JPH03121441A - Radiograph information reader - Google Patents

Abstract

PURPOSE:To speed up the superposing process by providing an image reading part in each accumulating type phosphon layer and carrying out parallel reading of radiograph information accumulated and recorded in each layer. CONSTITUTION:The accumulating phasphor layers 26A and 26B are each placed on one side and the other side of a belt 26 provided with light shielding property and with one radiation exposure, two pieces of radiograph information are each recorded in the accumulating phosphor layers 26A and 26B. Then, the image reading parts 51 to 56, 58, 59, 51' to 56', 58', and 59' which read the radiograph information accumulated and recorded in the accumulating phosphor layers 26A and 26B and erasing parts 60 and 60' which erase the residual radio graph of the accumulating phosphor layers 26A and 26B are provided exclusively for each of the accumulating phosphor layers 26A and 26B, and the two radio graph information are read out in parallel simultaneously. Thus, the superposing process can be carried out in a short reading time without carrying out the bothersome operation of extracting a sheet from a cassette.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention accumulates and records radiation image information on a stimulable phosphor sheet, then irradiates the same with excitation light, and generates images according to the accumulated and recorded image information. It relates to a radiation image information recording/reading device that detects photostimulated light and reads image information as an electrical image signal.More specifically, by overlapping stimulable phosphor sheets and photographing, images with good S/N can be obtained. The present invention relates to a radiation image information recording/reading device capable of obtaining signals.

(Prior art) When a certain type of phosphor is irradiated with radiation (X-rays, α-rays, β-rays, γ-rays, ultraviolet rays, electron beams, etc.), part of the energy of this radiation is accumulated in the phosphor. Then, when the phosphor is irradiated with excitation light such as visible light, the phosphor exhibits stimulated luminescence depending on the accumulated energy. A phosphor exhibiting such properties is called a stimulable phosphor (stimulable phosphor).

Using this stimulable phosphor, radiation image information of a subject such as a human body is recorded on a stimulable phosphor sheet (hereinafter referred to as a stimulable phosphor sheet), which is then scanned with excitation light and illuminated. A method has been proposed in which the stimulated emitted light is photoelectrically read to obtain an image signal, and the image signal is processed to obtain a radiographic image of a subject that is suitable for diagnosis (for example, Japanese Patent Application Laid-Open No. 1983-1981). No. 12429, No. 55-116340, No. 55-163472, No. 56-11395, No. 56-104645, etc.). This final image can be reproduced as a hard copy or on a CRT. In any case, in such a radiation image information recording and reproducing method, the stimulable phosphor sheet does not ultimately record image information, but temporarily stores image information in order to provide an image to the final recording medium as described above. Therefore, this stimulable phosphor sheet may be used repeatedly, and such repeated use is extremely economical.

In order to reuse the stimulable phosphor sheet as described above, the radiation energy remaining in the stimulable phosphor sheet after the stimulated luminescence light has been read can be absorbed by, for example,
As shown in No. 2, No. 56-12599, residual radiation images may be erased by irradiating the sheet with light or heat, and the stimulable phosphor sheet may be used again for recording radiation images.

On the other hand, a radiation image superposition process has been known for some time (for example, see Japanese Patent Laid-Open No. 11399/1983). Radiographic images are generally used for diagnostic and other purposes, and their use requires excellent detection of minute differences in radiation absorption of the subject. The degree of detection in a radiographic image is called contrast detectability or simply detectability, and it can be said that the higher the detectability, the higher the diagnostic performance and capability, and the radiological image has higher practical value.

Therefore, in order to improve diagnostic performance, it is desirable to increase this detection ability, but the most important factor that hinders this is various noises.

In a radiation image recording method using a stimulable phosphor sheet, the following noise is recognized to exist in the step of accumulating and recording a radiation image on the stimulable phosphor sheet and reading it out.

(1) Quantum noise of the radiation source (2) Noise due to unevenness in the phosphor coating distribution or phosphor particle distribution of the stimulable phosphor sheet (3) Excitation that causes the image stored and recorded on the stimulable phosphor sheet to emit stimulated light Optical noise (4) Electrical noise in the system that detects stimulated luminescent light and converts it into an electrical signal (5) Noise of stimulated luminescent light emitted from a stimulable phosphor sheet The superposition process eliminates these noises. This is a method that greatly reduces radiation absorption and makes it possible to clearly observe even the slightest radiation absorption difference in the subject in the final image, in other words, it greatly improves the detection ability.The general techniques and effects of superposition processing are as follows. It is.

