JP7200658B2 - optical devices and electronic devices - Google Patents

Description

The present invention relates to optical devices and electronic equipment.

2. Description of the Related Art Conventionally, a spectroscopic device (optical device) that transmits light of a predetermined wavelength from incident light is known (see Patent Document 1, for example).
In the optical device described in Patent Document 1, a fixed mirror is arranged on one surface of a substrate, and a movable mirror is arranged on the fixed mirror via a support member, thereby forming a first filter. Then, the movable mirror of the second filter is bonded onto the movable mirror of the first filter through a connection layer, and the fixed mirror of the second filter is joined onto the movable mirror of the second filter through a support member. are placed.
In such an optical device, when light having a wavelength included in a band where the spectral band of the first filter and the spectral band of the second filter overlap, the gap between both the first filter and the second filter is the spectral wavelength. Set the dimensions according to the Further, when the optical device disperses light having a wavelength included in a band that does not overlap with the spectral band of the second filter among the spectral bands of the first filter, only the gap of the first filter is sized according to the spectral wavelength. set. Similarly, when the optical device disperses light having a wavelength included in a band that does not overlap with the spectral band of the first filter among the spectral bands of the second filter, only the gap of the second filter has a dimension corresponding to the spectral wavelength. set to
With such a configuration, the wavelength variable band spectroscopy possible by the optical device is from the shortest wavelength of the spectral band of the first filter to the longest wavelength of the spectral band of the second filter. The wavelength tunable band can be widened as compared with the case of using only one.

Japanese Unexamined Patent Application Publication No. 2012-108370

However, in the optical device as described in Patent Document 1, since the movable mirror of the first filter and the movable mirror of the second filter are joined by a film-like connection layer, there is a gap between these movable mirrors. , multiple interference of light occurs. In other words, the movable mirror of the first filter and the movable mirror of the second filter function as a third filter that transmits light having a wavelength corresponding to the thickness of the connection layer. In this case, since light having a wavelength corresponding to the thickness of the connection layer is transmitted through the third filter, by matching the gap between the first filter and the second filter to the wavelength, the optical device can be transmitted with high transmittance. can be done. However, when the target wavelength is set to another wavelength, there is a problem that the transmittance of the third filter becomes low, and the amount of light transmitted through the optical device is reduced.

An optical device according to a first application example includes a first tunable interference filter in which a first reflective film and a second reflective film face each other across a first gap, a third reflective film, and a fourth reflective film. a second tunable interference filter facing across a second gap; and a translucent first substrate having a first surface and a second surface opposite to the first surface; The reflecting film is provided on the first surface of the first substrate, and the third reflecting film is provided on the second surface of the first substrate.

In the optical device of this application example, the first tunable interference filter includes a first electrode provided on the first reflective film and a second electrode provided on the second reflective film, The first electrode and the second electrode face each other across the first gap, and the second variable wavelength interference filter is provided on the third electrode provided on the third reflective film and on the fourth reflective film. a fourth electrode, wherein the third electrode and the fourth electrode face each other across the second gap; and the first substrate has a fourth electrode penetrating from the first surface to the second surface. It is preferable that one through hole is provided, and one of the first electrode and the second electrode is electrically connected to one of the third electrode and the fourth electrode through the first through hole.

An optical device according to a second application example includes a first tunable interference filter in which a first reflective film and a second reflective film face each other across a first gap, a third reflective film, and a fourth reflective film. a second tunable interference filter facing across a second gap; a translucent second substrate having a third surface and a fourth surface opposite to the third surface; a fifth surface; a translucent third substrate having a sixth surface opposite to the fifth surface, wherein the second reflective film is provided on the third surface of the second substrate, and the first reflective film is provided on the side opposite to the second substrate with respect to the second reflective film, the fourth reflective film is provided on the fifth surface of the third substrate, and the third reflective film is provided on the provided on the side opposite to the third substrate with respect to the fourth reflective film, the fourth surface of the second substrate is fixed to the fifth surface of the third substrate via a spacer, and the second A variable wavelength interference filter is arranged between the second substrate and the third substrate.

In the optical device of this application example, the first tunable interference filter includes a first electrode provided on the first reflective film and a second electrode provided on the second reflective film, The first electrode and the second electrode face each other across the first gap, and the second variable wavelength interference filter is provided on the third electrode provided on the third reflective film and on the fourth reflective film. and a fourth electrode, wherein the third electrode and the fourth electrode face each other across the second gap, the spacer includes a conductive spacer having conductivity, and the second substrate comprises: A second through hole penetrating from the third surface to the fourth surface is provided at a position in contact with the conductive spacer, and one of the first electrode and the second electrode is connected to the second through hole and the It is preferable to conduct to one of the third electrode and the fourth electrode via a conductive spacer.

An optical device according to a third application example includes a first tunable interference filter in which a first reflective film and a second reflective film face each other across a first gap, a third reflective film, and a fourth reflective film. a second tunable interference filter facing across a second gap; a translucent fourth substrate having a seventh surface and an eighth surface opposite to the seventh surface; a ninth surface; a translucent fifth substrate having a tenth surface opposite to the ninth surface, wherein the first reflective film is provided on the eighth surface of the fourth substrate; is provided on the side opposite to the fourth substrate with respect to the first reflective film, the fourth reflective film is provided on the ninth surface of the fifth substrate, and the third reflective film is provided on the provided on the side opposite to the fifth substrate with respect to the fourth reflective film, the eighth surface of the fourth substrate is fixed to the ninth surface of the fifth substrate via a spacer, and the first The wavelength tunable interference filter and the second wavelength tunable interference filter are arranged between the fourth substrate and the fifth substrate.

In the optical device of this application example, the first tunable interference filter includes a first electrode provided on the first reflective film and a second electrode provided on the second reflective film, The first electrode and the second electrode face each other across the first gap, and the second variable wavelength interference filter is provided on the third electrode provided on the third reflective film and on the fourth reflective film. and a fourth electrode, wherein the third electrode and the fourth electrode face each other across the second gap, the spacer includes a conductive spacer having conductivity, and the first electrode and the One of the second electrodes is preferably electrically connected to one of the third electrode and the fourth electrode via the conductive spacer.

In the optical device according to any one of the first application example to the third application example, the first wavelength tunable interference filter changes the dimension of the first gap to reduce the amount of light transmitted from the first wavelength tunable interference filter. A first transmission wavelength, which is a wavelength, is configured to be changeable within a range from the first wavelength to a second wavelength longer than the first wavelength, and the second wavelength tunable interference filter has the second By changing the dimension of the gap, the second transmission wavelength, which is the wavelength of light to be transmitted from the second wavelength tunable interference filter, is longer than the first wavelength and shorter than the second wavelength. from the third wavelength to the fourth wavelength longer than the second wavelength.

In the optical device according to any one of the first application example to the third application example, the distance between the second reflective film and the third reflective film is the center of the wavelength range from the first wavelength to the fourth wavelength. It is preferably at least 300 times the wavelength.

In the optical device according to any one of the first application example to the third application example, the distance between the second reflective film and the third reflective film is the center of the wavelength range from the first wavelength to the fourth wavelength. It is preferably 30000 times or less than the wavelength.

In the optical device according to any one of the first application example to the third application example, the distance between the second reflective film and the third reflective film is equal to the distance between the first reflective film and the second reflective film. distance and preferably greater than the distance between the third reflective film and the fourth reflective film.

An electronic apparatus according to a fourth application example includes the optical device according to any one of the first application example to the third application example, and a control unit that controls the optical device.

1 is a cross-sectional view showing a schematic configuration of a spectroscopic measurement device according to a first embodiment; FIG. FIG. 5 is a diagram showing an example of transmission characteristics of the first tunable interference filter and the second tunable interference filter of the first embodiment; FIG. 5 is a diagram showing transmission characteristics of a spectroscopic section when a second reflective film and a third reflective film are joined by a connecting film; FIG. 5 is a diagram showing transmission characteristics of a spectroscopic section when a second reflective film and a third reflective film are joined by a connecting film; 4A and 4B are diagrams showing transmission characteristics of the spectroscopic section of the first embodiment; FIG. FIG. 10 is a diagram showing changes in transmittance of light having a target wavelength that is transmitted through the spectroscopic section when the distance between the second reflective film and the third reflective film is changed; FIG. 5 is a diagram for explaining the range of measurement light that can be taken in by the spectroscopic section; FIG. 5 is a diagram showing the amount of light received by the light receiving unit when the distance between the second reflecting film and the third reflecting film is changed; 1 is a block diagram showing a schematic configuration of a spectroscopic measurement device according to a first embodiment; FIG. 4 is a flowchart showing a method of driving the spectroscopic measurement device according to the first embodiment; FIG. 4 is a diagram showing transmission characteristics of the spectroscopic section when light having a target wavelength included in a wavelength range from the second wavelength to the fourth wavelength is transmitted from the spectroscopic section in the first embodiment; FIG. 5 is a diagram showing transmission characteristics of the spectroscopic section when light of a target wavelength included in a wavelength range from the third wavelength to the second wavelength is transmitted from the spectroscopic section in the first embodiment; FIG. 4 is a diagram showing the transmission characteristics of the spectroscopic section when the spectroscopic section transmits light of a target wavelength included in the first to third wavelength ranges in the first embodiment; FIG. 2 is a cross-sectional view showing a schematic configuration of a spectroscopic measurement device according to a second embodiment; FIG. 5 is a cross-sectional view showing a schematic configuration of a spectroscopic measurement device according to a third embodiment; FIG. 5 is a cross-sectional view showing a schematic configuration of a spectroscopic section according to a modification of the first embodiment;

[First embodiment]
A first embodiment will be described below.
FIG. 1 is a cross-sectional view showing a schematic configuration of a spectroscopic measurement device 1 according to the first embodiment.
[Overall Configuration of Spectral Measurement Device 1]
The spectrometer 1 is an electronic device that separates measurement light incident from an object to be measured and measures the spectrum, chromaticity, and the like of the object to be measured. As shown in FIG. 1, the spectrometer 1 includes a spectroscopic section 10 which is an optical device, a light receiving section 20 for detecting the light split by the spectroscopic section 10, and a circuit holding the spectroscopic section 10 and the light receiving section 20. A substrate 30 is provided.

