JP2000028437A - Visualizing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a visualizing device which can accurately visualize an image formed of radiated infrared rays, etc., with high sensitivity. SOLUTION: The inclination of each reflecting section 5 two-dimensionally arranged on a substrate 1 varies depending upon the heat generated from the corresponding infrared-ray absorbing section which absorbs infrared rays from a heat source 31. The readout light from a light source 10 becomes a nearly parallel flux of rays 42 through a lens system 11 and is obliquely projected upon each reflecting section 5. The flux of reflected rays 43 from each section 5 passage through the lens system 11 and, after passing through the system 1, only a desired bundle of rays of the passed flux of rays 44 selectively passes through the opening 12a of a flux-of-ray restricting section 12. The passed flux of rays 45 reaches the light receiving surface CCD 20 conjugatively arranged with the reflecting sections 5 through another lens system 12 and forms an optical image composed of the image of each reflecting section 5 on the light receiving surface. The light quantity of the image of each reflecting section 5 varies depending upon the inclination of the section 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an imaging apparatus for detecting various kinds of radiation including invisible light such as infrared rays, X-rays, and ultraviolet rays, and for producing an image based on the radiation.

[0002]

2. Description of the Related Art An infrared detector is used for imaging of invisible infrared light, and various approaches have been taken for detection and imaging of infrared light. Thus, two types of detectors, a quantum infrared detector and a thermal infrared detector, have been used.

[0003]

However, even with today's advances in optomechatronics technology, infrared detection is not technically easy, and has not yet been widely used in the general public. The reason will be described below separately for the quantum infrared detector and the thermal infrared detector.

[0004] The quantum infrared detector is a detector that converts photon energy (E: hv) of infrared light into electron energy and detects it. The wavelength of infrared rays that is most useful in the general society is 3 to 12 μm, and the photon energy of this infrared ray is about 0.1 to 0.4 eV. This value is almost equal to the thermal energy of electrons in a normal temperature object. They are equal. Therefore, in order to convert only the font energy of incident infrared rays into electron energy,
The effects of the thermal energy of the electrons must be removed. That is, in the quantum infrared detector, it is essential to cool the detector and remove heat energy.

Usually, in order to suppress this thermal energy to a low level, it is necessary to cool the detector to about -200 ° C. (77 K). However, the cooler for this is large in volume and generates mechanical vibration. Life is short and expensive.
Therefore, the infrared camera using the quantum infrared detector cannot be reduced in size and cost, and is not widely used in the general society.

On the other hand, a conventional thermal infrared detector is
Converts the energy of the incident infrared rays into heat energy,
A change in the temperature of the detector is caused, and a change in the physical property value of the detector due to the change is electrically read. For example, in a resistive bolometer, the resistance value changes when the temperature changes. This bolometer is integrated in a plane, and when infrared light from the device under test is incident on the light-receiving device, the change in resistance due to temperature rise of the device is detected with high sensitivity, and the temperature distribution of the device under test is detected. For example, an imaging apparatus for imaging is disclosed in US Pat. No. 5,300,915.

This conventional thermal infrared detector does not require a large-scale cooler such as a quantum infrared detector, but has a problem in the detection principle itself. That is, in the conventional thermal infrared detector, although a temperature change of the detector due to only the incident infrared ray has to be detected, a current must be supplied to the detector in order to detect the temperature change.

That is, since the detector generates heat (usually called self-heating) due to a current for detecting a temperature change, it is difficult to detect a temperature change due to only incident infrared rays, and the detection accuracy is reduced. Was.

Furthermore, the conventional thermal infrared detector has a disadvantage that the sensitivity is low. In a conventional thermal infrared detector, for example, an object having a resistance change rate of about 2% when the resistance temperature changes by 1 ° C. is used. The rate of conversion to temperature is at most about 1%. Therefore, even if the temperature of the observation object changes by 1 ° C., the resistance changes only by 0.02%.

