JPH1124192A - Radiological image information recording and reading device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the effect of PSL afterglow and flare from the area of a sheet other than an area where an observed object image is recorded by providing a radioactive ray intercepting member which can move in accordance with the size of a subject. SOLUTION: Between the subject and the stimulable phosphor sheet 1, the radioactive ray intercepting member 50 is provided to move between a retreating position (b) where it does not intercept radioactive rays radiated to the sheet 1 and a shielding position (a) where it shields a part (direct radioactive ray radiation part, for example) except a photographing area (observed image recording area or image recording area) on the sheet 1 corresponding to a desired photographing part out of the subject from the radioactive rays. The member 50 can be moved by operation from the outside of this device 100. Therefore, the radioactive rays are not radiated to the area shielded by the member 50 out of the outside area of the sheet 1 to which the radioactive rays are directly radiated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation image information recording and reading apparatus, and more particularly to a PSL generated when an image is read from a stimulable phosphor sheet on which an image is only partially recorded.
The present invention relates to improvement of image quality deterioration due to afterglow or flare.

[0002]

2. Description of the Related Art A recorded radiographic image is read to obtain an image signal, and the image signal is subjected to appropriate image processing.
Reproduction and recording of images are performed in various fields.
In addition, the applicant (X-ray, α-ray, β-ray, γ
A part of this radiation energy is accumulated when irradiated with an electron beam, an electron beam, ultraviolet rays, etc., and thereafter, when irradiated with excitation light such as visible light, a stimulable phosphor (stimulated luminescence) which exhibits stimulated emission according to the accumulated energy. A radiation image of a subject such as a human body is once photographed and recorded on a sheet-like stimulable phosphor by using a stimulable phosphor, and the stimulable phosphor sheet is scanned with excitation light such as laser light to emit light. Light is generated, and the obtained photostimulated light is photoelectrically read to obtain image data. Based on the image data, a radiation image of the subject is output as a visible image on a recording material such as a photographic photosensitive material, a CRT, or the like. A radiation image recording / reproducing system has already been proposed (JP-A-55-12429).
Nos. 56-11395, 55-163472, 56-104645,
No. 55-116340).

According to this system, it is possible to obtain a radiation image having a wide latitude and excellent observation and interpretation suitability.

Further, the applicant of the present application has proposed a radiation image information recording / reading apparatus in which the stimulable phosphor sheet is circulated inside the apparatus and can be used repeatedly (Japanese Patent Laid-Open No. 59-192240).
And JP-A-3-238441), and efficient operation of the stimulable phosphor sheet is realized. That is, the radiation image information recording and reading apparatus includes a conveying unit that conveys a sheet along a circulation path, an image recording unit or an imaging unit that is on the circulation path and captures radiation image information of a subject on the sheet, And an erasing unit for releasing the radiation energy remaining on the stimulable phosphor sheet after reading the radiation image information on the circulation passage and reading the radiation image information.

[0005]

However, the above-mentioned radiation image information recording / reading apparatus merely contains a single-sized stimulable phosphor sheet and needs to take a large object. Is provided with a sheet of the largest size (so-called half-cut size). Even when photographing a small subject or a large subject and a desired observation region is a small area, one sheet of the largest size is provided. The recording of the image information is performed in the copy range.

However, even if the desired image is such a small subject or the like, the radiation is applied to substantially the entire surface of the sheet. For this reason, radiation energy is also accumulated in a region other than the region where the image of the subject or the observation target region is recorded on the sheet, and the entire surface of the sheet is illuminated by irradiating the sheet with excitation light to read the image from the sheet. Emitting light will be emitted. In particular, the region other than the region where the observation target image is recorded is a direct radiation portion, which is referred to as a transparent portion, where the radiation directly reaches the sheet without passing through the subject or the like, so The light emission amount is larger than the area where the observation target image is recorded. For this reason, especially near the end of the area where the observation target image is recorded, particularly around the end (the area other than the area where the observation target image is recorded),
Even after completion of the excitation light irradiation, the photostimulated light is affected by the afterglow phenomenon (stimulated light emission afterglow: hereinafter sometimes simply referred to as PSL afterglow), and the photostimulated light is emitted as an image signal. If the S / N of light is reduced and a visible image is reproduced based on such a signal, the image quality of the image may be degraded.

[0007] For the same reason as the above-mentioned PSL afterglow, the vicinity of the end of the area where the image to be observed is recorded is easily affected by flare such as excitation light from the surrounding area. Has a low S / N.

