JP2001194240A - Optical read type radiation-displacement transducing device, videoizing device using same, and method for displacement detection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect radiation with high sensitivity without requiring any half- mirror part. SOLUTION: Beltlike movable reflection parts 18 and fixed reflection parts 19 which are arranged by turns substantially form a reflection type diffraction grating. The movable reflection parts 18 are fixed to a displacement part 13. The fixed reflection parts 19 are fixed to a substrate 10. The displacement part 13 bends upward with the heat that a radiation absorption part 15 generates by receiving infrared rays (i). Consequently, the quantity of the step between the movable reflection parts 18 and fixed reflection parts 19 varies. Readout light (j) irradiating the reflection parts 18 and 19 is reflected by the reflection parts 18 and 19. The intensity of reflected light of each diffraction degree depends upon the mentioned step quantity, so it indicates the quantity of the incident infrared rays.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for detecting various kinds of radiation including invisible light such as infrared rays, X-rays and ultraviolet rays, and a displacement detecting method which can be used for the technique. The present invention relates to an optical readout radiation-displacement conversion device that converts a displacement into an optically readable displacement, an imaging device using the same, and a displacement detection method.

[0002]

2. Description of the Related Art Japanese Patent Laid-Open Publication No. Hei 10-260080 discloses an optical readout type radiation-to-displacement conversion apparatus which includes a base and a supported portion supported by the base, and which receives radiation to generate heat. A radiation absorbing portion to be converted, a displacement portion that is displaced with respect to the base in accordance with heat generated in the radiation absorbing portion,
A read-out type radiation comprising: a supported portion having: a read-out light beam; A displacement conversion device is disclosed, further comprising:
An imaging device using this is disclosed.

[0003] Japanese Patent Application Laid-Open No. Hei 10-260080 discloses an example in which an interference unit is used as an example of the light working unit. The interference part is a half mirror part that forms a part of the supported part and that is displaced in accordance with the displacement of the displacement part. The half mirror part that reflects only a part of the received read light, And a reflector fixed to the base so as to face the substrate.

According to this light-reading type radiation-displacement converter, radiation such as infrared rays, X-rays, and ultraviolet rays is absorbed by the radiation absorbing portion, converted into heat, and further converted into displacement of the displacement portion. On the other hand, readout light such as visible light is applied to the interference section, and readout light whose interference state has changed according to the displacement of the displacement section is emitted from the interference section. Therefore, the radiation applied to the radiation absorbing unit is converted into a change in the interference state of the readout light, and the radiation can be detected based on the readout light emitted from the interference unit.

As described above, according to the light-reading type radiation-displacement converter using the interference unit as the light acting unit, the interference state of the interference light emitted from the interference unit with respect to a minute change in the displacement of the displacement unit. Greatly changes, the radiation detection sensitivity increases.

[0006]

However, in the conventional optical readout type radiation-to-displacement converter using the above-mentioned interference unit, the half mirror unit is indispensable. The formation of the half mirror portion is not always easy compared with the ordinary film formation or the like since a desired reflectance must be ensured.

The present invention has been made in view of such circumstances, and does not require a half mirror unit.
Provided is an optical readout radiation-displacement converter that can detect radiation with the same high sensitivity as a conventional optical readout radiation-displacement converter using the above-described interference unit, and an imaging device using the same. The purpose is to do.

Another object of the present invention is to provide a displacement detecting method which can be used in connection with such an optical readout type radiation-to-displacement converter.

[0009]

According to a first aspect of the present invention, there is provided an optical readout type radiation-to-displacement conversion apparatus comprising: a base; and a supported portion supported by the base. A supported part having a radiation absorption part that receives radiation and converts it into heat, and a displacement part that is displaced with respect to the substrate in accordance with the heat generated in the radiation absorption part, and a substantially reflective diffraction grating A reflection unit that receives the readout light and reflects the received readout light as diffracted light;
It is provided with. A plurality of strip-shaped fixed reflectors fixed to the base and located substantially in the same plane with each other; and a plurality of band-shaped fixed reflectors fixed to the displacement unit and located substantially in the same plane with each other. And a plurality of strip-shaped movable reflecting portions. The plurality of fixed reflectors and the plurality of movable reflectors are alternately arranged. Then, the step amount between the plurality of fixed reflecting portions and the plurality of movable reflecting portions changes according to the displacement of the displacement portion.

According to the first aspect, infrared rays, X-rays,
Radiation such as ultraviolet rays is applied to the radiation absorbing portion of the supported portion, and the radiation is absorbed by the radiation absorbing portion and converted into heat.
The displacement part of the supported part is displaced with respect to the base in accordance with the heat generated in the radiation absorbing part. That is, the incident radiation is converted into a displacement of the displacement unit according to the amount. On the other hand, readout light such as visible light is applied to a reflecting portion substantially forming a reflective diffraction grating, and is reflected as diffracted light by this reflecting portion. Since the step amount between the plurality of fixed reflecting portions and the plurality of movable reflecting portions changes according to the displacement of the displacement portion, the intensity of the diffracted light of each diffraction order among the diffracted lights reflected by the reflecting portion is displaced. It is displaced according to the displacement of the part. Therefore, the radiation applied to the radiation absorbing unit is converted into a change in the intensity of the diffracted light of each diffraction order among the diffracted lights emitted by the reflecting unit. For this reason, the radiation can be detected based on the readout light reflected by the reflecting portion and converted into the diffracted light.

As described above, according to the first aspect, based on the principle of diffraction, the intensity of the diffracted light emitted from the reflecting portion greatly changes with respect to a minute change in the displacement of the displacement portion. The detection sensitivity of the radiation is increased, and the radiation can be detected with the same high sensitivity as that of the conventional optical readout radiation-displacement converter using the interference unit. Further, according to the first aspect, since a reflecting portion substantially forming a reflection type diffraction grating is used instead of the interference portion, a half mirror portion is unnecessary.

In the first aspect, the displacement portion constitutes a cantilever, and a direction from a fixed end to a free end of the cantilever and a direction in which the plurality of fixed reflecting portions and the plurality of movable reflecting portions extend are: It may be substantially parallel, substantially orthogonal, or oblique.

[0013] In the first aspect, it is preferable that the range of displacement of the displacement unit is limited so that the intensity change of the diffracted light due to the displacement of the displacement unit is monotonic. Unless the range of displacement of the displacement portion is limited, the intensity of the diffracted light of each diffraction order emitted from the reflection portion is more than a certain intensity because the step amount repeats the intensity every quarter of the wavelength of the read light. This is because, when radiation is incident, an inversion phenomenon occurs in which the intensity of the diffracted light is inverted.

[0014] The imaging device according to the second aspect of the present invention comprises:
The optical readout type radiation-displacement conversion device according to the first aspect, wherein the supported portion and the reflection portion have one element as a single element, and the element has a one-dimensional shape or a two-dimensional shape.
A light-reading radiation-displacement conversion device arranged in a two-dimensional manner, the reading unit irradiates each of the reading units with the reading light, and based on the diffracted light reflected by the reflecting units of the respective units, A readout optical system that forms an optical image in accordance with the displacement of the displacement portion of the element.

According to the second aspect, the optical image according to the displacement of the displacement portion of each element is formed by the readout optical system using the optical readout type radiation-displacement conversion device according to the first aspect. I have. Therefore, a radiation image can be formed with high sensitivity as the optical image. Further, according to the second aspect, since an optical image corresponding to the displacement of the displacement portion of each element is formed based on the readout light, using visible light as the readout light corresponds to a radiation image. The optical image can be observed with the naked eye. Further, in the second aspect, if an image pickup means for picking up the optical image is provided, an image by radiation can be picked up.

In the first embodiment, when radiation is simply detected, it is sufficient to have only one element (corresponding to a pixel).

An imaging device according to a third aspect of the present invention comprises:
In the imaging device according to the second aspect, when m is an integer whose absolute value is equal to or greater than 0, the readout optical system performs the displacement section of each element based on the m-th order diffracted light reflected by the reflection section. Is to form an optical image corresponding to the displacement of.

