JP2565708B2 - Radiation image information recording / reading device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a radiation image information recording / reading device for recording transmitted radiation image information of an object and then reading the image information as an electrical image signal, and more particularly, The present invention relates to a radiation image information recording / reading apparatus which stores and records the above-mentioned radiation image information on a stimulable phosphor sheet that stores radiation energy and enables tomographic panoramic imaging to be performed easily.

(Prior Art) Radiation (X-ray, α-ray, β-ray, γ-ray,
When irradiated with ultraviolet rays, electron beams, etc.), a part of the energy of this radiation is accumulated in the phosphor, and when the phosphor is subsequently irradiated with excitation light such as visible light, the phosphor is converted according to the accumulated energy. Indicates stimulated emission. A phosphor having such properties is called a stimulable phosphor (stimulable phosphor).

Using this stimulable phosphor, the radiation image information of a subject such as a human body is once recorded on a stimulable phosphor sheet (hereinafter referred to as a stimulable phosphor sheet), and this is scanned by excitation light to emit light. A method has been proposed in which exhaust emission is performed, this stimulated emission light is photoelectrically read to obtain an image signal, and this image signal is processed to obtain a radiation image of a subject with good diagnostic suitability (for example, JP-A-55-55). No. 12429, No. 55-116340, No. 55-16347
No. 2, No. 56-11395, No. 56-104645, etc.). This final image can be played back as a hard copy or
You can play it on T. In such a radiation image information recording / reproducing method, the stimulable phosphor sheet does not finally record the image information but temporarily holds the image information in order to give an image to the final recording medium as described above. Therefore, the stimulable phosphor sheet may be used repeatedly, and if used repeatedly, it is very economical.

To reuse the stimulable phosphor sheet as described above,
The radiation energy remaining in the stimulable phosphor sheet after the stimulated emission light is read is determined by, for example, JP-A-56-11392.
As described in JP-A Nos. 56-12599, the sheet may be irradiated with light or heat to release the residual radiographic image, and the stimulable phosphor sheet may be used again for radiographic image recording.

Therefore, the applicant has proposed a circulating conveyance unit for conveying a stimulable phosphor sheet capable of accumulating and recording a radiation image along a predetermined circulating passage, and irradiating the sheet with radiation through the subject in the circulating passage. An image recording unit that accumulates and records radiation image information of a subject on the sheet, and an excitation light source that emits excitation light that scans the sheet on which the radiation image information is accumulated and recorded in the image recording unit in the circulation path And an image reading section comprising photoelectric reading means for reading an stimulating light emitted from a sheet scanned by the excitation light to obtain an image signal; and performing image reading in the image reading section in the circulation path. And an erasing section for emitting radiation energy remaining on the sheet prior to image recording on the sheet after the image formation. Look, and the stimulable phosphor sheet previously proposed a radiation image information recording and reading apparatus designed to use repeatedly cycled between the respective units (JP 59-
192240). According to the radiation image information recording and reading apparatus having such a structure, recording and reading of radiation image information can be continuously and efficiently performed.

By the way, conventionally, as one of the special radiographic image capturing methods, tomographic panoramic image capturing of dentition, upper and lower measuring jawbone, indirect jaw, facial region, etc. has been known. Conventionally known X
A tomographic panoramic radiography apparatus using a radiographic film is arranged such that the cassette containing the X-ray photographic film and the radiation source are opposed to each other through a subject, and a slit is provided between the radiation source and the cassette. While linearly irradiating the cassette with the radiation, the radiation source and the cassette are swiveled around the subject while maintaining a predetermined positional relationship, and at the same time, the cassette is moved in a cycle with the swiveling of the radiation source to move the slice of the subject. The radiation image information of the surface is recorded.

