JP2013113900A - Wavelength variable interference filter, optical filter device, optical module, and electronic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wavelength variable interference filter, an optical filter device, an optical module and electronic equipment capable of extracting a specified wavelength from light in a broad wavelength band.SOLUTION: A wavelength variable interference filter 5 includes a first substrate 51 having a first reflection film 551 and a third reflection film 553, a second substrate 52 having a second reflection film 552 opposing to the first reflection film 551 via a first gap G1, a third substrate 53 having a fourth reflection film 554 opposing to the third reflection film 553 via a second gap G2, and an electrostatic actuator 56 for varying the first gap G1, and has an optical interference area Ar0 where each reflection film overlaps one another in a plan view. One of a plurality of measurement target wavelength regions in a wavelength variable interference part 57 composed of the first and second reflection films 551, 552 overlaps one of a plurality of transmissive wavelength regions of a wavelength fixed interference part 58 composed of the third and fourth reflection films 553, 554.

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, there has been known a wavelength variable interference filter in which reflection films are arranged on opposite surfaces of a pair of substrates with a predetermined gap therebetween (see, for example, Patent Document 1).
The wavelength λ of light extracted by such a wavelength variable interference filter satisfies the condition shown in the following formula (1).

[Equation 1]
mλ = 2nd cos θ (1)

In the formula (1), n is the refractive index of the medium between the reflective films (n = 1 in the case of air), and d is the distance between the reflective films. M is an order and takes an integer (m = 1, 2, 3,...). That is, the spectral characteristics of the wavelength tunable interference filter have a plurality of peak wavelengths having different orders m.
Therefore, when light having a wide wavelength band is incident on the wavelength variable interference filter, light corresponding to a plurality of peak wavelengths is transmitted, which is inconvenient when it is desired to extract only light having a specific peak wavelength.

On the other hand, an apparatus for extracting a predetermined peak wavelength from the wavelength variable interference filter as described above is known (see, for example, Patent Documents 2 and 3).
In Patent Document 2, a plurality of wavelength tunable interference filters are overlapped to extract light for a specific peak wavelength, and a wavelength tunable interference filter and a fixed interference filter with a fixed transmission wavelength range are overlapped and specified. The structure which extracts the light with respect to the peak wavelength of is disclosed.
Further, Patent Document 3 has a configuration in which a filter disk in which a plurality of filters are incorporated is arranged in front of the wavelength tunable interference filter, and the filter to be overlapped with the wavelength tunable interference filter is switched by rotating the filter disk. It is disclosed.

JP-A-1-94312 JP 2009-33222 A JP 2000-329617 A

  By the way, in the said patent document 2 and patent document 3, it becomes the structure which provides a wavelength fixed type interference filter and a color filter on the optical path of a wavelength variable interference filter. As the number of optical elements arranged on the optical path increases in this way, there is a problem that it is impossible to cope with complication and miniaturization of the apparatus, and a configuration that can extract a specific wavelength from light in a wide wavelength band with one filter Is desired.

  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 extract a specific wavelength from light in a wide wavelength band.

  The wavelength tunable interference filter of the present invention includes a first substrate, a second substrate disposed to face the first substrate, and a first reflection provided on a surface of the first substrate facing the second substrate. A film, a surface of the second substrate facing the first substrate, a second reflective film facing the first reflective film with a gap, and between the first reflective film and the second reflective film A gap changing portion for changing a gap amount of the gap; a third substrate disposed opposite to a surface of the first substrate opposite to the surface facing the second substrate; and the third substrate of the first substrate. A third reflective film provided on the surface facing the substrate, and a fourth reflective film provided on the surface of the third substrate facing the first substrate and facing the third reflective film via a gap From the substrate thickness direction of the first substrate, the second substrate, and the third substrate In the plan view, the region where the first reflective film, the second reflective film, the third reflective film, and the fourth reflective film overlap constitutes an optical interference region, and the first reflective film and the second reflective film The reflective film constitutes a wavelength variable interference unit having a plurality of wavelength bands to be measured corresponding to a plurality of peak wavelengths having different orders, and the third reflective film and the fourth reflective film have a plurality of peak wavelengths having different orders. A wavelength-fixed interference unit having a plurality of transmissive wavelength regions corresponding to the wavelength range of the measurement target light, and any one of the plurality of measurement target wavelength regions of the wavelength tunable interference unit is the wavelength fixed It overlaps with any one of the plurality of transmissive wavelength regions of the interference unit.

In the present invention, the variable wavelength interference unit is configured by the first reflective film and the second reflective film. The transmission characteristics of the wavelength tunable interference unit have a plurality of peak wavelengths corresponding to the order m, as shown in the above-described equation (1). Therefore, the light that can be transmitted through the wavelength variable interference unit is light corresponding to these peak wavelengths.
In the wavelength variable interference unit, the peak wavelength in the transmission characteristic can be changed by controlling the gap amount of the gap between the first reflective film and the second reflective film by the gap amount changing unit. For this reason, the wavelength range of light that can be extracted by the wavelength variable interference unit is a plurality of measurement target wavelength ranges corresponding to a plurality of peak wavelength fluctuation ranges. Therefore, when the measurement target light incident on the wavelength tunable interference filter has a wide wavelength band, a plurality of wavelengths of light corresponding to the plurality of measurement target wavelength ranges are transmitted from the wavelength variable interference unit.
On the other hand, in this invention, a wavelength fixed interference part is comprised by the 3rd reflective film and the 4th reflective film. Similar to the variable wavelength interference unit, the transmission characteristics of the fixed wavelength interference unit have a plurality of peak wavelengths corresponding to the order m as shown in the equation (1), and a predetermined transmissive wavelength centered on the peak wavelength. The light in the region can be transmitted. In the present invention, in the wavelength band of the measurement target light, any one of the measurement target wavelength ranges of the wavelength variable interference unit overlaps with any one of the transmittable wavelength ranges of the wavelength fixed interference unit. In such a configuration, light in a transmissive wavelength range that does not overlap with the measurement target wavelength region and light in the measurement target wavelength region that does not overlap with the transmissive wavelength region are not transmitted from the optical interference region, but transmitted through the measurement target wavelength region. Light of a specific wavelength within a range that overlaps the possible wavelength range is transmitted through the optical interference region.
For this reason, the variable wavelength interference filter of the present invention can extract light having a desired specific wavelength without using another bandpass filter or the like even when the wavelength band of the measurement target light is wide.

For example, the wavelength band of the measurement target light that can be measured by the variable wavelength interference filter is from the visible light region to the near infrared light region (for example, 400 nm to 1300 nm), and between the first reflective film and the second reflective film in the variable wavelength interference unit. When the gap amount of the gap can be changed between 450 nm and 600 nm, the measurable wavelength range of the wavelength tunable interference unit is 900 nm to 1200 nm corresponding to the fluctuation range of the primary peak wavelength, and the fluctuation range of the secondary peak wavelength. The corresponding 450 nm to 600 nm and 300 nm to 400 nm corresponding to the fluctuation range of the tertiary peak wavelength are obtained.
In this case, for example, when it is desired to transmit light in the visible light range (for example, 450 nm to 750 nm) from the wavelength variable interference filter, for example, the transmissive wavelength range centered on the primary peak wavelength of the wavelength fixed interference unit is used. The third reflective film, the fourth reflective film, and the gap amount of the gap between the third reflective film and the fourth reflective film may be set so as to overlap with the measurement target wavelength range corresponding to the visible light range. By using such a tunable interference filter, light having a predetermined wavelength in the visible light region can be transmitted from a measurement target having a wavelength band from the visible light region to the near infrared region.

In the wavelength tunable interference filter according to the aspect of the invention, at least one of the first substrate and the third substrate is provided with a recess on a surface facing the other, and the third reflection film or the fourth is formed on the bottom surface of the recess. A reflective film is preferably provided.
In the present invention, a recess is provided in at least one of the first substrate and the third substrate. As a formation position of a recessed part, it may be provided in both the 1st board | substrate and the 3rd board | substrate, and may be provided in either one of a 1st board | substrate and a 3rd board | substrate. By providing such a recess, the third reflective film and the fourth reflective film can be opposed to each other with a predetermined gap, and the configuration can be simplified.

In the wavelength tunable interference filter according to the aspect of the invention, it is preferable that the concave portion is provided on one of the first substrate and the third substrate.
In the present invention, the concave portion is formed on one of the first substrate and the third substrate. In such a configuration, for example, the substrate processing step can be simplified and the manufacturing efficiency can be improved as compared with the configuration in which the concave portions are provided in both the first substrate and the third substrate.

In the wavelength tunable interference filter according to the aspect of the invention, it is preferable that the optical interference region includes a plurality of small regions having different gap amounts between the third reflective film and the fourth reflective film.
In the present invention, since a plurality of small regions having different gap amounts between the third reflective film and the fourth reflective film are provided in the optical interference region, light of different wavelengths is transmitted in each small region. Can do.
For example, in the first small region, the measurement target wavelength region corresponding to the primary peak wavelength of the wavelength variable interference unit overlaps one of the plurality of transmissive wavelength regions of the fixed interference unit, and in the second small region, the wavelength The gap between the third reflective film and the fourth reflective film in each small region so that the measurement target wavelength region corresponding to the secondary peak wavelength of the variable interference unit overlaps one of the plurality of transmissive wavelength regions of the fixed interference unit. Design the gap amount. In this case, in the optical interference region, light in the measurement target wavelength region corresponding to the primary peak wavelength of the wavelength variable interference unit is transmitted from the first small region, and the secondary of the wavelength variable interference unit is transmitted from the second small region. Light in the wavelength range to be measured corresponding to the peak wavelength can be transmitted.
Thereby, light of a plurality of wavelengths can be independently extracted from the measurement target light by one (single) variable wavelength interference filter.

