JPH06100787B2 - Cassette for storage phosphor sheet - Google Patents

Description

TECHNICAL FIELD The present invention relates to a cassette which is a container for storing a stimulable phosphor sheet, and more particularly to a cassette having an erasing function, particularly a secondary erasing function.

<Prior art and its problems> As a method of obtaining a radiographic image as an image, a so-called radiographic system using a combination of a radiographic film having an emulsion layer made of a silver salt photosensitive material and an intensifying screen has been conventionally used. ing. Recently, as a substitute for the radiographic system, a radiographic image information recording / reproducing system using a stimulable phosphor has been attracting attention.

Here, the stimulable phosphor means radiation (X-ray, α-ray, β-ray,
When gamma rays, electron beams, ultraviolet rays, etc.) are irradiated, a part of the energy of this radiation is accumulated, and when excitation light such as visible light is then irradiated, it stimulates emission depending on the accumulated energy. Is referred to as a phosphor.

Using this stimulable phosphor, the radiation image information of a subject such as a human body is once stored and recorded on a sheet having a layer of the stimulable phosphor (hereinafter referred to as "accumulative phosphor sheet"), and this sheet is excited. Scanning with light causes stimulated emission, the generated stimulated emission is read by an optical element and converted into an electrical signal to obtain an image signal, and the image signal is processed to obtain a radiation image of a subject with a good diagnosis diagnosis. A radiation image information recording / reproducing system has been proposed (for example, JP-A-55-12429).
No. 56, No. 56-11395, No. 55-163472, No. 56-104645, No. 56-104645
55-116340 etc.).

In such a radiation image recording / reproducing system, the image reading device for reading the radiation image from the stimulable phosphor sheet on which the radiation image is accumulated and recorded is specifically configured as follows.

That is, the stimulable phosphor sheet on which a radiation image is stored and recorded is loaded into the image reading apparatus in a state of being housed in the cassette, and after closing the cassette, the stimulable phosphor sheet is removed from the cassette by a single sheet. Take it out. Next, the separated stimulable phosphor sheet is transported to the reading unit by a transport mechanism such as a belt conveyor. The reading unit performs sub-scanning by mechanically transporting the storage phosphor sheet in one direction, and emits a light beam such as a laser beam deflected in a direction substantially perpendicular to the transport direction of the storage phosphor sheet. Irradiation is performed and main scanning is performed, and photostimulated luminescent light emitted thereby is detected in time series by a photodetector such as a photomultiplier to obtain image information. The obtained image information is
Finally, it is reproduced as a hard copy or on a display device such as a CRT. Then, the stimulable phosphor sheet after completion of reading is conveyed to the erasing section, and the radiation image remaining on the stimulable phosphor sheet is erased by irradiating erasing light emitted from a light source such as a sodium lamp,
After that, they are accumulated in the accumulation tray.

After completion of reading using the erasing device as described above, erasing (hereinafter referred to as primary erasing) that releases residual radiation energy is performed, and then the stimulable phosphor sheet accumulated in the accumulating tray is Before being used again, it is exposed to radiation, such as exposed X-rays and natural radiation, which enters the collection tray, and unnecessary energy is accumulated. This appears as noise when the sheet is reused and adversely affects the image information. Therefore, erasing is performed again before using the sheet (hereinafter, referred to as secondary erasing).

This secondary erasing is conventionally performed by the following method.

It is carried out by the erasing device used for temporary erasing, and the stimulable phosphor sheet is conveyed to the erasing section by the conveying mechanism on the same line as the reading (the reading is not carried out).
After erasing, it is returned to the stacking tray and stored in the cassette.

Before using the sheet, the sheet is taken out from the stacking tray, and the sheet is secondarily erased by an erasing device separately provided outside the image reading device.

Secondary erasing is performed by the erasing device for secondary erasing installed near the loader section for inserting the accumulative phosphor sheet into the cassette from the accumulating tray.

However, in the above method, before reusing a sheet, the sheet has to be circulated once in the same line as reading, which is time-consuming, and during this time, the apparatus is occupied and another sheet is used. Cannot be read, and the efficiency of use of the device deteriorates.

