a discharge port 120D, a main body 130, It is configured with.
The main body unit 130 includes a sensor unit cover 131 having an opening through which the flow channel 120 can be attached, a discharge unit 133, a housing 134, an optical unit 135, a filter 136, a wavelength variable interference filter 5, a light receiving element 137 (detection unit), and the like. And a control unit 138 that processes the detected signal and controls the detection unit, a power supply unit 139 that supplies power, and the like. Note that an optical filter device 600 may be used instead of the variable wavelength interference filter 5. The optical unit 135 emits light, and a beam splitter 135B that reflects light incident from the light source 135A toward the sensor chip 110 and transmits light incident from the sensor chip toward the light receiving element 137. And lenses 135C, 135D, and 135E.
As shown in FIG. 14, an operation panel 140, a display unit 141, a connection unit 142 for interface with the outside, and a power supply unit 139 are provided on the surface of the gas detection device 100. When the power supply unit 139 is a secondary battery, a connection unit 143 for charging may be provided.
Further, as shown in FIG. 14, the control unit 138 of the gas detection apparatus 100 controls a signal processing unit 144 configured by a CPU or the like, a light source driver circuit 145 for controlling the light source 135A, and the variable wavelength interference filter 5. Voltage control unit 146, a light receiving circuit 147 that receives a signal from the light receiving element 137, a sensor chip detection that reads a code of the sensor chip 110 and receives a signal from a sensor chip detector 148 that detects the presence or absence of the sensor chip 110 A circuit 149, a discharge driver circuit 150 for controlling the discharge means 133, and the like are provided. Further, the gas detection device 100 includes a storage unit (not shown) that stores V-λ data.

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

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

The sensor chip 110 is a sensor that incorporates a plurality of metal nanostructures and uses localized surface plasmon resonance. In such a sensor chip 110, an enhanced electric field is formed between the metal nanostructures by the laser light, and when gas molecules enter the enhanced electric field, Raman scattered light and Rayleigh scattered light including information on molecular vibrations are generated. Occur.
These Rayleigh scattered light and Raman scattered light enter the filter 136 through the optical unit 135, and the Rayleigh scattered light is separated by the filter 136, and the Raman scattered light enters the wavelength variable interference filter 5. Then, the signal processing unit 144 outputs a control signal to the voltage control unit 146. Thereby, as shown in the first embodiment, the voltage control unit 146 reads the voltage value corresponding to the wavelength to be measured from the storage unit, applies the voltage to the electrostatic actuator 56 of the wavelength variable interference filter 5, The Raman scattered light corresponding to the gas molecules to be detected is dispersed by the wavelength variable interference filter 5. 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.

  13 and 14 exemplify 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. 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 5.

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. 15 is a diagram illustrating a schematic configuration of a food analyzer that is an example of an electronic apparatus using the wavelength variable interference filter 5.
As shown in FIG. 15, the food analyzer 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. Note that an optical filter device 600 may be used instead of the variable wavelength interference filter 5.
In addition, the control unit 220 controls the light source control unit 221 that controls the turning on / off of the light source 211 and the brightness control at the time of lighting, the voltage control unit 222 that controls the wavelength variable interference filter 5, and the imaging unit 213. , A detection control unit 223 that acquires a spectral image captured by the imaging unit 213, a signal processing unit 224, and a storage unit 225.

  In the food analyzer 200, when the system is driven, the light source 211 is controlled by the light source control unit 221, and light is irradiated from the light source 211 to the measurement object. Then, the light reflected by the measurement object enters the wavelength variable interference filter 5 through the imaging lens 212. The variable wavelength interference filter 5 is driven by the control of the voltage control unit 222. Thereby, the light of the target wavelength can be extracted from the variable wavelength interference filter 5 with high accuracy. Then, the extracted light is imaged by an imaging unit 213 configured by, for example, a CCD camera or the like. The captured light is accumulated in the storage unit 225 as a spectral image. In addition, the signal processing unit 224 controls the voltage control unit 222 to change the voltage value applied to the wavelength tunable interference filter 5, and acquires a spectral image for each wavelength.