In the wavelength tunable interference filter according to the aspect of the invention, the optical interference region includes a plurality of partial regions, and each of the partial regions has a plurality of gap amounts different from each other between the third reflective film and the fourth reflective film. It is preferable that a small region is provided.
In the present invention, the optical region is divided into a plurality of partial regions and further divided into smaller regions within the partial regions. And these small area | regions differ in the gap amount of the gap between a 3rd reflective film and a 4th reflective film similarly to the said invention, and permeate | transmit light of a different wavelength in each small area | region.
In such a tunable interference filter, the partial region can be divided, for example, in units of pixels, and a plurality of spectral images corresponding to a plurality of wavelengths can be extracted simultaneously.

The wavelength tunable interference filter according to the present invention preferably includes a light blocking portion that prevents light from entering a region boundary between the small regions adjacent to each other.
Here, the position where the light shielding portion is provided may be any position as long as it can prevent light from entering the region boundary. For example, of the third substrate and the second substrate, It may be provided on the surface of the substrate, or may be provided on the third reflective film or the fourth reflective film. Further, if the wavelength tunable interference unit is located closer to the light incident side than the wavelength fixed interference unit, it may be configured to be provided in the first reflection film or the second reflection film.

In the present invention, there is provided a light blocking portion that prevents light from entering the region boundary between the small regions as described above. Adjacent small regions are set to different values for the gap amount between the third reflective film and the fourth reflective film, respectively, so that a step or an inclined surface is formed at the boundary between the small regions. Become. When light enters such a step or inclined surface, the traveling direction of the light changes due to reflection or refraction of the light. In this way, when the traveling direction of light changes, for example, the light is transmitted without being incident on the reflective film, or the light is incident obliquely with respect to the surface of each reflective film, and the target wavelength to be extracted is Light of different wavelengths may be transmitted through the wavelength tunable interference filter, causing a reduction in resolution of the wavelength tunable interference filter.
On the other hand, in the present invention, since the light is blocked from entering the region boundary by the light shielding unit, the reflection and refraction of light at the region boundary as described above can be avoided, and the resolution of the wavelength variable interference filter can be reduced. Reduction can be suppressed.

  The optical filter device of the present invention includes a first substrate, a second substrate disposed to face the first substrate, a first reflective film provided on a surface of the first substrate facing the second substrate, On the surface of the second substrate facing the first substrate, the second reflective film facing the first reflective film via a gap, the gap amount of the gap between the first reflective film and the second reflective film A gap changing portion to be changed, a third substrate disposed opposite to a surface of the first substrate opposite to the surface facing the second substrate, and a surface of the first substrate facing the third substrate. And a fourth variable reflection filter provided on a surface of the third substrate facing the first substrate and facing the third reflection film via a gap. And a housing for housing the variable wavelength interference filter. The first reflective film, the second reflective film, the third reflective film, and the fourth reflective film in a plan view as viewed from the thickness direction of the first substrate, the second substrate, and the third substrate. A region where the two overlap each other constitutes a light interference region, and the first reflection film and the second reflection film corresponding to the light interference region have a plurality of measurement target wavelength regions corresponding to a plurality of peak wavelengths having different orders. A wavelength-fixed interference unit that constitutes a wavelength variable interference unit, and wherein the third reflective film and the fourth reflective film corresponding to the optical interference region have a plurality of transmissive wavelength regions corresponding to a plurality of peak wavelengths having different orders In the wavelength band of the measurement target light, any one of the plurality of measurement target wavelength ranges of the wavelength variable interference unit is any of the plurality of transmittable wavelength ranges of the fixed wavelength interference unit Characterized by overlapping one .

  In the optical filter device of the present invention, similar to the above-described invention, even when the measurement target light has a wide wavelength band, a specific wavelength within the range where the measurement target wavelength band and the transmittable wavelength band overlap is extracted. Light can be extracted. In addition, since the wavelength tunable interference filter is housed in the housing, it is possible to suppress the entry of foreign substances such as charged substances and water particles. As a result, the gap between the first reflecting film and the second reflecting film in the wavelength variable interference part due to the adhesion of the charged substance to the reflecting film, and the gap between the third reflecting film and the fourth reflecting film in the wavelength fixed interference part The deterioration of the reflective film can be prevented.

  The optical module of the present invention includes a first substrate, a second substrate disposed to face the first substrate, and a first reflective film provided on a surface of the first substrate facing the second substrate. A surface of the second substrate facing the first substrate, a second reflective film facing the first reflective film via a gap, and a gap between the first reflective film and the second reflective film. A gap changing portion for changing a gap amount, a third substrate disposed opposite to a surface of the first substrate opposite to the surface facing the second substrate, and the third substrate of the first substrate. A third reflective film provided on the facing surface, a fourth reflective film provided on a surface of the third substrate facing the first substrate and facing the third reflective film via a gap; A detection unit for detecting light, and a base of the first substrate, the second substrate, and the third substrate In a plan view viewed from the thickness direction, an area where the first reflection film, the second reflection film, the third reflection film, and the fourth reflection film overlap each other constitutes an optical interference area, and the optical interference area The corresponding first reflection film and the second reflection film constitute a wavelength variable interference unit having a plurality of wavelength bands to be measured corresponding to a plurality of peak wavelengths having different orders, and the first reflection film and the second reflection film correspond to the optical interference area. The three reflecting films and the fourth reflecting film constitute a wavelength-fixed interference unit having a plurality of transmissive wavelength bands corresponding to a plurality of peak wavelengths having different orders, and the wavelength variable interference is within the wavelength band of the measurement target light. Any one of a plurality of wavelength bands to be measured overlaps any one of the plurality of transmissible wavelength bands of the fixed wavelength interference unit, and the detection unit is extracted by the optical interference region Detecting light And features.

  In the present invention, even when the measurement target light has a wide wavelength band, it is possible to extract light of a specific wavelength within a range where the measurement target wavelength range and the transmittable wavelength range overlap, Light can be detected by the detector. Therefore, it is possible to accurately detect the amount of light of a desired specific wavelength from the measurement target light having a wide wavelength band.

  The electronic device of the present invention includes a first substrate, a second substrate disposed to face the first substrate, and a first reflective film provided on a surface of the first substrate facing the second substrate. A surface of the second substrate facing the first substrate, a second reflective film facing the first reflective film via a gap, and a gap between the first reflective film and the second reflective film. A gap changing portion for changing a gap amount, a third substrate disposed opposite to a surface of the first substrate opposite to the surface facing the second substrate, and the third substrate of the first substrate. A third reflective film provided on the facing surface, a fourth reflective film provided on a surface of the third substrate facing the first substrate and facing the third reflective film via a gap; In plan view as viewed from the thickness direction of the first substrate, the second substrate, and the third substrate. A region where the first reflection film, the second reflection film, the third reflection film, and the fourth reflection film overlap each other has a light interference region, and the first reflection film corresponding to the light interference region and The second reflective film constitutes a wavelength variable interference unit having a plurality of wavelength bands to be measured corresponding to a plurality of peak wavelengths having different orders, and the third reflective film and the fourth reflective corresponding to the optical interference area The film constitutes a fixed wavelength interference unit having a plurality of transmissive wavelength regions corresponding to a plurality of peak wavelengths having different orders, and within the wavelength band of the measurement target light, the plurality of measurement target wavelength regions of the wavelength variable interference unit Is overlapped with any one of the plurality of transmissive wavelength regions of the wavelength-fixed interference unit.

  In the present invention, even when the measurement target light has a wide wavelength band, it is possible to extract light for extracting a specific wavelength within a range where the measurement target wavelength range and the transmittable wavelength range overlap. Therefore, in the electronic device, for example, when detecting light of a specific wavelength that has passed through the optical interference region and performing various processes based on the detected light, light of a wavelength other than the specific wavelength is not mixed, Accurate processing can be performed. Furthermore, in an electronic device, for example, an electronic device that outputs light transmitted through a light interference region to the outside, light having a desired specific wavelength can be output to the outside.

  A wavelength tunable interference filter according to the present invention includes a substrate, two reflective films arranged to face each other via a displaceable gap, and a wavelength tunable interference unit including a gap changing unit that changes a gap amount of the gap, A wavelength-fixed interference unit having two reflective films disposed to face each other through a fixed gap, and one of the reflective films included in the wavelength-tunable interference unit is one of the substrates One of the reflective films included in the fixed wavelength interference portion is provided on a surface opposite to the one surface of the substrate, as viewed from the substrate thickness direction of the substrate. In plan view, the first reflective film and the third reflective film are arranged to overlap each other.