Radiographic images are taken on multiple stacked stimulable phosphor sheets (
Accumulation recording) A plurality of image signals obtained by subjecting the plurality of sheets to reading processing are superimposed. Due to this,
It is possible to reduce the various noises mentioned above. In other words, the noises (1) to (5) described above often have different distributions for each sheet image, so by overlapping the images of these sheets, each noise is averaged and the overlapping process is performed. Noise becomes less noticeable in the image. In other words, an image signal with a good S/N ratio can be obtained. More specifically, noises (1) to (5) include many noises that can be approximated by Poisson statistics, and in particular, noise of the radiation source is one of the dominant factors in the noise of radiological images. This is an example. Assuming that the noise can be approximated by Poisson statistics, the two radiation images each have a signal S! of the same size! , S2 and noises Nl and N2, the magnitude of the signal and noise when the two images are superimposed is sl+sz for the signal and N12+N22 for the noise.

On the other hand, S
/N, the S/N of each image before superimposition is S 1 / N 1 and S z / N z, respectively, but by performing the superposition process, the S/N becomes (
S1+Sz )l N12 +N22, S/N
will improve. Furthermore, when performing superimposition processing, it is possible to optimize the S/N improvement by weighting each signal.

When a radiation image is finally displayed based on the image data that has been superimposed, it is preferable for diagnosis to perform gradation processing to improve the contrast of the image. It is also possible to perform so-called frequency emphasis processing that improves only specific frequency components, or to perform both. When superimposing image data, it is better to add or average image data obtained from a stimulable phosphor sheet closer to the radiation source with greater weight than to simply add or average each image data. However, good images can be obtained.

The optimal value of the weighting coefficient varies depending on the number of stacked stimulable phosphor sheets, the thickness of the stimulable phosphor sheets, and the like.

Conventionally, in order to actually perform this superimposition process, for example, two stimulable phosphor sheets were stacked in a cassette, the subject was photographed, and the two stimulable phosphor sheets were scanned in a normal manner. By sequentially performing the same reading process as the processing,
A method is used in which two sets of image signals are obtained.

(Problem to be solved by the invention) However, when photographing is carried out by stacking multiple stimulable phosphor sheets as described above, since the stimulable phosphor sheets are placed in one cassette, it is necessary to perform the reading process. When loading the cassettes into the reading device, it is necessary to reload these stimulable phosphor sheets into separate cassettes, which has the disadvantage that the work is very complicated and time consuming.

Furthermore, if a plurality of stimulable phosphor sheets are sequentially read as described above, the time required for the reading process will naturally increase.

Superimposition processing is an effective method for diagnosis, but as mentioned above, it has the disadvantage of being complicated and time-consuming.
It is rarely used in group medical examinations, etc.

Therefore, the present invention provides a practical radiation image information recording/reading system that uses a stimulable phosphor sheet to perform the above-mentioned superposition process in a short reading time without the need for complicated operations such as taking out sheets from a cassette. The purpose is to provide a device.

(Means and effects for solving the problem) The radiation image information recording/reading device of the present invention has a layer of stimulable phosphor as described above on one surface and the other surface of the belt having light-shielding properties. an image reading section configured to record radiographic image information on each of the two stimulable phosphor layers by one radiation exposure, and read the radiographic image information accumulated and recorded on the stimulable phosphor layer; As described above, an erasing unit for erasing the residual radiation image of the stimulable phosphor layer was provided for each of the two stimulable phosphor layers, so that the two radiation image information could be read simultaneously in parallel. More specifically, it is characterized by a band-shaped flexible belt made of a light-shielding material as described above, and a first belt formed on one surface and the other surface of this belt, respectively.
and a second stimulable phosphor layer, a belt feeding means for tensioning the belt at a predetermined position and transporting the belt in the longitudinal direction so as to be able to return to the tensioned position; an image recording unit that accumulates and records radiation image information on the first and second stimulable phosphor layers by irradiating radiation having image information to the first and second stimulable phosphor layers; Excitation light is irradiated from the excitation light irradiation means to the first stimulable phosphor layer after recording, and the stimulated luminescent light emitted from the liquid layer by the irradiation of the excitation light is read by the photoelectric reading means to obtain an image signal. a second image reading section that similarly reads radiation image information from the second stimulable phosphor layer to obtain an image signal; a first erasing section that releases radiation energy remaining in the first stimulable phosphor layer prior to recording an image on the first stimulable phosphor layer after reading; A second erasing section similarly releases the radiation energy remaining in the second stimulable phosphor layer, and the image signals obtained in the first and second image reading sections are sent to correspond to each other. The superimposition calculation unit adds signals for pixels.

