JP2000261723A - Optical system for radiation image pickup device and radiation image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To release constraints on design and to expand the degree of freedom in a device movable mode by providing plural devices which receive a radiation as visible light and pick up an image and distributing the visible light to plural image picking up means without making it parallel beams of light once. SOLUTION: When exposure by a radiation source is performed, X-rays transmit an object to be detected and converted into an I.F. (image intensifier) output image by an I.I. part 4, and the I.I. output image is made to pass through a post-lens group 11 and reflected by 90o by a movable distributed mirror 14. The X-rays pass through a pre-lens group 13, are led to the secondary lens 8a of an I.I. indirect camera 8 and are formed on the camera 8 by the lens 8a. Thus, it is possible to realize a form that distributes an I.I. output optical image to a TV camera 7 and the camera 8. Because an image pickup device uses a mirror as both for a folded mirror and a mirror for distribution by adopting the form, the device can be made small-sized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical radiation imaging apparatus for imaging a radiation characteristic distribution in a subject using general radiation such as X-rays, and more particularly, to an image intensifier (hereinafter referred to as "intensifier"). This device is referred to as “II device”). I. The X-ray shadow image converted into a visible light image by the TV camera or I.D. I. The present invention relates to a radiation imaging apparatus that provides a diagnostic image by observing with an indirect camera, and a radiation imaging optical system provided in the radiation imaging apparatus.

[0002]

2. Description of the Related Art Conventionally, as an imaging apparatus using radiation such as X-rays, I.P. I. There is something called. FIG. I. 1 schematically shows the general overall structure of FIG.

[0003] In FIG. I. The apparatus 100 is provided with a radiation source 1 for irradiating a subject 2 with radiation such as X-rays, a bed 3 on which the subject 2 is placed, and a bed 3 provided below the bed 3. Converting the radiation that has passed through the subject into visible light I. I. Part 4 and this I.D. I. And an optical system 6 that receives the visible light converted by the unit 4 and forms an image on the imaging devices 7 and 8. These components are supported by the holding means 5 so that the angle and the position can be changed.

By the way, this I.I. I. In the optical system 6 provided in the device 100, for example, a TV camera or an I.P. I. It is necessary to use a plurality of types of imaging devices such as an indirect camera. Therefore, the I.D. shown in FIG. I. In the device 100, I.I. I. Part 4
Converted by I. I. By bending the output light image in two directions, imaging by a plurality of types of imaging devices is possible.

More specifically, as shown in FIGS. 5 (a) and 5 (b), the optical system 6 I. I. converted by the unit 4. I. The output light image is received, and the parallel light beam is converted to the secondary lens group 6.
3 or 64, and a primary lens group 61 composed of lens balls 6a to 6c and an I.P. I. A drive mirror 62 for bending the output light image at right angles to the optical axis L thereof. The driving mirror 62 is rotated about the optical axis L by a driving unit (not shown) to change the bending direction of the visible light in two directions.

According to such an optical system 6, I.P. I. I incident from part 4 I. The output light image is output from the primary lens group 61.
Are collimated, and are bent by the driving mirror 62 in the direction of the imaging device 7 or 8. I. The output light image is formed on the imaging device 7 or 8 by the secondary lens group 63 or 64 provided in front of the imaging device 7 or 8.

However, in recent years, high image quality in radiation imaging has been demanded, and it has become necessary to increase the number of lens balls, and it is not necessary to increase the distance d in the optical axis L direction. Tend not to be.

On the other hand, since the radiation imaging apparatus requires imaging from all angles and directions at the time of examination, it is necessary to operate the bed 3 on which the subject 2 is placed in all angles and directions. It is desirable that the optical system 6 that moves together is as small as possible.

As means for solving such a problem, for example, there is one shown in FIGS. 6 (a) and 6 (b). That is, as shown in the figure, I.P. is placed between the lens ball 6a of the front lens group and the lens ball 6b of the rear lens group that constitute the primary lens group 61. I. There is an optical system having a primary lens group that employs a so-called folded lens group in which a mirror 9 that bends the output light image by 90 degrees or more is disposed.

According to this method, the distance d can be reduced without reducing the number of lens balls constituting the primary lens group. In this folded primary lens system, when a plurality of imaging devices are provided as described above, a configuration as shown in FIG. That is, the primary lens group 61 is arranged so that the visible light beam bent by the mirror 9 is distributed to the plurality of imaging devices 7 and 8.
Driven mirror 62 between the lens and the secondary lens group 63 or 64
Is provided.