In the present invention, a wavelength tunable interference unit and a wavelength fixed interference unit are provided, and one of the two reflecting films constituting the wavelength tunable interference unit on one surface of the substrate is fixed on the other surface of the substrate. One of the two reflective films constituting the part is provided. In such a configuration, similarly to the above-described invention, the light transmitted through both the wavelength variable interference unit and the wavelength fixed interference unit is extracted. Here, if any one of the measurement target wavelength ranges of the wavelength variable interference unit is configured to overlap with any one of the transmittable wavelength ranges of the fixed wavelength interference unit, the measurement target light in a wide wavelength band It is possible to extract light of a specific wavelength from
Also, compared to a configuration in which a plurality of bandpass filters are separately arranged in series with respect to the wavelength variable interference filter, light of a specific wavelength can be extracted with one wavelength variable interference filter, so the configuration is simplified. Can be realized.

1 is a block diagram showing a schematic configuration of a spectrometer according to a first embodiment of the present invention. 1 is a cross-sectional view showing a schematic configuration of a variable wavelength interference filter according to a first embodiment. The figure which shows the measurement object wavelength range of the wavelength variable interference part in the 1st small area of 1st embodiment, and the transmissive wavelength range of a wavelength fixed interference part. The figure which shows the measurement object wavelength range of the wavelength variable interference part in the 2nd small area | region of 1st embodiment, and the transmissive wavelength range of a wavelength fixed interference part. The figure which shows the measurement possible wavelength range of the wavelength variable interference part in a modification, and a wavelength fixed interference part, and the transmissive wavelength range of a wavelength fixed interference part. The figure which shows schematic structure of the spectroscopic camera of 2nd embodiment. The top view which shows schematic structure of the recessed part in the 3rd board | substrate of the wavelength variable interference filter of 2nd embodiment. Sectional drawing which shows schematic structure of the optical filter device of 3rd embodiment. Schematic which shows the gas detection apparatus provided with the wavelength variable interference filter of this invention. The block diagram which shows the structure of the control system of the gas detection apparatus of FIG. The figure which shows schematic structure of the food analyzer provided with the wavelength variable interference filter of this invention.

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

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

[Configuration of wavelength tunable interference filter]
Next, a variable wavelength interference filter incorporated in the optical module will be described.
FIG. 2 is a cross-sectional view showing a schematic configuration of the variable wavelength interference filter 5.
As shown in FIG. 2, the variable wavelength interference filter 5 includes a first substrate 51, a second substrate 52, and a third substrate 53. Each of these substrates 51, 52, and 53 is formed of, for example, various glasses such as soda glass, crystalline glass, quartz glass, lead glass, potassium glass, borosilicate glass, and alkali-free glass, crystal, and the like. . The first substrate 51 and the second substrate 52 are bonded by a bonding film 54A, and the first substrate and the third substrate 53 are bonded by a bonding film 54B. As the bonding films 54A and 54B, for example, a plasma polymerized film mainly containing siloxane can be used.

A first reflective film 551 is provided on a surface of the first substrate 51 facing the second substrate 52 of the variable wavelength interference filter 5, and a second reflective film 552 is disposed on the surface of the second substrate 52 facing the first substrate 51. Is provided. The first reflective film 551 and the second reflective film 552 are disposed to face each other via the first gap G1.
Further, the variable wavelength interference filter 5, the electrostatic actuator 56 (gap change portion) used to adjust the gap amount g ₀ of the first gap G1 between the first reflecting film 551 and the second reflection film 552 Is provided. The electrostatic actuator 56 includes a first electrode 561 provided on the first substrate 51 side and a second electrode 562 provided on the second substrate 52 side.

Further, a third reflective film 553 is provided on the surface of the variable wavelength interference filter 5 that faces the third substrate 53 of the first substrate 51, and the fourth reflection is provided on the surface of the third substrate 53 that faces the first substrate 51. A membrane 554 is provided. The third reflective film 553 and the fourth reflective film 554 are disposed to face each other via the second gap G2. Here, the second gap G2, and a region where the third reflective layer 553 and the fourth reflective layer 554 is opposed with a gap weight g _1, the third reflective layer 553 and the fourth reflective layer 554 is opposed with a gap weight g ₂ And the area.

The first reflective film 551 and the second reflective film 552 are seen in a plan view (filter plan view) when the variable wavelength interference filter 5 is viewed from the thickness direction of the first substrate 51, the second substrate 52, and the third substrate 53. The region where the third reflective film 553 and the fourth reflective film 554 overlap is the optical interference region Ar0 of the present invention.
In the optical interference region Ar0, the variable wavelength interference portion 57 is configured by the first reflective film 551 and the second reflective film 552 facing each other. The wavelength variable interference unit 57 can change the wavelength of light transmitted through the first reflective film 551 and the second reflective film 552 by adjusting the gap amount g ₀ of the first gap G 1 by the electrostatic actuator 56. it can.
In addition, the fixed wavelength interference unit 58 is configured by the third reflective film 553 and the fourth reflective film 554 facing each other in the optical interference region Ar0. The fixed wavelength interference unit 58, different wavelengths in a first wavelength fixing interference portion 581 second gap G2 is the gap amount g _1, and the second wavelength fixing interference portion 582 second gap G2 is the gap amount g ₂ Of light. Here, in this optical interference region Ar0, the region where the gap amount of the second gap G2 of the wavelength fixed interference unit 58 is “g ₁ ” is the first small region Ar1, and the gap amount of the second gap G2 is “g ₂ ”. Is defined as a second small area Ar2.

Further, in the filter plan view, the plane center point O of each of the substrates 51, 52, 53 coincides with the center point of each of the reflection films 551, 552, 553, 554 and coincides with the center point of the movable portion 521 described later. .
In the present embodiment, the measurement target light incident on the optical module 10 is incident on the third substrate 53 side, and the light extracted by the respective reflective films 551, 552, 553, 554 is transmitted through the second substrate 52. Then, the light enters the detection unit 11.

[Configuration of the first substrate]
Next, the configuration of the first substrate 51 will be described in detail.
The first substrate 51 is formed to have a larger thickness than the second substrate 52, and electrostatic attraction when a voltage is applied between the first electrode 561 and the second electrode 562, and the inside of the first electrode 561. There is no bending of the first substrate 51 due to stress. The first substrate 51 includes an electrode arrangement groove 511 and a reflective film installation part 512 formed by etching.

  The electrode arrangement groove 511 is formed in an annular shape centering on the plane center point O of the first substrate 51 in the filter plan view. The reflection film installation portion 512 is formed to protrude from the center portion of the electrode arrangement groove 511 toward the second substrate 52 in the filter plan view. A first electrode 561 is provided on the groove bottom surface (electrode installation surface 511A) of the electrode arrangement groove 511, and a first reflection film 551 is provided on the protruding front end surface (reflection film installation surface 512A) of the reflection film installation part 512. It is done.

The first electrode 561 provided on the electrode installation surface 511A is formed in an annular shape centering on the plane center point O, and preferably formed in an annular shape. The ring shape includes a structure in which a part of the ring shape is divided, for example, a substantially C-shaped structure.
The first substrate 51 is formed with a first extraction electrode (not shown) extending from the outer peripheral edge of the first electrode 561 to the outer periphery of the first substrate 51. The first extraction electrode is a voltage control unit. 15 is connected.
As the first electrode 561 and the first extraction electrode, any electrode material may be used as long as it is a conductive film. For example, ITO, a Cr / Au laminated electrode, or the like can be used.
Note that an insulating film may be stacked on the first electrode 561 in order to ensure a withstand voltage between the first electrode 561 and the second electrode 562.

On the reflection film installation surface 512A of the reflection film installation unit 512, a first reflection film 551 is provided so as to cover at least the light interference region Ar0. As this 1st reflective film 551, metal films, such as Ag, and alloy films, such as Ag alloy, can be used, for example. Further, as the first reflective film 551, for example, a dielectric multilayer film in which the high refractive layer is TiO ₂ and the low refractive layer is SiO ₂ may be used, a reflective film in which a dielectric multilayer film and a metal film are laminated, A reflective film in which a dielectric single layer film and an alloy film are laminated may be used.

A third reflective film 553 is provided on the surface of the first substrate 51 facing the third substrate 53 so as to cover at least the light interference region Ar0. As the third reflective film 553, Ag or an Ag alloy can be used in the same manner as the first reflective film 551. Further, as the third reflective film 553, for example, a dielectric multilayer film in which a high refractive layer is TiO ₂ and a low refractive layer is SiO ₂ may be used, or a reflective film in which a dielectric multilayer film and a metal film are laminated, or A reflective film in which a dielectric single layer film and an alloy film are laminated may be used.

[Configuration of second substrate]
Next, the configuration of the second substrate 52 will be described in detail.
As shown in FIG. 2, the second substrate 52 includes a circular movable portion 521 centered on the plane center point O, and a holding portion 522 that is coaxial with the movable portion 521 and holds the movable portion 521.
The movable part 521 is formed to have a thickness dimension larger than that of the holding part 522. For example, in this embodiment, the movable part 521 is formed to have the same dimension as the thickness dimension of the second substrate 52. In addition, the movable portion 521 is formed to have a diameter larger than at least the diameter of the outer peripheral edge of the first electrode 561 in the filter plan view. The surface of the movable portion 521 facing the first substrate 51 is a movable surface 521A parallel to the reflective film installation surface 512A, and the second reflective film 552 and the second electrode 562 are provided.