Furthermore, when superimposing the stimulable phosphor sheets, the same type of stimulable phosphor sheets may be used.
As described in No. 1399, different 2N sheets with thicker phosphor layers and higher sensitivity to radiation are used for those located farther from the radiation source. May be used.

(Example) Hereinafter, the present invention will be described in detail based on an example shown in the drawings.

FIG. 1 shows a radiation image information recording/reading apparatus according to a first embodiment of the present invention. As an example, the apparatus of this embodiment includes a main body 20 and a radiation source storage section 30. As shown in the figure, a first winding shaft 22 and a second winding shaft 23 are arranged in parallel with each other with an interval between them within a casing 29 of the main body 20. These winding shafts 22.
23 are motors 2 which together with the shaft 22.23 and a roller 27.2g to be described later constitute a belt feeding means.
4.25, they are rotated in the directions of arrows A and B, respectively. One end side of a band-shaped flexible belt 26 made of black plastic, for example, PET, is wound around the first winding shaft 22 . This belt 26 is formed in the shape of a long belt with one end, and the other end is connected to the second winding shaft 23.
, and is wound onto the second winding shaft 23 from the other end side. Further, this belt 2B is stretched between rollers 27.28 between both winding shafts 22.23.

The upper and lower surfaces of the flexible belt 26 in the figure are respectively provided with first stimulable phosphor layers 26A on which radiation image information can be stored and recorded as described above.

A second stimulable phosphor layer 26B is formed.

A photographing stand 32 is provided at a position facing the belt 26 stretched between the rollers 27.2B.

The radiation source storage section 30 described above stores therein a radiation source 38 such as an X-ray tube, and this radiation source 33 faces the imaging table 32 . When radiographically photographing a subject (subject) 34, the subject 34 is placed, for example, on his back on the imaging table 32, and the radiation source 33 is activated in this state. As a result, the radiation 85 transmitted through the subject 34 is irradiated onto the stretched belt 2B, and a radiation image of the subject 34 is transferred to the first stimulable phosphor layer 26A carried on the belt 2B. Information is accumulated and recorded.

Furthermore, the radiation 35 that has passed through the first stimulable phosphor layer 28A and the belt 26 is irradiated to the second stimulable phosphor layer 28B on the back side of the belt 26, so that Radiographic image information of the subject 34 is also accumulated and recorded.

As is clear from the above description, in the apparatus of this embodiment, the image recording section 40 is composed of the imaging table 32 and the radiation source 33. Note that in this embodiment, the photographing table 32
A grid 91 for removing scattered radiation is arranged between the flexible belt 26 and the flexible belt 26 .