Since the intensity of the diffracted light of each diffraction order emitted from the reflecting portion changes depending on the amount of the step between the fixed reflecting portion and the movable reflecting portion, the m-th order diffracted light (any one of them) as in the third embodiment. By using (diffraction light of the diffraction order), a radiation image can be obtained as an optical image by readout light.

In the third aspect, the readout optical system may include a readout light supply unit for supplying the readout light, and the readout light system may be configured to transmit the readout light to each of the elements of the optical readout type radiation-to-displacement converter. A first lens system that guides the light to the first lens system, a selector that selectively passes the m-th order diffracted light of the diffracted light reflected by the reflection unit of each element after passing through the first lens system, and the first lens A second lens system that forms a conjugate position with the reflection unit of each element in cooperation with the system and guides the m-order diffracted light that has passed through the selection unit to the conjugate position. In this case, the readout light supply unit supplies the readout light so that the readout light passes through a region on one side with respect to the optical axis of the first lens system, and the selection unit converts the mth-order diffracted light. A portion to be selectively passed may be arranged in a region on the other side with respect to the optical axis of the first lens system.

An imaging device according to a fourth aspect of the present invention comprises:
In the imaging device according to the second aspect, the reading optical system may be configured such that m and n are integers whose absolute values are each equal to or greater than 0 and whose absolute values are not equal to each other.
A first optical image corresponding to the displacement of the displacement unit of each element is formed based on the m-th order diffracted light reflected by the reflecting unit, and the first optical image is formed based on the n-th order diffracted light reflected by the reflecting unit. A second element corresponding to the displacement of the displacement section of the element;
Is formed.

According to the fourth aspect, since the optical image formed by the m-th order diffracted light and the optical image formed by the n-th order diffracted light are formed, for example, both optical images are picked up by the respective image pickup means. By appropriately processing the image signal obtained from the above, it is possible to reduce noise components due to light reflected from portions other than the reflecting portion of the optical readout type radiation-to-displacement converter, and to obtain an image with a good S / N. be able to. In addition, by taking both optical images with the respective image pickup means and appropriately processing the image signals obtained from the respective image pickup means, even if the light amount of the readout light fluctuates, the influence can be reduced. Further, when the step amount between the fixed reflecting portion and the movable reflecting portion changes, the intensity change of the 0th-order diffracted light is opposite to the intensity change of the diffracted lights of other diffraction orders. If the nth-order diffracted light is diffracted light of a diffraction order other than the 0th order as well as the folded light, the optical image by the 0th-order diffracted light and the optical image by the diffracted light of the other diffraction orders will reverse the light and dark situation, Even when observing with the naked eye, it is possible to see an image in which the light and dark conditions are reversed.

In the fourth aspect, the readout optical system includes: a readout light supply unit for supplying the readout light; and a readout light supply unit for supplying the readout light to the reflection of each element of the optical readout type radiation-displacement conversion device. A first lens system that guides the m-th order diffracted light of the diffracted light reflected by the reflection unit of each element after passing through the first lens system; A second selector for selectively passing the nth-order diffracted light out of the diffracted light reflected by the reflector of each element after passing through the first lens system; and cooperating with the first lens system. A second lens system that forms a first position conjugate with the reflection unit of each element and guides the m-order diffracted light that has passed through the first selection unit to the conjugate first position; and the first lens system. And a second conjugate with the reflection part of each element in cooperation with A third lens system for guiding the n-order diffracted light passed through the second selecting unit to form a location and conjugated a second position, may have. In this case, the readout light supply unit supplies the readout light so that the readout light passes through a region on one side with respect to the optical axis of the first lens system, and the first and second selection units The part that selectively transmits the m-order diffracted light and the part that selectively transmits the n-th diffracted light may be arranged in a region on the other side with respect to the optical axis of the first lens system. .

An imaging device according to a fifth aspect of the present invention comprises:
In the imaging device according to the second aspect, the readout optical system includes a plurality of diffracted lights having different wavelengths reflected by the reflection unit, and a plurality of readout optical systems each corresponding to a displacement of the displacement unit of each element. A plurality of optical images are formed based on the respective diffracted lights, or a single optical image corresponding to the displacement of the displacement portion of each element.

According to the fifth aspect, since a plurality of diffracted lights having different wavelengths are used, the light amounts of the plurality of diffracted lights having different wavelengths depend on the step between the fixed reflecting portion and the movable reflecting portion. Because of the differences, an image of the radiation can be obtained as a pseudo-color image.

[0025] In the fifth aspect, the absolute values of the diffraction orders of the plurality of diffracted lights may be the same. In this case, it is preferable because the intensity of each diffracted light does not differ due to the difference in the diffraction order of the plurality of diffracted lights having different wavelengths. However, in the fifth aspect, the absolute values of the diffraction orders of the plurality of diffracted lights may not be the same.

In the fifth aspect, the readout optical system may further include a readout light supply unit for supplying the readout light, and the readout light system may be configured to transmit the readout light to the reflection of each element of the optical readout type radiation-displacement converter. A first lens system that guides the plurality of diffracted lights out of the diffracted lights reflected by the reflection units of the respective elements after passing through the first lens system; In cooperation with the first lens system, a plurality of positions conjugate with the reflecting portion of each of the elements are formed, and the plurality of diffracted lights that have passed through the plurality of selecting portions at the plurality of conjugate positions, respectively. And a plurality of second lens systems for guiding. In this case, the readout light supply unit supplies the readout light such that the readout light passes through a region on one side with respect to the optical axis of the first lens system, and the plurality of selection units include the plurality of selection units. A portion for selectively transmitting the diffracted light may be arranged in a region on the other side with respect to the optical axis of the first lens system.

In the fifth aspect, the readout optical system includes a readout light supply unit for supplying the readout light, and a readout light supply unit that supplies the readout light to each element of the optical readout type radiation-displacement conversion device. A first lens system that guides to the reflecting unit, a selecting unit that selectively passes the plurality of diffracted lights out of the diffracted lights reflected by the reflecting units of the respective elements after passing through the first lens system, A second lens system which forms a conjugate position with the reflecting portion of each element in cooperation with the first lens system and guides the plurality of diffracted lights passing through the selecting portion to the conjugate position. May be. In this case, the readout light supply unit supplies the readout light such that the readout light passes through a region on one side with respect to the optical axis of the first lens system, and the selecting unit includes the plurality of diffracted light beams. May be arranged in a region on the other side with respect to the optical axis of the first lens system.

A displacement detecting method according to a sixth aspect of the present invention is a displacement detecting method for detecting a displacement of a displacement portion which is displaced with respect to a base body. Irradiation is performed, and the displacement is detected based on the diffracted light reflected by the reflector. The reflecting portion used in the sixth aspect is a reflecting portion which substantially forms a reflective diffraction grating, receives the readout light, and reflects the received readout light as diffracted light, and is fixed to the base. A plurality of strip-shaped fixed reflectors which are located substantially in the same plane with each other, and a plurality of strip-shaped movable reflectors which are fixed to the displacement section and are located substantially in the same plane as each other. The plurality of fixed reflectors and the plurality of movable reflectors are alternately arranged, and the step difference between the plurality of fixed reflectors and the plurality of movable reflectors changes according to the displacement of the displacement unit. Things.

According to the sixth aspect, readout light such as visible light is applied to the reflecting portion substantially forming a reflective diffraction grating, and is reflected as diffracted light by this reflecting portion.
Since the step amount between the plurality of fixed reflecting portions and the plurality of movable reflecting portions changes according to the displacement of the displacement portion, the intensity of the diffracted light of each diffraction order among the diffracted lights reflected by the reflecting portion is displaced. It is displaced according to the displacement of the part. Therefore, the displacement of the displacement unit can be detected based on the read light reflected by the reflection unit and converted into the diffracted light.