The second reflective film 552 is a reflective film having the same configuration as the first reflective film 551 described above.
The second electrode 562 is provided in a region overlapping the first electrode 561 in the filter plan view. The second substrate 52 is formed with a second extraction electrode (not shown) extending from the outer peripheral edge of the second electrode 562 to the outer periphery of the second substrate 52, and the second extraction electrode is a voltage control unit. 15 is connected. As the second electrode 562 and the second extraction electrode, any electrode material may be used as long as it is a conductive film, like the first electrode 561 and the first extraction electrode. For example, ITO, Cr / Cr / An Au laminated electrode or the like can be used. Similarly to the first electrode 561, an insulating film may be stacked over the second electrode 562 in order to ensure a withstand voltage between the first electrode 561 and the second electrode 562.

  Further, an antireflection film may be formed on the movable portion 521 on the surface opposite to the first substrate 51. This antireflection film can be formed by alternately laminating a low refractive index film and a high refractive index film.

The holding part 522 is a diaphragm that surrounds the periphery of the movable part 521, and is formed with less rigidity in the thickness direction than the movable part 521.
For this reason, the holding part 522 is more easily bent than the movable part 521 and can be bent toward the first substrate 51 by a slight electrostatic attraction. At this time, since the movable portion 521 has a thickness dimension larger than that of the holding portion 522 and becomes rigid, even when a force that causes the second substrate 52 to bend due to electrostatic attraction acts, the movable portion 521 is hardly bent. Further, it is possible to prevent the second reflective film 552 formed on the movable portion 521 from being bent.
In this embodiment, the diaphragm-like holding part 522 is illustrated, but the present invention is not limited to this. For example, a configuration in which beam-like holding parts arranged at equiangular intervals around the plane center point O are provided. Etc.

[Configuration of third substrate]
Next, the configuration of the third substrate 53 will be described in detail.
The third substrate 53 has a thickness dimension similar to that of the first substrate 51, for example. Therefore, there is no bending of the third substrate 53 due to the internal stress of the fourth reflective film 554. The third substrate 53 includes a gap forming recess 531 formed by etching.
A fourth reflective film 554 is provided on the bottom surface of the recess 531. As the fourth reflective film 554, a reflective film having the same configuration as the third reflective film 553 described above is used.

The concave portion 531 includes a first concave portion 531A for setting the gap amount of the second gap G2 to “g ₁ ” and a second concave portion 531B for setting the gap amount of the second gap G2 to “g ₂ ”. Provided, each having a different groove depth.
In such a recess 531, the first recess 531 </ b> A corresponding to the first small region Ar <b> 1 and the second recess 531 </ b> B corresponding to the second small region Ar <b> 2 have different depth dimensions. An inclined surface (or step surface) is formed at the region boundary 532 between the recesses 531B.

Further, a light shielding portion 533 is provided on a surface (light incident surface) of the third substrate 53 that does not face the first substrate 51. The light shielding portion 533 is not particularly limited as long as it does not transmit light having a wavelength to be measured. For example, when using visible light, an Au film having a Cr film as a base may be used. You may be comprised by apply | coating black paint etc.
The light shielding portion 533 is formed in an annular shape, and the diameter of the optical interference region Ar0 is defined by the inner circumferential diameter 533A. That is, the light shielding unit 533 functions as an aperture.
Further, the light shielding portion 533 is also formed at a position overlapping the region boundary portion 532 of the concave portion 531 in the filter plan view. Thereby, it is possible to prevent light from entering the region boundary portion 532 and to suppress a decrease in optical characteristics of the wavelength variable interference filter 5.

  Further, an antireflection film may be formed on the light incident surface of the third substrate 53 in the light interference region Ar0. 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 light on the surface of the third substrate 53 and increases the transmittance.

[Transmission characteristics of tunable interference filter]
Next, transmission characteristics of the wavelength variable interference filter 5 as described above will be described with reference to the drawings.
FIG. 3 is a diagram illustrating spectral characteristics (transmission characteristics) of the first small region Ar1 in the wavelength tunable interference filter. In FIG. 3, the alternate long and short dash line indicates the transmission characteristic of the wavelength fixed interference unit 58 (first wavelength fixed interference unit 581), and the solid line indicates the transmission characteristic of the wavelength variable interference unit 57.
FIG. 4 is a diagram showing the spectral characteristics (transmission characteristics) of the second small region Ar2 in the variable wavelength interference filter. In FIG. 4, the alternate long and short dash line indicates the transmission characteristic of the wavelength fixed interference unit 58 (second wavelength fixed interference unit 582), and the solid line indicates the transmission characteristic of the wavelength variable interference unit 57.

In general, when light enters perpendicularly to an interference filter that faces a pair of reflecting films in parallel via air (refractive index n = 1), as shown in the above equation (1), λ = 2d / Light having a wavelength of m is transmitted.
Therefore, the transmission characteristics of the wavelength tunable interference unit 57 and the wavelength fixed interference unit 58 are characteristics having a plurality of peak wavelengths having different orders m as shown in FIGS.
Variable wavelength interference portion 57, since it is possible to vary the gap distance g ₀ of the first gap G1, as shown in FIGS. 3 and 4, the peak wavelength of the transmitted light in the measured wavelength range P1~P3 It can be changed.
On the other hand, in the first wavelength fixed interference unit 581 and the second wavelength fixed interference unit 582, since the gap amount of the second gap G2 is fixed, the position of the peak wavelength does not change. That is, the first wavelength fixed interference unit 581 and the second wavelength fixed interference unit 582 have peak wavelengths a1 to a4 corresponding to the gap amount of the second gap G2, and are predetermined with these peak wavelengths a1 to a4 as the center. Light in the wavelength range (transmittable wavelength ranges A1 to A4) is transmitted.

Here, in the tunable interference filter 5 of the present embodiment, the third-order peak wavelength of the tunable interference unit 57 is within the range from the visible light region to the near infrared light region (400 nm to 1000 nm), as shown in FIG. Part of the fluctuation range (measurement target wavelength region P3) overlaps with a part of the transmissible wavelength region A2 centered on the secondary peak wavelength of the first wavelength fixed interference unit 581.
The light that passes through the optical interference region Ar0 of the variable wavelength interference filter 5 is light that passes through both the variable wavelength interference unit 57 and the fixed wavelength interference unit 58. Therefore, the light transmitted through the first small region Ar1 is a wavelength region B1 where the measurement target wavelength region P3 and the transmissive wavelength region A2 overlap (in this embodiment, B1 = A2 as shown in FIG. 3).
Similarly, as shown in FIG. 4, transmission is possible with the fluctuation range of the secondary peak wavelength (measurement target wavelength region P2) of the wavelength variable interference unit 57 and the primary peak wavelength of the second wavelength fixed interference unit 582 as the center. The wavelength region A3 overlaps. Therefore, the light transmitted through the second small region Ar2 is a wavelength region B2 where the measurement target wavelength region P2 and the transmissive wavelength region A3 overlap (in this embodiment, B2 = A3 as shown in FIG. 4).

In the present embodiment, the wavelength fixed interference unit 58 has a transmission characteristic having a large transmissive wavelength range that can cover the measurement target wavelength range in the wavelength variable interference unit 57. For example, the wavelength variable interference unit In some cases, the wavelength region 57 to be measured is large, or the transmissive wavelength region of the wavelength fixed interference unit 58 is small (has a sharp peak).
In this case, for example, as shown in FIG. 5, the fixed wavelength interference unit 58 is divided into a region having a transmissive wavelength region A5 and a region having a transmissive wavelength region A6, and the transmissive wavelength region A5 and the transmissive wavelength region can be transmitted. What is necessary is just to set it as the structure etc. which cover the measurement object wavelength range P2 of the wavelength variable interference part 57 by wavelength range A6.

[Configuration of detector]
Next, returning to FIG. 1, the detection unit 11 of the optical module 10 will be described.
The detection unit 11 receives (detects) light transmitted through the optical interference region Ar0 of the wavelength variable interference filter 5, and outputs a detection signal based on the amount of received light.
Specifically, the detection unit 11 includes a plurality of imaging elements (for example, CCD elements) arranged in an array. In addition, in the detection unit 11, a region in which light in the first small region Ar1 is received and a region in which the second small region Ar2 is received in the light interference region Ar0 are set in advance. That is, the detection unit 11 can independently detect the light transmitted through the first small region Ar1 and the light transmitted through the second small region Ar2.

[Configuration of I-V Converter, Amplifier, A / D Converter, and Voltage Control Unit]
The detector 11 receives the light transmitted through the wavelength variable interference filter 5 and outputs a detection signal (current) corresponding to the light intensity (light quantity) of the received light.
The IV converter 12 converts the detection signal input from the detection unit 11 into a voltage value and outputs the voltage value to the amplifier 13.
The amplifier 13 amplifies a voltage (detection voltage) corresponding to the detection signal input from the IV converter 12.
The A / D converter 14 converts the detection voltage (analog signal) input from the amplifier 13 into a digital signal and outputs the digital signal to the control circuit unit 20.
The voltage control unit 15 applies a voltage to the electrostatic actuator 56 of the wavelength variable interference filter 5 based on the control of the control circuit unit 20. Thereby, the electrostatic attraction is generated between the first electrode 561 and second electrode 562 of the electrostatic actuator 56, the movable portion 521 is displaced to the side first substrate 51, the gap distance g ₀ of the first gap G1 Set to a predetermined value.