The present invention has been made in view of the above circumstances. Even when an image of a subject is recorded on a part of a single large-sized stimulable phosphor sheet, the image to be observed on the sheet is not changed. From the area other than the area to be recorded,
It is an object of the present invention to provide a radiation image information recording and reading apparatus in which the effects of SL afterglow and flare are suppressed.

[0009]

According to a first radiographic image information recording and reading apparatus of the present invention, in an image recording section, radiation is applied to an area of a sheet other than an area where an observation target image corresponding to a subject is recorded. The radiation shielding member is provided so as to be movable according to the size of the subject so as not to be performed.

That is, the first radiographic image information recording and reading apparatus of the present invention is a conveying means for conveying a stimulable phosphor sheet of a predetermined size capable of storing and recording radiographic image information along a predetermined circulation path. An image recording unit that irradiates the sheet with radiation through the subject in the circulation passage, thereby recording radiation image information of the subject on the sheet; and in the circulation passage, the radiation image information in the image recording unit. An image reading apparatus comprising: an excitation light source that emits excitation light that scans the sheet on which is stored and recorded; and a photoelectric reading unit that obtains an image signal by reading photostimulated emission light emitted from the sheet scanned by the excitation light. And before the image is recorded on the sheet after the image is read by the image reading unit in the circulation path, A radiation image information recording / reading device having an erasing unit for emitting residual radiation energy on the sheet, wherein the radiation irradiated to the sheet of the image recording unit is provided between the subject and the stimulable phosphor sheet. A photographing area (observed image recording area or image recording area; hereinafter the same) on the sheet corresponding to a retreat position that is not occluded and a desired photographing part of the subject.
And a radiation shielding member provided so as to be movable between a shielding position for shielding a portion excluding (for example, a direct radiation irradiating unit) from the radiation.

Here, as the radiation shielding member, for example, a radiation shielding member formed of a flexible film containing a heavy metal such as lead can be used.

The above-mentioned shielding position does not need to mean a boundary position on the sheet that strictly separates the photographing region and the non-photographing region, and may be any boundary position that roughly partitions the photographing region and the non-photographing region. .

That is, in the general relationship between the size of the stimulable phosphor sheet and the size of the subject to be imaged in the radiographic image capturing apparatus, the size of the stimulable phosphor sheet is half cut (14 inches wide × 17 inches long). Inch), large-size (14 inches wide x 14 inches high)
Inches x 14 inches), 6 slices (8 inches x height)
10 inches) and the shape is limited to a rectangular one, and the contour of any subject to be observed exactly matches one of these sheets. This is not realistic, and it is general that a radiographic technologist or the like selects and uses an appropriate one of the set sizes.

Therefore, the radiation shielding member is capable of shielding a predetermined range so as to have a photographing size at least similar to the discrete size of the sheet set for a general radiation image photographing apparatus. I just need.

As described above, the holding of the partitioning state by the shielding member is not limited to that which can be performed only at discrete positions corresponding to the half-cut size, the large-angle size, the 4-cut size, the 6-cut size, and the like. It may be one that can be held at any position within the movable range.

The movement of the shielding member may be manually performed by a radiographing technician in accordance with the size of the subject, or, for example, a table in which the correspondence between the size of the subject and the shielding position is set in advance. A storage unit for storing, input means for inputting the size of the subject, and moving the shielding member to a corresponding shielding position with reference to the table stored in the storage unit based on the size of the subject input to the input means The structure may further include a driving unit for moving the shielding member. Further, for example, the apparatus further includes a size calculation unit that calculates the size of the subject based on a shooting menu including a shooting part of the subject, a shooting direction, an age (for adults and children), a gender, and a person for inside and outside. By adopting a configuration in which the size of the subject obtained by the calculation means is input to the input means, a simpler apparatus can be configured.

In the second radiation image information recording / reading apparatus of the present invention, prior to irradiating the sheet with excitation light to emit stimulated emission light, the image reading section includes a sheet other than the image recording area of the sheet. A feature of the present invention is that a region is provided with a partial erasing means for erasing the recorded information without reading the recorded information (there is no direct information since there is no substantial information).