[Configuration of spectroscopic unit 10]
As shown in FIG. 1, the spectroscopic section 10 includes a first wavelength tunable interference filter 11, a second wavelength tunable interference filter 12, and a first wavelength tunable interference filter 11 and a second wavelength tunable interference filter 12. and a substrate 101 .
The first substrate 101 is a translucent parallel plate having a first surface 101A on which measurement light is incident and a second surface 101B opposite to the first surface 101A. Here, translucency means having a predetermined or more transmittance with respect to light in a wavelength range (spectroscopic band ΔΛ ₀ ) spectroscopic by the spectroscopic section 10 . For example, when the spectroscopic band ΔΛ ₀ is in the visible light range, the first substrate 101 is made of glass or the like capable of transmitting light in the visible light range. Further, when the spectroscopic band ΔΛ ₀ is from the near-infrared region to the infrared region, the first substrate 101 is composed of a Si substrate or the like.
The thickness dimension of the first substrate 101, that is, the distance d between the first surface 101A and the second surface 101B, which are two parallel planes, will be described later.

The first tunable interference filter 11 is provided on the first surface 101A side of the first substrate 101 . This first wavelength tunable interference filter 11 is a Fabry-Perot type wavelength tunable interference filter and includes a first reflecting film 111 and a second reflecting film 112 .
In this embodiment, a dielectric multilayer film in which low-refractive optical layers and high-refractive optical layers are alternately laminated is used as the first reflective film 111 and the second reflective film 112 . In such a dielectric multilayer film, the central wavelength of the reflection band can be set by setting the layer thicknesses of the low-refractive optical layer and the high-refractive optical layer. In the band, light can be reflected with high reflectance. By using the first reflecting film 111 and the second reflecting film 112 composed of such a dielectric multilayer film, the first spectral band ΔΛ ₁ , which is the range in which light is dispersed by the first variable wavelength interference filter 11, can be easily adjusted. can be designed to In addition, it is possible to transmit light of a desired target wavelength from the first variable wavelength interference filter 11 with high resolution.

A second reflective film 112 is provided on the first surface 101A of the first substrate 101 . That is, the surface of the second reflective film 112 is parallel to the first surface 101A.
On the other hand, the first reflective film 111 is arranged on the side opposite to the first substrate 101 with respect to the second reflective film 112 . The first reflective film 111 has a peripheral end joined to the second reflective film 112, and a part of the central portion faces the second reflective film 112 via the first gap G1.
Here, in the spectroscopic section 10 of the present embodiment, the direction from the first surface 101A of the first substrate 101 to the second surface 101B is defined as the thickness direction Z of the substrate, and the center of the first substrate 101 is parallel to the thickness direction Z. Measurement light is incident along the substrate center axis L _C passing through . Among the incident measurement light, the light in the measurement area _Ar1 within a predetermined diameter range from the substrate center axis LC is received by the light receiving section 20 .
In the first tunable interference filter 11, the first reflective film 111 and the second reflective film 112 are maintained parallel in this measurement area Ar1, and the dimensions of the first gap G1 are uniform. Therefore, the light of the first transmission wavelength corresponding to the dimension of the first gap G1 is transmitted through the first variable wavelength interference filter 11 .

The first tunable interference filter 11 also has a first gap changing section 113 that changes the dimension of the first gap G1. The first gap changing portion 113 is composed of a first electrode 113A and a second electrode 113B.
The first electrode 113A is provided on the surface of the first reflective film 111 facing the second reflective film 112 so as to surround the measurement area Ar1. That is, the first electrode _113A is arranged along a virtual circle having a predetermined diameter dimension from the substrate central axis LC.
The second electrode 113B is provided on the surface of the second reflective film 112 facing the first reflective film 111 so as to surround the measurement area Ar1. That is, the second electrode _113B is arranged along a virtual circle having a predetermined diameter dimension from the substrate central axis LC. The first electrode 113A and the second electrode 113B face each other across the first gap G1.
In the first gap changing section 113 having such a configuration, electrostatic attraction is generated between the first electrode 113A and the second electrode 113B by applying a driving voltage between the first electrode 113A and the second electrode 113B. do. As a result, the dimension of the first gap G1 changes, and the wavelength (first transmission wavelength) of light transmitted through the measurement region Ar1 of the first wavelength tunable interference filter 11 also changes according to the change in the dimension of the first gap G1. do. In this embodiment, the first wavelength tunable interference filter 11 changes the first gap G1 so that the first spectral band ΔΛ from the first wavelength λ ₁ to the second wavelength λ ₂ (λ ₂ >λ ₁ ) It is configured such that the first transmission wavelength can be changed within a range of _one .

On the other hand, the second wavelength tunable interference filter 12 is provided on the second surface 101B side of the first substrate 101 . The second wavelength tunable interference filter 12 is a Fabry-Perot type wavelength tunable interference filter, like the first wavelength tunable interference filter 11 , and includes a third reflecting film 121 and a fourth reflecting film 122 .
In the second wavelength tunable interference filter 12, similarly to the first wavelength tunable interference filter 11, the third reflecting film 121 and the fourth reflecting film 122 are composed of dielectric multilayer films. Therefore, in the second wavelength tunable interference filter 12, by setting the layer thickness of each layer, it is possible to easily design the _second spectral band ΔΛ2, which is the range in which light is dispersed by the second wavelength tunable interference filter 12. It is possible to transmit light of a desired target wavelength with high resolution.

A third reflective film 121 is provided on the second surface 101B of the first substrate 101 . Since the first surface 101A and the second surface 101B are parallel, the second reflecting film 112 provided on the first surface 101A and the third reflecting film 121 provided on the second surface 101B are parallel.
The fourth reflective film 122 is arranged on the side opposite to the first substrate 101 with respect to the third reflective film 121 .
Further, similarly to the first tunable interference filter 11, the fourth reflecting film 122 has its peripheral end joined to the third reflecting film 121, and a part of its central portion is connected to the third reflecting film 121 through the second gap G2. It faces the membrane 121 . In the second wavelength tunable interference filter 12, the third reflecting film 121 and the fourth reflecting film 122 are maintained parallel in the measurement area Ar1, and the dimensions of the second gap G2 are uniform. Therefore, the second wavelength tunable interference filter 12 transmits light having a second transmission wavelength corresponding to the dimension of the second gap G2.

The second wavelength tunable interference filter 12 also has a second gap changing section 123 that changes the dimension of the second gap G2. The second gap changing portion 123 is composed of a third electrode 123A and a fourth electrode 123B.
The third electrode 123A is provided on the surface of the third reflecting film 121 facing the fourth reflecting film 122 so as to surround the measurement area Ar1. The fourth electrode 123B is provided on the surface of the fourth reflective film 122 facing the third reflective film 121 so as to surround the measurement area Ar1. The third electrode 123A and the fourth electrode 123B face each other via the second gap G2.
Similarly to the first gap changing section 113, the second gap changing section 123 applies a drive voltage between the third electrode 123A and the fourth electrode 123B to generate static electricity between the third electrode 123A and the fourth electrode 123B. Generates electro-gravitational force. As a result, the dimension of the second gap G2 changes, and the second transmission wavelength, which is the wavelength of light that passes through the measurement area Ar1 of the second wavelength tunable interference filter 12, also changes. In this embodiment, the second wavelength tunable interference filter 12 changes the second gap G2 to change the third wavelength λ ₃ (λ ₁ <λ ₃ <λ ₂ ) to the fourth wavelength λ 4 (λ ₄ >λ ₃ >λ ₂ ), the second transmission wavelength can be changed in the second spectral band ΔΛ ₂ .

In addition, in the present embodiment, the first substrate 101 is provided with a first through hole 101C penetrating from the first surface 101A to the second surface 101B, and a wiring through hole 101D. As shown in FIG. 1, when the second reflecting film 112 covers the entire first surface 101A or when the third reflecting film 121 covers the entire second surface 101B, the first through holes 101C and the wiring The through-hole 101D for through-hole 101D penetrates from the surface of the second reflective film 112 opposite to the first substrate 101 to the surface of the third reflective film 121 opposite to the first substrate 101 .
Then, one of the first electrode 113A and the second electrode 113B of the first gap changing portion 113 is connected to one of the third electrode 123A and the fourth electrode 123B of the second gap changing portion 123 through the first through hole 101C. electrically conductive. In this embodiment, as shown in FIG. 1, the second electrode 113B provided on the second reflective film 112 and the third electrode 123A provided on the third reflective film 121 are electrically connected. These second electrode 113B and third electrode 123A are electrically connected to a ground circuit provided on the circuit board 30 and set to a common potential.
As a connection structure between the second electrode 113B and the third electrode 123A, a conductive member such as Ag paste is poured into the first through hole 101C to connect the second electrode 113B and the third electrode 123A. Alternatively, a through electrode may be inserted into the first through hole 101C to connect the second electrode 113B and the third electrode 123A.