[Configuration of control circuit section]
Next, the control circuit unit 20 of the spectrometer 1 will be described.
The control circuit 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 circuit unit 20 includes a filter driving unit 21, a light amount acquisition unit 22, and a spectral analysis unit 23.
In addition, the control circuit unit 20 includes a storage unit (not shown) that stores various data, and the storage unit stores the wavelength variable interference filter for the drive voltage applied to the electrostatic actuator 56 of the wavelength variable interference filter 5. V-λ data indicating the relationship of the wavelength of light transmitted through 5 is stored.

The filter drive unit 21 refers to the V-λ data stored in the storage unit, sequentially switches the voltage applied to the electrostatic actuator 56 of the wavelength variable interference filter 5, and the wavelength of the light transmitted through the wavelength variable interference filter 5. Switch sequentially.
The light quantity acquisition unit 22 acquires the light quantity detected by the detection unit 11 and stores it in the storage unit as the light quantity corresponding to the first gap G1 set by the filter driving unit 21.
As described above, the detection unit 11 includes a region that receives the first small region Ar1 and a region that receives the second small region Ar2 of the optical interference region Ar0, and a detection signal independent from each region is provided. Is output. Therefore, the light quantity acquisition unit 22 acquires the light quantity of the light transmitted through the first small area Ar1 and the light quantity of the light transmitted through the second small area Ar2 based on the detection signal output from each area.
The spectroscopic analysis unit 23 analyzes the spectral spectrum of the measurement target light based on the light amount for each wavelength acquired by the light amount acquisition unit 22 and stored in the storage unit.

[Operational effects of this embodiment]
In the wavelength tunable interference filter 5 of the present embodiment, the first reflective film 551 provided on the first substrate 51 and the second reflective film 552 provided on the second substrate 52 face each other through the first gap G1. The wavelength variable interference unit 57 is configured. The tunable interference section 57, by varying the voltage applied to the electrostatic actuator 56, it is possible to change the gap distance g ₀ of the first gap G1 as appropriate.
In addition, the third reflective film 553 of the first substrate 51 and the fourth reflective film 554 of the third substrate 53 are opposed to each other via the second gap G <b> 2 to constitute the wavelength fixed interference unit 58. The fixed wavelength interference unit 58 includes a first fixed wavelength interference portion 581 second gap G2 is the gap amount g _1, and a second fixed wavelength interference portion 582 second gap G2 is the gap amount g _2.
Furthermore, the wavelength tunable interference filter 5 includes a light interference region Ar0 in which the reflection films 551, 552, 553, and 554 overlap each other in the filter plan view. The light interference region Ar0 further includes the first wavelength fixed interference unit 581. The first small region Ar1 corresponding to the region to be provided and the second small region Ar2 corresponding to the region in which the second wavelength fixed interference unit 582 is provided.

In the wavelength tunable interference filter 5 of the present embodiment, in the wavelength band of the measurement target light, the measurement target wavelength region P3 corresponding to the third-order peak wavelength in the wavelength variable interference unit 57 and the first wavelength fixed interference unit 581 The transmissive wavelength region A2 corresponding to the next peak overlaps in the wavelength region B1. In addition, the measurement target wavelength region P2 corresponding to the secondary peak wavelength in the wavelength variable interference unit 57 and the transmittable wavelength region A3 corresponding to the primary peak wavelength in the second wavelength fixed interference unit 582 overlap in the wavelength region B2.
For this reason, light in the wavelength region B1 can be transmitted from the first small region Ar1, and light in other wavelength regions cannot be transmitted through at least one of the wavelength variable interference unit 57 and the wavelength fixed interference unit 58. . Similarly, light in the wavelength region B2 can be transmitted from the second small region Ar2, and light in other wavelength regions can be transmitted through at least one of the wavelength variable interference unit 57 and the wavelength fixed interference unit 58. Can not.
As a result, even when measurement target light having a wavelength band covering a wide range from visible light to near infrared light is incident on the tunable interference filter, light having one peak wavelength in each of the small regions Ar1 and Ar2. Can be extracted.
In addition, it is possible to extract light having a predetermined peak wavelength from a plurality of peak wavelengths by using only one (single) variable wavelength interference filter 5 without using another bandpass filter or the like. Therefore, the configuration of the optical module 10 and the spectroscopic measurement apparatus 1 can be simplified.

In the present embodiment, the third substrate 53 is provided with a recess 531, and the depth of the recess 531 defines the gap amount of the second gap G 2 in the wavelength fixed interference unit 58.
In such a configuration, for example, compared to a configuration in which the concave portions are formed in both the first substrate 51 and the third substrate 53, it is only necessary to process one substrate, so that the manufacturing efficiency can be improved.
Moreover, when forming a recessed part in the 1st board | substrate 51, since it is necessary to form the electrode arrangement | positioning groove | channel 511 in the surface facing the 2nd board | substrate 52 of the 1st board | substrate 51, an etching process is needed with respect to both board | substrate surfaces, respectively. Become. On the other hand, in the case where the concave portion 531 is formed in the third substrate 53, the etching process may be performed only on one surface of the first substrate 51 facing the second substrate 52, and the processing efficiency is improved.
In the present embodiment, the concave portion 531 is provided on the third substrate 53. However, the third substrate 53 may not be processed and the concave portion may be provided on the first substrate 51. Even in such a configuration, since the gap amount of the second gap G2 can be set by processing only one substrate as in the present embodiment, the manufacturing efficiency can be improved. Further, when the concave portion is provided in the first substrate 51, it is not necessary to perform substrate processing such as etching on the third substrate 53.

In the present embodiment, the fixed wavelength interference portion 58, the first fixed wavelength interference portion 581 second gap G2 is the gap amount g _1, and the second fixed wavelength interference portion where the second gap G2 is the gap amount g ₂ 582.
In such a configuration, the first wavelength fixed interference unit 581 and the second wavelength fixed interference unit 582 have different peak wavelengths of transmitted light, and different transmissive wavelength ranges corresponding to the peak wavelengths. Of the transmissive wavelength regions A1 and A2 of the first wavelength fixed interference unit 581, the transmissive wavelength region A2 overlaps the measurement target wavelength region P3 of the tunable interference unit 57, and the second wavelength fixed interference unit 582 is transmissive. Among the wavelength regions A3 and A4, the transmissive wavelength region A3 overlaps the measurement target wavelength region P2 of the wavelength variable interference unit 57. For this reason, in the first small region Ar1 of the variable wavelength interference filter 5, light in the wavelength region B1 can be extracted, and in the second small region Ar2, light in the wavelength region B2 can be extracted.
As described above, by providing a plurality of regions having different gap amounts of the second gap G2 of the wavelength fixed interference unit 58, it is possible to individually extract a plurality of wavelengths from one (single) variable wavelength interference filter 5. Light corresponding to a plurality of peak wavelengths can be acquired by one measurement.
Thereby, when measuring the light quantity of the light of each wavelength within the wavelength band of the light to be measured by the spectroscopic measurement device 1, the light quantity with respect to the two peak wavelengths can be acquired by one measurement. Thus, a rapid spectroscopic measurement can be performed.

In the present embodiment, a region boundary 532 serving as an inclined surface or a step surface is provided between the first wavelength fixed interference unit 581 and the second wavelength fixed interference unit 582 of the third substrate 53. The third substrate 53 is provided with a light shielding portion 533 that shields light incident on the region boundary portion 532.
For this reason, no light is incident on the region boundary portion 532, and no light is refracted or reflected by the inclined surface or the step surface of the region boundary portion 532. Therefore, there is no light component incident on each of the reflective films 551, 552, 553, and 554 at an inclined angle (an angle other than orthogonal), and a reduction in resolution in the wavelength variable interference filter 5 can be suppressed.

[Second Embodiment]
Next, a second embodiment of the present invention will be described based on the drawings.
In the first embodiment, the optical interference region Ar0 of the variable wavelength interference filter 5, a second gap G2 fixed wavelength interference portion 58 becomes the gap amount g ₁ become the first small area Ar @ 1, and a gap weight g ₂ The structure which provides two small area | region Ar2 was illustrated. On the other hand, the second embodiment is different from the first embodiment in that the optical interference area Ar0 is further finely divided.

  FIG. 6 is a diagram illustrating a schematic configuration of a spectroscopic camera (spectrometer) in the second embodiment. In the above embodiment, the same reference numerals are given to the same configurations as those in the first embodiment, and the description thereof is omitted or simplified.

As shown in FIG. 6, the spectroscopic camera 1A includes an optical module 10A and a control circuit unit 20A that processes a signal output from the optical module 10A.
The spectroscopic camera 1A is a device that acquires a spectroscopic image of each wavelength in image light (measurement target light) reflected by the measurement target X, for example.