That is, a second radiation image information recording and reading apparatus according to the present invention comprises: a conveying means for conveying a stimulable phosphor sheet of a predetermined size capable of storing and recording radiation image information along a predetermined circulation path; An image recording unit that irradiates the sheet with radiation through the subject in the circulation passage, thereby recording radiation image information of the subject on the sheet; and in the circulation passage, the radiation image information in the image recording unit. An image reading apparatus comprising: an excitation light source that emits excitation light that scans the sheet on which is stored and recorded; and a photoelectric reading unit that obtains an image signal by reading stimulated emission light emitted from the sheet scanned by the excitation light. And before the image is recorded on the sheet after the image is read by the image reading unit in the circulation path, In the radiation image information recording and reading apparatus provided with an erasing section for releasing residual radiation energy on the bets, corresponding to the desired imaging region of the subject,
A portion (for example, a direct radiation irradiator) excluding a photographing region (observed image recording region or image recording region; the same applies hereinafter) on the sheet is preceded by the image reading unit performing image reading. And a partial erasing means for releasing the radiation energy stored and recorded.

As the partial erasing means, one using an LED array, one using laser beam scanning, one using EL
(Electroluminescent) A panel using a panel or the like can be applied.

The portion of the subject corresponding to a desired photographing region except for the photographing region on the sheet means only a strictly non-photographing region of the photographing region and the non-photographing region on the sheet. There is no need to do so, and it is sufficient if it is almost a non-photographing area.

That is, in the general relationship between the size of the stimulable phosphor sheet and the size of the subject to be photographed in the radiation image photographing apparatus, the size and the like of the stimulable phosphor sheet are discretely set as described above. Has been
Similarly, in the erasing range by the partial erasing means, a predetermined range can be erased so as to leave an imaging area at least similar to the discrete size of a sheet set for a general radiographic imaging apparatus. I just need.

The erasing range is not limited to a discrete range corresponding to a half-cut size, a large-size size, a quarter-size size, a six-size size, etc., as described above. May be obtained.

The setting of the erasing range may be manually performed by the radiographing technician according to the size of the subject, or, for example, a table in which the correspondence between the size of the subject and the shielding position is set in advance. A storage unit for storing, input means for inputting the size of the subject, and setting means for setting a corresponding range by referring to a table stored in the storage unit based on the size of the subject input to the input means May be simply provided by adopting a configuration further including Further, for example, the apparatus further includes a size calculation unit that calculates the size of the subject based on a shooting menu including a shooting part of the subject, a shooting direction, an age (for adults and children), a gender, and a person for inside and outside. By adopting a configuration in which the size of the subject obtained by the calculation means is input to the input means, a simpler apparatus can be configured.

Prior to reading an image from a sheet to obtain image data to be used for reproducing an image (final reading), the excitation light is scanned more coarsely with excitation light having lower energy than the main reading. Thus, the erasure range may be set based on a so-called pre-read process in which an outline of image information recorded on a sheet is read.

[0025]

According to the first radiographic image information recording / reading apparatus of the present invention, in the image recording section, radiation is prevented from being applied to the area of the sheet other than the area where the observation target image corresponding to the subject is recorded. Then, by moving the radiation shielding member according to the size of the subject, an area of the sheet other than the area where the observation target image is recorded (non-imaging area)
Are not irradiated with the radiation, and therefore, even if the excitation light scans the non-imaging area, no PSL afterglow or flare is generated from the area, so that the noise is read from the imaging area by these noises. A reduction in the S / N of the image signal can be suppressed, and the deterioration of the reproduced image can be suppressed.

According to the second radiation image information recording / reading apparatus of the present invention, prior to irradiating the sheet with excitation light to emit stimulating light in the image reading section, the image reading area other than the image recording area of the sheet is used. By erasing the area without reading the recorded information by the partial erasing means, when the sheet is subsequently irradiated with excitation light to read stimulated emission light, an image to be observed of the sheet is recorded. Since no stimulating light is emitted from an area other than the area, no noise due to PSL afterglow or flare is generated from that area, and therefore, a reduction in the S / N of the image signal read from the imaging area is suppressed. However, it is possible to suppress the deterioration of the reproduced image.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the radiation image information recording and reading apparatus according to the present invention will be described with reference to the drawings.

FIG. 1 is a schematic view showing an embodiment of a radiation image information recording and reading apparatus according to the present invention, wherein (1) is a partially broken plan view in which a part of an image recording section is broken, and (2) is (). It is sectional drawing which shows the II line | wire cross section of the figure shown to 1).