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

FIG. 15 shows an example of the food analysis apparatus 200, but it can also be used as a non-invasive measurement apparatus for other information as described above with a substantially similar configuration. For example, it can be used as a biological analyzer for analyzing biological components such as measurement and analysis of body fluid components such as blood. As such a bioanalytical device, for example, a device that detects ethyl alcohol as a device that measures a body fluid component such as blood, it can be used as a drunk driving prevention device that detects the drunk state of the driver. Further, it can also be used as an electronic endoscope system provided with such a biological analyzer.
Furthermore, it can also be used as a mineral analyzer for performing component analysis of minerals.

Furthermore, the variable wavelength interference filter, the optical module, and the 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 with time. In this case, the wavelength variable interference filter 5 provided in the optical module can be used to transmit data of a specific wavelength. By separating the light and receiving the light at the light receiving unit, it is possible to extract the data transmitted by the light of a specific wavelength, and the electronic device equipped with such an optical module for data extraction uses the data of the light of each wavelength. By processing this, optical communication can also be performed.

Further, the electronic apparatus can be applied to a spectroscopic camera, a spectroscopic analyzer, or the like that captures a spectroscopic image by dispersing light with the variable wavelength interference filter of the present invention. As an example of such a spectroscopic camera, an infrared camera having a built-in variable wavelength interference filter 5 can be cited.
FIG. 16 is a schematic diagram showing a schematic configuration of the spectroscopic camera. As shown in FIG. 16, the spectroscopic camera 300 includes a camera body 310, an imaging lens unit 320, and an imaging unit 330 (detection unit).
The camera body 310 is a part that is gripped and operated by a user.
The imaging lens unit 320 is provided in the camera body 310 and guides incident image light to the imaging unit 330. Further, as shown in FIG. 16, the imaging lens unit 320 includes an objective lens 321, an imaging lens 322, and a variable wavelength interference filter 5 provided between these lenses.
The imaging unit 330 includes a light receiving element, and images the image light guided by the imaging lens unit 320.
In such a spectroscopic camera 300, a spectral image of light having a desired wavelength can be captured by transmitting light having a wavelength to be imaged by the variable wavelength interference filter 5.

Furthermore, the wavelength tunable interference filter of the present invention may be used as a bandpass filter. For example, only light in a narrow band centered on a predetermined wavelength out of light in a predetermined wavelength range emitted from the light emitting element can be wavelength-variable. It can also be used as an optical laser device that spectrally transmits through the interference filter 5.
In addition, the tunable interference filter of the present invention may be used as a biometric authentication device, and can be applied to authentication devices such as blood vessels, fingerprints, retinas, and irises using light in the near infrared region and visible region.

  Furthermore, an optical module and an electronic device can be used as a concentration detection device. In this case, the infrared energy (infrared light) emitted from the substance is spectrally analyzed by the wavelength tunable interference filter 5, and the analyte concentration in the sample is measured.

  As described above, the tunable interference filter, the optical module, and the electronic device of the present invention can be applied to any device that splits predetermined light from incident light. Since the wavelength tunable interference filter according to the present invention can split a plurality of wavelengths with one device as described above, it is possible to accurately measure a spectrum of a plurality of wavelengths and detect a plurality of components. it can. Therefore, compared with the conventional apparatus which takes out a desired wavelength with a plurality of devices, it is possible to promote downsizing of the optical module and the electronic apparatus, and for example, it can be suitably used as a portable or in-vehicle optical device.

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

  DESCRIPTION OF SYMBOLS 1 ... Spectrometer (electronic device), 5 ... Wavelength variable interference filter, 10 ... Optical module, 11 ... Detector (detection part), 20 ... Control part, 51 ... Fixed board | substrate (1st board | substrate), 52 ... Movable board | substrate ( Second substrate), 54 ... Fixed reflective film (first reflective film), 55 ... Movable reflective film (second reflective film), 100 ... Gas detector (electronic device), 137 ... Light receiving element (detector), 138 ... Control unit, 200 ... food analysis device (electronic device), 213 ... imaging unit (detection unit), 220 ... control unit, 300 ... spectral camera (electronic device), 330 ... imaging unit (detection unit), 400 ... colorimetry device (Electronic equipment) 430 ... Control device (control part) 511 ... Electrode placement groove (groove part) 511A ... Electrode installation surface (flat part) 511B ... Curved surface part 512 ... Reflection film installation part 512A ... Reflection film installation Surface (first surface), 521A, movable surface, 21B... First opposing region (first flat portion opposing region) 521C. Second opposing region (curved surface opposing region, groove facing region) 521D. Third opposing region (flat portion opposing region, groove facing region) 522 ... holding part, 561 ... fixed electrode (first electrode), 562 ... movable electrode (second electrode), G1 ... gap between reflection films.