The wiring through-hole 101D is a through-hole for conducting the fourth electrode 123B and the fourth electrode terminal 123C provided on the first surface 101A of the first substrate 101 . That is, in the present embodiment, the second surface 101B of the first substrate 101 is fixed by the fixing member 301 so as to face the circuit board 30, and the distance between the first substrate 101 and the circuit board 30 is narrow. Wiring to the fourth electrode 123B becomes difficult. On the other hand, by connecting the fourth electrode 123B to the fourth electrode terminal 123C provided on the first substrate 101 through the wiring through hole 101D, the wiring work can be simplified.

Further, in the spectroscopic section 10 of the present embodiment, the first transmission wavelength, which is the wavelength of light that is transmitted through the first tunable interference filter 11, and the second transmission wavelength, which is the wavelength of light that is transmitted through the second tunable interference filter 12 By appropriately setting , it is possible to disperse light of a desired target wavelength included in the spectroscopic band ΔΛ ₀ . On the other hand, light outside the spectroscopic band ΔΛ ₀ has a high transmittance and cannot be spectroscopically dispersed. Therefore, it is preferable to provide the spectroscopic section 10 with a cut filter 14 that blocks light of wavelengths other than the spectroscopic band _ΔΛ0 . The position where the cut filter 14 is provided is not particularly limited as long as it is on the optical axis of the light receiving section 20. For example, as shown in FIG. can do.

[Transmission characteristics of spectroscopic unit 10]
Next, transmission characteristics (spectral characteristics) of the spectroscopic section 10 as described above will be described.
FIG. 2 is a diagram showing an example of transmission characteristics of the first tunable interference filter 11 and the second tunable interference filter 12 of this embodiment.
The first wavelength tunable interference filter 11 changes the dimension of the first gap G1 to change the first transmission wavelength in the _first spectral band ΔΛ1 from the _first wavelength λ1 to the _second wavelength λ2. can be done.
In addition, the second wavelength tunable interference filter 12 changes the second transmission wavelength in the _second spectral band ΔΛ2 from the _third wavelength λ3 to the _fourth wavelength λ4 by changing the dimension of the second gap G2. can be made
Here, in the present embodiment, λ ₁ <λ ₃ <λ ₂ <λ ₄ , and the first spectral band ΔΛ ₁ and the second spectral band ΔΛ ₂ are separated from the third wavelength λ ₃ to the second wavelength λ ₂ . overlap with a common band ΔΛ of up to ₃ .
In such a spectroscopic section 10, it is possible to change the transmission wavelength and transmit light in the spectroscopic band _ΔΛ0 from the _first wavelength λ1 to the _fourth wavelength λ4.

By the way, in the spectroscopic section 10 using the first tunable interference filter 11 and the second tunable interference filter 12 as in the present embodiment, the second reflecting film 112 and the third reflecting film 121 are separated by a predetermined distance. are placed facing each other. Therefore, the second reflecting film 112 and the third reflecting film 121 function as interference filters.
In other words, when light is transmitted through the spectroscopic section 10 , the light of the target wavelength is composed of the first tunable interference filter 11 , the second tunable interference filter 12 , the second reflective film 112 and the third reflective film 121 . It must pass through an interference filter.

3 to 5, the first tunable interference filter 11 and the second tunable interference filter 12 are arranged on the optical axis, and the distance d between the second reflecting film 112 and the third reflecting film 121 is 3. 4 is a diagram showing the transmittance of light of a target wavelength that is transmitted through the spectroscopic section 10 when the pattern is changed. FIG.
The examples shown in FIGS. 3 and 4 are examples in which the second reflective film 112 and the third reflective film 121 are joined by, for example, a film-like connection film. In FIG. 4, the film thickness of the connection film is increased as compared with FIG. On the other hand, FIG. 5 shows the transmission characteristics of the spectroscopic section 10 of this embodiment.
As shown in FIGS. 3 to 5, the second reflective film 112 and the third reflective film 121 are joined by a film-like connecting film, or the like, so that the distance between the second reflective film 112 and the third reflective film 121 is reduced. When the distance d is small, the second reflecting film 112 and the third reflecting film 121 function as interference filters. That is, the light of wavelength _λA corresponding to the distance d between the second reflecting film 112 and the third reflecting film 121 is transmitted with high transmittance, but the transmittance of other wavelengths is low.

At this time, when the target wavelength is different from the wavelength λ _A , the light is transmitted through the interference filter composed of the second reflecting film 112 and the third reflecting film 121 with a low transmittance. For example, when the target wavelength is set between the first wavelength λ ₁ and the third wavelength λ ₃ , the first transmission wavelength that passes through the first wavelength tunable interference filter 11 is set as the target wavelength, and the second wavelength tunable interference filter 11 is set as the target wavelength. A second transmission wavelength that passes through the filter 12 is set to a predetermined wavelength included in the common band _ΔΛ3 . In this case, the light of the target wavelength is transmitted through the first tunable interference filter 11 and the second tunable interference filter 12 . However, as shown in FIG. 3, in the configuration in which the second reflecting film 112 and the third reflecting film 121 are joined by a connecting film, the interference filter configured by the second reflecting film 112 and the third reflecting film 121 has the The transmittance for light of the target wavelength is lowered. Therefore, as shown in FIG. 3, the transmittance of the light of the target wavelength in the spectroscopic section 10 also decreases. Therefore, transmitted light having a desired light intensity cannot be obtained from the spectroscopic unit 10, and the measurement accuracy of the spectroscopic measurement device 1 is also lowered.
In the case of FIG. 4, the distance d between the second reflecting film and the third reflecting film is larger than in the case of FIG. However, the transmittance of the light of the target wavelength in the spectroscopic section 10 cannot be sufficiently increased.

In contrast, in the present embodiment, the first tunable interference filter 11 is provided on the first surface 101A side of the first substrate 101, and the second tunable interference filter 12 is provided on the second surface 101B side. In such a configuration, the distance between the second reflective film 112 and the third reflective film 121 is sufficiently large compared to the case where the second reflective film 112 and the third reflective film 121 are joined by the connection film. can do. That is, in this embodiment, d>G1 and d>G2 are satisfied.
Therefore, as shown in FIG. 5, the transmission characteristics of the second reflecting film 112 and the third reflecting film 121 have a high transmittance over the entire spectroscopic band _ΔΛ0 . Therefore, the transmittance of the spectroscopic section 10 for the target wavelength can be increased.
In order to connect the second reflective film 112 and the third reflective film 121 with a connecting film and to obtain the transmission characteristics shown in FIG. 5, the film thickness of the connecting film may be increased. Conceivable. However, as the film thickness of the connection film increases, the film stress of the connection film also increases. In this case, the half-value width of the peak light in the transmission characteristics of the first tunable interference filter 11 and the second tunable interference filter 12 increases, and the wavelength resolution decreases. In other words, the spectroscopic measurement accuracy is lowered when the spectroscopic measurement is performed by the spectroscopic measurement device 1 .

FIG. 6 is a diagram showing changes in transmittance of light having a target wavelength that is transmitted through the spectroscopic section 10 when the distance d between the second reflecting film 112 and the third reflecting film 121 is changed. As shown in FIG. 6, when d/ _λ0 is changed with the central wavelength of the spectroscopic band ΔΛ0 of the spectroscopic section 10 set to _λ0 , the light of the target wavelength increases as the _value of d/ _λ0 increases. Transmittance increases. Then, when d/λ ₀ ≧300, the transmittance is saturated and becomes a substantially constant value.

FIG. 7 is a diagram for explaining the range of measurement light that can be taken in by the spectroscopic section 10. As shown in FIG.
As described above, increasing the distance d between the second reflecting film 112 and the third reflecting film 121 can reduce the influence of interference by the second reflecting film and the third reflecting film.
However, as shown in FIG. 7, when the distance d between the second reflecting film 112 and the third reflecting film 121 is increased from d1 to d2, the range of measurement light captured by the spectroscopic section 10 is reduced from R1 to R2. That is, when the distance d between the second reflecting film 112 and the third reflecting film 121 is increased, the amount of light transmitted through the spectroscopic section 10 decreases.

FIG. 8 is a diagram showing the amount of light received by the light receiving section 20 when d/ _λ0 is changed. FIG. 8 shows the light intensity ratio when the distance between the second reflecting film 112 and the third reflecting film 121 is 0, that is, when the second reflecting film 112 and the third reflecting film 121 are in contact with each other. ing.
As shown in FIG. 8, the amount of light transmitted through the spectroscopic section 10 decreases as the value of d/ _λ0 increases. Here, it is preferable that the light amount ratio of the light transmitted through the spectroscopic section 10 is 0.5 or more when spectroscopic measurement processing is performed. Therefore, d/λ ₀ is preferably 30000 or less, more preferably 500 or less at which the light amount ratio is 0.9 or more.