The illustrated radiation image information recording and reading apparatus 100
Is a half-size that can store and record radiographic image information (width 14
Circulating transport means 11, 12, 13, 14 and 15 for transporting the stimulable phosphor sheet 1 (inch × 17 inch) along a predetermined circulating path, and a sheet containing the sheet 1 in the circulating path. A photographing unit 20 having a storage unit and receiving radiation from the left through a subject (not shown) on the sheet 1 to accumulate and record radiation image information of the subject on the sheet 1; In 20, a laser light source 31 that emits a laser beam L that scans the sheet 1 on which the radiation image information is accumulated and recorded, and reads out the stimulated emission light emitted from the sheet 1 that is scanned by the emitted laser beam L to generate an image signal Get photo multiplier 33
And an image reading unit 30 having a light guide 32 and the like for guiding the stimulated emission light emitted from the sheet 1 to the photomultiplier 33, and after the image reading is performed in the image reading unit 30 in the circulation path. An erasing section 40 having a large number of erasing light sources 41 for emitting radiation energy remaining on the sheet 1 before a next image is recorded on the sheet 1;
A stacker 10 for temporarily holding the sheet 1, and furthermore, a retreat position b of the image recording unit 20 between the subject and the stimulable phosphor sheet 1, which does not shield the radiation applied to the sheet 1, A part (for example, a direct radiation irradiator) P2 other than a photographing area (observed image recording area or image recording area; the same applies hereinafter) P1 on the sheet 1 corresponding to a desired photographing part is shielded from radiation. A radiation shielding member 50 is provided movably between the position a. The radiation shielding member 50
Is configured such that the above movement can be performed by an operation from outside the apparatus 100.

FIG. 2 is a diagram showing the positional relationship between the shielding member 50 and the sheet 1 when the shielding member 50 is at the shielding position a, as viewed from the radiation irradiation direction. That is, when the shielding member 50 is at the shielding position a, the stimulable phosphor sheet 1 having a half-cut size (14 inches in width × 17 inches in height) is substantially shielded on both sides by the shielding member 50, Radiation is applied only to an area having the same width as the six-section size (width 8 inches × length 10 inches; shown by a dashed line). The radiation shielding member 50 is formed of a flexible film containing a heavy metal such as lead.

As shown in FIG. 1B, the sheet storage section of the image recording section 20 includes a front holding plate 21 and a rear holding plate 22 for holding the sheet 1 from front and rear. Reference numerals 21 and 22 denote a loading position A where the sheet 1 conveyed from the stacker 10 by the conveying means 11 is conveyed into the sheet accommodating portion, and irradiation of the radiation image is performed with the sheet 1 held between the holding plates 21 and 22. It is configured to be rotatable between a photographing position B where the image is taken and a carry-out position C where the sheet 1 is carried out from the inside of the sheet accommodating section to the carrying means 13 that carries the sheet 1 to the image reading section 30.

Next, the operation of the radiation image information recording and reading apparatus according to this embodiment will be described.

First, the sheet 1 accommodated in the stacker 10 is carried out of the stacker 10 for taking a radiographic image, and the conveying means 11 uses the carried sheet 1 as an image recording unit.
Transport to 20. At this time, in the image recording section 20, the front holding plate
21 and the rear holding plate 22 are arranged at the carry-in position A,
There is a gap between the two holding plates 21 and 22 for carrying in the sheet 1. Then, the sheet 1 conveyed by the conveying means 11 is carried in between the two holding plates 21 and 22 (sheet accommodating portion).

The sheet accommodating section into which the sheet 1 has been carried in rotates to the photographing position B in a state where the two holding plates 21 and 22 are integrated with the sheet 1 sandwiched from the front and back, and faces the subject (not shown).

Here, the size of the sheet 1 is a half-cut size as described above, but if the subject is small enough to be recorded on a six-cut size sheet,
An operator such as a radiological technician operates the radiation shielding member 50 from outside the apparatus 100 to move the shielding member 50 so that the position of the end is the shielding position a (see FIG. 2).

If the object is a large size that cannot be recorded unless the object is a half-size sheet, the radiation shielding member 50 may be moved so that the end portion is located at the retreat position b. In the case of intermediate size from half cut size to six cut size, according to the size,
What is necessary is just to operate so that the end part of the shielding member 50 may be any one between the retreat position b and the shielding position a. in this case,
It is desirable to provide a mechanism that can externally monitor where the end position of the shielding member 50 is located between a and b.

In the following, the present embodiment will be described on the assumption that the subject has a size small enough to be recorded on a six-section size sheet.

