JP2011081055A - Wavelength variable interference filter, colorimetry sensor and colorimetry module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wavelength variable interference filter, preventing a mirror between substrates from being damaged even when the substrates are pressurized and joined to each other, a colorimetry sensor including the wavelength variable interference filter, and a colorimetry module including the colorimetry sensor. <P>SOLUTION: An etalon 5 includes: a first substrate 51 having translucency; a translucent second substrate 52 opposite to one face side of the first substrate 51 and pressurized and joined to the first substrate 51; a pair of mirrors 56, 57 provided on the opposite surfaces of the first substrate 51 and the second substrate 52, respectively, and disposed opposite to each other; an electrostatic actuator 54 for varying the dimension between the pair of mirrors 56, 57; and a support projecting part 524 provided on the inner peripheral side of the movable mirror 57 of the second substrate 52 and projected toward the first substrate 51. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a wavelength variable interference filter that selects and emits light having a desired target wavelength from incident light, a colorimetric sensor including the wavelength variable interference filter, and a colorimetric module including the colorimetric sensor.

2. Description of the Related Art Conventionally, there is known a variable wavelength interference filter in which high reflection mirrors are arranged to face each other on a pair of substrates. In such a tunable interference filter, only light of a specific wavelength from incident light is reflected by reflecting light between a pair of mirrors, transmitting only light of a specific wavelength, and canceling light of other wavelengths by interference. Permeate.
Further, when manufacturing such a wavelength tunable interference filter, the mirrors are formed on the surfaces of the pair of substrates facing each other, and then bonded to the substrates by applying pressure (see, for example, Patent Document 1).

The variable wavelength interference filter described in Patent Document 1 is a variable wavelength interference filter in which a fixed substrate and a movable substrate are joined. In the fixed substrate of the variable wavelength interference filter, two cylindrical recesses are formed on the surface facing the movable substrate. Among these, the 1st recessed part is formed in the center part of the 2nd recessed part, the fixed reflection film | membrane which is a mirror is formed in the bottom face, and the conductive layer is formed in the bottom face of the 2nd recessed part. Further, the movable substrate has conductivity, and includes a movable portion disposed substantially at the center, a support portion that holds the movable portion so that the movable portion can be displaced, and an energization portion that energizes the movable portion. Further, the movable portion is configured to be opposed to the first concave portion, and a movable reflective film that is a mirror is formed on the surface facing the fixed substrate.
The tunable interference filter described in Patent Document 1 performs a fixed substrate processing step, a SOI (Silicon on Insulator) substrate processing step, a fixed substrate-SOI substrate bonding step, and a movable substrate processing step. It is manufactured by. That is, the first and second recesses, the fixed reflection film, and the conductive layer are formed on the fixed substrate in the processing step of the fixed substrate, and the movable reflection film is formed on the SOI substrate in the processing step of the SOI substrate. In the bonding step, the fixed substrate and the SOI substrate are bonded by anodic bonding, and in the movable substrate processing step, the SOI substrate is processed to form a movable substrate.

JP 2006-23606 A

  By the way, in Patent Document 1, conductive silicon is used as a movable substrate, and a fixed substrate, which is a glass substrate, and a movable substrate formed from an SOI substrate are joined by anodic bonding. In the case where conductive silicon is used as the movable substrate, strong bonding can be obtained by anodic bonding as described above. To perform this anodic bonding, one of the fixed substrate and the movable substrate is electrically conductive. It is necessary to form with the material which has property, and the choice is limited. Alternatively, anodic bonding can be performed by forming a conductive film on a non-conductive substrate. In this case, however, there is a problem that a separate conductive film needs to be formed and the manufacturing becomes complicated. .

  On the other hand, for example, as a bonding method for bonding glass substrates together, there is a bonding method such as room temperature activation bonding. This room temperature activated bonding is a bonding method in which the bonded surfaces of the fixed substrate and the movable substrate are activated by precision polishing or the like, and the activated surfaces are overlapped and pressed to bond the substrates together. However, in such a method of applying pressure to the substrates at the time of joining, the substrates may be bent at the time of pressurization, and the mirror surfaces arranged opposite to each other may come into contact with each other and stick. In this case, there is a problem that the pair of mirrors cannot be maintained in parallel or is damaged, and the mirror does not function as a wavelength variable interference filter that transmits only a desired wavelength.

  In view of the above-described problems, the present invention provides a wavelength tunable interference filter that does not damage a mirror between substrates even when the substrates are pressed and bonded together, a colorimetric sensor including the wavelength tunable interference filter, and this An object of the present invention is to provide a color measurement module including a color measurement sensor.

  The wavelength tunable interference filter of the present invention includes a first substrate having translucency, a translucent second substrate that is pressure-bonded to the first substrate while facing one surface side of the first substrate, A pair of mirrors provided on opposite surfaces of the first substrate and the second substrate, respectively, and a variable means for changing a dimension between the pair of mirrors; the first substrate and the second substrate; It is provided with the support protrusion part which protrudes toward the other board | substrate while being provided in the inner peripheral side of the said mirror of at least any one board | substrate among board | substrates.

In this invention, the wavelength variable interference filter is provided with the support protrusion on the inner peripheral side of at least one of the pair of mirrors. For this reason, when the wavelength variable interference filter is manufactured, when the first substrate and the second substrate are overlapped and pressed in the thickness direction, the substrate bends due to the pressure, and the pair of mirrors move in a direction close to each other. When the support protrusion comes into contact with the mirrors before the mirrors come into contact with each other, the mirrors do not come into contact with each other, and the mirrors are damaged, that is, the pair of mirrors are not parallel or the mirrors are damaged. Inconvenience can be prevented.
In addition, the variable wavelength interference filter can vary the light to be dispersed by adjusting the gap between the mirrors using the variable means. At this time, even if the gap between the mirrors is too small for the variable means. Since the support protrusion is provided, the mirrors can be prevented from contacting each other, and the mirror can be prevented from being damaged during normal use and the inconvenience that the parallel relationship between the pair of mirrors cannot be maintained. it can.