Further, there is a drawback that the cassette has to be loaded into the apparatus one by one, and this work is troublesome.

Further, in the above methods (1) and (2), it is necessary to separately provide an erasing device outside the image reading device or in the loader portion, and in the above method, there is a disadvantage that the secondary erasing takes time and labor.

Furthermore, in the above method, since the secondary erasing is performed when the stimulable phosphor sheet is stored in the cassette, the sheet is not used immediately after it is stored in the cassette, and when the sheet is used for a long time, it is re-recorded again. Next, it becomes necessary to perform erasure.

<Object of the Invention> The object of the present invention is to solve the above-mentioned drawbacks of the prior art, to save the time and labor required for erasing the stimulable phosphor sheet, particularly in the secondary erasing, and to perform the independent secondary erasing It is an object of the present invention to provide a cassette having an erasing function, which can eliminate the installation of a erasing device for erasing and can surely perform erasing regardless of the time when it is stored in the cassette.

<Simple Description of the Invention> In order to achieve such an object, as a result of intensive research by the present inventors, the cassette storing the stimulable phosphor sheet has an erasing function, and immediately before photographing. The inventors of the present invention have found that the erasure is performed in the first and second aspects of the present invention.

That is, the present invention is a cassette including a housing for accommodating the stimulable phosphor sheet and a lid body that is rotatably attached to the housing and that can be opened and closed. The present invention provides a cassette for a stimulable phosphor sheet, which has a light reflection means capable of reflecting or diffusing the light introduced thereinto and irradiating the image recording area of the stimulable phosphor sheet.

Further, it is preferable that the light reflecting means has a light reflecting surface for reflecting or diffusing light formed on the inner surface of the lid.

Here, the image recording area refers to the entire surface of the sheet when effective image information is recorded on the entire surface of the stimulable phosphor sheet, and when effective image information is recorded on a part of the sheet, For example, when a subject is placed in the center of the sheet for recording, that portion is referred to.

<Structure of the Invention> The cassette of the present invention will be described below in detail with reference to the preferred embodiments shown in the accompanying drawings.

FIG. 1 is a perspective view of a cassette of the present invention, and FIG. 2 is a partial sectional side view thereof.

As shown in these drawings, the cassette 1 of the present invention has a housing 2 in which an internal space 4 capable of accommodating the stimulable phosphor sheet 14 is formed, and one side of the housing 2 has, for example, a hinge 5. The lid 3 is rotatably attached by. This lid 3
Is preferably configured so as to rotate and open and close with respect to the housing and hold the stimulable phosphor sheet 14 in a light-tight manner when the lid 3 is closed. Further, a lock mechanism 6 for locking the lid 3 in a closed state is provided. As shown in FIG. 2, for example, the locking mechanism 6 includes an L-shaped claw member 7 having a lever portion 71 and a claw portion 72, and a front-back direction when the claw member 7 is viewed from the front surface 10 of the cassette (see FIG. 2). The guide member 8 is slidable in the left-right direction, and the spring 9 is housed in the guide member 8 and biases the claw member 7 toward the front of the cassette. Of the claw member 72 of the claw member protruding outward from the opening 32 formed in the
Penetrates through the locking portion 31 of the lid body, and its tip is inserted into a hole 101 formed in the inside portion of the housing 2 on the cassette front surface 10 side.

In this lock mechanism 6, when the lever portion 71 is pressed in the direction of the arrow in FIG. 2 against the elastic force of the spring 9, the claw member 7 slides along the guide member 8 and the tip of the claw portion 72 moves. Hole 10
It is designed to be unlocked after exiting from 1.

In the internal space 4 of the cassette 1, the back surface 16 of the stimulable phosphor sheet 14 is in contact with the bottom portion 21 of the housing 2, that is,
The stimulable phosphor sheet 14 is housed so that the surface 15 of the sheet faces upward.

Here, the structure of the stimulable phosphor sheet 14 is generally composed of a support a, a phosphor layer b provided thereon, and a surface of the phosphor layer b as shown in FIG. A protective layer c for physical or chemical protection and a back layer d provided on the back surface of the support a are laminated (for example,
(See JP-A-55-146447).