In a state where the end of the shielding member 50 is moved to the shielding position a (see FIGS. 1 and 2), radiation is irradiated toward the subject, and the radiation partially absorbed by the subject and transmitted therethrough. No direct radiation is applied to the stimulable phosphor sheet 1 set at the imaging position. At this time, the radiation image information corresponding to the dose of the irradiated radiation is accumulated and recorded on the sheet 1. However, as shown in FIG. 2, the radiation transmitted through the subject is substantially divided into six sections (shown by a dashed line) as shown in FIG. Area), and the direct radiation is applied to an area outside the six-section area. Here, among the outer regions of the sheet 1 to which the radiation is directly irradiated, the radiation is not irradiated to the region shielded by the shielding member 50 (the left and right side bands in FIG. 2).

When the photographing (image recording on the sheet 1) is completed in this manner, the two holding plates 21, 22 holding the sheet 1 are held.
Is rotated to the unloading position C in a state where the two
The sheets 1 and 22 open back and forth, and the sheet 1 is carried out of the sheet storage unit by a carrying-out mechanism (not shown).

The sheet 1 carried out from the image recording unit 20 is
The sheet is conveyed to the image reading unit 30 by the conveying unit 12, and the image reading unit
In 30, a laser light L is emitted from a light source 31, and the laser light L scans the entire surface of the sheet 1, and a stimulating light having a light amount corresponding to the image information stored and recorded on the sheet 1 is emitted from the sheet 1. Light is emitted.

Here, the area where the stimulated emission light is emitted is not the entire surface of the sheet 1 irradiated with the laser light L, but the area shielded by the radiation shielding member 50 in the image recording section 20 (the above-mentioned left and right side bands). Area). That is, since the left and right side bands of the subject are not irradiated with radiation, radiation energy does not accumulate. Therefore, the both side bands are not excited even when irradiated with the laser light L, which is the excitation light, and are not luminous. No emission light is emitted.

Furthermore, since the left and right side bands are originally direct radiation areas not to be observed, the radiation shielding member 50
If there is no occlusion by the radiation, the level of radiation energy stored therein is higher than the level of radiation energy stored in the area irradiated with the radiation transmitted through the subject (mainly, the six-section area in FIG. 2). And the intensity of the stimulated emission light emitted is also strong, so that the influence of the PSL afterglow and the influence of flare on the other area are also large. Therefore, the influence of the PSL afterglow and the influence of flare on the portion where the image of the subject is recorded are suppressed, and the S / N ratio of the stimulated emission light as the image signal light is reduced.
Can be improved.

The photostimulated luminescence light thus obtained is guided to the photomultiplier 33 by the light guide 32. An excitation light cut filter (a filter having a characteristic of transmitting stimulating light but not transmitting laser light L) (not shown) is provided between the light guide 32 and the photomultiplier 33. The incident laser beam L, which is a noise component, is prevented from being detected by the photomultiplier 33.

On the other hand, the stimulated emission light having a high S / N, which is photoelectrically detected by the photomultiplier 33, is directly converted into an image signal having a high S / N and output to an external image processing device or the like. .

The stimulable phosphor sheet 1 from which the image information has been read emits most of the stored radiation energy by emitting the stimulating light.
Note that radiation energy that has not been emitted remains on the sheet 1.

The sheet 1 that has been read is
The sheet is conveyed to the erasing section 40 along the circulation path by the conveying means 14.

The erasing section 40 irradiates the sheet 1 with erasing light of strong erasing energy emitted from the erasing light source 41, releases the radiation energy remaining on the sheet 1, and makes the sheet 1 reusable. The sheet is conveyed by the conveying means 15 and 11 and carried into the stacker 10, where it is temporarily stored until the next photographing.

As described above, according to the radiation image information recording / reading apparatus of the present embodiment, the image recording unit 20 irradiates the sheet 1 with an area other than the area where the observation target image corresponding to the subject is recorded. By moving the radiation shielding member 50 in accordance with the size of the subject so as not to be performed, radiation is not applied to an area (non-imaging area) of the sheet 1 other than the area where the observation target image is recorded.
Therefore, even if the laser light scans the non-photographing area, no PSL afterglow or flare is generated from the area, and the noise component causes the S / N of the image signal read from the photographing area to be reduced. The deterioration can be suppressed, and the deterioration of the reproduced image can be suppressed.