As described above, in this embodiment, the distance d from the second reflecting film 112 to the third reflecting film 121, that is, the thickness dimension of the substrate from the first surface 101A to the second surface 101B of the first substrate 101 is It is preferable to set it to 300 to 5000 times the central wavelength λ ₀ of the spectroscopic band ΔΛ ₀ that is split by the spectroscopic section 10 . For example, when the central wavelength λ ₀ is 500 nm, the distance d, that is, the thickness of the first substrate 101 is in the range of 150 μm to 15000 μm, more preferably in the range of 150 μm to 2500 μm. Thereby, in the spectroscopic section 10, the influence of interference between the second reflecting film 112 and the third reflecting film 121 can be suppressed, and the light of the target wavelength can be transmitted with high transmittance. Also, it is possible to suppress a decrease in the light amount ratio due to an excessively long distance from the second reflecting film 112 to the third reflecting film 121 .

[Configuration of Light Receiving Unit 20 and Circuit Board 30]
FIG. 9 is a block diagram showing a schematic configuration of the spectroscopic measurement device 1 of this embodiment.
The light receiving section 20 is a sensor that receives light transmitted through the spectroscopic section 10 , and is provided on the circuit board 30 at a position overlapping the board central axis _LC of the spectroscopic section 10 .
The circuit board 30 is a board to which the spectroscopic section 10 and the light receiving section 20 are fixed.
The circuit board 30 is provided with a spectroscopic drive circuit 31 for driving the spectroscopic section 10 and a light receiving drive circuit 32 for driving the light receiving section 20 . Further, the circuit board 30 is provided with a controller 33 which is a controller for controlling the overall operation of the spectroscopic measurement device 1 .
As shown in FIG. 9, the control section 33 includes a storage section 331, an arithmetic processing section 332, and the like.
The storage unit 331 is configured by a memory or the like for storing data. The storage unit 331 stores a first driving table for controlling the first tunable interference filter 11, a second driving table for controlling the second tunable interference filter 12, and the like.
The first drive table is data indicating the relationship between the drive voltage applied to the first gap changing section 113 and the first transmission wavelength. The second drive table is data indicating the relationship between the drive voltage applied to the second gap changing section 123 and the second transmission wavelength.

The arithmetic processing section 332 functions as a wavelength instruction section 332A, a light reception control section 332B, a measurement section 332C, and the like.
Wavelength command unit 332A controls spectroscopic unit 10 to change the wavelength of transmitted light that is transmitted through spectroscopic unit 10 .
The light receiving control section 332B drives the light receiving section 20 and receives the light receiving signal output from the light receiving section 20 .
332 C of measurement parts calculate the measurement result of a measuring object based on a light reception signal. For example, the measurement unit 332C measures the spectral spectrum of the measurement target, or calculates the chromaticity of the measurement target to perform colorimetry.

[Driving method of spectroscopic measurement device 1]
Next, a method for driving the spectrometer 1 as described above will be described.
FIG. 10 is a flow chart showing a method of driving the spectrometer 1. FIG.
The control unit 33 has an operation unit (not shown) and an interface capable of communicating with an external device. When an operation signal instructing spectroscopic measurement is received by the user operating the operation unit, or when a request signal requesting spectroscopic measurement is received from an external device, the control unit 33 operates the spectroscopic measurement device. 1 causes spectrometry processing to be performed. In this embodiment, the spectroscopic measurement apparatus 1 obtains the spectroscopic measurement result by measuring the amount of light of wavelengths at predetermined wavelength intervals included in the spectroscopic band ΔΛ ₀ .

To this end, first, the wavelength commanding unit 332A of the control unit 33 selects a wavelength region that does not overlap with the _first spectral band _ΔΛ1 of the _second spectral band ΔΛ2 in the spectroscopic band ΔΛ0, that is, the _second wavelength λ2 to the _fourth wavelength λ4.
Specifically, in step S1, the wavelength instruction section 332A reads the drive voltages to be applied to the first gap changer 113 and the second gap changer 123 from the drive table. In this step S1, the wavelength command unit 332A reads the first drive voltage corresponding to the common band center wavelength _λC of the common band _ΔΛ3 from the first drive table. Also, the wavelength command unit 332A reads the second drive voltage corresponding to the target wavelength λ _i from the second drive table.
Next, the wavelength command section 332A outputs a command signal based on the read drive voltage to the spectroscopic drive circuit 31 in step S2. By this step S2, the first driving voltage is applied from the spectral driving circuit 31 to the first gap changing section 113, and the second driving voltage is applied from the spectral driving circuit 31 to the second gap changing section 123. FIG.

FIG. 11 is a diagram showing transmission characteristics of the spectroscopic section 10 when light of a predetermined wavelength included in the wavelength range from the second wavelength λ ₂ to the fourth wavelength λ ₄ is transmitted from the spectroscopic section 10 .
In step S2, as shown in FIG. 11, the light of the target wavelength _λi is transmitted through the first tunable interference filter 11 and the second tunable interference filter 12 with high transmittance. On the other hand, the transmittance of either the first tunable interference filter 11 or the second tunable interference filter 12 is low for wavelengths other than the target wavelength λ _i in the spectroscopic band ΔΛ ₀ . Furthermore, the cut filter 14 blocks light of wavelengths other than the spectroscopic band ΔΛ ₀ .
In this embodiment, the second reflective film 112 and the third reflective film 121 have the thickness dimension of the first substrate 101, which is 300 times or more the center wavelength _λ0 . Therefore, even when an interference filter is configured by the second reflecting film 112 and the third reflecting film 121, the transmittance for the light of the target wavelength _λi is high. Therefore, the light of the target wavelength _λi is transmitted through each of the first tunable interference filter 11, the second tunable interference filter 12, and the interference filters composed of the second reflecting film 112 and the third reflecting film 121. It becomes possible to transmit the light from the spectroscopic section 10 with a high transmittance.

After step S2, the light receiving control section 332B performs step S3, drives the light receiving section 20, and detects the amount of light received by the light receiving section 20. FIG.
After that, the control unit 33 performs step S4, and is included in the wavelength range (the wavelength range from the _second wavelength λ2 to the _fourth wavelength λ4) other than the _first spectral band _ΔΛ1 of the spectroscopic band ΔΛ0. , determines whether or not the amount of light of all the measurement wavelengths has been detected. If the determination in step S4 is No, the target wavelength _λi is changed to the next wavelength and the process returns to step S1. That is, in the present embodiment, the target wavelength _λi is changed at predetermined intervals, and the processing from step S1 to step S3 is repeatedly performed to detect the light amount for each wavelength.

If it is determined as Yes in step S4, the wavelength instruction unit 332A of the control unit 33 selects a common band ΔΛ ₃ where the second spectral band ΔΛ ₂ and the first spectral band ΔΛ ₁ overlap in the spectroscopic band ΔΛ ₀ , that is, , from the _third wavelength λ3 to the _second wavelength λ2.
Specifically, in step S5, the wavelength command unit 332A reads the first drive voltage corresponding to the target wavelength λ _i from the first drive table, and reads the second drive voltage corresponding to the target wavelength λ _i from the second drive table. Read the drive voltage.
Then, in the following step S6, the wavelength command unit 332A issues a command signal for causing the first gap changer 113 to apply the first drive voltage and the second gap changer 123 to apply the second drive voltage. Output to circuit 31 .

FIG. 12 shows the transmission characteristics of the spectroscopic section 10 when the spectroscopic section 10 transmits light of a predetermined wavelength included in the wavelength range from the _third wavelength λ3 to the _second wavelength λ2.
As shown in FIG. 12, in the spectroscopic band ΔΛ ₀ , the light of the target wavelength λ _i is transmitted through the first tunable interference filter 11 and the second tunable interference filter 12 with high transmittance, and the light of the wavelength other than the target wavelength λ _i is transmitted. With respect to the light of the wavelength, the transmittance becomes lower in either the first tunable interference filter 11 or the second tunable interference filter 12 . Further, even when an interference filter is configured by the second reflecting film 112 and the third reflecting film 121, the transmittance for the light of the target wavelength _λi is high.
Therefore, in step S6 as well, the light of the target wavelength λ _i passes through the interference filter composed of the first tunable interference filter 11, the second tunable interference filter 12, the second reflecting film 112, and the third reflecting film 121. The transmittance increases for each of them, and the light is transmitted from the spectroscopic section 10 with a high transmittance.

After that, the process of step S7 is performed. In step S7, similarly to step S3, the light receiving control section 332B drives the light receiving section 20 and detects the amount of light transmitted through the spectroscopic section 10 in step S6.
And the control part 33 implements step S8. In step S8, the control unit 33 controls the wavelength range of the common band _ΔΛ3 of the spectroscopic band _ΔΛ0 (the wavelength range from the _third wavelength λ3 to the _second wavelength λ2). It is determined whether or not the amount of light has been detected. If the determination in step S8 is No, the target wavelength _λi is changed to the next wavelength and the process returns to step S5.

If the determination in step S8 is Yes, the wavelength commanding unit 332A of the control unit 33 selects a wavelength band that does not overlap the _second spectral band _ΔΛ2 of the _first spectral band ΔΛ1 in the spectroscopic band ΔΛ0. A spectroscopic measurement is performed for a wavelength range from one wavelength λ ₁ to a third wavelength λ ₃ .
For this, in step S9, the wavelength command unit 332A reads the first drive voltage corresponding to the target wavelength _λi from the first drive table, and the common band center wavelength _λC of the common band _ΔΛ3 from the second drive table. read out the second drive voltage corresponding to .
Next, the wavelength command section 332A performs step S10 and outputs a command signal based on the read drive voltage to the spectroscopic drive circuit 31. FIG.