FIGS. 7 (a) and 7 (b) show an I.D. having a large output light image diameter in order to realize a high definition diagnostic image. I. It is explanatory drawing which shows typically the general whole structure of the apparatus 100 'using. In this apparatus 100 ', a primary lens group having a long focal length is required as the diameter of the output light image increases, and the distance d in the direction of the optical axis L becomes considerably large as it is. The necessity of using the optical system 19 adopting the system is great. In addition, I.P. I. The portion 4 'tends to increase in the direction of the optical axis L, and accordingly, d of the optical system 6' needs to be further reduced.

[0012]

However, in an optical system for an X-ray diagnostic apparatus in which two or more imaging devices are mounted as shown in FIG. 6, the distance in the optical axis direction is increased by employing a folded primary lens. On the other hand, d can be reduced, but on the other hand, since two mirrors, the mirror 9 and the driving mirror 62, are required, there is a problem that the space is increased by this amount and the apparatus becomes large as a whole.

Further, in such a configuration, the I.P. I. Since the output light image is bent in the z-direction (the depth direction in FIG. 6A) by the driving mirror 62, as shown in FIG. 7A or FIG.
There is a problem that the size is increased in the direction and the size is increased in the y direction.

Further, the optical system 6 'shown in FIGS. 7A and 7B has one more mirror than the optical system 6 shown in FIG. 4, so that an indirect camera is combined with the optical system 6'. In some cases, to use in the same situation as the device 100,
It is necessary to provide another mirror in the combination part of the indirect camera in the optical system 6 ', and the optical system 6' is further enlarged.

Therefore, due to the above-mentioned effects, when the optical system is mounted on the holding device and the couch device, the operating range of the holding device and the couch portion must be limited and special installation conditions are required due to the problem of interference with external objects. There was a case.

Further, as described above, in the conventional structure shown in FIG. 6, I.P.M. is placed between the primary lens group 61 and the secondary lens groups 63 and 64 provided in each of the imaging devices 7 and 8. I.
In order to arrange the driving mirror 62 for distributing the output light image,
At least the distance between the primary lens group 61 and the secondary lens groups 63 and 64 (hereinafter, referred to as "tandem distance") is extended by the space of the mirror 62, and the image forming performance of the optical system (especially (Shading) is deteriorated.

In this regard, preventing such shading deterioration results in an increase in the diameter of the primary lens group 61 and an increase in the size of the mirrors 9 and 62, and a reduction in the distance d in the tube axis direction by the folded primary lens. In addition to offsetting the merits, there is a concern that the size may be increased in the y direction orthogonal to the tube axis direction.

Therefore, the present invention has been made in view of the above-mentioned problems, and I.I. I. In a radiation imaging apparatus, while enabling various imaging by a plurality of types of imaging devices,
Provides an optical system that can be downsized without deteriorating the imaging performance of the optical system, and alleviates design constraints when mounting it on holding devices and couch devices through downsizing of the optical system. Accordingly, it is an object of the present invention to provide a radiation imaging apparatus capable of expanding the degree of freedom in moving the apparatus.

[0019]

According to the present invention, there is provided an optical system for a radiation imaging apparatus comprising a plurality of imaging means for receiving radiation as visible light and imaging the radiation. There is provided a means for distributing the visible light to the plurality of imaging means without temporarily converting the visible light into a parallel light flux.

According to another aspect of the present invention, there is provided an optical system for a radiation imaging apparatus for imaging radiation as visible light, wherein a rear lens group disposed on the side where the visible light is incident, and a rear lens group disposed between the rear lens group and the rear lens group. A front lens group disposed on the side from which the visible light transmitted through the rear lens group is emitted, and the rear lens group and the front lens group. A primary lens group to be converted,
A distribution mirror that is disposed in the primary lens group and bends the visible light passing through the primary lens group in a direction orthogonal to the optical axis thereof, and turning the distribution mirror to change the bending direction Drive means for rotating the optical axis.

According to these inventions, a distributing mirror is provided between the front lens group and the rear lens group, whereby the I.V. I. In order to adopt a so-called folded method in which the output light image is bent, compared with a conventional primary lens group in which lens balls constituting the primary lens group are linearly arranged, the optical axis (I.I. The distance (height) can be reduced.