FIG. 3 is a diagram showing a main part of an image reading section 30 'of one embodiment of the second radiation image information recording / reading apparatus of the present invention. The radiation image information recording / reading apparatus of the present embodiment differs from the radiation image information recording / reading apparatus of the embodiment shown in FIG. 1 in that the image recording section 20 does not include the radiation shielding member 50, while In the section 30 ′, the radiation energy stored and recorded prior to the image reading is performed on a portion (for example, a direct radiation irradiating section) corresponding to the imaging region of the subject except the imaging area on the sheet 1. This is further provided with a partial erasing means 60 for emitting the light.

Here, as the partial erasing means 60, one using an LED array, one using laser light scanning,
(Electroluminescent) A panel using a panel or the like can be applied.

The portion of the subject corresponding to a desired photographing region except for the photographing region on the sheet means only a strictly non-photographing region of the photographing region and the non-photographing region on the sheet. There is no need to do so, and it is sufficient if it is almost a non-photographing area.

That is, in the general relationship between the size of the stimulable phosphor sheet and the size of the subject to be photographed in the radiation image photographing apparatus, the size and the like of the stimulable phosphor sheet 1 are discrete as described above. It is set, but similarly, in the erasing range by the partial erasing means 60, at least a predetermined range so as to leave an imaging area similar to the discrete size of the sheet set for at least a general radiographic imaging apparatus. Can be erased.

The erasing range is not limited to a discrete range corresponding to a half-cut size, a large-size size, a 4-cut size, a 6-cut size, etc., as described above. May be obtained.

The setting of the erasing range may be manually performed by the radiographing technician according to the size of the subject, or, for example, a correspondence table between the size of the subject and the shielding position may be set as a preset table. A storage unit for storing, input means for inputting the size of the subject, and setting means for setting a corresponding range by referring to a table stored in the storage unit based on the size of the subject input to the input means May be simply provided by adopting a configuration further including Further, for example, the apparatus further includes a size calculation unit that calculates the size of the subject based on a shooting menu including a shooting part of the subject, a shooting direction, an age (for adults and children), a gender, and a person for inside and outside. By adopting a configuration in which the size of the subject obtained by the calculation means is input to the input means, a simpler apparatus can be configured.

It is to be noted that, prior to image reading (final reading) from a sheet for obtaining image data to be used for reproducing an image, the excitation light is scanned with excitation light having a lower energy than the main reading and coarser than the main reading. Thus, the erasure range may be set based on a so-called pre-read process in which an outline of image information recorded on a sheet is read.

Next, the operation of the radiation image information recording / reading apparatus of this embodiment will be described.

First, the operation until the sheet 1 is conveyed from the stacker 10 to the image recording unit 20 is the same as the operation of the radiation image information recording and reading apparatus of the above-described embodiment.

In the image recording unit 20, unlike the above-described embodiment, there is no function of shielding the left and right side bands of the sheet 1 from radiation by the radiation shielding member according to the size of the subject, and regardless of the size of the subject. Radiation is applied to the entire surface of the half-sized sheet 1. Therefore, when the size of the subject is extremely small as compared with the size of the sheet, most of the area of the sheet is an area directly irradiated with radiation.

The sheet 1 carried out from the image recording unit 20 is
The sheet is conveyed to the image reading unit 30 by the conveying unit 12, and the image reading unit
In 30, a laser light L is emitted from a light source 31, and the laser light L scans the entire surface of the sheet 1, and a stimulating light having a light amount corresponding to the image information stored and recorded on the sheet 1 is emitted from the sheet 1. Although the light is emitted, in the present embodiment, prior to the scanning with the laser beam L, the partial erasing means 60 erases the erasing range according to the erasing range set by the radiographing technician.

When the laser beam L scans the sheet 1 by the partial erasure in advance, the left and right side bands corresponding to the portion where the subject is not recorded on the sheet 1 are direct radiation portions. Nevertheless, the stored radiation energy is reduced to very low levels.
Therefore, even when the laser beam L scans the entire surface of the sheet 1, the photostimulated light emitted from the left and right side bands of the sheet 1 is extremely weak, and the PSL afterglow of the photostimulated light is very weak. The influence of the flare on the stimulating light emitted from the subject recording area on the sheet 1 is suppressed, and the S / N of the stimulating light, which is the image signal light, can be improved.