As a recording medium in such tomographic panoramic radiography, it is of course possible to use a stimulable phosphor sheet instead of the X-ray photographic film. However, the above-mentioned JP-A-59-19
As in the radiation image information recording / reading apparatus of No. 2240, the stimulable phosphor sheet is circulated and conveyed, and the image recording section, the reading section,
When sequentially sending to the erasing section for use, it is necessary to rotate these sections and a large sheet circulating / conveying means around the subject. In order to realize this, a turning mechanism that is large and consumes extremely large energy is required, and therefore such a thing is practically impossible.

Therefore, the present applicant previously noted that in the radiation image information recording / reading device of the type in which the stimulable phosphor sheet is circulated and conveyed as described above, the radiation image information recording / reading that facilitates the above-mentioned tomographic panoramic imaging is performed. A device was proposed (Japanese Patent Laid-Open No. 61-103143). As described above, this radiation image information recording / reading device maintains a positional relationship between a radiation source that irradiates the radiation of the subject while rotating around the subject and the radiation source that is sandwiched between the subject and maintains the positional relationship. The slit is arranged so as to swirl around the subject together with the radiation source, has a slit on the side surface facing the radiation source, and further the slit while moving the stimulable phosphor sheet in synchronization with the swirling of the radiation source inside the slit. The tomographic panoramic radiographing and recording section having a radiographing box for accumulating the radiation incident through the sheet on the sheet, and the radiographic image information is read from the sheet on which the radiographic panoramic tomographic image is accumulated and recorded in the radiographing and recording section. An image reading unit such as the above, an erasing unit also as described above, and the above-mentioned image reading by loading the sheet from the photographing box of the photographing recording unit. And a erasing unit, and a reading / erasing unit provided with a circulating / conveying means for carrying the photographic recording / recording unit to the photographing box again. The photographing / recording unit is rotatably attached to the reading / erasing unit. It is a feature.

According to the radiation image information recording / reading device having such a configuration, the above-mentioned tomographic panoramic imaging can be easily performed.

(Problems to be Solved by the Invention) However, even in the radiation image information recording / reading apparatus having the above-mentioned configuration, the stimulable phosphor sheet is circulated and conveyed along the circulation path in the reading / erasing unit, and then sequentially transferred to the reading unit and the erasing unit. Since it is sent, there is a problem that the device tends to increase in size.

Further, in this apparatus, since it is necessary to transfer the stimulable phosphor sheet between the tomographic panoramic radiography recording section and the reading / erasing section which are configured independently of each other, the mechanism of the sheet transfer section becomes complicated. There is also the drawback of doing so.

Therefore, it is an object of the present invention to provide a radiation image information recording / reading device capable of easily performing tomographic panoramic imaging on a stimulable phosphor sheet and having a simplified mechanism and small size. It is a thing.

(Means and Actions for Solving the Problems) A radiation image information recording and reading apparatus according to the present invention provides an image recording unit, a reading unit,
Instead of sequentially sending to the erasing section, a small recording / reading unit equipped with a flexible belt-shaped stimulable phosphor sheet and having image recording, reading, and erasing functions is provided, and this unit is moved together with the radiation source. It is characterized in that it is configured to perform tomographic panoramic radiography, specifically, a radiation source that irradiates the subject with radiation, and a radiation source movement that causes the radiation source to rotate around the subject. Means, the recording / reading unit, and the unit around the subject so that the stimulable phosphor sheet in the photographing position maintains a predetermined positional relationship with respect to the subject and the rotating radiation source. It is composed of a unit moving means for turning.

The recording / reading unit for panoramic imaging described above has a housing that houses the stimulable phosphor sheet inside, and a slit that is arranged in a portion of the housing that faces the radiation source and that allows the radiation to pass therethrough. The slit plate having and the stimulable phosphor sheet in this housing are held at an imaging position where the radiation that has passed through the subject and passed through the slit is linearly irradiated, and the slit is synchronized with the rotation of the radiation source. An image recording unit that stores and records transmission radiation image information of a subject on the sheet while moving in a substantially right-angled direction, and excitation on a stimulable phosphor sheet that is arranged in the housing and has radiation image information stored and recorded. An image reading unit that irradiates light and photoelectrically reads the stimulated emission light emitted from the stimulable phosphor sheet by the irradiation of the excitation light to obtain an image signal, and is also arranged in the housing. In addition, before the image recording is performed on the stimulable phosphor sheet after the stimulated emission light is read, an erasing section for releasing the residual radiation energy on the sheet is provided. .