Further, in the conventional thermal infrared detector, since the obtained electric signal is extremely weak, the electric signal readout circuit is required to have a very high level of low noise, and the circuit scale is large. Was.

[0011] Further, it is originally desired that the infrared detector has higher detection sensitivity and higher S / N.

[0012] The above-mentioned situation is the same not only for infrared rays but also for other radiations.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and performs radiation detection with high detection accuracy, high sensitivity, and high S / N without the need for a cooler. It is an object of the present invention to provide an imaging device capable of well imaging with high sensitivity.

[0014]

According to a first aspect of the present invention, there is provided an imaging apparatus for converting radiation arriving within a predetermined range into an optical image. It is provided with an optical readout type radiation-displacement converter and a readout optical system. The light-reading type radiation-displacement conversion means includes a plurality of radiation absorption units arranged at a plurality of locations located within the predetermined range, each of which converts radiation received at the plurality of locations into heat, and the plurality of radiation absorption units. It includes a plurality of displacement units that convert each heat converted by the absorption unit into displacements at positions corresponding to the plurality of locations, and a plurality of reflection units whose inclinations change according to the displacements of the plurality of displacement units. The readout optical system includes a readout light supply unit that supplies readout light, a first lens system that guides the readout light to a plurality of reflection units of the light readout type radiation-displacement conversion unit, and a first lens system. A light beam restricting means for selectively passing only a desired light beam among the light beams of the read light reflected by the plurality of reflection portions after passing through the plurality of reflection portions; and the plurality of light beams in cooperation with the first lens system. And a second lens system that forms a conjugate position with the reflecting portion and guides the light beam that has passed through the light beam restricting means to the conjugate position. The reading light supply unit supplies the reading light such that the reading light passes through a region on one side of the optical axis of the first lens system. The light beam restricting means is configured such that a portion for selectively passing only the desired light beam is disposed in a region on the other side with respect to the optical axis of the first lens system. As described above, the light beam restricting means selectively passes only a desired light beam.
This is an expression including transmission and reflection.

According to the first aspect, radiation such as infrared rays, X-rays, and ultraviolet rays that reach a predetermined range is applied to the plurality of radiation absorbing sections, and the radiation is irradiated at the plurality of locations by the plurality of radiation absorbing sections. Each is absorbed and converted to heat. Each heat converted by the plurality of radiation absorption units is converted into a displacement at a position corresponding to the plurality of locations by the plurality of displacement units. And the inclination of a some reflection part changes according to the displacement of a some displacement part, respectively. That is, the radiation incident on each radiation absorbing section is converted into the inclination of each reflecting section according to the amount. On the other hand, readout light such as visible light or other light is emitted from the readout light supply unit to the plurality of reflection units via the first lens system. Therefore, the radiation applied to each radiation absorbing section is converted into the direction (reflection direction) of the readout light reflected by each reflecting section. The light beam bundle of the read light reflected by the plurality of reflecting portions passes through the first lens system, and only the desired light beam among the light beams after passing through the first lens system selectively passes through the light beam limiting means. The light beam that has passed through the light beam restricting means is positioned at a position conjugate with the plurality of reflecting portions formed by the first lens system and the second lens system.
Guided by the lens system. Therefore, the images of the plurality of reflecting portions due to the reading light are formed at the conjugate positions. Then, the individual light beams forming the image of each reflecting portion are
Since the amount of light is limited by the ray bundle restricting means by an amount corresponding to the direction of reflection by each reflector, the amount of light of each image of each reflector formed at the conjugate position is determined according to the inclination of each reflector.
That is, it differs according to the amount of radiation incident on the corresponding radiation absorbing section. In this way, the image of the radiation reaching the predetermined range is converted into an optical image by the readout light, and this optical image is formed at the conjugate position.