FIG. 13 shows the transmission characteristics of the spectroscopic section 10 when the spectroscopic section 10 transmits light of a predetermined wavelength included in the wavelength range from the _first wavelength λ1 to the _third wavelength λ3.
As shown in FIG. 13, in the spectroscopic band ΔΛ ₀ , the light of the target wavelength λ _i is transmitted through the first tunable interference filter 11 and the second tunable interference filter 12 with high transmittance, and the light of the wavelength other than the target wavelength λ _i With respect to the wavelength of light, either the first tunable interference filter 11 or the second tunable interference filter 12 has a low transmittance. Further, even when an interference filter is configured by the second reflecting film 112 and the third reflecting film 121, the transmittance for the light of the target wavelength _λi is high.
Therefore, in step S10 as well, the light of the target wavelength λ _i passes through the interference filter composed of the first tunable interference filter 11, the second tunable interference filter 12, the second reflecting film 112, and the third reflecting film 121. The transmittance increases for each of them, and the light is transmitted from the spectroscopic section 10 with a high transmittance.

Further, in step S11, the light receiving control section 332B drives the light receiving section 20 and detects the amount of light transmitted through the spectroscopic section 10. FIG.
Then, in step _{S12 ,} the control unit 33 _{controls all} of It is determined whether or not the amount of light of the measurement wavelength has been detected. If the determination in step S12 is No, the target wavelength λ _i is changed to the next wavelength and the process returns to step S9.
If determined as Yes in step S12, the measurement unit 332C performs a predetermined measurement process in step S13 based on the amount of light of each wavelength obtained in steps S3, S7, and S11. For example, the measurement unit 332C calculates the spectral spectrum of the measurement target, or calculates the chromaticity of the measurement target.

[Action and effect of the present embodiment]
The spectroscopic measurement device 1 of this embodiment includes a spectroscopic section 10 as a spectroscopic device and a control section 33 .
The spectroscopic section 10 includes a first tunable interference filter 11 , a second tunable interference filter 12 , and a first substrate 101 .
The first tunable interference filter 11 is a tunable interference filter in which a first reflective film 111 and a second reflective film 112 are arranged to face each other with a first gap G1 interposed therebetween. In this first wavelength tunable interference filter 11 , the second reflecting film 112 is provided on the first surface 101 A of the first substrate 101 , and the first reflecting film 111 is positioned between the first substrate 101 and the second reflecting film 112 . is located on the opposite side.
The second wavelength tunable interference filter 12 is a wavelength tunable interference filter in which a third reflective film 121 and a fourth reflective film 122 are arranged to face each other with a second gap G2 interposed therebetween. In this second wavelength tunable interference filter 12 , the third reflective film 121 is provided on the second surface 101 B of the first substrate 101 , and the fourth reflective film 122 is provided on the first substrate 101 with respect to the third reflective film 121 . is located on the opposite side. That is, in the spectroscopic section 10 of the present embodiment, a predetermined thickness dimension is provided between the second reflective film 112 of the first tunable interference filter 11 and the third reflective film 121 of the second tunable interference filter 12. A first substrate 101 is arranged.
In the spectroscopic section 10 having such a configuration, in a wide spectroscopic band ΔΛ ₀ including the first spectral band ΔΛ ₁ of the first tunable interference filter 11 and the second spectral band ΔΛ ₂ of the second tunable interference filter 12 , the target wavelength λ _i can be changed, and the wavelength range measurable by the spectrometer 1 can be expanded.

Further, in the present embodiment, the distance between the second reflective film 112 and the third reflective film 121 is higher than in the case where the second reflective film 112 and the third reflective film 121 are joined by a film-like connecting film or the like. You can increase the size. Therefore, even if the second reflective film 112 and the third reflective film 121 face each other, the influence of interference between the second reflective film 112 and the third reflective film 121 can be reduced. That is, it is possible to suppress a decrease in the transmittance of the light of the target wavelength λ _i due to the second reflecting film 112 and the third reflecting film 121 .
Also, in the spectrometer 1 including the spectroscopic unit 10, the spectroscopic band _{ΔΛ 0} can be widened, the reduction in the amount of light of the target wavelength λi can be suppressed, and the influence of the noise component can be suppressed. Highly accurate measurement processing can be implemented.

In the spectroscopic section 10 of this embodiment, the first variable wavelength interference filter 11 is composed of a first electrode 113A provided on the first reflecting film 111 and a second electrode 113B provided on the second reflecting film 112. and a first gap changer 113 . In addition, the second variable wavelength interference filter 12 has a second gap changing section 123 which is configured by a third electrode 123A provided on the third reflecting film 121 and a fourth electrode 123B provided on the fourth reflecting film 122. Prepare.
The first substrate 101 is provided with a first through hole 101C penetrating from the first surface 101A to the second surface 101B. 101C.
The first gap changing section 113 and the second gap changing section 123 are electrostatic actuators that change the first gap G1 and the second gap G2 by applying voltage. In such an electrostatic actuator, generally, one of a pair of electrodes is connected to a reference potential circuit such as a ground circuit and maintained at the reference potential, and a drive signal is input to the other of the pair of electrodes. As a result, the potential difference between the reference potential and the voltage value of the drive signal is applied to the electrostatic actuator, and the electrostatic attractive force acting on the electrostatic actuator can be easily changed simply by controlling the voltage value of the drive signal. It is possible to
In this embodiment, the second electrode 113B forming the first gap changing portion 113 and the third electrode 123A forming the second gap changing portion 123 are electrically connected via the first through hole 101C. In such a configuration, the second electrode 113B and the third electrode 123A can be connected to the reference potential circuit provided on the circuit board 30 by one wiring. Therefore, the number of wires for the spectroscopic section 10 can be reduced, and the configuration can be simplified.

In this embodiment, the first wavelength tunable interference filter 11 changes the dimension of the first gap G1 to change the first transmission wavelength from the _first wavelength λ1 to the second wavelength longer than the _first wavelength λ1. It is configured to be changeable in the _first spectral band _ΔΛ1 up to wavelength λ2. In addition, the second wavelength tunable interference filter 12 changes the dimension of the second gap G2 so that the second transmission wavelength is longer than the _first wavelength λ1 and shorter than the _second wavelength λ2. It is configured to be changeable in the _second spectral band ΔΛ2 from the _third wavelength λ3 to the _fourth wavelength λ4 longer than the _second wavelength λ2. That is, the relationship λ ₁ <λ ₃ <λ ₂ <λ ₄ is satisfied.
In such a spectroscopic section 10, when light from the first wavelength λ ₁ to the third wavelength λ ₃ is spectroscopically set as the target wavelength, the first gap G1 is set to a dimension corresponding to the target wavelength, and the second gap G2 is set to a dimension corresponding to the target wavelength. A dimension corresponding to an arbitrary wavelength of the common band _ΔΛ3 is set. Also, when light from the third wavelength λ3 to the second wavelength λ2 is to be dispersed as the target wavelength, both the first gap G1 and the second gap G2 are set to have dimensions corresponding to the target wavelength. Furthermore, when light from the second wavelength λ ₂ to the fourth wavelength λ ₄ is to be dispersed as the target wavelength, the second gap G2 is set to a dimension corresponding to the target wavelength, and the first gap G1 is set to an arbitrary wavelength in the common band ΔΛ ₃ . Set the dimension corresponding to the wavelength of
As a result, the light of the target wavelength can be accurately dispersed from the wide spectroscopic band ΔΛ ₀ including the first spectral band ΔΛ ₁ and the second spectral band ΔΛ ₂ from the spectroscopic section 10 .

In this embodiment, the distance d between the second reflective film 112 and the third reflective film 121, that is, the distance d from the first surface 101A to the second surface 101B of the first substrate 101 (the thickness of the first substrate 101 dimension) is 300 times or more the central wavelength λ ₀ of the spectroscopic band ΔΛ ₀ .
That is, when an interference filter is formed by the second reflecting film 112 and the third reflecting film 121, the transmittance of light of a predetermined wavelength _λA corresponding to the distance d increases, and the transmittance of light of wavelengths other than _λA increases. rate becomes lower. Therefore, if the wavelengths other than _λA include the target wavelength to be split by the spectroscopic section 10, the transmittance of the light of the target wavelength is reduced. By setting d/λ ₀ ≧300 as shown in FIG. 6, the transmittance of light of this target wavelength can be maintained at around 90%. In other words, in this embodiment, the problem of multiple interference of light between the second reflecting film 112 and the third reflecting film 121 is suppressed, and even if the target wavelength is set to any wavelength in the spectroscopic band ΔΛ ₀ , It is possible to transmit the light of the target wavelength with high transmittance.

Further, when the distance d between the second reflecting film 112 and the third reflecting film 121 exceeds 30000 times the central wavelength _λ0 of the spectroscopic band _ΔΛ0 , the distance between the second reflecting film 112 and the third reflecting film 121 becomes Compared to when the distance is 0, the amount of light transmitted through the spectroscopic section 10 is 1/2 or less.
On the other hand, in this embodiment, the distance d between the second reflecting film 112 and the third reflecting film 121 is 30000 times or less the central wavelength λ ₀ of the spectroscopic band ΔΛ ₀ . As a result, the problem that the amount of light transmitted from the spectroscopic section 10 is reduced can be suppressed.