The recording / reading unit for panoramic photography is turned by the unit moving means so as to move in a direction substantially perpendicular to the direction in which the slit extends.

(Examples) Hereinafter, the present invention will be described in detail based on examples shown in the drawings.

FIG. 1 is a schematic side view showing a radiation image information recording and reading apparatus according to one embodiment of the present invention. This radiation image information recording / reading apparatus includes a substantially U-shaped rotating arm 61 supported by a supporting arm 60, and one end 61a of the rotating arm 61 and the other end 61b thereof.
A recording / reading unit arranged at a position where a radiation source 10 such as an X-ray tube fixed with its side facing and a radiation 12 such as X-rays emitted from the radiation source 10 and transmitted through a subject 11 are irradiated.
It has 20 and.

The central portion of the rotating arm 61 is a connecting portion 61c, and the rotating arm 61 is rotatably supported by the support arm 60 via the connecting portion 61c in the direction of arrow C in the drawing. An arm drive means 63 composed of a motor or the like is fixed to the tip of the support arm 60, and the rotary arm 61 is rotated in the direction of the arrow C by the drive means 63. A slit plate 62 is attached to the radiation source 10 so that the subject 11 is not irradiated with the excessive radiation 12. The slit plate 62 is made of a material that absorbs the radiation 12, and has a thin slit (not shown) extending in the vertical direction in the drawing.

Next, the recording / reading unit 20 will be described in detail with reference to FIGS. 2 and 3 showing the planar shape and the front shape thereof. The endless recording belt 1 which is a flexible stimulable phosphor sheet in which a stimulable phosphor layer is formed on substantially the entire outer surface of the endless recording belt 1 has two rollers 41, 42 in a light-shielding casing 5.
It is stretched over a first roller portion 43 formed of and a second roller portion 46 formed of two rollers 44 and 45 which are arranged at a predetermined distance from the first roller portion 43. The rollers 41, 42, 44 are driven rollers that rotate with the movement of the recording belt 1, while the roller 45 is a drive roller connected to a rotating shaft 48a of a motor 48 by a power transmission means 47 such as a belt or a chain. is there. When the drive roller 45 is rotated, the recording belt 1 is rotationally moved in the arrow direction in FIG.

The recording / reading unit 20 is fixed to the other end 61b of the rotary arm 61 so that the recording belt 1 stretched between the roller portions 43 and 46 faces the radiation source 10. Then, on the surface of the casing 5 facing the radiation source 10, the first portion is formed in the central portion.
A slit plate 6 having a slit 65A extending vertically in the figure
5 is installed. This slit plate 65 is
It is formed from a lead plate or the like that absorbs 2.

When the radiation source 10 is activated after the subject 11 is placed below the connecting portion 16c, that is, between the radiation source 10 and the recording / reading unit 20, the slit 11 passes through the subject 11.
The radiation 12 that has passed through A is linearly formed on the recording belt 1 (first
Irradiation is performed in a direction extending vertically in the figure). Thus radiation
When 12 is illuminated, the rotating arm 61 is rotated as described above. This causes the radiation source 10 to orbit around the subject 12, while the recording and reading unit 20 also rotates.
And turns around the subject 12 while maintaining a position facing the. At the same time, the drive roller 45 is rotated in the recording / reading unit 20, and the recording belt 1 is synchronized with the rotation of the rotating arm 61 (that is, in synchronization with the rotation of the radiation source 10).
It is rotated. Thereby, the subject of the linear radiation 12
The scanning speed with respect to 11 and the moving speed of the recording belt 1 become equal, and the radiation tomographic panoramic image information of the tomographic plane of the dentition of the subject 11, for example, is accumulated and recorded in the stimulable phosphor layer of the recording belt 1.