  In the wavelength tunable interference filter according to the aspect of the invention, in the plan view of the mirror viewed from the thickness direction, the area occupied by the support protrusion may be 1 / 100,000 to 1/100 of the total area of the mirror. preferable.

In the present invention, in the mirror plan view, the area occupied by the support protrusion is formed to be a ratio of 1/100000 to 1/100 with respect to the total area of the mirror.
Here, when the area occupied by the support protrusion with respect to the total area of the mirror is smaller than 1/100000, it is difficult to form the support protrusion. Moreover, when a support protrusion part is too small, the contact prevention range of mirrors becomes narrow and there exists a possibility that it may not fully function as sticking prevention. That is, it is possible to prevent the mirrors from sticking to each other only in a small range around the support protrusion, but it is not possible to prevent the mirrors from sticking to each other in other ranges, and more support protrusions. It is necessary to provide a part.
In addition, when the area occupied by the support protrusion with respect to the total area of the mirror is larger than 1/100, the support protrusion reduces the amount of light transmitted through the wavelength tunable interference filter and deteriorates the transmittance of the dispersed light. There is a problem of doing.
On the other hand, as described above, by setting the area occupied by the support protrusion with respect to the total area of the mirror from 1 / 100,000 to 1/100, the manufacture of the support protrusion becomes easy, and the contact between the mirrors is reduced. It can be prevented over a wide range, and a decrease in the amount of light transmitted by the wavelength variable interference filter can be suppressed.

  In the wavelength tunable interference filter of the present invention, at least one of the first substrate and the second substrate is provided on the outer peripheral side of the mirror along at least a part of the outer peripheral edge of the mirror, and the other substrate It is preferable to provide an outer peripheral protrusion that protrudes toward the substrate.

Here, the position where the outer peripheral protrusion is provided may be provided on both of the pair of mirrors, or may be provided on either one of them. Further, the shape of the outer peripheral protrusion may be a structure in which a ring-shaped outer peripheral protrusion is provided over the entire outer periphery of the mirror, and an arc-shaped outer peripheral protrusion is provided in a part of the mirror outer peripheral edge. A structure may be sufficient and it is good also as a structure by which a several space | interval protrusion part is provided at predetermined intervals along a mirror outer periphery.
In this invention, in addition to the support protrusion of the above invention, an outer periphery protrusion is provided on the outer periphery of the mirror. When preventing the mirror from sticking only with the support protrusion, for example, when the pressure when joining the first and second substrates is large and the thickness dimension of each substrate is small, the mirror is stuck near the support protrusion. Although sticking can be prevented, the mirrors may come into contact with each other in the vicinity of the outer periphery of the mirror at a position far from the support protrusion due to the bending of the substrate. It is also possible to prevent the mirror from sticking by installing multiple support protrusions in the mirror, but in this case, the amount of light that is split and transmitted by the wavelength variable interference filter is reduced by the support protrusion. Resulting in.
On the other hand, by providing an outer peripheral protrusion along the outer periphery of the mirror as in the present invention, as described above, even when the pressure at the time of substrate bonding is large and the mirror bends greatly, it is supported. The protruding portion can prevent the inner peripheral side of the mirror, particularly the central portion of the mirror, from sticking, and the outer peripheral protruding portion can prevent the vicinity of the outer peripheral edge of the mirror from sticking.

  A colorimetric sensor according to the present invention includes the above-described wavelength tunable interference filter and light receiving means for receiving inspection target light transmitted through the wavelength tunable interference filter.

In this invention, similarly to the above-described invention, the sticking of the mirror is prevented by the support protrusion at the time of substrate bonding in the manufacture of the variable wavelength interference filter. Further, even when the gap between the mirrors of the wavelength variable interference filter is reduced by the variable means, the mirrors do not contact each other. For this reason, the deterioration of the transmittance | permeability and the fall of resolution resulting from mirror sticking in a wavelength variable interference filter are prevented.
By receiving the emitted light emitted from such a wavelength variable interference filter by the light receiving means, the colorimetric sensor can measure the exact light quantity of the light component of the desired wavelength contained in the inspection target light.

  The color measurement module of the present invention includes the above-described color measurement sensor and a color measurement processing unit that performs color measurement processing based on light received by the light receiving unit of the color measurement sensor. It is characterized by.

  In the present invention, since the sticking between the pair of mirrors of the wavelength tunable interference filter is prevented as in the above-described invention, there is no deterioration in the transmittance and resolution of the light transmitted through the wavelength tunable interference filter due to the mirror sticking. In the light receiving means of the colorimetric sensor, it is possible to accurately detect the light amount of the desired wavelength light included in the inspection target light. Therefore, the processing means can also accurately analyze the intensity of each color component of the inspection target light based on the exact light amount of the light having the desired wavelength included in the inspection target light.

It is a figure which shows schematic structure of the color measurement module of one Embodiment which concerns on this invention. It is a top view which shows schematic structure of the etalon which comprises the wavelength variable interference filter of the said embodiment. FIG. 3 is a cross-sectional view of the etalon taken along line III-III in FIG. It is the enlarged plan view which expanded the movable surface vicinity of the movable part of the said embodiment. It is a figure which shows the manufacture structure of the 1st board | substrate in manufacture of the etalon of the said embodiment, (A) is the schematic of the resist formation process which forms the resist for mirror fixed surface 512A formation in the 1st board | substrate 51, (B ) Is a schematic diagram of the first groove forming step for forming the mirror fixing surface 512A, (C) is a schematic diagram of the second groove forming step for forming the electrode fixing surface 511A, and (D) is for forming the AgC layer. The schematic of an AgC formation process, (E) is the schematic which shows an AgC removal process. It is a figure which shows the outline of the manufacturing process of a 2nd board | substrate, (A) is the schematic of the 2nd resist formation process which forms the resist for support protrusion part and outer periphery protrusion part formation on a 2nd board | substrate, (B) , Schematic of the protrusion forming step for forming the supporting protrusion and the outer peripheral protrusion, (C) is a schematic of the second AgC forming step for forming the AgC layer, (D) shows the second AgC removal step FIG. It is a figure which shows the manufacturing process of an etalon, (A) is the schematic which shows a joining process, (B) is the schematic which shows the movable part vicinity at the time of a weight being added in the joining process, (C) is FIG. 3 is a schematic view showing a diaphragm forming step.