As described above, according to the sixth aspect, based on the principle of diffraction, the intensity of the diffracted light emitted from the reflecting portion greatly changes with respect to a minute change in the displacement of the displacement portion. The detection sensitivity of the displacement of the displacement portion is increased.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Prior to the description of the embodiments of the present invention, a general reflection type diffraction grating to be compared with the reflection portion of the optical readout radiation-displacement conversion device according to the present invention will be described.
This will be described with reference to FIG. For convenience of explanation, in FIG. 20, an X axis, a Y axis, and a Z axis that are orthogonal to each other are defined as illustrated.

This reflection type diffraction grating is called a reflection type phase grating, and has a plurality of band-shaped reflection portions 1 extending in the Y-axis direction and a plurality of band-shaped reflection portions 2 extending in the Y-axis direction. I have. The plurality of reflectors 1 and the plurality of reflectors 2 are alternately arranged in the X-axis direction. The plurality of reflectors 1 are located in the same plane parallel to the XY plane, the plurality of reflectors 2 are located in the same plane parallel to the XY plane, and both faces are displaced by the step amount h in the Z-axis direction. I have.

As shown in FIG. 20, the grating constant of the reflection type diffraction grating is d, the incident angle of incident light incident on the reflection type diffraction grating is i, the wavelength of the incident light is λ, and the reflection type diffraction grating is used. Assuming that the emission angle of the emitted light that is reflected and emitted is θ and the diffraction order is m, the following equation 1 holds. Incident light is Z
When the light is incident from the axial direction (that is, when i = 0), the following equation 2 is established. Hereinafter, the mth-order diffracted light is simply referred to as the mth-order light.

[0034]

## EQU1 ## sin (i) + sin (θ) = mλ / d

[0035]

## EQU2 ## sin (θ) = mλ / d

In the reflection type diffraction grating shown in FIG. 20, in the case of normal incidence (ie, when i = 0), the relationship between the outgoing angle θ and the intensity of the outgoing light is as shown in FIG. Become. In FIG. 21, the horizontal axis represents sin (θ), and the vertical axis represents the intensity of the emitted light (normalized intensity). In FIG. 21, the curve P1 is when the step amount h is 0, the curve P2 is when the step amount h is λ / 16, the curve P3 is when the step amount h is λ / 8, and the curve P4 is when the step amount h is λ / 4 is shown.

In FIG. 21, the vicinity of the intensity peak at sin (θ) = 0 indicates the zero-order light, and the vicinity of the relatively large intensity peak on both sides of the intensity peak is the + 1st-order light and −1.
Indicates the next light. As can be seen from FIG. 21, as the level difference h increases from 0 to λ / 4, the intensity of the zero-order light gradually decreases to zero, and the intensity of the ± first-order light gradually increases from zero. In addition,
Although not shown in the drawing, if the number of the reflecting portions 1 and 2 is small, the spread of the diffracted light of each diffraction order is widened,
When the number of 2 is large, the spread of diffracted light of each diffraction order becomes narrow.

Hereinafter, an optical readout type radiation-to-displacement conversion device according to the present invention, an imaging device using the same, and a displacement detection method will be described with reference to the drawings. In the following description, an example will be described in which the radiation is infrared light and the readout light is visible light.
It may be a line, ultraviolet light, or other various radiation, and the readout light may be other light than visible light.

[First Embodiment]

FIG. 1 is a schematic plan view showing an optical readout type radiation-to-displacement converter (hereinafter, simply referred to as “converter”) according to a first embodiment of the present invention. FIG. 2 shows FIG.
It is an outline sectional view along the AB line in the inside. FIG.
It is a schematic sectional drawing in alignment with the AC line. FIG.
It is a schematic sectional drawing along the A-D line in the inside. 2 to 4
Indicates a state in which the infrared ray i from the target object is not incident. FIG. 5 is a schematic cross-sectional view along a line AB in FIG. 1 in a state where the infrared ray i from the target object is incident, and corresponds to FIG. In FIGS. 1 to 5, the fixed reflector is hatched in order to make the distinction between the fixed reflector and the movable reflector clearer.

The conversion device according to the present embodiment floats on the substrate 10 via a substrate 10 such as a Si substrate that transmits infrared rays i as a base, and two legs 11 and 12 rising from the substrate 10. It has two displacement parts 13 and 14 supported in a state, and an infrared absorption part 15 made of a film of gold or the like which receives infrared rays i from below and converts them into heat.

The legs 11, 12 are made of, for example, a SiO film. 1 to 5, reference numerals 11a and 12a denote legs 1
1 and 2 show contact portions with the substrate 10.

In this embodiment, the fixed ends of the displacement parts 13 and 14 are fixed to the legs 11 and 12, respectively, and the free ends of the displacement parts 13 and 14 are fixed to the radiation absorbing part 15. Reference numerals 13 and 14 constitute a cantilever.

The displacement units 13 and 14 and the radiation absorption unit 15
It constitutes a supported part supported on the substrate 10.
Each of the displacement parts 13 and 14 is composed of two films 16 and 17 overlapping each other. The film 16 and the film 17 are made of different materials having different expansion coefficients, and have a so-called thermal bimorph structure (bi-material element).
Also called. ). Since the displacement parts 13 and 14 constitute a cantilever, as in the present embodiment,
When the expansion coefficient of the lower film 17 is larger than the expansion coefficient of the upper film 16, the infrared absorber 15 is curved upward and inclined as shown in FIG. . Conversely, the expansion coefficient of the lower membrane 17 is
May be smaller than the expansion coefficient, and in this case, the heat causes the heat to curve downward and tilt. For example, one of the films 16 and 17 can be an Al film, and the other can be an SiN film.

Further, the converter according to the present embodiment is provided with a plurality of strip-shaped movable reflectors 18 and a plurality of strip-shaped fixed reflectors 19. The movable reflecting portion 18 and the fixed reflecting portion 19 are arranged above the infrared absorbing portion 15 with a space therebetween. The movable reflecting section 18 is fixed to the infrared absorbing section 15 via the connecting section 20, whereby the displacement section 1 is moved.
3 and 14 are fixed. The movable reflection part 18 and the connection part 20 are formed of one continuous reflection film, for example, an Al film. The fixed reflecting section 19 is fixed to the substrate 10 via the connecting section 21 and the leg section 22. The fixed reflecting portion 19 and the connecting portion 21 are formed of one continuous reflecting film,
For example, it is composed of an Al film. The leg 22 is made of, for example, a SiO film. 1 to 5, 22a
Indicates a contact portion of the leg portion 22 with the substrate 10.

In the present embodiment, a plurality of fixed reflecting portions 19
Are arranged in the same plane parallel to the substrate 10. The movable reflection unit 18 is configured to move the substrate 1 in a state where the infrared rays i from the target object do not enter and the displacement units 13 and 14 are not curved.
It is arranged in the same plane parallel to zero, and is also arranged in the same plane as the plurality of fixed reflecting parts 19, and the step amount between the plurality of fixed reflecting parts 19 and the plurality of movable reflecting parts 18 becomes zero. It has become. Then, when infrared rays i from the target object enter and the displacement portions 13 and 14 are curved, as shown in FIG. 5, the plurality of fixed reflection portions 19 and the plurality of movable reflection portions are provided in accordance with the displacement amounts of the displacement portions 13 and 14. 18 is changed. However, in the present invention, the step amount between the plurality of fixed reflecting portions 19 and the plurality of movable reflecting portions 18 may be a predetermined amount in a state where the infrared rays i from the target object are not incident. In the state shown in FIG. 5, the plane formed by the movable reflecting section 18 is the fixed reflecting section 1.
Since inclined relative to 9 forms the plane of, the step amount h _1, h ₂ of the step amount h ₀ and around both sides of the vicinity of the center are different from each other.