According to the first aspect, the radiation is converted into heat, the heat is converted into displacement, and the displacement is detected as a change in the amount of light by the readout optical system.
The radiation image is converted into an optical image and visualized. Since the above-described displacement detection by the readout optical system can be performed with high sensitivity, radiation can be detected with high sensitivity, and thus, an image due to radiation can be visualized with high sensitivity. Further, in the first embodiment, unlike the above-mentioned conventional thermal infrared detector, the radiation is not converted into a resistance value (electric signal) through heat, but the radiation is read out through heat and displacement, and the change of the read light is not changed. Therefore, there is no need to supply a current in the light-reading type radiation-displacement converter, and self-heating does not occur. Therefore, according to the first aspect, since only the heat due to the incident radiation is detected, the detection accuracy is improved, and the image due to the radiation can be converted into an optical image with high accuracy. Needless to say, in the first embodiment, a cooler required in the quantum infrared detector is not required, as in the above-described conventional thermal infrared detector. Further, in the first embodiment, since the radiation is not read out as an electric signal, the reading circuit for a weak electric signal which is required in the above-mentioned conventional thermal infrared detector becomes unnecessary.

According to the first aspect, since an optical image corresponding to the inclination of each reflecting portion is formed based on the readout light, using visible light as the readout light corresponds to a radiation image. This optical image can be observed with the naked eye. In the case of using a conventional infrared imaging device, it is impossible to observe an infrared image unless an image is displayed on a display device based on an electric signal or image data after conversion into an electric signal, In the first aspect, if visible light is used as the readout light, the radiation image can be observed with the naked eye without intervening electric signals or image data.

An imaging device according to a second aspect of the present invention comprises:
In the imaging device according to the first aspect, the readout light supply unit includes a readout light stop arranged on the one side. This readout light stop limits the light flux of the readout light.

It is preferable to provide a readout light stop as in the second embodiment because the contrast of the optical image is increased.

An imaging device according to a third aspect of the present invention comprises:
In the imaging device according to the first or second aspect, the light flux restricting unit has a property of transmitting light incident on a predetermined area and not transmitting light incident on an area around the predetermined area, The second lens system guides the light beam transmitted through the light beam limiting means to the conjugate position.

An imaging device according to a fourth aspect of the present invention comprises:
In the imaging device according to the first or second aspect, the light beam restricting unit has a characteristic of reflecting light incident on a predetermined area and not reflecting light incident on an area around the predetermined area, The second lens system guides the light beam reflected by the light beam restricting means to the conjugate position.

An imaging device according to a fifth aspect of the present invention comprises:
In the imaging device according to the first or second aspect, the light flux restricting unit has a property of not transmitting light incident on a predetermined area and transmitting light incident on an area around the predetermined area, The second lens system guides the light beam transmitted through the light beam limiting means to the conjugate position.

An imaging device according to a sixth aspect of the present invention comprises:
In the imaging device according to the first or second aspect, the light beam restricting unit has a property of not reflecting light incident on a predetermined area and reflecting light incident on an area around the predetermined area, The second lens system guides the light beam reflected by the light beam restricting means to the conjugate position.

The third to sixth aspects exemplify the light beam restricting means. In the third and fourth aspects, the light beam transmitted or reflected only in the predetermined area surrounded by the surrounding area is guided to the conjugate position to form the optical image. Conversely, in the fifth and sixth aspects, the light beam transmitted or reflected only in the surrounding area is guided to the conjugate position to form the optical image. Therefore, in the fifth and sixth aspects, the NA of light forming an optical image is higher than in the third and fourth aspects.
Therefore, the advantage that the resolution of the optical image is increased can be obtained.

It is to be noted that the imaging device according to any one of the first to sixth aspects may include an image pickup means for picking up the optical image. As described above, when the image pickup device for picking up an optical image formed by the readout optical system is provided, an image by radiation can be picked up in the same manner as a conventional infrared image pickup device.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an imaging device according to the present invention 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. However, in the present invention, the radiation may be X-rays, ultraviolet rays, or other various radiations other than infrared light, May be other light than visible light.