First stimulable phosphor layer 28A, second stimulable phosphor layer 2
The radiation image information accumulated and recorded in 8B is
is read as an electrical image signal by the image reading section and the second image reading section. The first image reading unit includes a laser light source 51, a light deflector 53 such as a polygon mirror that reflects and deflects a laser light 52 as excitation light emitted from the laser light source 51, and a light deflector 53 that reflects the deflected laser light 52. First stimulable phosphor layer 2BA on the upper surface side of the flexible belt 2B
Long mirrors 59A, 59B, and 59C are disposed between the mirror 59A and the optical deflector 53 to one-dimensionally scan the laser beam 52 to the first stimulable phosphor layer 26.
A scanning lens 5B that focuses on a small spot with a predetermined diameter at every scanning position on A, a motor 25 or 24 as a sub-scanning means that rotates at a constant speed while winding up the flexible belt 2B, and a stimulable fluorescence generated by a laser beam 52. A long photomultiplier 54 serving as a charge reading means is disposed so that its light receiving surface extends along the scanning line (main scanning line) on the body belt 26. A long light guide 55 is optically coupled to the light-receiving surface of the multiplier tube 54, and a filter (Fig. (not shown). After the radiation image information of the subject 34 is accumulated and recorded in the first stimulable phosphor layer 28A as described above, the belt 2B is moved at a constant speed to the left in the figure by rotating the motor 25. be done. At this time, the second winding shaft 23 is rotated and the belt 2
6 is wound around the shaft 23. Further, an appropriate load is applied to the first winding shaft 22 side by a known means, so that the belt 2B is always maintained in a tensioned state. belt 2
While B is transferred, the laser light source 51 and optical deflector 53 are activated, and the laser light 52 scans over the first stimulable phosphor layer 28A. This stimulable phosphor layer 28A,
From the location irradiated with the laser beam 52, stimulated luminescence light 5 carrying radiation image information accumulated and recorded in the liquid layer 26A is emitted.
6 is issued. This stimulated luminescence light 5B is guided by a light guide 55 and efficiently detected by a long photomultiplier tube 54. The main scanning of the laser beam 52 is performed as described above, and the belt 2B (that is, the stimulable phosphor layer 2
6A) is transferred and sub-scanned as described above, so that the stimulated luminescent light 5B (ie, radiation image information) is read two-dimensionally from the first stimulable phosphor layer 28A. The output Sl of the long photomultiplier tube 54 is transmitted to the reading circuit 5.
Sent to 7.

On the other hand, the 12 image reading sections have the second stimulable phosphor layer 26B.
Read the radiation image information recorded in the. This second
The elements constituting the image reading section are basically the same as those in the first image reading section described above, so in FIG.
(dash) is added and the explanation thereof will be omitted.

Note that the sub-scanning means of the second image reading section is also used as that of the first image reading section.

That is, by rotating the motor 25 or 24 and transporting the belt 2B, the second stimulable phosphor layer 26B is sub-scanned by the laser beam at 52 degrees.

Further, in this second image reading section, a single long mirror 59' is provided in order to reflect the deflected laser beam 52° toward the second stimulable phosphor layer 28B. . This second image reading section long photomultiplier tube 54
° output Sz (i.e. second stimulable phosphor layer 26
(indicating radiation image information recorded in B) is also sent to the reading circuit 57. The long photomultiplier tube is described in detail in, for example, Japanese Patent Laid-Open No. 16666/1983.

Next, the processing in the reading circuit 57 will be explained with reference to FIG. 2, which schematically shows its configuration. Long photomultiplier tube 5
4 is logarithmically amplified by a logarithmic amplifier 80 and then digitized by an A/D converter 81. The digital read image signal 1ogs1 thus obtained is temporarily stored in the frame memory 82, and then read out from there and input to the superimposition calculation circuit 83. Similarly, the output S2 of the long photomultiplier tube 54' is logarithmically amplified by a logarithmic amplifier 84 and then digitized by an A/D converter 85. Digital read image signal 1og obtained in this way
S2 is also temporarily stored in the frame memory 82, and then read out from there and input to the superimposition calculation circuit 83.

The superposition calculation circuit 83 receives two input image signals 1.
0g5l, IogS2 are weighted appropriately and added for each corresponding pixel, resulting in a digital addition signal 5add = a ・IogSl +b φIogSz
+c [a and b are weighting coefficients, and C is a bias component]. After this addition signal 5add undergoes image processing such as gradation processing and frequency processing in the image processing circuit 87,
It is sent to an image reproducing device 88 outside the recording/reading device and used for reproducing the radiation image. This playback device 88 is a CRT
It may be a display means such as, a recording device that performs optical scanning recording on a photosensitive film, or it may be replaced with a device that temporarily stores the image signal in an image file such as an optical disk or a magnetic disk. .

When performing the superposition operation as described above, the coefficients a1b and c
By appropriately determining , the obtained addition signal 5add gives
It is possible to obtain radiation image information with a high S/N ratio, that is, with good detectability. When performing this superimposition operation, it is necessary to perform addition between corresponding pixels as described above. To do this, for example, as shown in FIG. 1, a marker 92 is placed near the subject 34, and a signal indicating this marker 92 is used as a reference signal in both image signals log Sls Iog S2. All you have to do is perform alignment.

However, since the relative positional relationship between the phosphor layers 26A and 28B is fixed, if the readout position is always fixed, it is not necessarily necessary to use a marker to make the pixels correspond.