In this embodiment, the distance d between the second reflective film 112 and the third reflective film 121 is greater than the first gap G1, which is the distance between the first reflective film 111 and the second reflective film 112, It is larger than the second gap G2, which is the distance between the third reflective film 121 and the fourth reflective film 122. As a result, as described above, even if the second reflecting film 112 and the third reflecting film 121 are opposed to each other, the influence of interference by the second reflecting film 112 and the third reflecting film 121 is reduced, and the target wavelength λ A decrease in the transmittance of light _i can be suppressed.

[Second embodiment]
Next, a second embodiment will be described.
In the first embodiment described above, both the first tunable interference filter 11 and the second tunable interference filter 12 are provided on one first substrate 101 . On the other hand, in the second embodiment, the second substrate provided with the first tunable interference filter 11 and the third substrate provided with the second tunable interference filter 12 are provided. differ from
In the following description, the same reference numerals are given to the configurations already described, and the description thereof will be omitted or simplified.

FIG. 14 is a cross-sectional view showing a schematic configuration of the spectroscopic measurement device 1A of the second embodiment. The spectroscopic measurement apparatus 1A of the present embodiment is obtained by replacing the spectroscopic section 10 with the spectroscopic section 10A in the spectroscopic measurement apparatus 1 of the first embodiment, and the configurations of the light receiving section 20 and the circuit board 30 are substantially the same. Therefore, the description here is omitted.

As shown in FIG. 14, the spectroscopic section 10A of this embodiment includes a second substrate 102, a third substrate 103, a first wavelength tunable interference filter 11A, and a second wavelength tunable interference filter 12A. .
The second substrate 102 and the third substrate 103 are made of a material that is translucent to the spectroscopic band _ΔΛ0 , and have substantially the same shape as the first substrate 101 . That is, the second substrate 102 is a parallel flat plate having a third surface 102A and a fourth surface 102B opposite to the third surface 102A, and the third surface 102A and the fourth surface 102B are parallel. The third substrate 103 is a parallel flat plate having a fifth surface 103A and a sixth surface 103B opposite to the fifth surface 103A, and the fifth surface 103A and the sixth surface 103B are parallel.

In this embodiment, the second substrate 102 is provided with the first wavelength tunable interference filter 11A, and the third substrate 103 is provided with the second wavelength tunable interference filter 12A.
Specifically, the first tunable interference filter 11A is provided with a second reflecting film 112 on the third surface 102A of the second substrate 102, and a It is configured by arranging the first reflecting film 111 . As in the first embodiment, the first reflective film 111 has its peripheral end joined to the second reflective film 112, and a part of its central portion faces the second reflective film 112 via the first gap G1. do.
Further, as in the first embodiment, the first tunable interference filter 11A is provided with a first gap changing section 113 that changes the dimension of the first gap G1.

The second wavelength tunable interference filter 12A has a fourth reflecting film 122 provided on the fifth surface 103A of the third substrate 103, and a third reflecting film 121 on the side opposite to the third substrate 103 with respect to the fourth reflecting film 122. is arranged. The third reflective film 121 has a peripheral end joined to the fourth reflective film 122 and a part of the center faces the third reflective film 121 via the second gap G2.
Further, as in the first embodiment, the second tunable interference filter 12A is provided with a second gap changing section 123 that changes the dimension of the second gap G2.

In the spectral section 10A of the present embodiment, the sixth surface 103B of the third substrate 103 faces the circuit board 30, and the sixth surface 103B is fixed to the circuit board 30 by the fixing member 301. The second substrate 102 is arranged such that the fourth surface 102B faces the fifth surface 103A of the third substrate 103 . A spacer 16 is arranged between the second substrate 102 and the third substrate 103 , and the second substrate 102 is fixed to the third substrate 103 by the spacer 16 .
That is, the second wavelength tunable interference filter 12A is arranged between the second substrate 102 and the third substrate 103. FIG. In other words, the second substrate 102 is arranged between the second reflective film 112 of the first tunable interference filter 11A and the third reflective film 121 of the second tunable interference filter 12A.
Therefore, as in the first embodiment, in the present embodiment as well, compared to the configuration in which the second reflective film 112 and the third reflective film 121 are joined by a connection film, the second reflective film 112 and the third reflective film 121 are The distance d between the membrane 121 can be increased. That is, the distance d satisfies d>G1 and d>G2. As in the first embodiment, this distance d is 300 times or more and 30000 times or less, more preferably 300 times or more and 5000 times or less, the central wavelength λ ₀ of the spectroscopic band ΔΛ ₀ .

Also, the spacer 16 fixes the second substrate 102 to the third substrate 103 at a predetermined position. A plurality of spacers 16 may be provided, or only one annular spacer 16 may be provided. When a plurality of spacers 16 are provided, at least one of the plurality of spacers 16 is a conductive spacer 16A having conductivity. Note that the configuration example shown in FIG. 14 illustrates a configuration in which a plurality of spacers 16 are provided and include conductive spacers 16A and non-conductive fixing spacers 16B. If it is composed of only one spacer, the spacer may be the conductive spacer 16A.

Further, the second substrate 102 is provided with a second through hole 102C penetrating from the third surface 102A to the fourth surface 102B.
This second through hole 102C is provided facing the conductive spacer 16A. In this embodiment, the second electrode 113B of the first gap changing portion 113 is electrically connected to the fourth electrode 123B of the second gap changing portion 123 via the second through hole 102C and the conductive spacer 16A.

[Action and effect of the present embodiment]
A spectroscopic section 10A of a spectroscopic measurement apparatus 1A of this embodiment includes a first tunable interference filter 11A, a second tunable interference filter 12A, a second substrate 102, and a third substrate 103. FIG.
The first tunable interference filter 11A is a tunable interference filter in which a first reflecting film 111 and a second reflecting film 112 are arranged to face each other with a first gap G1 interposed therebetween. Provided on the third surface 102A of the second substrate 102, the first reflective film 111 is arranged on the side opposite to the second substrate 102 with respect to the second reflective film 112. As shown in FIG. Also, the second wavelength tunable interference filter 12A is a wavelength tunable interference filter in which a third reflecting film 121 and a fourth reflecting film 122 are arranged to face each other across a second gap G2. is provided on the fifth surface 103 A of the third substrate 103 , and the third reflective film 121 is arranged on the side opposite to the third substrate 103 with respect to the fourth reflective film 122 . Second substrate 102 is fixed to third substrate 103 via spacer 16 such that fourth surface 102B of second substrate 102 faces fifth surface 103A of third substrate 103 . That is, in the spectroscopic section 10A of this embodiment, the second variable wavelength interference filter 12A is arranged between the second substrate 102 and the third substrate 103, and the second reflecting film 112 and the third reflecting film 121 A second substrate 102 is arranged between.
As in the first embodiment, the spectroscopic section 10A having such a configuration includes the first spectral band ΔΛ ₁ of the first tunable interference filter 11A and the second spectral band ΔΛ ₂ of the second tunable interference filter 12A. With a wide spectroscopic band ΔΛ ₀ , the target wavelength λ _i can be changed, and the wavelength range measurable by the spectroscopic measurement device 1A can be widened.
Further, since the second substrate 102 is arranged between the second reflective film 112 and the third reflective film 121, the second reflective film 112 and the third reflective film 121 are joined by a film-like connecting film or the like. The dimension between the second reflective film 112 and the third reflective film 121 can be increased compared to the case where the second reflective film 112 and the third reflective film 121 are provided. For this reason, it is possible to suppress the inconvenience that the transmittance of the light of the target wavelength is reduced due to the influence of the interference by the second reflecting film 112 and the third reflecting film 121 .

In the spectroscopic section 10A of the present embodiment, the first variable wavelength interference filter 11A is composed of a first electrode 113A provided on the first reflecting film 111 and a second electrode 113B provided on the second reflecting film 112. and a first gap changer 113 . In addition, the second tunable interference filter 12A has a second gap changing section 123 which is configured by a third electrode 123A provided on the third reflecting film 121 and a fourth electrode 123B provided on the fourth reflecting film 122. Prepare.
Also, the second substrate 102 is fixed to the third substrate 103 by spacers 16 including conductive spacers 16A.
Further, the second substrate 102 is provided with a second through hole 102C penetrating from the third surface 102A to the fourth surface 102B. 102C, and conductive spacer 16A.
Therefore, the second electrode 113B and the fourth electrode 123B can be connected to the reference potential circuit provided on the circuit board 30 by one wiring, and the number of wirings for the spectroscopic section 10A can be reduced. can be simplified.

[Third Embodiment]
Next, a third embodiment will be described.
In the third embodiment, another configuration example of the spectroscopic section using two substrates will be described.
FIG. 15 is a cross-sectional view showing a schematic configuration of a spectroscopic measurement device 1B according to the third embodiment. The spectroscopic measurement apparatus 1B of the present embodiment is obtained by replacing the spectroscopic section 10 with the spectroscopic section 10B in the spectroscopic measurement apparatus 1 of the first embodiment, and the configurations of the light receiving section 20 and the circuit board 30 are substantially the same. Therefore, the description here is omitted.