(First Embodiment) FIG. 1 is a schematic configuration diagram showing an imaging apparatus according to a first embodiment of the present invention. FIG. 2 is a diagram showing an optical readout radiation-displacement converter 100 used in the present embodiment, and FIG. 2A shows a state in which infrared rays i of the unit pixel (unit element) are not incident. FIG. 2B is a diagram schematically illustrating a cross section of a unit pixel in a state where infrared rays i are incident.

As shown in FIG. 1, the imaging device according to the present embodiment includes an optical readout radiation-displacement conversion device 100. As shown in FIG. 2, the conversion apparatus 100 includes a substrate 1 such as a silicon substrate that transmits infrared rays i,
And a supported portion 3 supported in a state of floating above the substrate 1 with a space 6 therebetween via the leg portion 2. The supported part 3 is
It has two membranes 4, 5 that overlap each other. The lower film 4 is an infrared absorbing portion that receives the infrared light i and converts it into heat. One end of each of the membranes 4 and 5 is supported via the leg portion 2 to form a cantilever. Membrane 4
The film 5 and the film 5 are made of different materials having different expansion coefficients, and form a so-called thermal bimorph structure. Therefore, in the present embodiment, the films 4 and 5 are:
It constitutes a displacement portion that displaces with respect to the substrate 1 in accordance with heat generated in the film 4 as an infrared absorbing portion. Lower membrane 4
If the expansion coefficient is larger than the expansion coefficient of the upper film 5, the heat causes the film to be curved upward and inclined as shown in FIG. 2B. The upper film 5 constitutes a reflecting portion that reflects read light (visible light or the like) j from above. For this reason, the film 5 as a reflection part receives the readout light j and reflects the received readout light in a reflection direction corresponding to the displacement of the films 4 and 5. Note that, in the present embodiment, the film 5 is parallel to the surface of the substrate 1 in a state where the infrared ray i is not received. However, the films 4 and 5 may be tilted in advance in a state where the infrared rays i are not received.

As can be seen from the above description, in this embodiment, the film 4 also serves as a part of the displacement part and the infrared absorbing part, and the film 5 also serves as the other part of the displacement part and the readout light reflecting part. are doing. However, these can also be constituted by separate films, respectively.

In this embodiment, the films 4 and 5 and the leg 2 are used as unit pixels (unit elements), and the pixels
They are arranged in a dimension.

The converter 100 can be manufactured using semiconductor manufacturing techniques such as film formation and patterning, sacrificial layer formation and removal, and the like.

Referring again to FIG. 1, the imaging device according to the present embodiment includes a reading optical system, a two-dimensional CCD 20 as an image pickup means, an observation device, in addition to the above-described light reading type radiation-displacement conversion device 100. An infrared imaging lens 30 that focuses infrared light from the heat source 31 as an object and forms an infrared image of the heat source 31 on the surface of the converter 100 on which the film 4 as an infrared absorbing unit is distributed. It is configured.

In this embodiment, the readout optical system includes an LD (laser diode) 10 as readout light supply means for supplying readout light, and a plurality of reflection portions of the conversion device 100 for reading light from the LD 10. 5 (film 5), and selectively passes only a desired light beam among the light beams of the readout light reflected by the plurality of reflectors 5 after passing through the first lens system 11. A second light beam restricting unit that forms a conjugate position with the plurality of reflecting units in cooperation with the first lens system, and guides the light beam that has passed through the light beam restricting unit to the conjugate position. Lens system 13
It is composed of CCD20 at the conjugate position
Are arranged, and the plurality of reflecting portions 5 and the plurality of light receiving elements of the CCD 20 are optically conjugated by the lens systems 11 and 13.

The LD 10 is arranged on one side (the right side in FIG. 1) with respect to the optical axis O of the first lens system 11, and supplies the reading light so that the reading light passes through the one side area. I do. In the present embodiment, the LD 10 is disposed near the focal plane of the first lens system 11 on the side of the second lens system 13, and the readout light passing through the first lens system 11 is converted into a substantially parallel light flux to form a plurality of reflection units. 5 is irradiated. In the present embodiment, the conversion device 100 includes the substrate 1
(In the present embodiment, parallel to the surface of the reflecting portion 5 when no infrared light enters) is disposed so as to be orthogonal to the optical axis O. However, it is not limited to such an arrangement.