Hereinafter, a color measurement module according to an embodiment of the present invention will be described with reference to the drawings.
[1. Overall configuration of the color measurement module)
FIG. 1 is a diagram showing a schematic configuration of a color measurement module according to the first embodiment of the present invention.
As shown in FIG. 1, the color measurement module 1 includes a light source device 2 that emits light to an inspection target A, a color measurement sensor 3 according to the present invention, and a control device 4 that controls the overall operation of the color measurement module 1. And. The color measurement module 1 reflects the light emitted from the light source device 2 by the inspection target A, receives the reflected inspection target light by the color measurement sensor, and outputs the light from the color measurement sensor 3. This module analyzes and measures the chromaticity of the inspection target light, that is, the color of the inspection target A based on the detection signal.

[2. Configuration of light source device]
The light source device 2 includes a light source 21 and a plurality of lenses 22 (only one is shown in FIG. 1), and emits white light to the inspection target A. Further, the plurality of lenses 22 include a collimator lens. The light source device 2 converts the white light emitted from the light source 21 into parallel light by the collimator lens, and passes from the projection lens (not shown) to the object A to be inspected. Ejected towards.

[3. (Configuration of colorimetric sensor)
As shown in FIG. 1, the colorimetric sensor 3 transmits the etalon 5 constituting the wavelength tunable interference filter of the present invention, a light receiving element 31 as a light receiving means for receiving light transmitted through the etalon 5, and the etalon 5. Voltage control means 6 for changing the wavelength of light. Further, the colorimetric sensor 3 includes an incident optical lens (not shown) that guides reflected light (inspection target light) reflected by the inspection target A at a position facing the etalon 5. The colorimetric sensor 3 uses the etalon 5 to split only the light having a predetermined wavelength out of the inspection target light incident from the incident optical lens, and the light receiving element 31 receives the split light.
The light receiving element 31 includes a plurality of photoelectric exchange elements, and generates an electrical signal corresponding to the amount of received light. The light receiving element 31 is connected to the control device 4 and outputs the generated electrical signal to the control device 4 as a light reception signal.

(3-1. Composition of etalon)
FIG. 2 is a plan view showing a schematic configuration of the etalon 5 constituting the tunable interference filter of the present invention, and FIG. 3 is a cross-sectional view showing a schematic configuration of the etalon 5. In FIG. 1, the inspection target light is incident on the etalon 5 from the lower side in the figure, but in FIG. 3, the inspection target light is incident from the upper side in the figure.
As shown in FIG. 2, the etalon 5 is a planar square plate-shaped optical member, and one side is formed to be 10 mm, for example. The etalon 5 includes a first substrate 51 and a second substrate 52 as shown in FIG. These two substrates 51 and 52 are each formed of, for example, various glasses such as soda glass, crystalline glass, quartz glass, lead glass, potassium glass, borosilicate glass, and alkali-free glass, or crystal. . Among these, as a constituent material of each board | substrate 51,52, the glass containing alkali metals, such as sodium (Na) and potassium (K), for example is preferable, and each board | substrate 51,52 is formed with such glass. Thus, it becomes possible to improve the adhesion between the mirrors 56 and 57, which will be described later, and the electrodes, and the bonding strength between the substrates. And these two board | substrates 51 and 52 are comprised integrally by the joining surfaces 513 and 523 formed in the outer peripheral part vicinity being pressure-bonded, for example, normal temperature activation joining.

Further, between the first substrate 51 and the second substrate 52, a fixed mirror 56 and a movable mirror 57 constituting a pair of mirrors of the present invention are provided. Here, the fixed mirror 56 is fixed to the surface of the first substrate 51 facing the second substrate 52, and the movable mirror 57 is fixed to the surface of the second substrate 52 facing the first substrate 51. Further, the fixed mirror 56 and the movable mirror 57 are disposed to face each other with a gap G between the mirrors.
Furthermore, an electrostatic actuator 54 for adjusting the dimension of the inter-mirror gap G between the fixed mirror 56 and the movable mirror 57 is provided between the first substrate 51 and the second substrate 52.

(3-1-1. Configuration of the first substrate)
The first substrate 51 is formed by processing a glass substrate having a thickness of, for example, 500 μm by etching. Specifically, as shown in FIG. 3, an electrode forming groove 511 and a mirror fixing portion 512 are formed on the first substrate 51 by etching.
The electrode formation groove 511 is formed in a circular shape centered on the plane center point in a plan view (hereinafter referred to as an etalon plan view) of the etalon 5 as seen from the thickness direction as shown in FIG. The mirror fixing portion 512 is formed so as to protrude from the center portion of the electrode forming groove 511 toward the second substrate 52 in the plan view.

The electrode forming groove 511 is formed with a ring-shaped electrode fixing surface 511A between the outer peripheral edge of the mirror fixing portion 512 and the inner peripheral wall surface of the electrode forming groove 511, and the electrode fixing surface 511A is used for the first displacement. An electrode 541 is formed. Further, from a part of the outer peripheral edge of the first displacement electrode 541, the first displacement electrode lead-out portion 541A is directed toward the lower right direction and the upper left direction of the etalon 5 in the plan view of the etalon as shown in FIG. Each is formed to extend. Further, first displacement electrode pads 541B are respectively formed at the tips of the first displacement electrode lead portions 541A, and these first displacement electrode pads 541B are connected to the voltage control means 6.
Here, when the electrostatic actuator 54 is driven, a voltage is applied to only one of the pair of first displacement electrode pads 541B by the voltage control means 6. The other first displacement electrode pad 541B is used as a detection terminal for detecting the charge retention amount of the first displacement electrode 541.

  A plurality of contact prevention pins 511 </ b> B are formed to protrude toward the second substrate 52 on the electrode fixing surface 511 </ b> A. Specifically, these contact prevention pins 511B extend in the radial direction of the cylindrical mirror fixing portion 512 in the plan view of the etalon and are evenly spaced along a plurality of virtual radiations 511C that are spaced from each other by 45 degrees. Is formed.