The distance between the two roller portions 43 and 46 is substantially equal to the length of one screen of the panoramic image recorded (captured) as described above. Therefore, the radiation image information is accumulated and recorded on the approximately half circumference portion of the recording belt 1 by one photographing. As described above, two rollers are used in this example.
The image recording unit 4 is set in the portion between 41 and 44.

The rotation of the arm 61 may be performed with the center of the subject photographing parts arranged in a circular shape as an axis (pantomography), or when the photographing part is not circular like a dentition during photographing. The axis of rotation may be moved so that the subject 11 is always irradiated with the radiation 12 from the positive direction (orthopantomography).

Although not shown in FIG. 1, an appropriate subject support section may be provided to prevent the subject 11 from moving during radiographic image capturing.

The recording belt 1 is continuously moved even after the photographing is completed. In this way, the portion of the recording belt 1 on which the image has been recorded is conveyed to the image reading unit 30 provided behind the recording belt 1 (on the right side in FIG. 2). A rotary encoder 39 is attached to the rotary shaft 48a of the motor 48, and movement and stop of the recording belt 1 are controlled based on the amount of rotation detected by the rotary encoder 39.

The image reading section 30 is provided with an excitation light source 21 such as a He-Ne laser that emits the excitation light 21A so as to extend in the width direction of the recording belt 1 (vertical direction in FIG. 3), and records the excitation light 21A. On the belt 1, there is provided a rotary polygon mirror 24 which is an optical deflector for performing main scanning in the width direction. Excitation light source 21
The excitation light 21A emitted from the mirror group 22 shown in FIG.
After the optical path is changed by, the light passes through an incident optical system 23 including a beam expander, a cylindrical lens, etc., and enters a rotating polygon mirror 24. The excitation light 21A reflected and deflected by the rotary polygon mirror 24 passes through a scanning optical system 25 composed of an fθ lens or the like as shown in FIG. 2, and is further passed through five mirrors 26a, 26b, 26c, 26d, and 26e. Is changed, the light is incident on the recording belt 1 on the rear peripheral surface of the roller 42, and the main scanning is performed on the belt 1 as described above. The above mirror
26c is a cylindrical mirror that focuses the excitation light 21A only in a plane parallel to the paper surface of FIG. 2, and in the above-mentioned optical system, the action of the mirror 26c and the cylindrical lens in the incident optical system 23 causes Rotating polygon mirror 24
Even if the shaft is shaken, the surface is tilted, or the like, the pitch unevenness of the scanning lines does not occur on the recording belt 1. When the main scanning of the excitation light 21A is performed, the recording belt 1 is rotated by the driving roller 45 at a constant speed. As a result, the sub-scanning of the excitation light 21A is performed, and the portion of the recording belt 1 on which the radiation image information is stored is irradiated with the excitation light 21A over substantially the entire surface.

From the excitation light irradiation portion of the recording belt 1, a stimulated emission light 40 having a light amount corresponding to the accumulated and recorded image information is generated, and the stimulated emission light 40 is detected by the photoelectric reading means 27. The photoelectric reading means 27 in the present device is a long photomultiplier (photomultiplier tube) 28 having a light receiving surface extending over the length of the main scanning line in the main scanning direction, and the photomultiplier 28 receiving light. A filter that is provided on the surface and selectively transmits only the stimulated emission light 40 and cuts the excitation light 21A reflected on the belt surface from entering the photomultiplier 28.
29A, and a light guide mounted on the filter 29A and transmitting the stimulated emission light 40 to the photomultiplier 28.
It consists of 29B. A mirror 29C is arranged at a position where the excitation light scanning line on the recording belt 1 faces from the side opposite to the photoelectric reading means 27. The mirror 29C efficiently reflects the stimulated emission light 40 emitted to the mirror side toward the light incident end of the light guide 29B.