The light beam restricting unit 12 is arranged such that a portion for selectively passing only the desired light beam is on the other side (left side in FIG. 1) with respect to the optical axis O of the first lens system 11. It is configured as follows.

FIG. 3 shows the light beam restricting unit 12. FIG.
FIG. 3A is a schematic plan view, and FIG. 3B is a schematic sectional view taken along line AA ′ in FIG. The light beam restricting unit 12 includes a light shielding plate 12b having an opening 12a.
It is configured as an aperture stop. Therefore, the light flux restricting portion 12 has a characteristic of transmitting light incident on the area of the opening 12a and not transmitting light incident on the surrounding area. In the present embodiment, when no infrared ray is incident on the infrared absorption section corresponding to any of the reflection sections 5 and the surfaces of all the reflection sections 5 are parallel to the surface of the substrate 1, all the reflection sections 5 The beam bundle is limited so that the position of the converging point where the light beam reflected by the above (the bundle of the individual light beams reflected by each reflecting unit 5) is converged by the first lens system 11 and the position of the opening 12a substantially coincide. The part 12 is arranged. Also,
The size of the opening 12a is determined so as to substantially match the size of the cross section of the light beam bundle at the converging point. However, it is not limited to such an arrangement and size. For example, the position of the opening 12a is such that, for example, when infrared light having a relatively high intensity is incident and all the reflecting portions 5 are inclined to the greatest extent, the light beam reflected by all the reflecting portions 5 becomes the first light beam.
It may be arranged so as to substantially coincide with the position of the condensing point condensed by the lens system 11. In this case, the CCD 20
The light / dark state of the optical image formed thereon will be reversed.

In the present embodiment, the area of the opening 12a of the light beam restricting section 12 is a portion for selectively passing (transmitting in the present embodiment) only the desired light beam. The lens system 13 guides the light beam transmitted through the opening 12a to the conjugate position.

According to the present embodiment, the light beam 41 of the reading light emitted from the LD 10 enters the first lens system 11 and becomes a substantially parallel light beam 42. Next, the substantially collimated light beam 42 is incident on all the reflection portions 5 of the conversion device 100 at an angle with respect to the normal line of the substrate 1.

On the other hand, a heat source 31 is
Is focused, and an infrared image of the heat source 31 is formed on the surface of the converter 100 on which the film 4 as the infrared absorbing portion is distributed. As a result, infrared light is incident on the film 4 as the infrared absorbing part of the supported part 3 of each pixel of the conversion device 100. This incident infrared ray is absorbed by the film 4 as an infrared ray absorbing portion and converted into heat. In accordance with the heat generated in the film 4, the films 4 and 5 as the displacement portions constituting the cantilever are curved upward and inclined. For this reason, each reflecting portion 5 is inclined with respect to the surface of the substrate 1 by an amount corresponding to the amount of infrared light incident on the infrared absorbing portion 4 corresponding to the reflecting portion 5.

Now, it is assumed that no infrared rays are incident on all the infrared absorbing sections 4 and all the reflecting sections 5 are parallel to the substrate 1. The light beam 42 incident on the plurality of reflectors 5 is reflected by the plurality of reflectors 5 to become a light beam 43, and is again the first light beam 43.
This time, the light enters the lens system 11 from the side opposite to the side of the LD 10 and becomes a condensed light beam 44. Collect light. As a result, the condensed light beam 44 passes through the opening 12a, becomes a divergent light beam 45, and enters the second lens system 13. The divergent light beam 45 incident on the second lens system 13 is converted into, for example, a substantially parallel light beam 46 by the second lens system 13 to generate a C light beam.
The light enters the light receiving surface of the CD 20. Here, the plurality of reflection units 5
And the light receiving surface of the CCD 20 are conjugated by the lens systems 11 and 13, so that the images of the respective reflecting portions 5 are formed on the corresponding portions on the light receiving surface of the CCD 20, respectively. Is formed as an optical image.