In the present embodiment, a plurality of movable reflecting portions 18
And the plurality of fixed reflecting portions 19 are alternately arranged. The movable reflecting portion 18 and the fixed reflecting portion 19 are arranged such that their extending direction is orthogonal to the direction from the fixed ends of the displacement portions 13 and 14 to the free ends. Are located in Further, the width of the movable reflecting portion 18 and the fixed reflecting portion 19 and the size of the gap between them are all the same.

As can be seen by comparing the plurality of movable reflectors 18 and the plurality of fixed reflectors 19 with the reflection type diffraction grating shown in FIG. 20, these movable reflectors 18 and fixed reflectors 19 are formed as a whole. , Substantially constitutes a reflection portion forming a reflection type diffraction grating. The movable reflector 18 corresponds to the reflector 1 in FIG. 20, and the fixed reflector 19 corresponds to the reflector 2 in FIG.
Is equivalent to The reflecting portion as a whole of the plurality of movable reflecting portions 18 and the plurality of fixed reflecting portions 19 receives the readout light j, and outputs the readout light j to the 0th order light, ± 1st order light, ± 2nd order light,.
・ It is reflected as diffracted light.

In the present invention, the numbers of the movable reflecting portions 18 and the fixed reflecting portions 19 are not particularly limited. However, if the number is too small, the spread of the diffracted light of each diffraction order is too wide, and the diffracted light of the desired diffraction order and the diffraction light of the adjacent diffraction order overlap, and the diffraction of the desired diffraction order is performed. It becomes difficult to separate light from other diffracted light. Therefore, in practice, the number of the movable reflecting portions 18 and the number of the fixed reflecting portions 19 may be determined in consideration of this point.

For example, the number of movable reflectors 18 can be six, the number of fixed reflectors 19 can be five, the width of each reflector 18, 19 can be 3 μm, and the lattice constant in FIG. 1 can be 8 μm.

Although not shown in the drawings, in the conversion device according to the present embodiment, the displacement units 13 and 14, the legs 11, 1
2. Using the infrared absorbing unit 15 and the reflecting units 18 and 19 as unit elements (pixels), the pixels are arranged on the substrate 10 in a one-dimensional or two-dimensional manner.

The converter according to the present embodiment can be manufactured using semiconductor manufacturing techniques such as film formation and patterning, sacrificial layer formation and removal, and for example, by the following method. be able to.

Although not shown in the drawings, first, a resist as a sacrificial layer is applied on the Si substrate 10. The contact portions 11a, 11a,
Openings corresponding to 12a and 22a are formed by photolithography. Next, after depositing the SiO film by a P-CVD method or the like, the SiO film is patterned by a photolithographic etching method to form the legs 11, 12, and 22. After that, a gold black film to be the infrared absorbing portion 15 is deposited by a vapor deposition method or the like, and then patterned by a photolithographic etching method to form the infrared absorbing portion 15. Next, after depositing an Al film to be the film 17 by a vapor deposition method or the like, patterning is performed by a photolithographic etching method to form the film 17. Next, after depositing the SiN film to be the film 16 by the P-CVD method or the like, the SiN film is patterned by the photolithography etching method to form the film 16. A resist as a sacrificial layer is applied again on the entire surface of the substrate in this state. Next, openings corresponding to the connection portions 20 and 21 are formed in the resist by photolithography. Then, after depositing the Al films to be the connection portions 20 and 21 and the reflection portions 18 and 19 by a vapor deposition method or the like, the Al films are patterned by the photolithography etching method to form the reflection portions 18 and 19. Finally, the resultant is divided into chips by dicing or the like, and the resist as a sacrificial layer is removed by ashing or the like.
Thus, the conversion device shown in FIG. 1 is completed.

According to the converter according to the first embodiment shown in FIGS. 1 to 5 described above, the infrared rays i are incident from below in FIGS. This infrared light i
0 is absorbed by the infrared absorbing unit 15 and converted into heat. As shown in FIG. 5, in response to the heat generated in the infrared absorbing section 15, the displacement sections 13 and 14 are curved upward,
The movable reflecting portion 18 is inclined upward, and the displacement portions 13 and 14
In accordance with the displacement, the step difference between the plurality of fixed reflecting portions 19 and the plurality of movable reflecting portions 18 changes. That is, the incident infrared light i is converted into a displacement of the displacement units 13 and 14 according to the amount thereof, and is further converted into a step difference between the reflection units 18 and 19. On the other hand, a readout optical system, which will be described later, causes a readout light j of visible light to be incident from above in FIGS.
8 and 19 are irradiated. This read light j is reflected by the reflection unit 1
The light is reflected as diffracted light such as 0th order light, ± 1st order light, ± 2nd order light. Since the intensity of the diffracted light of each diffraction order reflected and emitted by the reflecting portions 18 and 19 changes according to the step amount, the zero-order light, the ± first-order light, and the ± 2 light emitted by the reflecting portions 18 and 19 are eventually obtained. It is converted into the intensity of the diffracted light such as the next light. For this reason, as described later, the infrared light i can be detected based on the read light reflected by the reflecting units 18 and 19 and diffracted.

As described above, according to the present embodiment, based on the principle of diffraction, the intensity of the diffracted light emitted from the reflecting portions 18 and 19 with respect to a slight change in the displacement of the displacement portions 13 and 14 Is greatly changed, the detection sensitivity of the infrared ray i is increased, and the infrared ray i can be detected with the same high sensitivity as that of a conventional optical readout radiation-displacement converter using an interference unit. Further, according to the present embodiment, since the reflecting portions 18 and 19 substantially forming a reflection type diffraction grating are used instead of the interference portion, the half mirror portion is unnecessary.

[0056] Incidentally, as described above, as shown in FIG. 5, the plane formed of the movable reflecting portion 18 is inclined relative to a plane formed of the fixed reflecting portion 19, in the vicinity of the center level difference h ₀ and near both sides The step differences h ₁ and h ₂ are different from each other. However, the difference between these step amounts is not so large (see FIG. 5).
Here, the slope is greatly exaggerated for easy viewing. )
Therefore, the influence of the inclination does not substantially matter. It can be considered that the average step amount of the step amounts h ₀ , h ₁ , h ₂ substantially corresponds to the step amount h in FIG. When the plane formed by the movable reflecting section 18 is inclined with respect to the plane formed by the fixed reflecting section 19, the diffraction direction changes accordingly. However, the inclination of the reflecting sections 18 and 19 is at a level that does not substantially cause a problem. Also, the change in the diffraction direction is not a problem.
However, when the temperature range of the target object is extremely wide, the change in the diffraction direction may become a level that cannot be ignored. Such a case will be described in detail in [Third Embodiment] below.

The range of displacement of the displacement parts 13 and 14 is limited so that the intensity change of the diffracted light due to the displacement of the displacement parts 13 and 14 (that is, the change of the incident infrared ray i) becomes monotonous. Is preferred.

[0058] In the present embodiment, when the infrared absorbing section 15 is struck with the fixed reflecting portion 19 (when the distance _{g 1} in FIG. 5 becomes 0), the displacement portions 13 and 14 and the movable reflecting portion 18 The movement stops. Therefore, for example, by setting g ₁ <(λ / 4), the change in the intensity of the obtained diffracted light can be made monotonic. Here, λ is the wavelength of the reading light j.

On the other hand, in the converter according to the present embodiment, the magnitude relationship between the expansion coefficients of the upper film 16 and the lower film 17 in the displacement portions 13 and 14 is reversed, and the infrared rays i When the movable portions 13 and 14 are bent downward when the light enters the radiation absorbing portion 15 when the movable reflecting portion 18 collides with the leg 22 (the distance g _{2 in} FIG. 4).
When the value becomes 0), the movements of the displacement units 13 and 14 and the movable reflection unit 18 stop. Therefore, for example, g ₂ <(λ /
By setting 4), the change in the intensity of the obtained diffracted light can be made monotonic.