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

[Configuration of wavelength tunable interference filter]
The wavelength tunable interference filter 5A of this embodiment has substantially the same configuration as the wavelength tunable interference filter 5 of the first embodiment, and the configuration of the third substrate 53A is different from the third substrate 53 of the first embodiment. .
FIG. 7 is a plan view showing a schematic configuration of the recess 534 of the third substrate 53A of the second embodiment.
As shown in FIG. 7, the third substrate 53 </ b> A of the present embodiment includes a recess 534 that is divided into regions with a finer depth.
Specifically, in the variable wavelength interference filter 5A of the present embodiment, the optical interference region Ar0 includes a plurality of partial regions Ar3 divided into an array. This partial area Ar3 is divided in units of pixels of the spectral image to be acquired. The partial area Ar3 is further divided into three small areas (first small area Ar31, second small area Ar32, and third small area Ar33).

  The concave portion 534 of the third substrate 53A is formed to have different depth dimensions between adjacent regions corresponding to the partial region Ar3 and the small regions Ar31, Ar32, Ar33. In FIG. 7, the area corresponding to the first small area Ar31 is numbered “1”, the area corresponding to the second small area Ar32 is “2”, and the area corresponding to the third small area Ar33 is numbered “3”. The boundary line of the partial area Ar3 is indicated by a bold line.

In this embodiment, the peak wavelengths of the light transmitted through the small regions Ar31, Ar32, Ar33 in the wavelength fixed interference unit 58 are different, and have different transmissive wavelength ranges.
And the wavelength fixed interference part 58 corresponding to 1st small area | region Ar31 respond | corresponded to the secondary peak wavelength of the wavelength variable interference part 57 in the wavelength band (for example, visible light region to near-infrared light region) of light to be measured. It has a primary peak wavelength that overlaps the wavelength range to be measured, and has a transmissible wavelength range corresponding to the primary peak wavelength. Further, in the wavelength fixed interference unit 58 corresponding to the first small region Ar31, in the wavelength band of the measurement target light, the other peak wavelengths (secondary and subsequent peak wavelengths) and the transmissible wavelength region corresponding to the peak wavelength are as follows: It does not overlap with the measurement target wavelength range of the wavelength variable interference unit 57. Therefore, in the first small region Ar31, the measurement target wavelength region corresponding to the secondary peak wavelength of the wavelength variable interference unit 57 and the transmittable wavelength region corresponding to the primary peak wavelength of the wavelength fixed interference unit 58 overlap. Only light in the wavelength band can be transmitted.

  The fixed wavelength interference unit 58 corresponding to the second small region Ar32 has a secondary (or primary) peak that overlaps the measurement target wavelength region corresponding to the tertiary peak wavelength of the wavelength variable interference unit 57 in the wavelength band of the measurement target light. It has a wavelength and has a transmissible wavelength range corresponding to the peak wavelength. Further, in the wavelength fixed interference unit 58 corresponding to the second small region Ar32, in the wavelength band of the measurement target light, the other peak wavelength and the transmissive wavelength range corresponding to the peak wavelength are the measurement target of the wavelength variable interference unit 57. Does not overlap with wavelength range. Therefore, in the second small region Ar32, the measurement target wavelength region corresponding to the tertiary peak wavelength of the wavelength variable interference unit 57 and the transmittable wavelength region corresponding to the secondary (or primary) peak wavelength of the wavelength fixed interference unit 58 Only the light in the second wavelength region where the two overlap can be transmitted.

The fixed wavelength interference unit 58 corresponding to the third small region Ar33 has a third order (or second order or first order) overlapping with the measurement target wavelength region corresponding to the fourth order peak wavelength of the wavelength variable interference unit 57 in the wavelength band of the measurement target light. Next) It has a peak wavelength and has a transmissible wavelength region corresponding to the peak wavelength. Further, in the wavelength fixed interference unit 58 corresponding to the third small region Ar33, in the wavelength band of the measurement target light, the other peak wavelength and the transmissive wavelength range corresponding to the peak wavelength are measured by the wavelength variable interference unit 57. Does not overlap with wavelength range. Therefore, in the third small region Ar33, the measurement target wavelength region corresponding to the fourth order peak wavelength of the wavelength variable interference unit 57 and the transmission corresponding to the third order (or second order or first order) peak wavelength of the wavelength fixed interference unit 58 are provided. Only light in the third wavelength region that overlaps the possible wavelength region can be transmitted.
Although omitted in FIG. 7, as in the first embodiment, the region boundary 532 between the small regions Ar <b> 31, Ar <b> 32, Ar <b> 33 is formed on the surface of the third substrate 53 </ b> A that does not face the first substrate 51. A light shielding portion is provided to prevent light from entering the light.

[Configuration of imaging unit]
The imaging unit 11A includes an imaging area corresponding to the optical interference area Ar0, and in this imaging area, has a pixel area corresponding to each partial area Ar3. Each pixel region of the imaging unit 11A includes three imaging elements associated with the small regions Ar31, Ar32, Ar33. That is, light transmitted through one small region (Ar31, Ar32, Ar33) is incident on one image sensor associated with the small region.
In such an imaging unit 11A, the image light transmitted through the wavelength variable interference filter 5A can be acquired (captured) as an image using each partial region and the transmitted light as one pixel. In each pixel region, light having a wavelength corresponding to each of the small regions Ar31, Ar32, and Ar33 can be received, so that a spectral image corresponding to each wavelength can be acquired. For example, a spectral image of a predetermined wavelength corresponding to the first small region Ar31 can be acquired by an imaging element corresponding to the first small region Ar31 of each pixel region.

[Configuration of control unit]
As illustrated in FIG. 6, the control circuit unit 20 </ b> A includes a filter driving unit 21, a light amount acquisition unit 22, and a spectral image acquisition unit 24.
The spectral image acquisition unit 24 acquires a captured image (spectral image) captured by the imaging unit 11 </ b> A based on the detection signal from each imaging element acquired by the light amount acquisition unit 22. As described above, in the present embodiment, the imaging unit 11A includes each pixel area corresponding to each partial area Ar3, and an imaging element corresponding to each small area Ar31, Ar32, Ar33 is arranged in each pixel area. . Therefore, the spectral image acquisition unit 24 obtains a spectral image of the wavelength in the measurement target wavelength range corresponding to the secondary peak wavelength of the wavelength variable interference unit 57 based on the detection signal from the imaging element corresponding to the first small region Ar31. You can get it. Similarly, the spectral image acquisition unit 24 can acquire a spectral image of a wavelength in the measurement target wavelength region corresponding to the third-order peak wavelength of the wavelength variable interference unit 57 from the imaging element corresponding to the second small region Ar32. Based on the detection signal from the image sensor corresponding to the small region Ar33, a spectral image of the wavelength in the measurement target wavelength region corresponding to the fourth-order peak wavelength of the wavelength variable interference unit 57 can be acquired.

[Operational effects of this embodiment]
In the present embodiment, the optical interference area Ar0 is divided into a plurality of partial areas Ar3 corresponding to the pixel areas of the image captured by the imaging unit 11A, and these partial areas Ar3 are further divided into a plurality (three) of small areas. The area is divided into Ar31, Ar32, and Ar33. And the recessed part 534 provided in the 3rd board | substrate 53 is formed so that the part corresponding to each small area | region Ar31, Ar32, Ar33 may become a different depth dimension. Here, in the wavelength fixed interference unit 58 corresponding to the first small region Ar31, the first transmissive wavelength region is overlapped with the measurement target wavelength region corresponding to the secondary peak wavelength of the wavelength variable interference unit 57. A gap amount of two gaps is set. Further, in the wavelength fixed interference unit 58 corresponding to the second small region Ar32, the second transmissive wavelength region is overlapped with the measurement target wavelength region corresponding to the tertiary peak wavelength of the wavelength variable interference unit 57. The gap amount of the gap is set. Further, in the wavelength fixed interference unit 58 corresponding to the third small region Ar33, the second transmissive wavelength region overlaps the measurement target wavelength region corresponding to the fourth-order peak wavelength of the wavelength variable interference unit 57. The gap amount of the gap is set.
As a result, even if the measurement target light has a wide wavelength band from, for example, the visible light region to the near infrared light region, the secondary peak wavelength, the tertiary peak wavelength, and the quaternary wavelength of the wavelength variable interference unit 57 are obtained. Light corresponding to the peak wavelength can be emitted independently from each of the small regions Ar31, Ar32, Ar33.

  In addition, since each partial region corresponds to the pixel region of the imaging unit 11A, a spectral image corresponding to each peak wavelength is obtained based on the detection signal from each imaging device corresponding to each small region Ar31, Ar32, Ar33. Can be acquired. In such a configuration, a spectral image corresponding to three peak wavelengths can be acquired by one imaging. Therefore, for example, when it is desired to capture spectral images of a plurality of wavelengths, the time required for imaging can be shortened.

  Further, in the present embodiment, a single (single) variable wavelength interference filter 5A can acquire spectral images corresponding to a plurality of peak wavelengths having different orders, and for example, no other bandpass filter is required. Therefore, the configuration can be simplified.

[Third embodiment]
Next, 4th embodiment of this invention is described based on drawing.
In the spectroscopic measurement device 1 of the first embodiment or the spectroscopic camera 1A of the second embodiment, the variable wavelength interference filters 5 and 5A are directly provided to the optical modules 10 and 10A. 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 allows the wavelength variable interference filters 5 and 5A to be easily installed even for such an optical module will be described below.
FIG. 8 is a sectional view showing a schematic configuration of the optical filter device according to the third embodiment of the present invention.