Note that the read image signal IogS1 or logs2 is not particularly sent to the superimposition calculation circuit 88, and these signals 10
It is also possible to reproduce a normal radiation image based on g5l or logS2, and for this purpose, these image signals 10g5l and +ogs2 may be recorded and stored in an image file on an optical disc or the like.

The portion of the belt 2B carrying the first and second stimulable phosphor layers 26A and 26B whose images have been read as described above is wound around the second winding shaft 23 and stored there. . At the same time, another part of the belt 2B that was wound around the first winding shaft 22 is stretched between the rollers 27 and 28, so that the stimulable phosphor layer 28A and the stimulable phosphor layer 28A carried on this part Radiographic image information can be recorded on 28B in the same manner as described above. In this way, radiographic image information is recorded over almost the entire length of the belt 26, and all of the belt 2B that has been wound and stored around the first winding shaft 22 is sent out to the second winding shaft 23. , the motor 24 is driven, and the first winding shaft 22 is rotated in the direction indicated by the arrow. As a result, the second winding shaft 231
;The belt 26 that has been wound is all attached to the first winding shaft 2.
At this time, the first erasing section 60 and the second erasing section 60° arranged near the roller 27 are returned to the belt 2 side.
B passes through the first and second belts carried on the V belt.
The stimulable phosphor layers 26A and 26B undergo image (afterimage) erasure. These erasing units BO 160° are composed of, for example, erasing light sources at and at' disposed above and below the stretched belt 2B, respectively. These erasing light sources 61.61° are composed of, for example, fluorescent lamps, etc., and mainly emit light in the excitation wavelength range of the stimulable phosphor, and are turned on when the belt 2B is returned to the first winding shaft 22 side. be done. The radiation energy remaining in the first and second stimulable phosphor belt layers 28A and 28B after the image reading is removed from the core layer 28 by being irradiated with the above light.
A.

Released from 28B.

In this way, the belt 2B carrying the stimulable phosphor layers 2eA and 26B, whose images (afterimages) have been erased to the extent that radiation image information can be recorded again, is mounted on the first winding shaft 22.
Since the images are stored, it becomes possible to repeat the above-described image recording (photographing) and reading using this belt 2B. In addition to the above-mentioned fluorescent lamp, the erasing light source B1.61' may include, for example, a tungsten lamp, a halogen lamp, an infrared lamp as shown in JP-A-56-11392,
A xenon flash lamp or the like may be optionally used.

Further, the erasing units eo and so' are constructed from the above-mentioned erasing light source, and also include, for example, an LED (Light Eii
ttlng D 1ode) may be constructed from a planar light source such as a panel or an EL (electro-luminescence) plate in which light beams (ttlng D 1ode) are two-dimensionally arranged.

In the above, a case has been described in which the radiation image information is stored and recorded in the stimulable phosphor layers 28A and 28B, and then immediately read by the image reading unit. It can also be used to record a large number of images one after another at a later date.

In other words, in this case, the entire portion of the belt 26 carrying the stimulable phosphor layers 26A and 26B on which images have been recorded is wound around the second winding shaft 23, and after a series of image recording is completed, , the belt 2B may be returned from the second winding shaft 23 to the first winding shaft 22 side, and at that time, the image reading section may read the image.

Next, a second embodiment of the present invention will be described with reference to FIG. Note that in FIG. 3, elements equivalent to those in FIG. 1 are given the same numbers, and explanations thereof will be omitted unless particularly necessary. In the apparatus shown in FIG. 3, the belt 12B is an endless belt, which is stretched in an annular manner between a pair of rollers 122 and 123, and the drive roller 123 is rotated by the motor 25, so that the image recording section, The images are sequentially sent to the image reading section and the erasing section. In this example,
A laser light source 51°, a light deflector 53', and the like constituting a second image reading section that reads radiation image information from the second stimulable phosphor layer 28B are arranged inside the belt 12B.

In this embodiment, a plurality of erasing light sources 61'' constituting the second erasing unit BO° are arranged inside the belt 12B.
Image-recordable stimulable phosphor layer 26 supported on 6
It is turned on when the part B is fed into the image recording section 40. On the other hand, the first erasing section B.

The erasing light source 61 constituting the image recording section 12 is turned on while the image-recordable stimulable phosphor layer 28A carried by the belt 12B is being conveyed toward the image recording section 40.