[Second Embodiment]

FIG. 6 is a schematic plan view showing an optical readout type radiation-to-displacement converter according to a second embodiment of the present invention. FIG. 7 is a schematic cross-sectional view along the line EE ′ in FIG. 6 in a state where infrared rays i from the target object are not incident. FIG. 8 is a schematic cross-sectional view along a line EE ′ in FIG. 6 in a state where infrared rays i from the target object are incident. 6 to 8, the same or corresponding elements as those in FIGS. 1 to 5 are denoted by the same reference numerals, and redundant description will be omitted.

The point that this embodiment is different from the first embodiment is that, in the first embodiment, the movable reflecting portion 18
And the direction in which the fixed reflecting portion 19 extends is orthogonal to the direction from the fixed end to the free end of the displacement portions 13 and 14, whereas the direction in which the movable reflecting portion 18 and the fixed reflecting portion 19 extend is the displacement portions 13 and 14. Only parallel to the direction from the fixed end to the free end.

According to this embodiment, advantages similar to those of the first embodiment can be obtained.

In the present invention, the direction in which the movable reflecting portion 18 and the fixed reflecting portion 19 extend may be oblique to the direction from the fixed ends of the displacement portions 13 and 14 to the free ends.

[Third Embodiment]

FIG. 9 is a schematic configuration diagram showing an imaging device according to the third embodiment of the present invention. FIG. 10 is a diagram for explaining the principle of the imaging device shown in FIG.

The imaging apparatus according to the present embodiment is the same as the conversion apparatus according to the first or second embodiment (indicated by reference numeral 100 in FIG. 9, the upward and downward directions in FIG. 8 corresponds to the right and left directions in FIG. 8, respectively, and the upward and downward directions in FIG. 8 correspond to the right and left directions in FIG. 9), respectively, and infrared rays i from the heat source as the observation target. And the infrared ray absorbing portion 15 of the conversion device 100
Imaging lens 40 for forming an infrared image on a surface where the light is distributed, movable reflecting portion 18 and fixed reflecting portion 1 as reflecting portions of the respective elements (pixels) of converter 100.
9 is irradiated with the readout light, and an optical image corresponding to the displacement of the displacement parts 13 and 14 of each element is formed based on the diffracted light reflected by the movable reflection part 18 and the fixed reflection part 19 of each element. The optical system includes a readout optical system to be formed, and a two-dimensional CCD 41 as imaging means for imaging the optical image. In the present embodiment, the readout optical system is configured to use the zero-order light, and the reflection part of each element by the zero-order light reflected by the movable reflection part 18 and the fixed reflection part 19 of each element. An optical image composed of images 18 and 19,
The optical image is configured such that the amount of light of the image of the reflection sections 18 and 19 of each element in the optical image is different depending on the step between the fixed reflection section 19 and the movable reflection section 18 of each element.

Specifically, the imaging apparatus according to the present embodiment includes a light source (a white light source or a monochromatic light source) 42, an illumination lens 43, first and second lens systems 44 and 45, A beam splitter 46 and a stop 47 are provided, and these constitute the readout optical system.

The light source 42, the illumination lens 43, and the beam splitter 46 constitute a reading light supply section for supplying reading light. The first lens system 44 guides the reading light to the movable reflecting section 18 and the fixed reflecting section 19. The lens 4 is set so that the reading light from the light source 42 via the lenses 43 and 44 irradiates the conversion device 100.
3, 44 are set.

The surface on which the movable reflector 18 and the fixed reflector 19 as the reflectors of the converter 100 are distributed and the CCD 4
The one light receiving surface is disposed at a position substantially conjugate to each other with respect to the lens systems 44 and 45. That is, the second lens system 45 cooperates with the first lens system 44 to form a conjugate position with the reflecting portions 18 and 19 of the respective elements on the light receiving surface of the CCD 41 and to stop at the conjugate position. 0 passed through 47
It is designed to guide the next light. Further, the fixed reflecting section 19 and the movable reflecting section 18 of the conversion device 100 are arranged on the front focal plane of the lens 44, and the stop 47 is arranged on the rear focal plane of the lens 44, respectively.

As shown in FIG. 10, the stop 47 is provided so that only the zero-order light of the light emitted from the light source 42 out of the diffracted light reflected by the movable reflector 18 and the fixed reflector 19 can be extracted.
The size and position of the opening 47a are set. In the present embodiment, the aperture 47 constitutes a selector that selectively passes the zero-order light. In FIG. 10, the zero-order light and the one
Only the state of the next light is shown.

In the present embodiment, the infrared rays i are condensed by the imaging lens 40 and an infrared image is formed on the surface of the conversion device 100 on which the infrared absorbing portions 15 are distributed.
As a result, the infrared absorbing unit 15 of each pixel of the conversion device 100
As described with respect to the first embodiment, a step occurs between the fixed reflection portion 19 and the movable reflection portion 18 of each pixel according to the amount of incident infrared rays with respect to the first embodiment.

The light emitted from the light source 42 is
Then, the light is reflected by the beam splitter 46 via the lens system 44, and irradiates the conversion device 100 as readout light via the lens system 44. Since the reflection portions 18 and 19 and the light receiving surface of the CCD 41 have a conjugate relationship, the reflection portions 18 and 19 of the readout light applied to the conversion device 100 are reflected by the reflection portions 18 and 19 (diffraction light). Irrespective of the amount of step between
An optical image composed of the images of the reflecting portions 18 and 19 is formed at a predetermined position on the light receiving surface of the CD 41.

If there is no step in the reflecting portions 18 and 19, the reflected light of the readout light applied to the reflecting portions 18 and 19 is substantially only the zero-order light.
Is used to extract the zero-order light.
The image of the reflecting portions 18 and 19 of the element on the light receiving surface of the light emitting element 1 becomes bright. If the diaphragm 47 extracts diffracted light of any other diffraction order, the images of the elements 18 and 19 on the light receiving surface of the CCD 41 become dark.

However, if a step is generated between the reflecting portions 18 and 19 in accordance with the amount of the incident infrared light i, the 0-order light of the reflected light of the read light by the reflecting portions 18 and 19 is reduced in accordance with the amount of the step, and Components other than the zero-order light (diffraction lights of orders other than the zero-order light) increase. As a result, in the present embodiment, the aperture 47
Is used to extract the zero-order light.
The image of the reflection portions 18 and 19 of the element on the light receiving surface of No. 1 becomes dark. If the diaphragm 47 extracts diffracted light of any other diffraction order, the images of the elements 18 and 19 on the light receiving surface of the CCD 41 become brighter.

Therefore, according to the present embodiment, the images of the reflection portions 18 and 19 of each pixel are formed on the CCD 41,
The brightness of each image changes according to the level difference between the reflection portions 18 and 19 of each pixel, that is, the amount of incident infrared light to each pixel. Thus, the incident infrared image is converted into a visible image, and the visible image is captured by the CCD 41. In addition, even when the readout light applied to the conversion device 100 is white light, a change in the amount of light of the images of the reflection units 18 and 19 of the respective elements on the light receiving surface of the CCD 41 is observed. The change in the amount of light is more remarkable in the case of monochromatic light.

In this embodiment, the zero-order light is used. However, the diaphragm 47 may be used to selectively pass only the diffracted lights of other orders. In this case, for the diffracted light of the other orders, the direction in which the light is reflected by the reflecting portions 18 and 19 differs depending on the wavelength (see Expression 1).
Is preferably monochromatic light rather than white light.

In the present embodiment, the visible image is picked up by the CCD 41. However, the visible image may be observed with the naked eye using an eyepiece or the like.

Here, an example of setting the aperture 47a of the diaphragm 47 in the present embodiment will be described with reference to FIGS.

FIGS. 11 and 12 are explanatory diagrams schematically showing examples of the setting. FIG. 11 shows the conversion apparatus 100 according to the second embodiment shown in FIGS.
FIG. 12 shows the conversion device 100 according to the first embodiment shown in FIGS.
The case where 00 is used is shown. For convenience of explanation, in FIGS. 11 and 12, X axes orthogonal to each other,
The Y axis and the Z axis are defined as shown.