As shown in FIG. 8, the optical filter device 600 includes a wavelength tunable interference filter 5 and a housing 601 that houses the wavelength tunable interference filter 5. In this embodiment, the wavelength variable interference filter 5 is illustrated as an example, but the wavelength variable interference filter 5A of the second embodiment may be used.
The housing 601 includes a base substrate 610, a lid 620, a base side glass substrate 630, and a lid side glass substrate 640.

  The base substrate 610 is configured by, for example, a single layer ceramic substrate. On the base substrate 610, the second substrate 52 of the variable wavelength interference filter 5 is installed. The second substrate 52 may be disposed on the base substrate 610 by, for example, being disposed via an adhesive layer or the like, and disposed by being fitted to another fixing member or the like. May be. In addition, a light passage hole 611 is formed in the base substrate 610 in a region facing the light interference region Ar0. 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.

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

As shown in FIG. 8, the lid 620 includes a lid bonding portion 624 bonded to the base bonding portion 617 of the base substrate 610, a side wall portion 625 that continues from the lid bonding portion 624 and rises away from the base substrate 610, A top surface portion 626 that is continuous from the side wall portion 625 and covers the first substrate 51 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. In the top surface portion 626, a light passage hole 621 is formed in a region facing the light interference region Ar0 of the wavelength variable interference filter 5. And the lid side glass substrate 640 is joined so that this light passage hole 621 may be covered. As a method for bonding the lid-side glass substrate 640, for example, glass frit bonding, adhesion using an epoxy resin, or the like can be used as in the case of bonding the base-side glass substrate 630.

[Operational effects of the third embodiment]
In the optical filter device 600 of the present embodiment, since the wavelength tunable interference filter 5 is protected by the housing 601, it is possible to prevent changes in the characteristics of the wavelength tunable interference filter 5 due to foreign matters, gases contained in the atmosphere, and the like. It is possible to prevent the wavelength tunable interference filter 5 from being damaged due to mechanical factors. In addition, since intrusion of charged particles can be prevented, charging of the first electrode 561 and the second electrode 562 can be prevented. Therefore, the generation of Coulomb force due to charging can be suppressed, and the parallelism of the reflective films 551 and 552 can be more reliably maintained.

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

[Modification]
It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.

For example, in the above embodiment, the optical interference area Ar0 is divided into a plurality of small areas Ar1, Ar2, or divided into a plurality of partial areas Ar3, and each partial area is divided into a plurality of small areas Ar31, Ar32, Ar33. Although the structure divided | segmented was illustrated, it is not limited to this.
That is, the gap amount of the second gap G2 may be a uniform dimension in the optical interference region Ar0. In this case, for example, the second of the fixed wavelength interference unit 58 is transmitted so that light in the measurement wavelength range to be measured out of the measurement target wavelength ranges corresponding to the plurality of peak wavelengths of the wavelength variable interference unit 57 is transmitted. The gap amount of the gap G2 only needs to be set.

In the second embodiment, an example in which three small regions Ar31, AR32, Ar33 are provided in each partial region Ar3 has been described, but a configuration in which four or more small regions are provided may be employed.
Moreover, although the example in which each partial area Ar3 is provided corresponding to the pixel unit of the spectral image captured by the imaging unit 11A is shown, a configuration in which partial areas corresponding to a plurality of pixels may be provided.

In the second embodiment, the gap amount of the second gap G2 in each of the small regions Ar31, Ar32, Ar33 is set in correspondence with the measurement target wavelengths corresponding to the peak wavelengths having different orders in the wavelength variable interference unit 57. That is, in the second embodiment, light in the measurement target wavelength range corresponding to the secondary peak wavelength of the wavelength variable interference unit 57 from the first small region Ar31, and the tertiary peak wavelength of the wavelength variable interference unit 57 from the second small region Ar32. The gap amount of the second gap is set so that the light of the measurement target wavelength corresponding to λ and the light of the measurement target wavelength corresponding to the fourth-order peak wavelength of the wavelength variable interference unit 57 are transmitted from the third small region Ar33. Yes.
On the other hand, as shown in FIG. 5, it is good also as a structure which takes out the light of one measuring object wavelength range by several different small area | regions. For example, in a wavelength tunable interference filter intended to extract light in a measurement target wavelength region (450 nm to 600 nm) corresponding to the secondary peak wavelength of the wavelength tunable interference unit 57, the transmission wavelength is set in the first to third small regions. The 1st-3rd wavelength fixed interference part in which a zone overlaps with a measurement object wavelength zone is arranged.
Here, the transmission wavelength region corresponding to the primary peak wavelength of the first wavelength fixed interference unit is 450 nm to 500 nm, the transmission wavelength region corresponding to the primary peak wavelength of the second wavelength fixed interference unit is 500 nm to 550 nm, It is assumed that the transmission wavelength range corresponding to the primary peak wavelength of the three-wavelength fixed interference unit is 550 nm to 600 nm, and there is no overlap with other measurement target wavelength ranges of the wavelength variable interference unit in other transmission wavelength ranges.
In such a configuration, the light to be measured wavelength range has a structure which transmits one of the first to third sub-region in accordance with the gap amount g ₀ of the first gap G1. Even in this case, light corresponding to other peak wavelengths of the wavelength tunable interference unit does not pass through the wavelength tunable interference filter, and only light in a specific wavelength region can be extracted.

In the first and second embodiments, the configuration in which the light shielding portion 533 is provided on the light incident surface of the third substrate 53 is shown, but the present invention is not limited to this. As a position where the light shielding part 533 is provided, for example, a configuration may be adopted in which the light shielding part 533 is provided on the region boundary part 532 of the recesses 531 and 534 or on the fourth reflection film 554.
In the present embodiment, an example in which light is incident on the wavelength tunable interference filter 5 from the third substrate 53 side is shown. However, for example, a configuration may be adopted in which light is incident from the second substrate 52 side. In this case, for example, a configuration in which a light shielding unit is provided on the first substrate 51, the second substrate 52, the first reflective film 551, and the second reflective film 552 so that the light shielding unit prevents light from entering the region boundary 532. Also good.

In the above embodiments, as the gap amount changing unit of the variable wavelength interference filter 5, 5A, is exemplified electrostatic actuator 56 for varying the gap distance g ₀ of the first gap G1 by electrostatic attraction by application of voltage, to It is not limited.
For example, instead of the first electrode 561, a first dielectric coil may be arranged and a dielectric actuator in which a second dielectric coil or a permanent magnet is arranged instead of the second electrode 562 may be 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.

Further, as the electronic apparatus of the present invention, the spectroscopic measurement apparatus 1 is illustrated in the first embodiment, and the spectroscopic camera 1A is illustrated in the second embodiment. Filter devices, optical modules, and electronic equipment can be used.
For example, it can be used as a light-based system for detecting the presence of a specific substance. As such a system, for example, an in-vehicle gas leak detector that detects a specific gas with high sensitivity by adopting a spectroscopic measurement method using the variable wavelength interference filter of the present invention, or a photoacoustic rare gas detection for a breath test. A gas detection device such as a vessel can be exemplified.
An example of such a gas detection device will be described below with reference to the drawings.

FIG. 9 is a schematic diagram illustrating an example of a gas detection apparatus including a wavelength variable interference filter.
FIG. 10 is a block diagram showing a configuration of a control system of the gas detection device of FIG.
As illustrated in FIG. 9, 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. 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. Instead of the variable wavelength interference filter 5, a variable wavelength interference filter 5A or an optical filter device 600 may be disposed.
As shown in FIG. 10, 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.
Furthermore, as shown in FIG. 10, the control unit 138 of the gas detection device 100 controls a signal processing unit 144 configured by a CPU or the like, a light source driver circuit 145 for controlling the light source 135A, and the variable wavelength interference filter 5. Voltage control unit 146, a light receiving circuit 147 that receives a signal from the light receiving element 137, a sensor chip detection that reads a code of the sensor chip 110 and receives a signal from a sensor chip detector 148 that detects the presence or absence of the sensor chip 110 A circuit 149, a discharge driver circuit 150 for controlling the discharge means 133, and the like are provided.

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

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

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

  9 and 10 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.

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. 11 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. 11, the food analysis apparatus 200 includes a detector 210 (optical module), a control unit 220, and a display unit 230. The detector 210 includes a light source 211 that emits light, an imaging lens 212 into which light from the measurement target is introduced, a wavelength variable interference filter 5 that splits the light introduced from the imaging lens 212, and the dispersed light. And an imaging unit 213 (detection unit) for detecting. Instead of the variable wavelength interference filter 5, a variable wavelength interference filter 5A or an optical filter device 600 may be disposed.
In addition, the control unit 220 controls the light source control unit 221 that controls the turning on / off of the light source 211 and the brightness control at the time of lighting, the voltage control unit 222 that controls the wavelength variable interference filter 5, and the imaging unit 213. , A detection control unit 223 that acquires a spectral image captured by the imaging unit 213, a signal processing unit 224, and a storage unit 225.