During this period, image reading is generally performed, so a suitable light shielding plate or a pair of nip rollers (not shown) is used to irradiate the light emitted by the erasing light source 61 onto the stimulable phosphor layers 28A and 28B before image reading. to avoid being

Furthermore, it is also possible to configure the apparatus so that the first and second image reading sections share part of the excitation light source, optical deflector, or other lenses, mirrors, and the like.

(Effects of the Invention) As explained in detail above, in the radiation image information recording/reading device of the present invention, the first and second stimulable phosphor layers are formed on one surface and the other surface of the flexible belt having light-shielding properties. By doing so, it is possible to simultaneously record (photograph) radiographic image information for overlay processing on these layers, and an image reading section is provided for each stimulable phosphor layer, so that the information stored and recorded in each layer can be recorded. Since the device is configured to read radiation image information in parallel, it is possible to quickly perform the superimposition process, and it can provide radiation images with a higher S/N ratio, that is, higher detectability, thereby preventing misdiagnosis. It is possible to obtain effects such as prevention of cancer and early detection of lesions, and at the same time, it is possible to significantly improve the efficiency of diagnostic work, especially in mass medical examinations.

[Brief explanation of drawings]

FIG. 1 is a schematic side view showing a first embodiment of the present invention; FIG. 2 is a block diagram showing the configuration of a radiation image information reading circuit of the above embodiment; FIG. 3 is a second embodiment of the present invention. FIG. 2 is a schematic side view showing the device. 20...Main body 22...First winding shaft 23...Second winding shaft 24.25...Motor 2B, 12B...Flexible belt 26A...First stimulable fluorescence Body layer 26B...Second stimulable phosphor layer 27...Roller 28...Drive roller 30...Radiation source storage section 32...Photographing table 8
3... Radiation source 34... Subject 35.
...Radiation 40...Image recording section 51,
51'...Laser light source 52.52'...Laser light 53.53°...Light deflector 54.54゛
... Photomultiplier tube 56.56' ... Stimulated luminescence light
57...reading circuit 60, BOo...erasing section
81.61'... Erasing light source 80.84... Logarithmic amplifier 81.85... A/D converter 82.8
B...Frame memory 83...Superposition calculation circuit 122...Roller, 123...Drive roller IogS1, IogSz=・Read image signal S add・
... Addition signal Fig. 1 Fig. 3 Fig. 2

Claims (3)

[Claims] (1) A band-shaped flexible belt made of a light-shielding material, and first and second stimulable phosphor layers formed on one surface and the other surface of this belt to store and record radiation image information, respectively. and a belt feeding means for tensioning the belt at a predetermined position and transporting the belt in the longitudinal direction so as to be able to return to the tensioned position; and first and second stimulable fluorescence in the tensioned portion of the belt. an image recording section that accumulates and records radiation image information in these stimulable phosphor layers by irradiating radiation having image information to body layers; a first image reading section that irradiates the stimulable phosphor layer with excitation light from an excitation light irradiation means and reads stimulated luminescence light emitted from the layer by the irradiation of the excitation light with a photoelectric reading means to obtain an image signal; , irradiating excitation light from an excitation light irradiation means to the second stimulable phosphor layer after the radiation image information has been accumulated and recorded, and converting the stimulated luminescence light emitted from the layer by the irradiation of excitation light into a photoelectron. a second image reading section that reads an image signal by a reading means; and a second image reading section that reads an image signal by a reading means; and a first erasing unit that releases radiation energy remaining in the stimulable phosphor layer; and an image reading unit that prints an image on the second stimulable phosphor layer after the image is read in the second image reading unit. a second erasing section that releases radiation energy remaining in the stimulable phosphor layer prior to recording; and each image signal obtained in the first and second image reading sections. A radiation image information recording/reading device comprising a superposition calculation unit that adds signals for corresponding pixels. (2) The flexible belt is formed into a belt shape with ends, and the belt feeding means for transporting the belt includes two winding shafts that wind one end and the other end of the belt, respectively. The radiation image information recording/reading device according to claim 1, characterized in that: (3) The flexible belt is formed in the shape of an endless belt, and the belt feeding means for transporting the belt includes a plurality of rollers that stretch the belt in an annular shape. 1. The radiation image information recording/reading device according to 1.