The photomultiplier 28 is, for example, a fourth
As shown in FIG. 5 and FIG. 5, it has an electrode structure called a Venetian blind type, the main body 28A has a cylindrical shape, and the photocathode 28b extends along the main body 28A so as to face the light receiving surface 28a. Is provided, and a plurality of (13 in this example) dynodes 28c are superposed via an insulating member 28d on the lower side in the figure, and are fixed by pins 28e to form a multiplication section 28f. Each of the dynodes 28c is formed in a blind shape by bending a large number of U-shaped cuts in one conductive plate. Below the multiplication part 28f in the figure, a shield electrode 28d is provided with a pin 28 through an insulating member 28d.
e, and an anode 28h is provided in the shield electrode 28g. Each of these electrodes is connected one-to-one with each terminal of a terminal group 28i provided at a side end of the main body 28A. Note that the shield electrode 28g is not necessarily provided.

FIG. 6 shows an electric circuit for driving the photomultiplier 28 to take out a photoelectric output, and each part of the photomultiplier 28 is denoted by the same reference numeral as in FIGS. Hereinafter, the operation of the photomultiplier 28 will be described with reference to FIG. A negative high voltage is applied to the photocathode 28b via the negative high voltage applying terminal 35an. The negative high voltage thus applied to the negative high voltage applying terminal 35a is applied to the dynode 28c divided by the bleeder resistor group 35b. The shield electrode 28g is grounded, and the anode 28h is connected to the bleeder resistor group 35b via the resistor 35c and to the amplifier 35d. The photoelectrons emitted from the cathode 28b under the irradiation of the stimulated emission light 40 hit the dynode 28c when flowing toward the anode 28h, whereby secondary electrons are emitted from the dynode 28c. As described above, photoelectrons are successively multiplied by each dynode 28c, and the current obtained thereby is input to the amplifier 35d. In this way, the photoelectrically converted image information is taken out as an analog electric signal (read image signal) S from the output terminal 35e of the amplifier 35d.

A part of the recording belt 1 from which the image reading has been completed is further moved by the driving roller 45 and sent to the erasing unit 33.
The erasing section 33 includes a box 31 and three erasing light sources 32 as an example arranged inside the box 31. The erasing light source 32 composed of a fluorescent lamp or the like mainly emits light in the excitation wavelength region of the stimulable phosphor layer of the recording belt 1, and the radiation energy remaining in the phosphor layer after image reading is reduced by the recording belt. When the light 1 is irradiated on the entire image forming area while being moved, the light is emitted from the phosphor layer. The portion of the recording belt 1 that has been erased by the erasing section 33 is again sent to the photographing position and is ready for new recording. A lead plate 2 for shielding the radiation 12 is arranged in the recording / reading unit 20, and the radiation 12 emitted at the time of photographing is applied to the recording belt 1 in the image reading unit 30 and the erasing unit 33 described above. The radiation 12 is prevented from adversely affecting the image reading unit 30 and the erasing unit 33.

As the erasing light source 32, a tungsten lamp, a halogen lamp, an infrared lamp, a xenon flash lamp, etc. as shown in JP-A-56-11392 can be arbitrarily selected and used in addition to the above-mentioned fluorescent lamp. In addition, the erasing unit 33
Besides being composed of a large number of erasing light sources 32 as described above, it may also be composed of a planar light source such as a panel in which LEDs (Light Emitting Diodes) are arranged two-dimensionally or an EL (electroluminescence) plate. .

The output signal (read image signal) S of the amplifier (log amplifier) 35d is, as shown in FIG.
And digitized by the A / D converter 70. The digital read image signal D indicating the radiation tomographic panoramic image information of the subject 11 thus obtained is sent to the image reproducing device 72 through the image processing device 71 that performs gradation processing, frequency processing, and the like. The image reproducing device 72 is composed of, for example, a CRT, an optical scanning recording device, or the like, and displays an image carried by the image signal D, that is, a radiation tomographic panoramic image of the subject 11 accumulated and recorded on the recording sheet 1 on the screen. Or play it as a hard copy.