Further, according to the present invention, by rotating the distributing mirror by the driving means, I.I. I. Since the output light image can be bent in multiple directions, one I.P.M. I. An output light image can be incident, and imaging can be performed by a plurality of imaging devices installed in each front lens group.

Further, by using both the mirror for the folded type primary lens and the mirror for distribution, the number of mirrors can be reduced, and the tandem distance can be shortened by the reduced mirror space. Without deteriorating the imaging performance (particularly shading) of the optical system, it is possible to avoid the enlargement of the primary lens and the size of the mirror, and to reduce the size of the entire optical system.

Further, if the present invention is applied, I.I. I. Are output to the plurality of imaging means without temporarily converting the output light image into a parallel light flux. I. Output light image can be distributed,
Since a secondary lens is not required, a more miniaturized optical system can be realized.

As a result, according to the present invention, a TV camera or an I.D. I. In an optical system for an X-ray diagnostic apparatus to which two or more imaging devices such as an indirect camera are attached, I.D. I. While taking advantage of downsizing in the tube axis direction,
Even in the direction in which the tube axis is bent and the direction in which the tube is bent, the size can be reduced as compared with an optical system employing a conventional folded primary lens.

Further, according to the present invention, by realizing the miniaturization, it is possible to relax a special limitation in mounting the optical system on the holding device and the bed device.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Configuration of Imaging Apparatus) Hereinafter, a radiation imaging apparatus according to a preferred embodiment of the present invention will be described with reference to the drawings. FIGS. 1A and 1B schematically show the overall configuration of an imaging device 10 according to the present embodiment.

In FIG. 1, an imaging device 10 includes a subject 2
A source 1 for exposing X-rays to a subject, a bed 3 on which a subject 2 is placed, and a bed 3 are arranged so as to face the source 1 with the bed 3 interposed therebetween. I. I. Conversion into an output light image (visible light) I. Part 4; I. I. from part 4 I. An optical system 16 for condensing and bending the output light image; I. TV camera 7 or I.P. I. It is schematically composed of an indirect camera 8 and holding means 5 for holding each of these devices.

I. I. As shown in FIG. 2A, the unit 4 includes an input phosphor screen 4a that receives X-rays emitted from the radiation source 1 and transmitted through the subject 2 and emits photoelectrons, and a rear part of the input phosphor screen 4a. Provided, and converts the electron image formed by the accelerated photoelectrons into a visible light image. I. And an output fluorescent screen 4b for outputting as an output light image.

As shown in FIGS. 2A and 2B, the optical system 16 constitutes a folded system as a whole. I. The rear lens group 11 disposed on the side receiving the output light image and the I.P.
I. A distribution mirror 14 for bending the output light image in a direction orthogonal to the tube axis L;
I. Driving means 15 for rotating the bending direction of the output light image,
Bent I. I. It comprises two sets of front lens groups 12 and 13 arranged around a driving mirror 14 so that an output light image can be emitted to the outside.

In detail, I.I. I. The output light image passes through the rear lens unit 11 and I. TV with output light image distribution mirror 14
Camera 7 or I. I. Reflected in the direction of the indirect camera 8,
After passing through the front lens groups 12 and 13, the secondary lens groups 17 and 18
To the TV camera 7 by the secondary lens groups 17 and 18.
Or I. I. An image is formed on the indirect camera 8.

The distribution mirror 14 is rotatably supported by a rotating shaft 14a. The rotating shaft 14a passes through a lower portion of the casing 16a and is connected to a gear 14b provided at a lower portion of the casing 16a. . The driving means 15 includes a mirror rotation motor 15 and a belt 15b for transmitting the rotation force from the gear 15a of the mirror rotation motor 15 to the gear 14b.

In this embodiment, as the image pickup means,
TV camera 7 and I.P. I. The case where the indirect camera 8 is used will be described, but the present invention is not limited to this, and a well-known imaging unit can be employed. In particular,
I. I. The indirect camera 8 is an I.D. I. TV camera can be employed.