  As described above, the mirror fixing portion 512 is formed in a columnar shape that is coaxial with the electrode forming groove 511 and has a smaller diameter than the electrode forming groove 511. In the present embodiment, as shown in FIG. 3, the mirror fixing surface 512A facing the second substrate 52 of the mirror fixing portion 512 is formed closer to the second substrate 52 than the electrode fixing surface 511A. However, the present invention is not limited to this. The height positions of the electrode fixing surface 511A and the mirror fixing surface 512A are the dimensions of the inter-mirror gap G between the fixed mirror 56 fixed to the mirror fixing surface 512A and the movable mirror 57 formed on the second substrate 52. It is appropriately set according to the dimension between the first displacement electrode 541 and the second displacement electrode 542 described later formed on the second substrate 52 and the thickness dimension of the fixed mirror 56 and the movable mirror 57. It is not limited to the configuration. For example, when dielectric multilayer mirrors are used as the mirrors 56 and 57 and the thickness dimension thereof increases, a configuration in which the electrode fixing surface 511A and the mirror fixing surface 512A are formed on the same surface, or the central portion of the electrode fixing surface 511A Alternatively, a mirror fixing groove on the cylindrical concave groove may be formed, and a mirror fixing surface 512A may be formed on the bottom surface of the mirror fixing groove.

  In addition, the mirror fixing surface 512A of the mirror fixing portion 512 is preferably designed with a groove depth in consideration of the wavelength range through which the etalon 5 is transmitted. For example, in this embodiment, the initial value of the inter-mirror gap G between the fixed mirror 56 and the movable mirror 57 (between the mirrors in a state where no voltage is applied between the first displacement electrode 541 and the second displacement electrode 542). The dimension of the gap G) is set to 450 nm, and by applying a voltage between the first displacement electrode 541 and the second displacement electrode 542, the movable mirror 57 is displaced until the inter-mirror gap G becomes, for example, 250 nm. As a result, by changing the voltage between the first displacement electrode 541 and the second displacement electrode 542, light having a wavelength in the entire visible light range can be selectively dispersed and transmitted. It becomes possible. In this case, if the film thickness of the fixed mirror 56 and the movable mirror 57 and the height dimension of the mirror fixing surface 512A and the electrode fixing surface 511A are set to values that allow the gap G between the mirrors to be displaced between 250 nm and 450 nm. Good.

A fixed mirror 56 formed in a circular shape having a diameter of about 3 mm is fixed to the mirror fixing surface 512A. The fixed mirror 56 is a mirror formed of an AgC single layer, and is formed on the mirror fixed surface 512A by a technique such as sputtering.
In the present embodiment, an example in which an AgC single layer mirror that can cover the entire visible light region as a wavelength region that can be dispersed by the etalon 5 is used as the fixed mirror 56 is not limited to this. Although the spectral wavelength range is narrow, the transmittance of the dispersed light is larger than that of the AgC single layer mirror, the half width of the transmittance is narrow, and the resolution is good. For example, a TiO ₂ —SiO ₂ dielectric multilayer mirror It is good also as a structure using. However, in this case, as described above, the height positions of the mirror fixing surface 512A and the electrode fixing surface 511A of the first substrate 51 are appropriately set by the fixed mirror 56, the movable mirror 57, the wavelength selection range of the light to be dispersed, and the like. There is a need to.

  Furthermore, the first substrate 51 is provided with an antireflection film (AR) (not shown) at a position corresponding to the fixed mirror 56 on the lower surface opposite to the upper surface facing the second substrate 52. This antireflection film is formed by alternately laminating low refractive index films and high refractive index films, and reduces the reflectance of visible light on the surface of the first substrate 51 and increases the transmittance.

(3-1-2. Configuration of Second Substrate)
The second substrate 52 is formed by processing a glass substrate having a thickness of, for example, 200 μm by etching.
Specifically, the second substrate 52 has a circular movable portion 521 centered on the substrate center point and a connection that is coaxial with the movable portion 521 and holds the movable portion 521 in a plan view as shown in FIG. Holding part 522.

FIG. 4 is an enlarged plan view of the movable surface 521A of the movable portion 521.
The movable portion 521 is formed to have a thickness dimension larger than that of the connection holding portion 522. For example, in the present embodiment, the movable portion 521 is formed to be 200 μm, which is the same dimension as the thickness dimension of the second substrate 52. The movable portion 521 includes a movable surface 521A parallel to the mirror fixing portion 512, and the movable mirror 57 is fixed to the movable surface 521A. Here, the movable mirror 57 and the fixed mirror 56 described above constitute a pair of mirrors of the present invention. In the present embodiment, the inter-mirror gap G between the movable mirror 57 and the fixed mirror 56 is set to 450 nm in the initial state.
Here, the movable mirror 57 is a mirror having the same configuration as the fixed mirror 56 described above, and in this embodiment, an AgC single layer mirror is used. The film thickness dimension of the AgC single layer mirror is, for example, 0.03 μm.

  The movable surface 521A is provided with a support protrusion 524 that protrudes toward the first substrate 51 at the center position of the movable surface 521A in plan view of the etalon, and the movable mirror 57 is located outside the support protrusion 524. Is formed. The support protrusion 524 is made of, for example, glass that is the same material as the second substrate 52. Moreover, this support protrusion part 524 is formed in a column shape, and the diameter dimension of a cross-sectional circle is formed in 30 micrometers, for example. Further, the support protrusion 524 has a protrusion dimension from the movable surface 521 </ b> A to the protrusion tip of the support protrusion 524, for example, 0.15 μm, and protrudes from the mirror surface of the movable mirror 57 toward the first substrate 51. Yes. Such a support protrusion 524 has a cross-sectional diameter that is sufficiently larger than the protrusion, so that it does not break or break even when a force is applied from the outside.