Now, it is assumed that a certain amount of infrared light is incident on the infrared absorbing portion 4 corresponding to a certain reflecting portion 5, and the reflecting portion 5 is inclined with respect to the surface of the substrate 1 by an amount corresponding to the amount of incident light. .
The individual light beams incident on the reflecting portion 5 of the light beam 42 are reflected by the reflecting portion 5 in directions different from each other by the amount of the inclination, so that after passing through the first lens system 11, the individual light beams correspond to the amount of the inclination. The focus point (ie, the aperture 12)
The light is condensed at a position deviated from the position a), and is blocked by the light flux limiting unit 12 by an amount corresponding to the amount of inclination.
Therefore, the amount of light of the image of the reflecting portion 5 in the entire optical image formed on the CCD 20 decreases by an amount corresponding to the amount of inclination of the reflecting portion 5.

Therefore, the optical image formed by the read light on the light receiving surface of the CCD 20 reflects the infrared image incident on the conversion device 100. This optical image is
An image is captured by the CCD 20. It is preferable that the reflection section 5 of each pixel of the conversion device 100 corresponds to each pixel of the CCD 20. The optical image may be observed with the naked eye using an eyepiece or the like without using the CCD 20.

According to the present embodiment, the infrared rays are converted into heat, the heat is converted into displacement, and this displacement is read out and detected as a change in the amount of light by the optical system.
The infrared image is converted into an optical image and visualized. Since the displacement detection by the readout optical system described above can be performed with high sensitivity, infrared rays can be detected with high sensitivity,
Thereby, an infrared image can be visualized with high sensitivity. Further, in the present embodiment, the infrared ray is not converted into a resistance value (electric signal) through heat, but is converted into a change in readout light through heat and displacement.
No current needs to flow at 00, and no self-heating occurs. Therefore, according to the present embodiment, since heat is detected only by the incident infrared light, the detection accuracy is improved, and the infrared image can be accurately converted to an optical image. Needless to say, in the present embodiment, the cooler that was required in the quantum infrared detector is not required. Further, in the present embodiment, since infrared light is not read out as an electric signal, a readout circuit for a weak electric signal which is required in the above-described conventional thermal infrared detector becomes unnecessary.

In FIG. 1, a conversion device having only a single pixel (element) is used as the conversion device 100.
If a photodetector having only a single light receiving unit is used instead of the two-dimensional CCD, a radiation detection device as a so-called point sensor for infrared rays can be configured.

(Second Embodiment) An imaging apparatus according to a second embodiment of the present invention is different from the first embodiment in that the light beam limiting unit 12 shown in FIG. The other configuration is the same as that of the first embodiment. 4A is a schematic plan view of the light beam restricting unit 50, and FIG. 4B is a schematic cross-sectional view along the line BB 'in FIG. 4A.

The light beam restricting section 50 reverses the relationship between transmission and light blocking for the readout light transmitting area (the area of the opening 12a) and the readout light shielding area (the area around the opening 12a) of the light beam restricting section 12. It is a thing. Specifically, the light beam limiting unit 50 includes a transparent plate 50 that transmits readout light.
has a structure in which a light shielding film 50b is formed on a. The region of the light shielding film 50b corresponds to the region of the opening 12a of the light beam restricting unit 12. Therefore, the light beam limiting unit 50
Has the property of not transmitting light incident on the region of the light shielding film 50b and transmitting light incident on the surrounding region.

In the present embodiment, the area around the light-shielding film 50b of the light-beam-flux restricting section 50 is a portion that selectively allows only the desired light beam to pass (in the present embodiment). The second lens system 13 guides the light beam transmitted through the area around the light shielding film 50b to the conjugate position.

According to this embodiment, the brightness of the optical image formed on the light receiving surface of the CCD 20 is inverted from that of the first embodiment, but is basically the same as that of the first embodiment. It operates and provides similar advantages.