(Operation and Function of Imaging Apparatus) In the imaging apparatus 10 having such a configuration, for example, an operator operates a button (not shown) for executing X-ray irradiation to capture an image by the TV camera 7. Is selected, the distribution mirror 14 rotates so that the reflection surface of the distribution mirror 14 faces the direction of the TV camera 7. That is, the mirror rotation motor 15 is operated in conjunction with the button, and the rotation force from the gear 15a directly connected to the mirror rotation motor 15 is transmitted by the belt 15b and transmitted to the gear 14b. This allows the gear 14b
In other words, the distribution mirror 14 rotates about the tube axis L via the rotation axis 14a, and the reflection surface faces the direction of the TV camera 7 (shown by a solid line in FIG. 2A).

In this state, when the irradiation by the radiation source 1 is performed, the X-rays pass through the subject 2 and the I.D. I. Unit 4 where the I.I. I. The light is converted into an output light image and is incident on the optical system 16. And I. I. The output light image passes through the rear lens group 11 of the primary lens group 19 and passes through the distribution mirror 14.
Is reflected at 90 degrees, passes through the front lens group 12, is guided to the secondary lens 7a of the TV camera, and is
An image is formed on the camera 7.

Next, the operator sets the I.D. I. When the imaging by the indirect camera 8 is selected, the reflection surface of the distribution mirror 14 is set to I.D. I. Distribution mirror 1 so as to face indirect camera 8
4 rotates. That is, the mirror rotation motor 15 is operated in conjunction with the button, the distribution mirror 14 connected to the mirror rotation motor 15 rotates about the tube axis L, and the reflection surface changes to I.V. I. The camera is turned to the direction of the indirect camera 8 (illustrated by a dotted line in FIG. 2A).

In this state, when the irradiation by the radiation source 1 is performed, the X-rays pass through the subject 2 and pass through the I.D. I. In part 4, I.I.
I. Is converted into an output light image. I. The output light image passes through the rear lens group 11, is reflected by the distribution mirror 14 at 90 degrees, passes through the front lens group 13, and passes through the I.I. I. The light is guided to the secondary lens 8a of the indirect camera 8, and is transmitted through the secondary lens 8a. I.
An image is formed on the indirect camera 8.

According to the image pickup apparatus 10 described above, the distribution mirror 14 between the rear lens group 11 and the front lens groups 12 and 13 in the folding type optical system 16 is a driving mirror. I. The output light image is transmitted to TV camera 7 and I.V. I. A mode of distribution to the indirect camera 8 can be realized.

According to this embodiment, according to the imaging apparatus 10,
The folding mirror and the distributing mirror can be shared, and the number of mirrors can be reduced, and the device can be downsized. In addition, since the number of mirrors is reduced, the distance between tandems can be reduced accordingly. By reducing the distance between the tandems, the rear lens group 11, the front lenses 12, 13 of the primary lens group 19 can be made small in diameter without deteriorating the shading, thereby also realizing the miniaturization of the apparatus. can do.

Further, in the image pickup apparatus 10, the distribution mirror for the folded system is a driving mirror, so that the TV camera 7 and the I.V. I. The mounting direction of the camera 8 is the same as that of the normal optical system, and it is possible to avoid an increase in the size of the camera 8 in the Y direction bent at 90 degrees or more.

For example, the optical system 16 as described above is
When the tube for irradiating the X-rays is mounted on an over-TUBE type bed apparatus which is arranged at the top of the bed section, a folded primary lens is used. I. Due to the downsizing in the tube axis direction, the necessity of mounting the bed part on the floor surface by raising the bed part is eased.

In the image pickup apparatus 10, a TV camera and an I.P. I. Since the mounting direction of the indirect camera to the optical system is the same as that of the normal optical system, the TV camera and the I.P. I. It is not necessary to have a bed with space for an indirect camera.

Further, in the image pickup apparatus 10, the I.D. I. Since it is miniaturized in the tube axis direction (L direction) and not enlarged in the direction (Y direction) bent at least 90 degrees from the tube axis direction, the tube for irradiating X-rays and the I.V. I. The use restriction in the examination in which the bed is moved up and down while the patient is moved to the position of the subject's head and feet is relaxed.

The effect of the optical system 16 is particularly effective in realizing a high-definition diagnostic image. I. I. large output light diameter I. In a system optical system for mounting a fluoroscopic TV camera and a high-definition TV camera dedicated to photographing, it is effective because it is possible to achieve both high definition of a diagnostic image and improvement of the degree of freedom of examination.

(Modification) In the above embodiment,
TV camera 7 and I.P. I. Although two types of imaging devices of the indirect camera 8 are provided, the present invention is not limited to this. By arranging three, four or more front lens groups and imaging devices radially at the center of the distribution mirror 14, it is possible to perform imaging by various methods.