The support protrusion 524 prevents sticking due to contact between the movable mirror 57 and the fixed mirror 56 formed on the first substrate 51 when the movable portion 521 is moved to the first substrate 51 side. .
More specifically, in the manufacture of the etalon 5, it is necessary to perform a bonding step in which the first substrate 51 and the second substrate 52 are bonded by a bonding method such as room temperature activation bonding. At this time, a load is applied to the first substrate 51 and the second substrate 52 in a direction orthogonal to the bonding surfaces 513 and 523, and the bonding surfaces 513 and 523 are bonded to each other by the pressure. Here, as described above, the inter-mirror gap G in the etalon 5 is formed at 450 nm, for example, and is a minute gap space. For this reason, if the movable part 521 moves due to the load at the time of joining, the fixed mirror 56 and the movable mirror 57 may come into contact with each other, and may stick to each other. In this case, even if the mirrors 56 and 57 are separated from each other, The parallel relationship is lost, and the etalon 5 that disperses and transmits only light of a desired wavelength is not functioned. On the other hand, in the configuration in which the support protrusion 524 is provided, the mirrors 56 and 57 are in contact with each other even when pressure is applied to move the movable portion 521 to the first substrate 51 side beyond the distance G between the mirrors. Before this, the projecting tip surface of the support projecting portion 524 comes into contact with the fixed mirror 56 and restricts the movement of the movable portion 521. Thereby, the mirrors 56 and 57 do not contact each other, and sticking can be prevented.
In addition, the etalon 5 applies a predetermined voltage to the electrostatic actuator 54, thereby moving the movable portion 521 along the substrate thickness direction to adjust the gap G between the mirrors and select light to be split from the inspection target light. It becomes possible to do. At this time, when the voltage applied to the electrostatic actuator 54 becomes a predetermined threshold value or more, the moving amount of the movable portion 521 exceeds the initial value (for example, 450 nm) of the inter-mirror gap G. Even in this case, by providing the support protrusion 524, sticking due to contact between the fixed mirror 56 and the movable mirror 57 can be prevented, and damage to the etalon 5 due to erroneous operation of the etalon 5 can also be prevented. Become.

In the present embodiment, the above-described dimensions are illustrated as an example of the support protrusion 524, but the present invention is not limited to this. In other words, the support protrusion 524 may be formed so that the ratio of the cross-sectional area to the total area of the mirror is about 1 / 100,000 to 1/100 in the etalon plan view. Here, when the ratio of the cross-sectional area of the support protrusion 524 to the total area of the mirror is smaller than 1/100000, it is difficult to form the support protrusion 524 on the movable surface 521A. That is, as in the present embodiment, in the support protrusion 524 formed of the same material as the second substrate 52, the movable surface 521A and the support protrusion 524 are formed by dry etching the second substrate 52. At this time, if the cross-sectional area of the support protrusion 524 is too small as described above, more precise etching accuracy is required, and the manufacture of the support protrusion 524 becomes difficult.
Further, in the manufacture of the etalon 5, as described above, by applying a load to the first substrate 51 and the second substrate 52, the first substrate 51 and the second substrate 52 are joined, and the support protrusion 524 The movement of the movable part 521 is restricted to prevent the mirrors 56 and 57 from contacting each other. At this time, if the cross-sectional area of the support protrusion 524 is smaller than 1/100000 with respect to the total area of the mirror, it becomes difficult to prevent the entire mirror surface from being attached by one support protrusion 524. For example, when the support protrusion 524 is formed in the center of the mirror, it is possible to prevent only a part of the mirror near the mirror center from sticking, but it is not possible to prevent the mirror from sticking out of the range. .
On the other hand, when the cross-sectional area of the support protrusion 524 is larger than 1/100 with respect to the total area of the mirror, the light incident on the etalon 5 is obstructed by the support protrusion 524 and the amount of incident light is reduced. This makes it difficult to accurately measure the amount of light of a predetermined wavelength in incident light.
On the other hand, as described above, in the etalon plan view, the supporting protrusion 524 in which the ratio of the cross-sectional area to the total area of the mirror is 1/100000 to 1/100 is easily obtained by various manufacturing methods such as dry etching. It can be formed, and contact can be prevented over the entire surfaces of the mirrors 56 and 57, and a decrease in the amount of light transmitted through the etalon 5 can be suppressed.

Further, the movable surface 521A is formed with an outer peripheral protrusion 525 that is substantially ring-shaped in plan view of the etalon and protrudes from the movable surface 521A to the first substrate 51 side. As shown in FIGS. 2 to 4, the outer peripheral protrusion 525 is formed along the outer peripheral edge of the movable mirror 57 on the outer peripheral side of the movable mirror 57. The outer peripheral protrusion 525 has a ring width dimension of, for example, 30 μm in a plan view of the etalon and a protrusion dimension from the movable surface 521A of, for example, 0.15 μm. It protrudes to the side.
Similar to the support protrusion 524 provided on the inner peripheral side of the movable mirror 57, the outer peripheral protrusion 525 prevents the mirrors 56 and 57 from sticking to each other when the movable part 521 moves to the first substrate 51 side. .

  Further, the movable portion 521 has an antireflection film (AR) (not shown) formed at a position corresponding to the movable mirror 57 on the upper surface opposite to the movable surface 521A. This antireflection film has the same configuration as the antireflection film formed on the first substrate 51, and is formed by alternately laminating a low refractive index film and a high refractive index film.

The connection holding part 522 is a diaphragm surrounding the periphery of the movable part 521, and has a thickness dimension of, for example, 50 μm. A ring-shaped second displacement electrode 542 facing the first displacement electrode 541 with an electromagnetic gap of about 1 μm is formed on the surface of the connection holding portion 522 facing the first substrate 51. . Here, the second displacement electrode 542 and the first displacement electrode 541 described above constitute an electrostatic actuator 54 which is a variable means of the present invention.
Also, a pair of second displacement electrode lead portions 542A are formed from the part of the outer peripheral edge of the second displacement electrode 542 toward the outer peripheral direction, and at the tip of these second displacement electrode lead portions 542A A second displacement electrode pad 542B is formed. More specifically, the second displacement electrode lead-out portion 542A extends toward the lower left direction and the upper right direction of the etalon 5 in the plan view of the etalon, as shown in FIG. It is formed symmetrically with respect to the point.
Similarly to the first displacement electrode pad 541B, the second displacement electrode pad 542B is connected to the voltage control means 6, and when the electrostatic actuator 54 is driven, of the pair of second displacement electrode pads 542B. A voltage is applied to only one of them. The other second displacement electrode pad 542B is used as a detection terminal for detecting the charge retention amount of the second displacement electrode 542.