In the first and second embodiments, an LD (laser diode) is used as the reading light supply means, but an LED (light emitting diode) may be used instead.

(Third Embodiment) FIG. 5 is a schematic configuration diagram showing an imaging device according to a third embodiment of the present invention. 5, elements that are the same as elements in FIG. 1 or that correspond to elements in FIG.

This embodiment is different from the first embodiment in that the reading light supply means is replaced with the LD 10 and
The only difference is that the xenon lamp 60, the condenser lens 61, the reflection mirror 62, and the illumination light diaphragm 63 are used.
The illumination light stop 63 has an opening 6 at a position corresponding to the readout light emission position of the LD 10 in FIG.
This is configured by providing 3a. However,
The illumination light stop 63 may be configured to be independent of the light beam restriction unit 12.

The light beam 4 emitted from the xenon lamp 60
7 is condensed by the condenser lens 61 and reflected by the reflection mirror 62, and then condensed on the opening 63a. The divergent light beam 41 emitted from the opening 63a is transmitted to the first lens system 11
And is made substantially parallel. The subsequent operation is the same as in the first embodiment.

According to this embodiment, the same advantages as those of the first embodiment can be obtained. It is not always necessary to provide the illumination light stop 63, but it is preferable to provide the illumination light stop 63 in order to increase the contrast of the optical image on the CCD 20. Note that also in the first embodiment, LD1
A readout light stop may be provided in front of 0.

(Fourth Embodiment) FIG. 6 is a schematic configuration diagram showing an imaging device according to a fourth embodiment of the present invention. 6, elements that are the same as elements in FIG. 1 or that correspond to elements in FIG. 1 are given the same reference numerals, and overlapping descriptions are omitted.

This embodiment is different from the first embodiment in that a light beam restricting unit 70 shown in FIG. 7 is used instead of the light beam restricting unit 12, and the second lens system 13 and The only difference is that the arrangement of the CCD 20 is changed. FIG.
FIG. 7A is a schematic plan view of the light beam restricting unit 70, and FIG. 7B is a schematic cross-sectional view along the line CC ′ in FIG. 7A.

The light beam limiting unit 70 is configured to use reflected light instead of transmitted light. Specifically, the light beam restricting unit 70 includes a transparent plate 70a that transmits readout light.
It has a structure in which a reflective film 70b is formed thereon. The area of the reflection film 70b corresponds to the area of the opening 12a of the light beam restricting unit 12. Therefore, this light flux limiting unit 70
Has a characteristic of reflecting light incident on the region of the reflective film 70b and not reflecting light incident on the surrounding region.

In the present embodiment, the area of the reflection film 70b of the light beam restricting section 70 is a portion for selectively passing (in the present embodiment, reflecting) only the desired light beam. The two-lens system 13 guides the light beam reflected by the light shielding film 70b to the conjugate position.

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

(Fifth Embodiment) The imaging apparatus according to the fifth embodiment of the present invention is different from the imaging apparatus according to the fourth embodiment in that the light beam limiting unit 70 is replaced with the light beam limiting unit 70 shown in FIG.
And the other configuration is the same as that of the sixth embodiment. FIG. 8A is a schematic plan view of the light beam restricting unit 80, and FIG.
It is an outline sectional view along the DD 'line in the inside.

The light beam restricting unit 80 determines the reflection and transmission of the read light reflection area (area of the reflective film 70b) and the area where the read light is not reflected (area around the reflective film 70b) of the light beam restrictor 70. It is the reverse of the relationship.
Specifically, the light beam restricting unit 80 has a structure in which an opening 80b is provided in a reflecting plate 80a that reflects read light. The area of the opening 80b is the reflection film 7 of the light beam
0b. Therefore, the light flux restricting section 80 has a characteristic of not reflecting light incident on the area of the opening 80b and reflecting light incident on the surrounding area.