For example, as shown in FIG. 3, three types of imaging devices can be provided in addition to a high-resolution camera 21 for high-resolution shooting. In this case, a third front lens group 22 is provided on the casing of the optical system 16 so as to be orthogonal to the tube axis, and the third front lens group 22
The high-resolution camera 21 is installed so as to face. Then, when performing high-resolution imaging, the mirror rotating motor 15 is driven so that the reflection surface of the distribution mirror 14 is directed toward the third front lens group 22.

[0047]

According to the optical system according to the present invention and the radiation imaging apparatus having the optical system, I.I. I. In a radiation imaging apparatus, it is possible to reduce the size of an optical system without deteriorating imaging performance while enabling various types of imaging by a plurality of types of imaging devices, and to a holding device and a bed device through miniaturization of an optical system. In mounting the device, it is possible to relax design restrictions and to increase the degree of freedom in the operation of the device.

[Brief description of the drawings]

FIG. 1 is a configuration diagram schematically showing an entire radiation imaging apparatus according to an embodiment of the present invention, wherein FIG. 1 (a) is a side view thereof, and FIG. 1 (b) is a front view seen from the z direction in FIG. FIG.

FIGS. 2A and 2B are configuration diagrams schematically showing an optical system according to an embodiment of the present invention, FIG. 2A is a side view thereof, and FIG. 2B is a cross-sectional view taken along line CC in FIG.

FIG. 3 is a sectional view showing a modified example of the optical system of the present invention.

FIG. I. FIG. 1 is a configuration diagram schematically showing the entire apparatus.

5 (a) and 5 (b) are schematic diagrams of an optical system in a case where a conventional normal folded type primary lens is not used, and FIGS. 5 (c) and 5 (d) are diagrams showing an I / O having a large output aperture. . I. 1 is a configuration diagram schematically showing an entire apparatus in which a conventional folded primary lens is combined with the apparatus.

FIG. 6 is a schematic view of an optical system employing a conventional folded primary lens.

FIG. I. FIG. 1 is a configuration diagram schematically showing the entire apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Source 2 Subject 3 Couch part 4 I. I. Part 5 Holding means 6, 16 Optical system 7 TV camera 7a Secondary lens group (for TV camera) 8 I. I. Indirect camera 8a Secondary lens (for II indirect camera) 10 Imaging device 11 Rear lens group 12 Front lens group (for TV camera) 13 Front lens group (for II indirect camera) 14 Movable distribution mirror 14a Rotating shaft 14b Gear 15 Mirror rotation motor 15a Gear 15b Belt

Claims (4)

[Claims] 1. An optical system for a radiation imaging apparatus comprising a plurality of image pickup means for receiving radiation as visible light and imaging the same, wherein the visible light is not converted into a parallel light beam, and the plurality of image pickup means are provided to the plurality of image pickup means. An optical system for a radiation imaging apparatus, comprising: means for distributing the visible light. 2. An optical system for a radiation imaging apparatus for imaging radiation as visible light, comprising: a rear lens group disposed on a side on which the visible light is incident; and at least two sets of the rear lens group. A front lens group disposed on the side from which the visible light transmitted through the rear lens group is emitted, and a primary lens group including the rear lens group and the front lens group, which converts the visible light into a parallel light flux. A distributing mirror disposed in the primary lens group and bending the visible light passing through the primary lens group in a direction perpendicular to the optical axis thereof; and rotating the distributing mirror to change the bending direction. An optical system for a radiation imaging apparatus, comprising: a driving unit configured to rotate the optical axis about the optical axis. 3. The radiation according to claim 2, wherein three or more sets of the front lens groups are provided, and the front lens groups are radially arranged around a rotation axis of the distribution mirror. Optical system for imaging devices. 4. A radiation source for irradiating the subject with the radiation, a bed on which the subject is placed, and a bed arranged to face the radiation source with the bed interposed therebetween. A conversion unit configured to convert the radiation into visible light, the optical system disposed at a position where the visible light converted by the conversion unit can be received by the rear lens group, and provided to face the front lens group, respectively. And a plurality of image pickup means for receiving the visible light beams emitted from the front lens group.
A radiation imaging apparatus comprising the optical system for a radiation imaging apparatus according to any one of claims 1 to 3.