In the recording / reading unit 20 described above, the recording belt 1 is stretched between two sets of roller portions 43 and 46 arranged at intervals substantially equal to the length of one screen of the radiation image, and image recording is performed on the front side of the recording belt 1. Since the image reading is performed on the rear side, the unit 20 is placed in a small housing 5 having vertical and horizontal dimensions slightly larger than the recording area of one image screen.
It contains all the mechanisms. By using the recording and reading unit 20 having such a configuration,
The entire radiation image information recording / reading device can also be made small and lightweight. A so-called Bucky device may be provided on the front side of the recording belt 1 of the recording / reading unit 20, the grid absorbing absorption of scattered radiation from the subject 11 and a means for reciprocating the grid in addition to the grid.

As described above, the recording / reading unit 20 is integrated in the small housing 5 which is slightly larger than the recording area of one image screen. However, as such a small recording / reading unit, another one is used. You may be asked. Hereinafter, another example of a small recording / reading unit that can be used in the apparatus of the present invention will be described with reference to FIG. In the light-shielding housing 229 of the recording / reading unit 200 of FIG. 7, a first winding shaft 222 and a second winding shaft 223 are provided.
And are arranged in parallel at a distance from each other. These take-up shafts 222 and 223 are rotated in the clockwise and counterclockwise directions in the drawing by motors 224 and 225 as sheet feeding means, respectively. On the first winding shaft 222,
As described above, one end side of the stimulable phosphor sheet 226 capable of accumulating and recording the radiation image information is wound. The stimulable phosphor sheet 226 is formed in a long strip shape by using a flexible support, and the other end is the second winding shaft 223.
And is wound around the second winding shaft 223 from the other end side. In addition, the stimulable phosphor sheet 22
6 is a roller 201, 202, 2 between the two winding shafts 222, 223.
It is stretched over 03,204,205. A slit plate 206 having a slit 206A is arranged at a position facing the stretched sheet 226. Here, the stimulable phosphor sheet 226 is a stimulable phosphor having a flexible support through which the radiation 12 radiated from the left side of the drawing is satisfactorily transmitted on the left side of the drawing, and which is carried on the support. The layers are arranged so that they are located on the right side. This recording / reading unit 200 is the first
It can be used in place of the recording / reading unit 20 described above in the apparatus shown in the figure, and in that case as well, the radiation image recording (imaging) of the subject is described above by the radiation 12 passing through the slit 206A of the slit plate 206. It is performed in the same manner as the case. That is, in this example, the image recording unit 280 is set in the portion between the rollers 203 and 204. The stimulable phosphor sheet 226 is provided with a lead plate 299 on the back side of the portion irradiated with the radiation 12, and the lead plate 299 is such that the radiation 12 emitted at the time of photographing adversely affects the image reading unit 250 and the like. To prevent.

An image reading unit 250 is provided on the right side of the stimulable phosphor sheet 226 at a position close to the second winding shaft 223. This image reading unit 250 is provided with an excitation light source 2 such as a semiconductor laser.
51, a mirror 253 that reflects the excitation light 252 emitted from the excitation light source 251, a beam expander 254 that adjusts the beam diameter of the excitation light 252, and a deflection deflection of the excitation light 252 on the sheet 226 (more specifically, the storage property From the rotating polygon mirror 255, which is an optical deflector for one-dimensionally scanning on the phosphor layer), the scanning optical system 256 including an fθ lens, and the long photomultiplier 28 similar to that shown in FIG. The photoelectric reading means 27, the driving roller 205 as a sub-scanning means which is composed of a nip roller sandwiching the stimulable phosphor sheet 226 and is rotated at a constant speed, and a long length arranged along the long length photomultiplier 28. It is composed of a condensing reflection mirror 257.