As shown in FIG. 15, the spectroscopic section 10B of this embodiment includes a fourth substrate 104, a fifth substrate 105, a first tunable interference filter 11B, and a second tunable interference filter 12B. .
The fourth substrate 104 and the fifth substrate 105 are made of a material having translucency with respect to the spectroscopic band _ΔΛ0 , and have substantially the same shape as the first substrate 101 . That is, the fourth substrate 104 is a parallel flat plate having a seventh surface 104A and an eighth surface 104B opposite to the seventh surface 104A, and the seventh surface 104A and the eighth surface 104B are parallel. The fifth substrate 105 is a parallel flat plate having a ninth surface 105A and a tenth surface 105B opposite to the ninth surface 105A.

In this embodiment, the fourth substrate 104 is provided with the first wavelength tunable interference filter 11B, and the fifth substrate 105 is provided with the second wavelength tunable interference filter 12B.
Specifically, the first tunable interference filter 11B is provided with the first reflective film 111 on the eighth surface 104B of the fourth substrate 104, and the first reflective film 111 is provided on the side opposite to the fourth substrate 104 with respect to the first reflective film 111. It is configured by arranging the second reflective film 112 . The second reflective film 112 has a peripheral end joined to the first reflective film 111 and a part of the central portion facing the first reflective film 111 via the first gap G1.
Further, the first tunable interference filter 11B is provided with a first gap changing section 113 that changes the dimension of the first gap G1. That is, the first reflective film 111 is provided with the first electrode 113A, and the second reflective film 112 is provided with the second electrode 113B.

The second wavelength tunable interference filter 12B has a fourth reflecting film 122 on the ninth surface 105A of the fifth substrate 105, and a third reflecting film 121 on the side opposite to the fifth substrate 105 with respect to the fourth reflecting film 122. is arranged. The third reflective film 121 has a peripheral end joined to the fourth reflective film 122 and a part of the center faces the third reflective film 121 via the second gap G2.
Further, as in the first embodiment, the second tunable interference filter 12B is provided with a second gap changing section 123 that changes the dimension of the second gap G2. That is, the third reflective film 121 is provided with the third electrode 123A, and the fourth reflective film 122 is provided with the fourth electrode 123B.

In the spectral section 10B of the present embodiment, the tenth surface 105B of the fifth substrate 105 faces the circuit board 30, and the tenth surface 105B is fixed to the circuit board 30 by the fixing member 301. FIG. The fourth substrate 104 is arranged such that the eighth surface 104B faces the ninth surface 105A of the fifth substrate 105 . A spacer 16 is arranged between the fourth substrate 104 and the fifth substrate 105 as in the second embodiment, and the fourth substrate 104 is fixed to the fifth substrate 105 by the spacer 16 .
That is, the configuration is such that the first tunable interference filter 11B and the second tunable interference filter 12B are arranged between the fourth substrate 104 and the fifth substrate 105 .
In this embodiment, unlike the first and second embodiments, no substrate is interposed between the second reflective film 112 and the third reflective film 121. The position of the substrate 104 can be fixed at a desired position, and the distance d between the second reflective film 112 and the third reflective film 121 can be determined by the spacer 16 . Here, also in this embodiment, the distance d satisfies d>G1 and d>G2. In this embodiment, the spacer 16 is arranged so that the distance d between the second reflecting film 112 and the third reflecting film 121 is 300 times or more and 30000 times or less the central wavelength λ ₀ of the spectroscopic band ΔΛ ₀ . , More preferably, the fourth substrate 104 is fixed to the fifth substrate 105 so as to be 300 times or more and 5000 times or less.

As in the second embodiment, the spacer 16 may be provided in plural or may be singular. The example shown in FIG. 15 shows a configuration in which spacers 16 include conductive spacers 16A and non-conductive fixing spacers 16B.
In this embodiment, the conductive spacer 16A is provided in contact with the first electrode 113A and the fourth electrode 123B. conducts to

[Action and effect of the present embodiment]
The spectroscopic section 10B of the spectroscopic measurement apparatus 1B of this embodiment includes a first tunable interference filter 11B, a second tunable interference filter 12B, a fourth substrate 104, and a fifth substrate 105. FIG.
The first tunable interference filter 11B is a tunable interference filter in which a first reflecting film 111 and a second reflecting film 112 are arranged to face each other across a first gap G1. Provided on the eighth surface 104B of the fourth substrate 104, the second reflective film 112 is arranged on the side opposite to the fourth substrate 104 with respect to the first reflective film 111. As shown in FIG. The second tunable interference filter 12B is a tunable interference filter in which a third reflecting film 121 and a fourth reflecting film 122 are arranged to face each other with a second gap G2 interposed therebetween. is provided on the ninth surface 105 A of the fifth substrate 105 , and the third reflective film 121 is arranged on the side opposite to the fifth substrate 105 with respect to the fourth reflective film 122 . The fourth substrate 104 is fixed to the fifth substrate 105 via spacers 16 such that the eighth surface 104B of the fourth substrate 104 faces the ninth surface 105A of the fifth substrate 105 . That is, in the spectroscopic section 10B of the present embodiment, the first tunable interference filter 11B and the second tunable interference filter 12B are arranged between the fourth substrate 104 and the fifth substrate 105. FIG. In this embodiment, the fourth substrate 104 is arranged with respect to the fifth substrate 105 by the spacers 16 . At this time, by selecting the height dimension of the spacer 16 so as not to cause interference between the second reflecting film 112 and the third reflecting film 121, the interference caused by the second reflecting film 112 and the third reflecting film 121 causes the , it is possible to suppress the inconvenience that the transmittance for the light of the target wavelength is reduced.

In the spectroscopic section 10B of this embodiment, the first variable wavelength interference filter 11B is composed of a first electrode 113A provided on the first reflecting film 111 and a second electrode 113B provided on the second reflecting film 112. and a first gap changer 113 . In addition, the second tunable interference filter 12B has a second gap changing section 123 configured by a third electrode 123A provided on the third reflecting film 121 and a fourth electrode 123B provided on the fourth reflecting film 122. Prepare.
The fourth substrate 104 is fixed to the fifth substrate 105 by spacers 16 including conductive spacers 16A, and the first electrode 113A and the fourth electrode 123B are connected via the conductive spacers 16A. Conducted.
Therefore, the first electrode 113A and the fourth electrode 123B can be connected to the reference potential circuit provided on the circuit board 30 by one wiring, and the number of wirings for the spectroscopic section 10B can be reduced. can be simplified.

[Modification]
It should be noted that the present invention is not limited to the above-described embodiments, and includes modifications, improvements, etc. within the scope of achieving the object of the present invention.

[Modification 1]
In the above embodiment, one of the pair of reflective films is provided on the substrate and the other is provided on the peripheral edge of the first tunable interference filters 11, 11A, 11B and the second tunable interference filters 12, 12A, 12B. part is joined to one reflecting film provided on the substrate, and a part of the central part faces the one reflecting film through a gap. Alternatively, both of the pair of reflective films may be provided on the substrates, and these substrates may be arranged to face each other.
FIG. 16 is a cross-sectional view showing an example of a spectroscopic section 10C according to Modification 1. As shown in FIG.
A spectroscopic section 10C shown in FIG. 16 is a modification of the spectroscopic section 10 of the first embodiment, and includes a first tunable interference filter 11C, a second tunable interference filter 12C, a sixth substrate 106, and a seventh A substrate 107 and an eighth substrate 108 are provided.
The surface of the sixth substrate 106 facing the seventh substrate 107 and the surface facing the eighth substrate 108 are opposite sides. The surface facing the seventh substrate 107 is provided with a concave groove formed by processing, for example, etching, etc., and the first arrangement surface 106A and the second arrangement surrounding the first arrangement surface 106A by the groove bottom surface. A surface 106B is configured. A portion of the surface facing the seventh substrate 107 where the grooves are not formed serves as a first bonding surface 106C to which the seventh substrate 107 is bonded. Similarly, the surface facing the eighth substrate 108 is provided with a concave groove formed by processing such as etching, for example, and the bottom surface of the groove surrounds the third arrangement surface 106D and the third arrangement surface 106D. A fourth placement surface 106E is configured. A portion of the surface facing the eighth substrate 108 where no groove is formed serves as a second bonding surface 106F to which the eighth substrate 108 is bonded.

106 A of 1st arrangement|positioning surfaces are surfaces which make the 3rd arrangement|positioning surface 106D and front and back, and are parallel to 3rd arrangement|positioning surface 106D. The first arrangement surface 106A is provided with a second reflecting film 112 that constitutes the first wavelength tunable interference filter 11C. A third reflection film 121 that constitutes the second wavelength tunable interference filter 12C is provided on the third arrangement surface 106D.
A second electrode 113B forming the first gap changing portion 113 is arranged on the second arrangement surface 106B, and a third electrode 123A forming the second gap changing portion 123 is arranged on the fourth arrangement surface 106E. be.

The seventh substrate 107 is joined to a first movable portion 107A facing the first arrangement surface 106A, a first holding portion 107B holding the first movable portion 107A movably in the Z direction, and a first joint surface 106C. It has a first joint portion 107C.
The first movable portion 107A has a flat surface facing the first placement surface 106A and the second placement surface 106B, and the flat surface is provided with the first reflecting film 111 that constitutes the first wavelength tunable interference filter 11C. The first reflective film 111 and the second reflective film 112 face each other with the first gap G1 interposed therebetween. The first movable portion 107A is further provided with a first electrode 113A facing the second electrode 113B, and the first gap changing portion 113 is configured by the first electrode 113A and the second electrode 113B.
The first holding portion 107B is, for example, a diaphragm formed by processing the surface of the seventh substrate 107 opposite to the sixth substrate 106 by etching or the like.
The first bonding portion 107C is bonded to the first bonding surface 106C via a bonding film (not shown).