In the case of FIG. 11, the direction from the fixed ends of the displacement parts 13 and 14 to the free ends is the X-axis direction, and the movable reflection part 18 and the fixed reflection part 19 extend in the X-axis direction.
When the displacement parts 13 and 14 are not displaced without the infrared ray from the target object being incident, the reflection parts 18 and 19 are in the same plane parallel to the XZ plane. Therefore, in this case,
After passing through the first lens system, the surface of the stop 47 (ie,
0th-order light spot 200 formed on the rear focal plane of the first lens system), + 1st-order light spot 201 formed on the surface of the aperture 47, and -1st-order formed on the surface of the aperture 47 As shown in FIG. 11, the light spots 202 are arranged in the Z-axis direction with an interval corresponding to each diffraction angle. Strictly speaking, when the reflecting portions 18 and 19 are in the same plane, the intensity of the spot other than the zero-order light becomes zero.

In the case of FIG. 11, when the infrared rays from the target object enter and the displacement units 13 and 14 are displaced, the movable reflection unit 18 is rotated about an axis parallel to the Z axis. 11, the spots 200 to 202 move in the X-axis direction, respectively, as shown in FIG. In the embodiment shown in FIGS. 9 and 10, in order to selectively pass the zero-order light even if the spot 200 moves as described above, the aperture 47 has, for example, an aperture having a shape shown in FIG. 47a may be formed. Similarly, even if the spots 201 and 202 move as described above, in order to selectively pass the + 1st-order light or the −1st-order light without being eclipsed, the diaphragm 47 is provided, for example, as shown in FIG.
The opening 47b or 47c having the shape shown therein may be formed.

In the case of FIG. 12, the direction from the fixed ends of the displacement parts 13 and 14 to the free ends is the X-axis direction, and the movable reflection part 18 and the fixed reflection part 19 extend in the Z-axis direction.
When the displacement parts 13 and 14 are not displaced without the infrared ray from the target object being incident, the reflection parts 18 and 19 are in the same plane parallel to the XZ plane. Therefore, in this case,
After passing through the first lens system, the surface of the stop 47 (ie,
0th-order light spot 200 formed on the rear focal plane of the first lens system), + 1st-order light spot 201 formed on the surface of the aperture 47, and -1st-order formed on the surface of the aperture 47 As shown in FIG. 12, the light spots 202 are arranged in the X-axis direction with an interval corresponding to each diffraction angle. Strictly speaking, when the reflecting portions 18 and 19 are in the same plane, the intensity of the spot other than the zero-order light becomes zero.

In the case of FIG. 12, when the displacement portions 13 and 14 are displaced by the infrared rays from the target object, the movable reflection portion 18 is rotated about an axis parallel to the Z axis. 12, the spots 200 to 202 move in the X-axis direction, respectively, as shown in FIG. In the embodiment shown in FIG. 9 and FIG. 10, in order to selectively pass the zero-order light without moving even if the spot 200 moves as described above, an aperture having a shape shown in FIG. 47a may be formed. Similarly, even if the spots 201 and 202 move as described above, in order to selectively pass the + 1st-order light or the -1st-order light without being eclipsed, the diaphragm 47 is provided, for example, as shown in FIG.
The opening 47b or 47c having the shape shown therein may be formed.

Note that, as shown in FIG.
8 and the direction in which the fixed reflecting portion 19 extends are the displacement portions 13 and 14.
When the conversion device 100 (the conversion device shown in FIGS. 1 to 5) that is orthogonal to the direction from the fixed end to the free end is used,
Spots 200 to 202 due to diffracted light of each diffraction order are
They are arranged in the same X-axis direction as the moving direction due to the displacement of the displacement units 13 and 14. Therefore, when the amount of incident infrared rays is extremely large, for example, the spot 202 may pass through the opening 47a for the zero-order light. In this case, only the 0th-order diffracted light cannot be separated and selected from other orders of diffracted light.

On the other hand, as shown in FIG.
8 and the direction in which the fixed reflecting portion 19 extends are the displacement portions 13 and 14.
When the conversion device 100 (the conversion device shown in FIGS. 6 to 8) which is parallel to the direction from the fixed end to the free end is used, the spots 200 to 202 by the diffracted lights of the respective diffraction orders are used.
Are arranged in the Z-axis direction orthogonal to the X-axis direction, which is the moving direction due to the displacement of the displacement units 13 and 14. Therefore, even if the amount of incident infrared rays is very large, there is no possibility that, for example, the spot 202 passes through the opening 47a for the zero-order light.

Therefore, when the temperature range of the target object to be observed is extremely wide, it is preferable to use the converter shown in FIGS. 6 to 8 as compared with the converter shown in FIGS. .

[Fourth Embodiment]

FIG. 13 is a schematic configuration diagram showing an imaging device according to the fourth embodiment of the present invention. 13, elements that are the same as elements in FIG. 9 or that correspond to elements in FIG. 9 are given the same reference numerals, and overlapping descriptions are omitted.

This embodiment is different from the third embodiment shown in FIGS. 9 and 10 in that the illumination lens 4 shown in FIG.
3 and the beam splitter 46 are removed, and the light source 42 is disposed on the front focal plane of the first lens system 44 on one side (lower side in FIG. 13) with respect to the optical axis O of the first lens system 44. A point that the reading light is supplied so that the reading light passes through the area on one side;
Along with this, the only point is that the aperture 47a of the stop 47 for passing only the 0th-order light is arranged in the area on the other side (upper side in FIG. 13) with respect to the optical axis O of the first lens system 44. In the present embodiment, a laser diode is used as the light source 42.

The present embodiment is substantially the same as the third embodiment, but in this embodiment, the illumination lens 4
3 and the beam splitter 46 are not used,
The configuration is simple. Further, the beam splitter 46
Is not used, the loss of light quantity can be reduced.

[Fifth Embodiment]

FIG. 14 is a schematic configuration diagram showing an imaging device according to the fifth embodiment of the present invention. FIG.
FIG. 5 is an explanatory view of the principle of the imaging device shown in FIG. 4. In FIGS. 14 and 15, the same or corresponding elements as those in FIGS. 9 and 10 are denoted by the same reference numerals, and redundant description will be omitted.

This embodiment is different from the third embodiment shown in FIGS. 9 and 10 in that the aperture 47 has an aperture 47b for selectively passing + 1st-order light in addition to the aperture 47a.
Are also formed, the mirror 52, the lens system 55 and the CCD 51
Is added.

In the present embodiment, the readout optical system
It is configured so as to use the next-order light and the + 1st-order light, and includes an image of the reflection units 18 and 19 of each element by the 0-order light reflected by the movable reflection unit 18 and the fixed reflection unit 19 of each element. The first optical image, wherein the amount of light of the image of the reflectors 18 and 19 of each element in the first optical image is different depending on the level difference between the fixed reflector 19 and the movable reflector 18 of each element. A second optical image which forms the first optical image and is composed of the images of the reflection portions 18 and 19 of each element by the +1 order light reflected by the movable reflection portion 18 and the fixed reflection portion 19 of each element. , The reflection part 1 of each element in the second optical image
The second optical image is formed such that the light amounts of the images 8 and 19 are different depending on the level difference between the fixed reflecting portion 19 and the movable reflecting portion 18 of each element.

In this embodiment, the aperture 47b of the aperture 47 is
Is reflected by the mirror 52 and guided to the light receiving surface of the CCD 51 via the lens system 55.

Similar to the light receiving surface of the CCD 41, the CCD 51
Also, the light receiving surface of the conversion device 100 with respect to the surface on which the movable reflection portion 18 and the fixed reflection portion 19 as the reflection portion of the conversion device 100 are distributed,
The lens systems 44 and 55 are arranged at positions substantially conjugate to each other. That is, the lens system 55 cooperates with the first lens system 44 to form a conjugate position on the light-receiving surface of the CCD 51 with the reflecting portions 18 and 19 of the respective elements, and to set the diaphragm 47 at the conjugate position. The + 1st-order light that has passed through the opening 47b is guided.