(3-2. Configuration of voltage control means)
The voltage control means 6 constitutes the variable wavelength interference filter of the present invention together with the etalon 5. The voltage control means 6 controls the voltage applied to the first displacement electrode 541 and the second displacement electrode 542 of the electrostatic actuator 54 based on the control signal input from the control device 4.

[4. Configuration of control device]
The control device 4 controls the overall operation of the color measurement module 1.
As the control device 4, for example, a general-purpose personal computer, a portable information terminal, other color measurement dedicated computer, or the like can be used.
As shown in FIG. 1, the control device 4 includes a light source control unit 41, a colorimetric sensor control unit 42, a colorimetric processing unit 43, and the like.
The light source control unit 41 is connected to the light source device 2. Then, the light source control unit 41 outputs a predetermined control signal to the light source device 2 based on, for example, a user setting input, and causes the light source device 2 to emit white light with a predetermined brightness.
The colorimetric sensor control unit 42 is connected to the colorimetric sensor 3. The colorimetric sensor control unit 42 sets a wavelength of light received by the colorimetric sensor 3 based on, for example, a user's setting input, and outputs a control signal for detecting the amount of light received at this wavelength. Output to the colorimetric sensor 3. Thereby, the voltage control means 6 of the colorimetric sensor 3 sets the voltage applied to the electrostatic actuator 54 so as to transmit only the wavelength of light desired by the user based on the control signal.

[5. Etalon Manufacturing Method)
Next, a method for manufacturing the etalon 5 will be described with reference to the drawings.
(5-1. Production of first substrate)
5A and 5B are diagrams showing a manufacturing process of the first substrate of the etalon 5, and FIG. 5A is a schematic diagram of a resist forming process for forming a resist for forming the mirror fixing surface 512A on the first substrate 51. FIG. Is a schematic diagram of the first groove forming step for forming the mirror fixing surface 512A, (C) is a schematic diagram of the second groove forming step for forming the electrode fixing surface 511A, and (D) is an AgC for forming the AgC layer. The schematic of a formation process and (E) are schematic which shows an AgC removal process.

In order to manufacture the first substrate 51, first, as shown in FIG. 5A, a resist 61 is formed on a glass substrate which is a manufacturing material of the first substrate 51 (resist forming step), and FIG. ), The first groove 62 including the mirror fixing surface 512A is formed (first groove forming step).
Specifically, in the resist formation step, a resist 61 is formed on the bonding surface 513. In the first groove forming step, portions other than the bonding surface 513 where the resist 61 is not formed are anisotropically etched to form the first groove 62 including the mirror fixing surface 512A.

  Further, after the formation of the first groove 62, a resist 61 is formed at the positions where the mirror fixing surface 512A and the contact prevention pin 511B of the first groove 62 are formed, and anisotropic etching is performed (second groove forming step). ). Thereby, the electrode forming groove 511 having the contact prevention pin 511B and the mirror fixing portion 512 are formed.

Thereafter, as shown in FIG. 5D, the resist 61 of the first substrate 51 is removed, and an AgC thin film 63 is formed on the surface facing the second substrate 52 so as to have a thickness dimension of, for example, 30 nm (AgC Forming step). In the AgC formation step, resists 61 are formed on the formed portion of the fixed mirror 56 and the formation portion of the first displacement electrode 541 on the formed AgC film 63, respectively.
Then, by removing the portion of the AgC thin film 63 where the resist 61 is not provided, the fixed mirror 56 and the first displacement electrode 541 are formed as shown in FIG. 5E (AgC removal step). .
Thus, the first substrate 51 is formed.

(5-2. Production of second substrate)
Next, a method for manufacturing the second substrate 52 will be described.
FIG. 6 is a diagram showing an outline of the manufacturing process of the second substrate, and FIG. 6A is a second resist forming process of forming a resist for forming the support protrusion 524 and the outer peripheral protrusion 525 on the second substrate 52. Schematic view, (B) is a schematic view of a protrusion forming step for forming the support protrusion 524 and the outer peripheral protrusion 525, (C) is a schematic view of a second AgC forming step for forming an AgC layer, (D). These are the schematic diagrams which show a 2nd AgC removal process.

In the manufacture of the second substrate 52, first, as shown in FIG. 6A, the formation position of the bonding surface 523, the formation position of the support protrusion 524, and the outer periphery protrusion of the glass substrate that is the manufacturing material of the second substrate 52. Resist 61 is formed at each position where 525 is formed (second resist forming step).
Thereafter, the portion where the resist 61 is not provided is anisotropically etched to form the movable surface 521A, the support protrusion 524, and the outer peripheral protrusion 525 as shown in FIG. 6B.

Thereafter, as shown in FIG. 6C, the resist 61 of the second substrate 52 is removed, and an AgC thin film 63 is formed on the surface facing the first substrate 51 so that the thickness dimension is, for example, 30 nm (first). Two AgC forming step). In the second AgC forming step, resists 61 are formed on the formed portion of the movable mirror 57 and the second displacement electrode 542 on the formed AgC film 63, respectively.
Then, by etching the portion where the resist 61 is not provided, the AgC thin film 63 is removed as shown in FIG. 6D (second AgC removing step). Thereby, the second substrate 52 is formed.

(5-3. Production of etalon)
Next, the manufacture of the etalon 5 using the first substrate 51 and the second substrate 52 manufactured as described above will be described.
7A and 7B are diagrams showing a manufacturing process of the etalon 5, wherein FIG. 7A is a schematic diagram showing the joining process, and FIG. 7B is a schematic showing the vicinity of the movable part 521 when a weight is applied in the joining process. FIG. 3C is a schematic diagram showing a diaphragm forming process.