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

Then, the signal processing unit 224 performs arithmetic processing on the data of each pixel in each image accumulated in the storage unit 225, and obtains a spectrum at each pixel. In addition, the storage unit 225 stores, for example, information related to food components with respect to the spectrum, and the signal processing unit 224 analyzes the obtained spectrum data based on the information related to food stored in the storage unit 225. The food component contained in the detection target and 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.

Moreover, although the example of the food analysis apparatus 200 is shown in FIG. 11, it can utilize also as a noninvasive measurement apparatus of the other information as mentioned above by the substantially same structure. For example, it can be used as a biological analyzer for analyzing biological components such as measurement and analysis of body fluid components such as blood. As such a bioanalytical device, for example, a device that detects ethyl alcohol as a device that measures a body fluid component such as blood, it can be used as a drunk driving prevention device that detects the drunk state of the driver. Further, it can also be used as an electronic endoscope system provided with such a biological analyzer.
Furthermore, it can also be used as a mineral analyzer for performing component analysis of minerals.

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

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

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

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

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

  DESCRIPTION OF SYMBOLS 1 ... Spectrometer (electronic device) 1A ... Spectral camera (electronic device) 5, 5A ... Variable wavelength interference filter, 11 ... Detection part, 11A ... Imaging part (detection part), 51 ... First substrate, 52 ... 2nd board | substrate, 53 ... 3rd board | substrate, 56 ... electrostatic actuator (gap change part), 57 ... wavelength variable interference part, 58 ... wavelength fixed interference part, 100 ... gas detection apparatus (electronic device), 200 ... food analyzer (Electronic equipment), 551 ... first reflective film, 552 ... second reflective film, 553 ... third reflective film, 554 ... fourth reflective film, 600 ... optical filter device, 601 ... housing, A1, A2, A3 A4: Transmittable wavelength region, Ar0: Optical interference region, Ar1: First small region, Ar2: Second small region, Ar3: Partial region, Ar31: First small region, Ar32: Second small region, Ar33: Third Small area, G1 ... first , G2 ... second gap, P1, P2, P3, P4 ... measured wavelength range, X ... measured.

Claims (10)

A first substrate;
A second substrate disposed opposite the first substrate;
A first reflective film provided on a surface of the first substrate facing the second substrate;
A second reflective film opposed to the first reflective film through a gap on a surface of the second substrate facing the first substrate;
A gap changing unit that changes a gap amount of the gap between the first reflective film and the second reflective film;
A third substrate disposed opposite to a surface opposite to the surface facing the second substrate of the first substrate;
A third reflective film provided on a surface of the first substrate facing the third substrate;
A fourth reflective film provided on a surface of the third substrate facing the first substrate and facing the third reflective film via a gap;
Comprising
The first reflective film, the second reflective film, the third reflective film, and the fourth reflective film in a plan view as viewed from the thickness direction of the first substrate, the second substrate, and the third substrate. The area where the
The first reflective film and the second reflective film constitute a wavelength variable interference unit having a plurality of measurement target wavelength ranges corresponding to a plurality of peak wavelengths having different orders,
The third reflective film and the fourth reflective film constitute a wavelength-fixed interference unit having a plurality of transmissive wavelength regions corresponding to a plurality of peak wavelengths having different orders,
Within the wavelength band of the measurement target light, any one of the plurality of measurement target wavelength ranges of the wavelength variable interference unit overlaps any one of the plurality of transmittable wavelength ranges of the wavelength fixed interference unit. Tunable interference filter characterized by The tunable interference filter according to claim 1,
At least one of the first substrate and the third substrate is provided with a recess on the surface facing the other,
The variable wavelength interference filter, wherein the third reflective film or the fourth reflective film is provided on a bottom surface of the recess. The tunable interference filter according to claim 2,
The tunable interference filter, wherein the concave portion is provided on one of the first substrate and the third substrate. In the wavelength variable interference filter according to any one of claims 1 to 3,
The wavelength tunable interference filter, wherein the optical interference region includes a plurality of small regions having different gap amounts between the third reflective film and the fourth reflective film. In the wavelength variable interference filter according to any one of claims 1 to 4,
The optical interference region includes a plurality of partial regions,
Each of the partial regions is provided with a plurality of small regions having different gap amounts between the third reflective film and the fourth reflective film. The wavelength tunable interference filter according to claim 4 or 5,
A wavelength tunable interference filter, comprising: a light blocking unit that blocks light from entering a region boundary between the adjacent small regions. A first substrate, a second substrate disposed opposite to the first substrate, a first reflective film provided on a surface of the first substrate facing the second substrate, and a first substrate of the second substrate A second reflecting film facing the first reflecting film through a gap, a gap changing unit that changes a gap amount of the gap between the first reflecting film and the second reflecting film, A third substrate disposed opposite to a surface opposite to the surface facing the second substrate of one substrate, a third reflective film provided on a surface of the first substrate facing the third substrate, and A wavelength tunable interference filter provided on a surface of the third substrate facing the first substrate and having a fourth reflective film facing the third reflective film via a gap;
A housing that houses the variable wavelength interference filter;
Comprising
The first reflective film, the second reflective film, the third reflective film, and the fourth reflective film in a plan view as viewed from the thickness direction of the first substrate, the second substrate, and the third substrate. The area where the
The first reflecting film and the second reflecting film corresponding to the optical interference region constitute a wavelength variable interference unit having a plurality of measurement target wavelength regions corresponding to a plurality of peak wavelengths having different orders,
The third reflection film and the fourth reflection film corresponding to the light interference region constitute a wavelength fixed interference unit having a plurality of transmissive wavelength regions corresponding to a plurality of peak wavelengths having different orders,
Within the wavelength band of the measurement target light, any one of the plurality of measurement target wavelength ranges of the wavelength variable interference unit overlaps any one of the plurality of transmittable wavelength ranges of the wavelength fixed interference unit. Optical filter device characterized by. A first substrate;
A second substrate disposed opposite the first substrate;
A first reflective film provided on a surface of the first substrate facing the second substrate;
A second reflective film opposed to the first reflective film through a gap on a surface of the second substrate facing the first substrate;
A gap changing unit that changes a gap amount of the gap between the first reflective film and the second reflective film;
A third substrate disposed opposite to a surface opposite to the surface facing the second substrate of the first substrate;
A third reflective film provided on a surface of the first substrate facing the third substrate;
A fourth reflective film provided on a surface of the third substrate facing the first substrate and facing the third reflective film via a gap;
A detector for detecting light;
Comprising
The first reflective film, the second reflective film, the third reflective film, and the fourth reflective film in a plan view as viewed from the thickness direction of the first substrate, the second substrate, and the third substrate. The area where the
The first reflecting film and the second reflecting film corresponding to the optical interference region constitute a wavelength variable interference unit having a plurality of measurement target wavelength regions corresponding to a plurality of peak wavelengths having different orders,
The third reflection film and the fourth reflection film corresponding to the light interference region constitute a wavelength fixed interference unit having a plurality of transmissive wavelength regions corresponding to a plurality of peak wavelengths having different orders,
Within the wavelength band of the measurement target light, any one of the plurality of measurement target wavelength ranges of the wavelength variable interference unit overlaps any one of the plurality of transmittable wavelength ranges of the wavelength fixed interference unit,
The optical module, wherein the detection unit detects light extracted by the optical interference region. A first substrate;
A second substrate disposed opposite the first substrate;
A first reflective film provided on a surface of the first substrate facing the second substrate;
A second reflective film opposed to the first reflective film through a gap on a surface of the second substrate facing the first substrate;
A gap changing unit that changes a gap amount of the gap between the first reflective film and the second reflective film;
A third substrate disposed opposite to a surface opposite to the surface facing the second substrate of the first substrate;
A third reflective film provided on a surface of the first substrate facing the third substrate;
A fourth reflective film provided on a surface of the third substrate facing the first substrate and facing the third reflective film via a gap;
Comprising
The first reflective film, the second reflective film, the third reflective film, and the fourth reflective film in a plan view as viewed from the thickness direction of the first substrate, the second substrate, and the third substrate. The area where the
The first reflecting film and the second reflecting film corresponding to the optical interference region constitute a wavelength variable interference unit having a plurality of measurement target wavelength regions corresponding to a plurality of peak wavelengths having different orders,
The third reflection film and the fourth reflection film corresponding to the light interference region constitute a wavelength fixed interference unit having a plurality of transmissive wavelength regions corresponding to a plurality of peak wavelengths having different orders,
Within the wavelength band of the measurement target light, any one of the plurality of measurement target wavelength ranges of the wavelength variable interference unit overlaps any one of the plurality of transmittable wavelength ranges of the wavelength fixed interference unit. Electronic equipment characterized by A substrate,
A tunable interference unit having two reflective films arranged to face each other via a displaceable gap, and a gap changing unit that changes a gap amount of the gap;
A wavelength-fixed interference unit having two reflective films disposed to face each other through a fixed gap,
One of the reflective films included in the wavelength variable interference unit is provided on one surface of the substrate,
One of the reflective films included in the wavelength fixed interference part is provided on a surface opposite to the one surface of the substrate,
The wavelength tunable interference filter, wherein two reflective films provided on the substrate are disposed so as to overlap each other in a plan view of the substrate viewed from the substrate thickness direction.

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