According to the present embodiment, the incident infrared image is converted into a visible image based on the 0th-order light and a visible image based on the + 1st-order light, and the respective visible images are captured by the CCDs 41 and 51, respectively. Become.

Therefore, by appropriately processing the image signals obtained from the CCDs 41 and 51, noise components due to light reflected from portions other than the reflecting portion of the light-reading type radiation-to-displacement converter, dark output of the CCD, etc. Can be reduced, and an image with good S / N can be obtained. This is because the noise component mixed in the image signal obtained from the CCD 41 is different from the noise component mixed in the image signal obtained from the CCD 51. For example, in the optical image of the 0th-order light, in addition to the 0th-order light as the signal light, the 0
Noise light traveling in the diffraction direction of the next-order diffracted light is included, and +1
In the optical image by the next light, in addition to the + 1st order light which is the signal light,
Although noise light and the like reflected in a portion other than the reflection portion of the conversion device 100 and traveling in the diffraction direction of the + 1st-order diffracted light are included, the diffraction directions of the 0th-order light and the + 1st-order light are different. The components of the noise light are different.

As the processing of the image signal, for example, the following processing can be mentioned. That is, an object whose temperature is known is observed, and the image data obtained from the CCDs 41 and 51 and the true image data are stored in the memory in association with each other. Further, based on the stored data, a function or a table for obtaining true image data is obtained using the image data obtained from the CCDs 41 and 51 as parameters. Then, at the time of observation of the observation target, image data is obtained according to the function or the table based on the image data obtained from the CCDs 41 and 51. By performing such processing, an image having a good S / N can be obtained.

In the present embodiment, the movable reflecting portion 18
As the step between the and the fixed reflector 19 increases from 0 to λ / 4, the intensity of the zero-order light gradually decreases to 0, and conversely,
The intensity of the +1 order light gradually increases from 0 (see FIG. 21).
Therefore, in the image signal obtained from the CCD 41 based on the zero-order light, the S / N is better as the step amount is closer to 0, and the S / N is worse as the step amount is closer to λ / 4. Conversely, +1
In the image signal obtained from the CCD 51 based on the next light,
The closer the step amount is to 0, the worse the S / N ratio and the step amount becomes λ.
The closer to / 4, the better the S / N. Therefore, after matching the two levels, the signal obtained from the CCD 41 is used when the step amount is close to 0, and the signal obtained from the CCD 51 is used when the step amount is close to λ / 4. If the processing is performed so as to use the image, an image having a good S / N can be obtained.

Further, by processing the image signals obtained from the CCDs 41 and 51 as described below, even if the light amount of the readout light emitted from the light source 42 varies, the effect can be reduced. In the present embodiment, as described above, as the level difference between the movable reflecting portion 18 and the fixed reflecting portion 19 increases from 0 to λ / 4, the intensity of the zero-order light gradually decreases to 0, and conversely, The intensity of the +1 order light gradually increases from 0 (see FIG. 21). In addition, the intensity of the 0th-order light and the + 1st-order light increases and decreases as the light amount of the readout light increases and decreases. Therefore, if the ratio between the intensity of the 0th-order light and the intensity of the + 1st-order light is obtained,
The ratio reflects the step amount without being affected by an increase or decrease in the amount of read light. For this reason, if the ratio of the image signal obtained from the CCD 41 to the image signal obtained from the CCD 51 is obtained for each pixel to obtain an image signal based on the ratio, the effect of fluctuations in the amount of readout light is reduced. Image can be obtained.

Further, as described above, the movable reflecting portion 18
When the step amount between the first and second fixed reflection portions 19 changes, the change in the intensity of the 0th-order light and the change in the intensity of the + 1st-order light are opposite.
The optical image formed by the 0th-order diffracted light and the optical image formed by the + 1st-order light have the opposite light / dark state. Therefore, CCD4
Even in the case of observing with the naked eye using an eyepiece or the like instead of 1, 51, it is possible to see an image in which the light / dark state is reversed.

The imaging apparatus according to the present embodiment may be modified by the same method as the modification of the imaging apparatus shown in FIG. 9 to the imaging apparatus shown in FIG.

In the present embodiment, the 0th-order light and the + 1st-order light are used. Instead, m and n are each an integer whose absolute value is not less than 0 and whose absolute values are not equal to each other. If so, m-order light and n-order light may be used.

[Sixth Embodiment]

FIG. 16 is a schematic configuration diagram showing an imaging device according to the sixth embodiment of the present invention. FIG.
FIG. 7 is a diagram illustrating the principle of the imaging device shown in FIG. 16 and 17, the same or corresponding elements as those in FIGS. 9 and 10 are denoted by the same reference numerals, and the description thereof will not be repeated.

This embodiment is different from the third embodiment shown in FIGS. 9 and 10 in that a beam splitter 46 is used.
That the mirror 66 is used instead of
Is that a stop 68 is provided in place of the stop 47 on the front focal plane, and mirrors 67b, 67c, lens systems 65a, 65b, 65c, and CCDs 61a, 61b, 61c are used instead of the lens system 45 and the CCD 41. It is only the point that is. In the present embodiment, the light source 42 is a white light source.

In the present embodiment, the readout optical system is R
It is configured to use + 1st-order light of light (red light), + 1st-order light of G light (green light), and + 1st-order light of B light (blue light). Fixed reflector 1
Reflecting portion 1 of each element by + 1st-order light of R light reflected at 9
A first optical image consisting of images 8 and 19,
Forming a first optical image in which the amount of light of the image of the reflection portions 18 and 19 of each element in the optical image of each element is different according to the step between the fixed reflection portion 19 and the movable reflection portion 18 of each element; Is a second optical image composed of the images of the reflection units 18 and 19 of the respective elements due to the + 1st-order light of the G light reflected by the movable reflection unit 18 and the fixed reflection unit 19, and each of the second optical images in the second optical image The second is that the amount of light of the image of the reflection sections 18 and 19 of the elements differs according to the step between the fixed reflection section 19 and the movable reflection section 18 of each element.
Is a third optical image composed of the images of the reflection portions 18 and 19 of each element due to the + 1st order light of the B light reflected by the movable reflection portion 18 and the fixed reflection portion 19 of each element. Thus, the reflection portions 18, 1 of each element in the third optical image
9 has a fixed reflection portion 19 and a movable reflection portion 1 of each element.
8 is formed so as to form a different third optical image in accordance with the step between them.

In this embodiment, the stop 68 is provided with the light source 4
An aperture 68d through which the reading light emitted from 2 and reflected by the mirror 66 via the lens 43 passes, +1 of the B light.
An opening 68a for selectively transmitting the next light, an opening 68b for selectively transmitting the + 1st-order light of G light, and an opening 68c for selectively transmitting the + 1st-order light of the R light are formed.

+1 of the B light selectively passed through the opening 68a
The next light is guided to the light receiving surface of the CCD 61a via the lens system 65a. The + 1st order G light that has selectively passed through the opening 68b is reflected by the mirror 67b and guided to the light receiving surface of the CCD 61b via the lens system 65b. The + 1st-order light of the R light that has selectively passed through the opening 68c is reflected by the mirror 67c and guided to the light receiving surface of the CCD 61c via the lens system 65c.

The surface of the conversion device 100 on which the movable reflecting portion 18 and the fixed reflecting portion 19 as the reflecting portion are distributed and the CCD 6
The light receiving surfaces of 1a, 61b, and 61c are arranged at substantially conjugate positions with respect to the lens system 44 and the lenses 65a, 65b, and 65c. That is, the lens system 65a,
65b and 65c cooperate with the first lens system 44 to form a plurality of positions conjugate with the reflecting portions 18 and 19 of the respective elements, respectively.
B light, + 1st-order light of G light, + 1st-order light of G light, and + 1st-order light of R light that have passed through 8a, 68b, and 68c, respectively, are guided.