In the manufacture of the etalon 5, first, as shown in FIG. 7A, a joining step for joining the first substrate 51 and the second substrate 52 is performed.
In this bonding step, for example, room temperature activated bonding is used. That is, in the bonding step, the bonding surfaces 513 and 523 are activated by placing the substrates 51 and 52 in a vacuum chamber and performing ion beam irradiation and plasma treatment in a vacuum state. The activated bonding surfaces 513 and 523 are overlapped with each other, and a load is applied to the thickness direction of the first substrate 51 and the second substrate 52 to bond the first substrate 51 and the second substrate 52. To do. Here, when a load is applied to the first substrate 51 and the second substrate 52, the second substrate 52 having a small thickness may be bent by the load, and the movable portion 521 may be displaced to the first substrate 51 side. As described above, the inter-mirror gap G in the etalon 5 is formed with an initial value of, for example, 450 nm, and the distance thereof is extremely small. Therefore, when the support protrusion 524 is not formed, the mirror central portion where the deflection amount is maximum. , The movable mirror 57 and the fixed mirror 56 may be close to each other and come into contact with each other.
On the other hand, in the present embodiment, since the second substrate 52 is provided with the support protrusion 524 and the outer periphery protrusion 525, the movable mirror 57 is fixed to the fixed mirror 56 as shown in FIG. Since the support protrusion 524 contacts the fixed mirror 56 before contacting the mirror, contact between the mirrors 56 and 57 at the center of the mirror can be prevented, and when the outer peripheral protrusion 525 contacts the mirror fixing surface 512A, the mirror Contact between the mirrors 56 and 57 at the outer peripheral portion can be prevented.
Thereafter, as shown in FIG. 7C, a groove for forming the connection holding portion 522 is formed in the second substrate 52 by etching (diaphragm forming step). Thus, the etalon 5 is manufactured.

  In addition, although the manufacturing method which implements a diaphragm formation process after a joining process was illustrated, it is not limited to this, For example, you may implement a diaphragm formation process at the time of manufacture of the 2nd board | substrate 52. That is, when the support protrusion 524 is not formed and the diaphragm forming process is performed during the manufacture of the second substrate 52, the movable part 521 is greatly bent in the bonding process, and the mirrors 56 and 57 are brought into contact with each other with a slight load. There is a problem of end up. However, in the configuration in which the support protrusion 524 is formed as in this embodiment, the support protrusion 524 can reliably prevent the mirrors 56 and 57 from contacting each other. Therefore, a diaphragm forming step may be performed when the second substrate 52 is manufactured.

[6. Effect of First Embodiment)
As described above, in the etalon 5 of the first embodiment, the second substrate 52 includes the support protrusion 524 that protrudes toward the first substrate 51 on the inner peripheral side of the movable mirror 57 on the movable surface 521A. .
For this reason, in the joining process at the time of manufacturing the etalon 5, when a weight is applied to the first substrate 51 and the second substrate 52 to join the joining surfaces 513 and 523, the movable mirror 57 forming part of the second substrate 52 is formed. Even if it is bent toward the first substrate 51 due to the load, the support protrusion 524 comes into contact with the fixed mirror 56 and restricts the bending of the second substrate 52. Thereby, the movable mirror 57 does not contact the fixed mirror 56, the sticking of the mirrors 56, 57 is prevented, and the manufacturing efficiency of the etalon 5 can be improved.
Further, when a voltage is applied to the electrostatic actuator 54 to displace the movable portion 521 toward the first substrate 51, or when an external load is applied when the etalon 5 is assembled to the colorimetric sensor 3, for example, the movable portion Even if 521 is greatly bent toward the first substrate 51, the contact between the mirrors 56 and 57 can be prevented, and sticking can be prevented. Therefore, damage due to contact between the mirrors 56 and 57 and a decrease in the performance of the etalon 5 can be prevented.

Further, in the etalon plan view, the ratio of the cross-sectional area of the support protrusion 524 to the total area of the mirror is formed to be 1/100000 to 1/100.
As described above, when the ratio of the support protrusion 524 to the total mirror area is smaller than 1/100000, it is difficult to manufacture the support protrusion 524, and the area where the support protrusion 524 can prevent the mirrors 56 and 57 from contacting each other. Becomes smaller. When the ratio of the support protrusion 524 to the total area of the mirror is greater than 1/100, the amount of transmitted light of the etalon 5 decreases, and accordingly, transmitted light received by the colorimetric sensor 3. The amount of received light and the colorimetric accuracy of the colorimetric module 1 are also reduced. On the other hand, the problem as described above can be avoided by forming the support projecting portion 524 so that the ratio of the cross-sectional area is 1 / 100,000 to 1/100 as described above. That is, at the time of manufacture, the support protrusion 524 can be easily manufactured by etching the second substrate 52, and the single support protrusion 524 can prevent the entire mirror from sticking. Further, it is possible to suppress the decrease in transmitted light of the etalon 5 by the support protrusion 524 to the extent that the colorimetric processing is not affected.

The second substrate 52 includes an outer peripheral protrusion 525 formed along the outer peripheral edge of the movable mirror 57 on the outer peripheral side of the movable mirror 57.
As described above, the provision of the outer peripheral protrusion 525 in addition to the support protrusion 524 can more reliably prevent the mirrors 56 and 57 from contacting each other. In particular, when the support protrusion 524 is provided at the center of the mirror as in the present embodiment, the support protrusion 524 is located near the center of the mirror where the amount of bending becomes maximum when the second substrate 52 is bent. The contact between the mirrors 56 and 57 can be prevented. On the other hand, for example, when the etalon 5 is installed in the colorimetric sensor, when a load is applied to a part of the outer peripheral portion of the movable portion 521, the vicinity of the outer peripheral edge of the movable mirror 57 is the largest and bends toward the first substrate 51 side. It is also possible. Even in such a case, in the present embodiment, the contact between the mirrors 56 and 57 can be prevented by the outer peripheral protrusion 525 contacting the mirror fixing surface 512A.
Further, since the outer peripheral protrusion 525 is formed on the outer peripheral side of the movable mirror 57, it does not affect the amount of light transmitted through the etalon 5, and the accuracy of the colorimetric processing does not decrease.