The eighth substrate 108 has substantially the same configuration as the seventh substrate 107, and includes a second movable portion 108A facing the third placement surface 106D and a second movable portion 108A that holds the second movable portion 108A movably in the Z direction. The holding portion 108B has a second joint portion 108C joined to the second joint surface 106F.
The second movable portion 108A has a flat surface facing the third placement surface 106D and the fourth placement surface 106E. A fourth reflecting film 122 that constitutes the second wavelength tunable interference filter 12C is provided on the flat surface so as to face the third reflecting film 121 . A fourth electrode 123B constituting the second gap changing portion 123 is provided on the flat surface so as to face the third electrode 123A.
The second holding portion 108B is, for example, a diaphragm formed by processing the surface of the eighth substrate 108 opposite to the sixth substrate 106 by etching or the like. The second bonding portion 108C is bonded to the second bonding surface 106F via a bonding film (not shown).

In such a spectroscopic section 10C as well, the second reflecting film 112 and the third reflecting film 121 face each other with the sixth substrate 106 interposed therebetween. The distance d between the second reflective film 112 and the third reflective film 121 can be increased as compared with a configuration in which they are joined by a connection film. This distance d is 300 times or more and 30000 times or less, more preferably 300 times or more and 5000 times or less, the center wavelength λ ₀ of the spectroscopic band ΔΛ ₀ of the spectroscopic section 10C, as in each of the above embodiments. . As a result, the light of the target wavelength can be transmitted with a high transmittance even through the interference filter composed of the second reflecting film 112 and the third reflecting film 121 .

[Modification 2]
In each of the above embodiments, the first reflective film 111, the second reflective film 112, the third reflective film 121,
And as the fourth reflective film 122, an optical multilayer mirror configured by stacking a low refractive optical layer and a high refractive optical layer is exemplified, but it is not limited to this. For example, these reflective films may be composed of a metal film such as Ag or a metal alloy film.

[Modification 3]
In each of the above embodiments, the first spectral band ΔΛ1 of the _first tunable interference filters 11, 11A, and 11B is the wavelength range from the _first wavelength λ1 to the _second wavelength λ2, and the second tunable interference filter 12 , 12A and 12B is _a wavelength range from the _third wavelength _λ3 to the _fourth wavelength _{λ4 ,} and an example where λ1< _λ3 <λ2<λ4 is shown.
On the other hand, for example, the _first spectral band ΔΛ1 and the _second spectral band ΔΛ2 may not overlap. In this case, for example, two types of cut filters are arranged on the optical axes of the spectroscopic units 10, 10A, and 10B so as to move forward and backward.
For example, in the spectroscopic section 10 of the first embodiment, when the first spectral band ΔΛ ₁ and the second spectral band ΔΛ ₂ do not overlap and the target wavelength is included in the first spectral band ΔΛ ₁ , the first The gap G1 has a dimension corresponding to the target wavelength, and a cut filter for blocking light other than the _first spectral band ΔΛ1 is inserted in the optical path. When the target wavelength is changed to a wavelength included in the _second spectral band ΔΛ2, the second gap G2 has dimensions corresponding to the target wavelength, and a cut filter that blocks light other than the _second spectral band ΔΛ2 is provided in the optical path. , and instead, a cut filter for blocking light other than the _second spectral band ΔΛ2 is inserted into the optical path.

[Modification 4]
In the first embodiment, the configuration in which the second electrode 113B and the third electrode 123A are electrically connected through the first through hole 101C is illustrated. In the second embodiment, the configuration in which the second electrode 113B and the fourth electrode 123B are electrically connected via the second through hole 102C and the conductive spacer 16A is exemplified. Furthermore, in the third embodiment, the configuration in which the first electrode 113A and the fourth electrode 123B are electrically connected through the conductive spacer 16A has been exemplified. On the other hand, it is sufficient that one of the pair of electrodes forming the first gap changing portion 113 and one of the pair of electrodes forming the second gap changing portion 123 are electrically connected. Not limited.
For example, in the first embodiment, the second electrode 113B and the fourth electrode 123B may be electrically connected, the first electrode 113A and the third electrode 123A may be electrically connected, and the first electrode 113A and the third electrode 113A may be electrically connected. The four electrodes 123B may be electrically connected.

[Modification 5]
In the first embodiment, as a method of driving the spectroscopic measurement device 1, an example is shown in which the target wavelength is changed at predetermined intervals in the spectroscopic band ΔΛ ₀ , and the amount of light with respect to each target wavelength is measured. The spectrometer 1 may be driven so as to transmit light of a specific target wavelength based on a wavelength designation signal input from an operation unit or an external device.
[Modification 6]
In each embodiment, the first gap changing section 113 and the second gap changing section 123 are provided with a pair of electrodes, and the first gap G1 and the second gap G2 are changed by changing the voltage applied between the pair of electrodes. Although an example is shown, it is not limited to this.
For example, piezoelectric bodies are arranged between the first reflective film 111 and the second reflective film 112, and between the third reflective film 121 and the fourth reflective film 122. By changing the voltage applied to the piezoelectric bodies, , the dimensions of the first gap G1 and the second gap G2 may be changed. Alternatively, the dimension of the gap may be changed by changing the pressure between the pair of reflective films.

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

1, 1A, 1B... spectrometer (electronic device), 10, 10A, 10B, 10C... spectroscopic section (optical device), 11, 11A, 11B, 11C... first variable wavelength interference filter, 12, 12A, 12B, 12C... Second wavelength tunable interference filter 14... Cut filter 16... Spacer 16A... Conductive spacer 16B... Fixing spacer 20... Light receiving part 30... Circuit board 33... Control part 101... First substrate , 101A...first surface, 101B...second surface, 101C...first through hole, 101D...wiring through hole, 102...second substrate, 102A...third surface, 102B...fourth surface, 102C...second through Hole 103... Third substrate 103A... Fifth surface 103B... Sixth surface 104... Fourth substrate 104A... Seventh surface 104B... Eighth surface 105... Fifth substrate 105A... Ninth surface 105B... Tenth surface 111... First reflecting film 112... Second reflecting film 113... First gap changing portion 113A... First electrode 113B... Second electrode 121... Third reflecting film 122... Third Four reflecting films 123 Second gap changing section 123A Third electrode 123B Fourth electrode 123C Fourth electrode terminal 301 Fixed member 331 Storage section 332 Arithmetic processing section 332A Wavelength command unit 332B light receiving control unit _332C measurement unit Ar1 measurement area G1 first gap G2 second gap LC substrate center axis d second reflection film and third reflection film ΔΛ ₀ . . . spectroscopic band ΔΛ ₁ .. _first spectral band _{ΔΛ 2} .. _second spectral band ΔΛ ₃ . Wavelengths, λ ₃ ... third wavelength, λ ₄ ... fourth wavelength.

Claims (6)

a first variable wavelength interference filter in which the first reflective film and the second reflective film face each other across a first gap;
a second variable wavelength interference filter in which the third reflecting film and the fourth reflecting film face each other across a second gap;
a translucent first substrate having a first surface and a second surface opposite to the first surface;
The second reflective film is provided on the first surface of the first substrate,
The third reflective film is provided on the second surface of the first substrate ,
The first variable wavelength interference filter includes a first electrode provided on the first reflective film,
a second electrode provided on the second reflective film,
the first electrode and the second electrode face each other across the first gap;
The second variable wavelength interference filter includes a third electrode provided on the third reflecting film,
and a fourth electrode provided on the four reflective films,
the third electrode and the fourth electrode face each other across the second gap,
The first substrate has a first through hole penetrating from the first surface to the second surface,
One of the first electrode and the second electrode is connected to the third electrode through the first through hole.
conductive to one of the pole and the fourth electrode
An optical device characterized by: An optical device according to claim 1 , wherein
In the first wavelength tunable interference filter, by changing the dimension of the first gap, the first transmission wavelength, which is the wavelength of light to be transmitted from the first wavelength tunable interference filter, is changed from the first wavelength to the first It is configured to be changeable within a range up to a second wavelength longer than the wavelength,
The second wavelength tunable interference filter changes the dimension of the second gap to make the second transmission wavelength, which is the wavelength of light transmitted from the second wavelength tunable interference filter, longer than the first wavelength. and is configured to be changeable within a range from a third wavelength shorter than the second wavelength to a fourth wavelength longer than the second wavelength. 3. The optical device according to claim 2 , wherein
The optical device, wherein the distance between the second reflecting film and the third reflecting film is 300 times or more the center wavelength of the wavelength region from the first wavelength to the fourth wavelength. 4. The optical device according to claim 2 or 3 ,
The optical device, wherein the distance between the second reflecting film and the third reflecting film is 30000 times or less of the center wavelength of the wavelength region from the first wavelength to the fourth wavelength. The optical device according to any one of claims 1 to 4 ,
The distance between the second reflective film and the third reflective film is greater than the distance between the first reflective film and the second reflective film, and the distance between the third reflective film and the fourth reflective film An optical device characterized in that it is greater than the distance between an optical device according to any one of claims 1 to 5 ;
and a controller that controls the optical device.

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