According to the present embodiment, the incident infrared image is converted into a visible image based on the + 1st-order light of B light, a visible image based on the + 1st-order light of G light, and a visible image based on the + 1st-order light of the R light. Each visible image is a CCD 61a, 61b, 61
Each image is taken at c.

Accordingly, the amount of the RGB + 1st-order light varies depending on the level difference between the movable reflecting portion 18 and the fixed reflecting portion 19, so that the incident infrared image can be obtained as a pseudo color image.

In the present embodiment, RGB + 1st-order light has been described as an example of a plurality of diffracted lights having different wavelengths, but the present invention is not limited to this.

The distance between the opening 68a and the CCD 61a, the distance between the opening 68b and the CCD 61b, and the distance between the opening 68a and the CCD 61b.
If a band-pass filter or the like that selectively passes the corresponding color light is disposed between c and the CCD 61c,
More effective.

The imaging apparatus according to the present embodiment may be modified by the same method as the modification of the imaging apparatus shown in FIG. 9 to the imaging apparatus shown in FIG.

[Seventh Embodiment]

FIG. 18 is a schematic configuration diagram showing an imaging device according to the seventh embodiment of the present invention. FIG. 19 shows FIG.
FIG. 9 is a diagram illustrating the principle of the imaging device shown in FIG. In FIGS. 18 and 19, the same or corresponding elements as those in FIGS. 16 and 17 are denoted by the same reference numerals, and redundant description will be omitted.

This embodiment is different from the sixth embodiment shown in FIGS. 16 and 17 in that mirrors 67b and 67
c, lens systems 65b, 65c and CCDs 61b, 61c
Is removed, the RGB + 1st-order light is guided to the CCD 61a through the lens system 65a, and the images of the movable reflection unit 18 and the fixed reflection unit 19 of the conversion device 100 by the RGB + 1st-order light are combined to form a light receiving surface of the CCD 61a. Only the points formed above.

If a color CCD is used as the CCD 61a, an incident infrared image can be obtained as a pseudo color image, as in the sixth embodiment. Further, a color image may be observed with the naked eye using an eyepiece or the like.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments. For example, the displacement detection method according to the present invention can be used not only in connection with an optical readout type radiation-to-displacement conversion device or an imaging device, but also in various other uses.

[0123]

As described above, according to the present invention,
An optical readout radiation-displacement converter capable of detecting radiation without the need for a half-mirror unit and with the same high sensitivity as a conventional optical readout radiation-displacement converter using an interference unit, and Can be provided.

Further, according to the present invention, it is possible to provide a displacement detecting method which can be used in connection with such an optical readout type radiation-displacement converter.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing an optical readout type radiation-to-displacement converter according to a first embodiment of the present invention.

FIG. 2 is a schematic sectional view taken along line AB in FIG.

FIG. 3 is a schematic cross-sectional view taken along line AC in FIG.

FIG. 4 is a schematic cross-sectional view along the line A-D in FIG.

FIG. 5 is a schematic cross-sectional view along a line AB in FIG. 1 in a state where infrared rays are incident;

FIG. 6 is a schematic plan view showing an optical readout radiation-displacement conversion device according to a second embodiment of the present invention.

FIG. 7 shows E in FIG. 6 in a state where no infrared ray is incident.
FIG. 4 is a schematic cross-sectional view along the line −E ′.

8 is a diagram showing E- in FIG. 6 in a state where infrared rays are incident;
FIG. 4 is a schematic sectional view taken along line E ′.

FIG. 9 is a schematic configuration diagram showing an imaging device according to a third embodiment of the present invention.

FIG. 10 is a diagram illustrating the principle of the imaging device shown in FIG. 9;

FIG. 11 is an explanatory view schematically showing a setting example of an aperture of a diaphragm.

FIG. 12 is another explanatory view schematically showing an example of setting the aperture of the stop.

FIG. 13 is a schematic configuration diagram showing an imaging device according to a fourth embodiment of the present invention.

FIG. 14 is a schematic configuration diagram showing an imaging device according to a fifth embodiment of the present invention.

15 is a diagram illustrating the principle of the imaging device illustrated in FIG. 14;

FIG. 16 is a schematic configuration diagram showing an imaging device according to a sixth embodiment of the present invention.

FIG. 17 is a diagram illustrating the principle of the imaging device shown in FIG. 16;

FIG. 18 is a schematic configuration diagram showing an imaging device according to a seventh embodiment of the present invention.

FIG. 19 is a diagram illustrating the principle of the imaging device shown in FIG. 18;

FIG. 20 is a diagram showing a general reflection type diffraction grating.

FIG. 21 is a characteristic diagram showing characteristics of a reflection type diffraction grating.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Substrate 13,14 Displacement part 15 Radiation absorption part 18 Movable reflection part 19 Fixed reflection part

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Motoo Koyama 3-2-3 Marunouchi, Chiyoda-ku, Tokyo Nikon Corporation F-term (reference) 2F065 AA19 AA65 BB18 CC25 DD02 EE01 FF48 GG04 GG22 GG24 JJ03 JJ26 LL00 LL30 LL46 UU02 UU03 2G066 BA14 BA20 BA31 BB03 CA02

Claims (6)

[Claims] 1. A base, a supported part supported by the base, a radiation absorbing part receiving radiation and converting the radiation to heat, and a base in accordance with heat generated in the radiation absorbing part. A supported portion having a displacement portion that is displaced by a displacement, and a reflection portion that substantially forms a reflection type diffraction grating, receives the readout light, and reflects the received readout light as diffracted light. A plurality of belt-shaped fixed reflectors, which are fixed to the base and are located substantially in the same plane with each other,
A plurality of band-shaped movable reflectors fixed to the displacement unit and positioned substantially in the same plane with each other, wherein the plurality of fixed reflectors and the plurality of movable reflectors are alternately arranged, An optical read-out radiation-displacement converter, wherein a step difference between the plurality of fixed reflecting portions and the plurality of movable reflecting portions changes according to the displacement of the displacement portion. 2. The optical-readout radiation-displacement conversion device according to claim 1, wherein the supported part and the reflection part are one element, and the element is a one-dimensional element. Or a light-reading type radiation-displacement converter arranged two-dimensionally, and irradiating the readout light to each of the reflection portions of the respective elements, based on the diffracted light reflected by the reflection portions of the respective elements. A readout optical system that forms an optical image according to the displacement of the displacement section of each of the elements. 3. m is an integer whose absolute value is 0 or more.
The readout optical system includes m
The imaging device according to claim 2, wherein an optical image corresponding to the displacement of the displacement portion of each element is formed based on the next-order diffracted light. 4. The reading optical system, wherein m and n are each an integer whose absolute value is equal to or greater than 0 and whose absolute values are not equal to each other. Forming a first optical image corresponding to the displacement of the displacement section of the element, and a second optical image corresponding to the displacement of the displacement section of each element based on the n-th order diffracted light reflected by the reflection section; 3. The imaging device according to claim 2, wherein 5. The readout optical system includes a plurality of optical images corresponding to displacements of the displacement portions of the respective elements, based on a plurality of diffracted lights having different wavelengths reflected by the reflection portion. 3. The imaging apparatus according to claim 2, wherein a plurality of optical images based on each of the diffracted lights or a single optical image corresponding to the displacement of the displacement unit of each element is formed. 6. A displacement detection method for detecting a displacement of a displacement portion displaced with respect to a base, comprising a reflection type diffraction grating, receiving reading light, and using the received reading light as diffraction light. A plurality of band-shaped fixed reflecting portions fixed to the base and located substantially in the same plane with each other, and substantially coplanar with each other fixed to the displacement portion; Having a plurality of band-shaped movable reflectors located in, the plurality of fixed reflectors and the plurality of movable reflectors are alternately arranged,
A step portion between the plurality of fixed reflecting portions and the plurality of movable reflecting portions uses a reflecting portion that changes in accordance with the displacement of the displacement portion. The reflecting portion is irradiated with the readout light, and reflected by the reflecting portion. And detecting the displacement based on the diffracted light.