Claims (10)

A first substrate;
A second substrate disposed opposite the first substrate;
A first reflective film that is provided on the first substrate and reflects a part of incident light and transmits a part thereof;
A second reflective film provided on the second substrate, facing the first reflective film, reflecting a part of incident light and transmitting a part thereof;
The first substrate has a first flat portion facing the second substrate, and a groove portion surrounding the outer periphery of the first flat portion in a plan view of the first substrate and the second substrate viewed from the substrate thickness direction. And
The tunable interference filter according to claim 1, wherein the first reflective film is continuously provided on the first flat surface portion and at least a partial region of the groove portion. The tunable interference filter according to claim 1,
The distance from the said groove part to said 2nd board | substrate is longer than the distance from said 1st plane part to said 2nd board | substrate. The variable wavelength interference filter characterized by the above-mentioned. In the wavelength tunable interference filter according to claim 1 or 2,
The groove part includes a flat part facing the second substrate, and a curved part provided between the flat part and the first flat part,
An outer peripheral edge of the first reflective film is located at a boundary between the curved surface portion and the flat portion or outside the boundary. The tunable interference filter according to claim 3,
A first electrode provided on the first substrate;
A second electrode provided on the second substrate and facing the first electrode;
The wavelength variable interference filter, wherein the first electrode is provided on the flat portion. In the wavelength variable interference filter according to any one of claims 1 to 4,
The groove portion is provided in an annular shape surrounding the first flat surface portion in the plan view. In the wavelength tunable interference filter according to any one of claims 1 to 5,
The second reflective film is continuously provided in a first planar portion facing region facing the first planar portion of the second substrate and at least a part of the groove facing region facing the groove in the plan view. A tunable interference filter characterized by The tunable interference filter according to claim 6,
The groove part includes a flat part facing the second substrate, and a curved part provided between the flat part and the first flat part,
The groove facing region includes a flat portion facing region facing the flat portion, and a curved surface facing region facing the curved portion,
An outer peripheral edge of the second reflective film is located at a boundary between the flat portion facing region and the curved surface facing region or outside the boundary. A first substrate, a second substrate disposed opposite the first substrate, a first reflective film provided on the first substrate and reflecting a part of incident light and transmitting a part thereof; A wavelength tunable interference filter provided with a second reflection film facing the first reflection film and reflecting a part of incident light and transmitting a part thereof;
A housing for housing the variable wavelength interference filter,
The first substrate has a first flat portion facing the second substrate, and a groove portion surrounding the outer periphery of the first flat portion in a plan view of the first substrate and the second substrate viewed from the substrate thickness direction. And
The optical filter device, wherein the first reflective film is continuously provided on the first flat surface portion and at least a partial region of the groove portion. A first substrate;
A second substrate disposed opposite the first substrate;
A first reflective film that is provided on the first substrate and reflects a part of incident light and transmits a part thereof;
A second reflective film provided on the second substrate, facing the first reflective film, reflecting a part of incident light and transmitting a part thereof;
A detector that detects light having a wavelength selected by interference of light incident between the first reflective film and the second reflective film; and
The first substrate has a first flat portion facing the second substrate, and a groove portion surrounding the outer periphery of the first flat portion in a plan view of the first substrate and the second substrate viewed from the substrate thickness direction. And
The optical module, wherein the first reflective film is continuously provided on the first flat surface portion and at least a partial region of the groove portion. A first substrate, a second substrate disposed opposite the first substrate, a first reflective film provided on the first substrate and reflecting a part of incident light and transmitting a part thereof; A wavelength tunable interference filter provided with a second reflection film facing the first reflection film and reflecting a part of incident light and transmitting a part thereof;
A control unit for controlling the wavelength variable interference filter,
The first substrate has a first flat portion facing the second substrate, and a groove portion surrounding the outer periphery of the first flat portion in a plan view of the first substrate and the second substrate viewed from the substrate thickness direction. And
The electronic apparatus according to claim 1, wherein the first reflective film is continuously provided on the first flat surface portion and at least a partial region of the groove portion.

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