The stimulated emission light thus obtained is guided by the light guide 32 to the photomultiplier 33. An excitation light cut filter (a filter having a characteristic of transmitting stimulating light but not transmitting laser light L) (not shown) is provided between the light guide 32 and the photomultiplier 33. The incident laser beam L, which is a noise component, is prevented from being detected by the photomultiplier 33.

On the other hand, the stimulated emission light having a high S / N, which is photoelectrically detected by the photomultiplier 33, is directly converted into an image signal having a high S / N and output to an external image processing device or the like. .

The stimulable phosphor sheet 1 from which the image information has been read is conveyed to the erasing section 40 along the circulation path by the conveying means 14, and the erasing section 40 uses the erasing light of strong erasing energy emitted from the erasing light source 41. Is irradiated on the sheet 1 and the radiation energy remaining on the sheet 1 is released.
Are made reusable, transported by the transporting means 15 and 11, transported into the stacker 10, and temporarily stored until the next photographing.

As described above, according to the radiation image information recording / reading apparatus of the present embodiment, prior to the image reading section 30 irradiating the sheet 1 with the laser beam L to emit the stimulating light, the sheet 1 By erasing the area other than the image recording area by the partial erasing means 60 without reading the recorded information, when the sheet 1 is subsequently irradiated with the laser beam L and the stimulated emission light is read, No stimulating light is emitted from an area of the sheet 1 other than the area where the observation target image is recorded.
No noise due to afterglow or flare is generated, and therefore, a reduction in the S / N of the image signal read from the shooting area is suppressed,
Deterioration of the reproduced image can be suppressed.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an embodiment of a radiation image information recording and reading apparatus according to the present invention, in which (1) is a partially broken plan view in which a part of an image recording section is broken, and (2) is (1). Sectional view showing a section taken along line II of the figure shown in FIG.

FIG. 2 is a diagram showing an image recording unit (image recording unit) of the radiation image information recording and reading apparatus shown in FIG.

FIG. 3 is a schematic diagram showing an image reading unit of another embodiment of the radiation image information recording and reading apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Storage phosphor sheet 10 Stacker 11,12,13,14,15 Conveying means 20 Image recording part (image recording part) 21,22 Holding plate 30 Image reading part 31 Laser light source 32 Light guide 33 Photomultiplier 40 Erase part 41 Erase light source 50 Radiation shielding film 100 Radiation image information recording / reading device A Loading position B Shooting position C Unloading position L Laser light

Claims (3)

[Claims] 1. Conveying means for conveying a stimulable phosphor sheet of a predetermined size capable of accumulating and recording radiation image information along a predetermined circulating path. In the circulating path, the sheet is irradiated with radiation through a subject. An image recording unit that records the radiation image information of the subject on the sheet; emits excitation light that scans the sheet on which the radiation image information is stored and recorded in the image recording unit in the circulation path. An image reading unit having an excitation light source, and photoelectric reading means for reading an stimulating light emitted from the sheet scanned by the excitation light to obtain an image signal, and the image reading unit in the circulation path Prior to the image recording being performed on the sheet after the image reading is performed, an erasing unit that emits residual radiation energy on the sheet is provided. A radiation image information recording and reading apparatus, wherein a retreat position of the image recording section between the subject and the stimulable phosphor sheet which does not block radiation applied to the sheet; A radiation image recording and reading apparatus further comprising a radiation shielding member movably provided between a shielding position corresponding to a part, excluding an imaging region on the sheet except for an imaging region, from the radiation. apparatus. 2. The radiation image information recording and reading apparatus according to claim 1, wherein the radiation shielding member is formed in a flexible film shape. 3. Conveying means for conveying a stimulable phosphor sheet of a predetermined size capable of accumulating and recording radiation image information along a predetermined circulation path, and irradiating the sheet with radiation through the subject in the circulation path. An image recording unit that records the radiation image information of the subject on the sheet; emits excitation light that scans the sheet on which the radiation image information is stored and recorded in the image recording unit in the circulation path. An image reading unit having an excitation light source and photoelectric reading means for reading an stimulating light emitted from the sheet scanned by the excitation light to obtain an image signal; and the image reading unit in the circulation path. And an erasing section for emitting residual radiation energy on the sheet prior to image recording on the sheet after image reading is performed in In the radiation image information recording and reading apparatus, a part corresponding to a desired imaging part of the subject, excluding an imaging area on the sheet, is stored before the image reading unit performs image reading. A radiation image information recording and reading apparatus further comprising a partial erasing means for emitting recorded radiation energy.