When the radiation tomographic panoramic image of the subject is accumulated and recorded on the stimulable phosphor sheet 226, the drive roller 205 is rotated so that the portion of the sheet 226 facing the slit 206A moves from the upper side to the lower side in the drawing. It is transported at a constant speed. At this time, the second winding shaft 223 is rotated and the stimulable phosphor sheet 226 is wound around the shaft 223. An appropriate load is applied to the first winding shaft 222 side by a known means, so that the stimulable phosphor sheet 226 is always kept in a tensioned state. While the sheet 226 is conveyed, the excitation light source 251 and the rotary polygon mirror 255 are operated to generate the excitation light 252.
Main scans on the sheet 226 in the width direction (direction perpendicular to the paper surface of FIG. 7). Of this stimulable phosphor sheet 226,
From the portion irradiated with the excitation light 252, stimulated emission light 40 that carries the radiation image information accumulated and recorded on the sheet 226 is emitted. This stimulated emission light 40 is reflected directly or on the reflection mirror 257 for condensing, and is guided by the light guide 29B and the filter.
It is efficiently detected by the photomultiplier 28 via 29A. The excitation light 252 is main-scanned as described above, and the stimulable phosphor sheet 226 is conveyed and sub-scanned as described above.
The stimulated emission light 40 is two-dimensionally read from 6.

The portion of the stimulable phosphor sheet 226 for which image reading has been completed as described above is wound around the second winding shaft 223 and stored there. At the same time, another part of the stimulable phosphor sheet 226 wound around the first winding shaft 222 is
Since it is stretched between 03 and 204, new radiation image information can be recorded on this portion of the stimulable phosphor sheet 226 in the same manner as described above. In this way, the radiation image information recording / reading is performed using the substantially entire length of the stimulable phosphor sheet 226, and all the sheets 226 wound around the first winding shaft 222 and stored are on the second winding shaft 223 side. When it has been sent out, the motor 224 is driven and the first winding shaft 222 is rotated clockwise in the drawing. Thereby, the second
All of the stimulable phosphor sheets 226 wound on the winding shaft 223 after the image reading is returned to the first winding shaft 222 side, but at this time, between the roller 201 and the first winding shaft 222. The stimulable phosphor sheet 226 passes through the arranged erasing section 260, and the sheet 226 undergoes image (afterimage) erasing. As an example, the erasing section 260 is composed of an erasing light source 261 arranged below the stretched sheet 226 in the figure, and a reflecting member 262.
The erasing light source 261 is composed of, for example, a fluorescent lamp, and the sheet 226.
The light is mainly emitted in the excitation wavelength region of the stimulable phosphor, and is turned on when the sheet 226 is returned to the first winding shaft 222 side. After the image is read, the stimulable phosphor sheet 22
The radiation energy remaining in 6 is emitted from the sheet 226 by irradiating the sheet 226 with the above-mentioned light.

In this way, the first winding shaft 222 stores the stimulable phosphor sheet 226 from which the image (afterimage) has been erased to such an extent that the radiation image information can be recorded again. It is possible to repeat the panorama image recording (shooting) and reading.

The erasing light source 261 of the erasing unit 260 is a stimulable phosphor sheet.
It may be turned on when 226 is delivered from the first winding shaft 222 for recording radiation image information. When the stimulable phosphor sheet 226 has been stored in the first winding shaft 222 for a long period of time after being subjected to image (afterimage) erasing in the erasing section 260, the phosphors are stored in the sheet 226. Radioactive elements such as ²²⁶ Ra contained as impurities in the sheet and radiation energy due to environmental radiation (which is a component that becomes noise to the stored record information) may be stored. This radiation energy is also released by irradiating 226 with erase light.

In the above example, the first winding shaft 2 is attached to the stimulable phosphor sheet 226.
While the image is recorded (photographed) and read alternately during winding from the second winding shaft 223 to the second winding shaft 223, only the image recording is performed first, and then the second winding shaft 223 is moved to the first winding shaft 223. When rewinding the stimulable phosphor sheet 226 to 222, image reading and erasing may be performed.

(Effects of the Invention) As described in detail above, in the radiation image information recording / reading apparatus of the present invention, the recording / reading unit formed by using the flexible belt-shaped stimulable phosphor sheet is formed in a very small size together with the radiation source. Since the device is swiveled around the subject, this device does not require a large-sized transport means for circulating and transporting the stimulable phosphor sheets one by one, and the stimulable phosphor sheet is provided between the revolving part and the fixed part. A complicated mechanism for delivering and receiving is also unnecessary, and the mechanism can be made extremely simple and compact and lightweight.