The etalon 5 includes a plurality of contact prevention pins 511B that protrude from the electrode fixing surface 511A to the second substrate 52 side.
For this reason, in the joining process at the time of manufacturing the etalon 5, in addition to the support protrusion 524 and the outer periphery protrusion 525 described above, these contact prevention pins 511B can prevent the second substrate 52 from being bent, and more reliably the mirror. Damage due to contact between 56 and 57 can be prevented.

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

  For example, in the above-described embodiment, an example in which the support protrusion 524 is formed on the movable surface 521A of the second substrate 52 has been described. However, the present invention is not limited thereto, and for example, the second substrate may be disposed on the mirror fixing surface 512A of the first substrate 51. It is good also as a structure which provides the support protrusion part which protrudes in 52 side. Furthermore, it is good also as a structure by which a support protrusion part is provided in both the movable surface 521A and the mirror fixed surface 512A.

  Similarly, the outer peripheral protrusion 525 may be formed on the mirror fixing surface 512A of the first substrate 51, or may be provided on both the mirror fixing surface 512A and the movable surface 521A.

  Furthermore, in the etalon plan view, an example in which the ratio of the area occupied by the support protrusion 524 to the total area of the mirror is 1 / 100,000 to 1/100 is shown, but the present invention is not limited to this. That is, in the mirror having a diameter dimension of about 3 mm as in the above embodiment, the area ratio of the support protrusions 524 is preferably set as described above. For example, in a configuration with a larger mirror area, Even when the area of the support protrusion 524 is smaller than 1/10000, there may be no manufacturing problem. In addition, in this case, there is a case where the contact of the entire area of the mirror cannot be prevented by one support protrusion 524. For example, by providing a plurality of support protrusions 524 on the inner peripheral side of the mirror, Contact can be prevented. Further, in the case where the mirror area is large as described above and a sufficient amount of light can be obtained as the light transmitted through the etalon 5, the area of the support protrusion 524 may be formed larger.

And although the support protrusion part 524 and the outer periphery protrusion part 525 showed the example formed by etching the glass substrate which is a manufacturing raw material of the 2nd board | substrate 52, it is not limited to this.
For example, the support protrusion 524 and the outer peripheral protrusion 525 may be separately fixed and formed on the surface of the second substrate 52 facing the first substrate 51. In this case, the support protrusion 524 and the outer periphery protrusion 525 can also be formed by, for example, an opaque member.

  Moreover, although the structure which forms the outer periphery protrusion part 525 in the ring shape along the outer periphery of the movable mirror 57 was illustrated, it is not limited to this, For example, along the outer periphery of the movable mirror 57, several circular arc-shaped outer periphery It is good also as a structure which provides a protrusion part. Moreover, it is good also as a structure by which a cylindrical outer periphery protrusion part is provided in the substantially equal space | interval along the outer periphery of the movable mirror 57. FIG.

  Furthermore, although the support protrusion 524 is configured to be provided at the center of the movable mirror 57, for example, it may be configured to be provided at a position away from the center by a predetermined dimension. In this case, a configuration in which the support protrusions 524 are provided at equal intervals on a virtual circle having a predetermined diameter from the mirror center point, or a second direction intersecting the predetermined first direction and the first direction on the inner peripheral side of the mirror In other words, it is possible to prevent the mirrors 56 and 57 from sticking to the entire surface of the mirror.

  Moreover, in the said embodiment, in the joining process which joins the 1st board | substrate 51 and the 2nd board | substrate 52, the joining surface 513 of the 1st board | substrate 51 and the joining surface 523 of the 2nd board | substrate 52 were each activated and activated Although so-called room temperature activation bonding was performed in which 513 and 523 are overlapped and pressure bonded to each other, the present invention is not limited to this. For example, a configuration may be adopted in which a bonding layer is formed between the bonding surfaces 513 and 523, and the first substrate 51 and the second substrate 52 are bonded via the bonding layer. In this case, bonding is performed by applying a weight in a state where the substrates 51 and 52 are overlapped via the bonding layer. Also in such a joining method, when the load is applied, the support protrusion 524 is formed, so that the movable mirror 57 of the second substrate 52 can come into contact with the fixed mirror 56 of the first substrate 51. In addition, it is possible to prevent damage due to sticking between the mirrors 56 and 57.

  In addition, the specific structure and procedure for carrying out the present invention can be changed as appropriate to other structures and the like within the scope of achieving the object of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Color measuring module, 3 ... Color measuring sensor, 4 ... Control apparatus, 5 ... Etalon which comprises a wavelength variable interference filter, 6 ... Voltage control means which comprises a wavelength variable interference filter, 31 ... Light receiving element which is a light receiving means, DESCRIPTION OF SYMBOLS 43 ... Colorimetric processing part, 51 ... 1st board | substrate, 52 ... 2nd board | substrate, 54 ... Electrostatic actuator which is a variable means, 56 ... Fixed mirror, 57 ... Movable mirror, 524 ... Support protrusion part, 525 ... Outer periphery protrusion part .

Claims (5)

A first substrate having translucency;
A translucent second substrate bonded to one surface side of the first substrate;
A pair of mirrors provided on opposite surfaces of the first substrate and the second substrate, respectively, and arranged to face each other;
Variable means for varying the dimension between the pair of mirrors;
A support protrusion that is provided on the inner peripheral side of the mirror of at least one of the first substrate and the second substrate, and protrudes toward the other substrate;
A wavelength tunable interference filter comprising: The tunable interference filter according to claim 1,
In the plan view of the mirror viewed from the thickness direction, the area occupied by the support protrusion is formed from 1/100000 to 1/100 of the total area of the mirror. In the wavelength tunable interference filter according to claim 1 or 2,
An outer peripheral protrusion that is provided along at least a part of the outer peripheral edge of the mirror on the outer peripheral side of the mirror of at least one of the first substrate and the second substrate and protrudes toward the other substrate A wavelength tunable interference filter characterized by comprising: The wavelength variable interference filter according to any one of claims 1 to 3,
A light receiving means for receiving the inspection object light transmitted through the wavelength variable interference filter;
A colorimetric sensor comprising: A colorimetric sensor according to claim 4;
A colorimetric processing unit that performs colorimetric processing based on the light received by the light receiving means of the colorimetric sensor;
A colorimetry module comprising:

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