In the present embodiment, the area around the opening 80b of the light beam restricting section 80 is a portion for selectively passing (reflecting in the present embodiment) only the desired light beam. The second lens system 13 guides the light beam reflected from the area around the opening 80b to the conjugate position.

According to the present embodiment, the brightness of the optical image formed on the light receiving surface of the CCD 20 is inverted from that of the fourth embodiment, but is basically the same as that of the fourth embodiment. It operates and provides similar advantages.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments. For example, the configuration of the optical readout radiation-to-displacement converter is not limited to the configuration described above.

[0064]

As described above, according to the present invention,
By detecting radiation having high detection accuracy, sensitivity, and high S / N without the need for a cooler, an image of the radiation can be accurately and highly sensitively imaged.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an imaging device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an optical readout type radiation-to-displacement converter used in the first embodiment.

FIG. 3 is a diagram showing a light beam restricting unit used in the first embodiment.

FIG. 4 is a diagram showing a light beam restricting unit used in a second embodiment of the present invention.

FIG. 5 is a schematic configuration diagram showing an imaging device according to a third embodiment of the present invention.

FIG. 6 is a schematic configuration diagram showing an imaging device according to a fourth embodiment of the present invention.

FIG. 7 is a diagram showing a light beam restricting unit used in the fourth embodiment.

FIG. 8 is a diagram illustrating a light beam restricting unit used in a fifth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 4 Film which doubles as a part of displacement part and infrared absorption part 5 Film which doubles as a part of displacement part and reflection part 10 Light source (LD) 11 1st lens system 12, 50, 70, 80 Ray bundle limiting part Reference Signs List 13 second lens system 20 two-dimensional CCD 30 imaging lens for infrared ray 60 xenon lamp 61 condenser lens 62 reflection mirror 63 readout light stop 100 light readout radiation-displacement converter

Claims (6)

[Claims] 1. An imaging device for converting radiation arriving within a predetermined range into an optical image, wherein the radiation is arranged at a plurality of positions located within the predetermined range, and receives radiation received at the plurality of positions, respectively. A plurality of radiation-absorbing units that convert heat, a plurality of displacement units that convert each heat converted by the plurality of radiation-absorbing units into displacements at positions corresponding to the plurality of locations, and a plurality of displacement units. An optical read-out radiation-displacement conversion unit including a plurality of reflectors whose inclination changes in accordance with the displacement; a read-out light supply unit for supplying read-out light; A first lens system for guiding to the plurality of reflecting portions, and selectively passing only a desired light beam among the light beams of the readout light reflected by the plurality of reflecting portions after passing through the first lens system. Light flux limiting means A readout optical system comprising: a second lens system that forms a conjugate position with the plurality of reflecting portions in cooperation with the first lens system and guides a light beam that has passed through the light beam limiting means to the conjugate position. When;
Wherein 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, An imaging apparatus, wherein a portion for selectively passing only a light beam is arranged in a region on the other side with respect to an optical axis of the first lens system. 2. The imaging apparatus according to claim 1, wherein said readout light supply means has a readout light stop arranged on said one side. 3. The light beam restricting means has a characteristic of transmitting light incident on a predetermined area and not transmitting light incident on an area around the predetermined area. 2. The light beam transmitted through the beam limiting means is guided to the conjugate position.
Or the imaging device according to 2. 4. The light beam restricting means has a characteristic of reflecting light incident on a predetermined area and not reflecting light incident on an area around the predetermined area. The imaging device according to claim 1, wherein the light beam reflected by the light beam restricting unit is guided to the conjugate position. 5. The light beam restricting means has a property of not transmitting light incident on a predetermined area and transmitting light incident on an area around the predetermined area. 2. The light beam transmitted through the beam limiting means is guided to the conjugate position.
Or the imaging device according to 2. 6. The light beam restricting means has a characteristic of not reflecting light incident on a predetermined area and reflecting light incident on an area around the predetermined area. The imaging device according to claim 1, wherein the light beam reflected by the light beam restricting unit is guided to the conjugate position.