[Brief description of drawings]

FIG. 1 is a schematic side view of an apparatus according to an embodiment of the present invention, and FIGS. 2 and 3 are II-II line and II line of FIG. 1, respectively.
A plane sectional view and a vertical sectional view of a portion taken along the line I-III, and FIGS. 4 and 5 are respectively a partially cutaway perspective view and a side sectional view of a photomultiplier used in the recording / reading unit. FIG. 6 is a circuit diagram showing an electric circuit of the photomultiplier, and FIG. 7 is a schematic plan view showing another example of the recording / reading unit used in the apparatus of the present invention. 1,226 …… Storable phosphor sheet 4,280 …… Image recorder, 5,229 …… Case 10 …… Radiation source, 11 …… Subject 12 …… Radiation, 20,200 …… Record reading unit 21,251 …… Excitation light source, 21A, 252 ...... Excitation light 24,255 …… Rotating polygon mirror 28 …… Photomultiplier 30,250 …… Image reading unit, 32,261 …… Erasing light source 33,260 …… Erasing unit, 40 …… Stimulated emission light 43,46 …… Roller unit, 42,205 ...... Drive roller 48,224,225 …… Motor, 61 …… Rotary arm 63 …… Arm drive means, 65,206 …… Slit plate 65A, 206A …… Slit, S …… Read image signal

Continuation of front page (56) Reference JP-A-58-67246 (JP, A) JP-A-58-200269 (JP, A) JP-A-61-103143 (JP, A)

Claims (3)

(57) [Claims] 1. A radiation source for irradiating a subject with radiation, a radiation source moving means for rotating the radiation source around the subject, and a flexible belt-shaped stimulable phosphor sheet housed inside. A case, a slit plate disposed in a portion of the case facing the radiation source and having a slit for passing the radiation in a part, a stimulable phosphor sheet in the case,
While holding the shooting position where the radiation that has passed through the subject and passed through the slit is linearly irradiated, while moving in a direction substantially perpendicular to the slit in synchronization with the rotation of the radiation source,
An image recording unit for accumulating and recording transmitted radiation image information of the subject on the sheet, irradiating excitation light onto a stimulable phosphor sheet arranged in the housing and accumulating and recording radiation image information, and irradiating this excitation light An image reading unit that photoelectrically reads the stimulated emission light emitted from the stimulable phosphor sheet to obtain an image signal, and is arranged in the housing, and the accumulation after the readout of the stimulated emission light is performed. Recording / reading unit for panoramic photography, which is provided with an erasing unit for releasing the residual radiation energy on the sheet before the image recording is performed on the luminescent sheet, and the recording / reading unit is provided at the photographing position. The stimulable phosphor sheet maintains a predetermined positional relationship with the subject and the rotating radiation source, and the unit moves in a direction substantially perpendicular to the direction in which the slit extends. A radiographic image information recording / reading apparatus, comprising unit moving means for rotating the object around the subject so as to move. 2. The roller according to claim 1, wherein said stimulable phosphor sheet is formed in an endless belt shape, and said endless belt-shaped stimulable phosphor sheet is disposed at a distance substantially equal to the length of one image. When a portion where the radiation image of the stimulable phosphor sheet is accumulated and recorded is sent out from the shooting position and another portion of the sheet is sent to the shooting position, 2. The radiation image information recording / reading apparatus according to claim 1, wherein the excitation light is sub-scanned by this movement to read the stimulated emission light. 3. One end and the other end of the stimulable phosphor sheet are wound around first and second winding shafts, respectively, and the sheet is stretched at a photographing position between the two shafts. 2. The constitution is such that the stimulative emission light is read by sub-scanning the excitation light by winding up and moving the stimulable phosphor sheet with. Radiation image information recording / reading device.