In this case, the support a is formed of an organic polymer material such as polyethylene terephthalate, paper or the like, and the phosphor layer b is a binder made of an organic polymer material such as nitrocellulose, and is dispersed in the binder. It is formed by stimulable phosphor particles. Further, the protective layer c is formed of a film of polyethylene terephthalate, polyethylene, polyvinylidene chloride, polyamide, cellulose derivative or the like, and the back layer d is preferably polypropylene or the like.

In this specification, the protective layer c side is described as the front (front) surface 15 of the stimulable phosphor sheet 14, and the back layer d side is described as the back surface 16 of the stimulable phosphor sheet 14. A portion of the stimulable phosphor sheet 14 on which image information is substantially recorded is referred to as an image recording area 151 (inside an area indicated by a dotted line in FIG. 8). Phosphor sheet 14
May correspond to almost the entire surface, or may correspond to a predetermined portion.

The cassette 1 of the present invention reflects the erasing light introduced from the outside of the cassette, and the image recording area 15 of the stimulable phosphor sheet 14.
The purpose is to provide a light reflecting means capable of irradiating the whole of 1. That is, as shown in FIG. 1 and FIG.
A light reflection surface (11) for reflecting or diffusing (diffuse reflection) the erasing light is formed on the inner surface (33). The lid 3 of the cassette 1 is opened at a predetermined angle, and light emitted from a light source 12 installed outside the cassette or light that has passed through an optical system 13 such as a lens, a prism or a mirror is introduced into the cassette 1. Accumulative phosphor sheet that reflects or diffuses light by the light reflecting surface 11
At least the entire image recording area 151 of 14 is irradiated.

The light reflecting surface 11 can be formed by any method or means, but for example, as shown in FIG.
It is obtained by applying a paint having a color having a relatively high lightness, for example, a white paint, to a predetermined area of, and forming a white coating film 111. Further, a metal foil such as an aluminum foil, a resin film having the same color as described above, or the like may be attached to a predetermined area of the inner surface 33 of the lid.

Further, instead of positively forming the white coating film 111 and the like, the lid 3 itself is made of a material such as metal color or white, and the inner surface 33 thereof is the light reflecting surface 11 in a passive manner. But it's okay.

Such a light reflecting surface 11 does not necessarily have to be formed on the entire inner surface 33 of the lid 3, and may be partially formed on the inner surface 33.

For example, if the image recording area 151 is substantially the entire surface of the sheet 14, the light reflecting surface 11 is formed over substantially the entire inner surface 33 of the lid, and if the image recording area 151 is a predetermined portion of the sheet 14, It may be formed so as to correspond to this portion.

The light source 12 that emits the erasing light 17 may be any one such as a sodium lamp, a laser, a fluorescent lamp, a halogen lamp, a mercury lamp, and an incandescent lamp.

<Operation> The operation of the cassette of the present invention will be described below.

The stimulable phosphor sheet 14 is housed in the internal space 4 of the cassette 1 with the surface 15 of the stimulable phosphor sheet 14 facing upward.

When the stimulable phosphor sheet 14 is stored in the cassette 1, the lever portion 71 of the claw member 7 is pushed in the direction of the arrow in the figure from the state where the lid 3 of the cassette 1 is closed (the state shown in FIG. 2). Then, the tip of the claw portion 72 is pulled out from the hole 101 to unlock the lock mechanism 6, and at the same time, the lid body 3 is opened by sucking and lifting the lid body 3 with a suction plate (not shown) having a suction mechanism. Then, the stimulable phosphor sheet 14 is inserted into the internal space 4 of the cassette 1, the suction plate is then moved to close the lid 3, and the lock mechanism 6 locks the lid 3 again.
Note that such work may be performed automatically or manually.

Next, the stimulable phosphor sheet 14 stored in the cassette 1
Erase just before using.

First, the lid body 3 of the cassette 1 is opened at a predetermined angle as described above, then the light source 12 is turned on, and the light is applied to the light reflection surface 11 of the lid inner surface 33 to reflect or diffuse the light. The 14 image recording areas 151 are irradiated. Erase light like this 1
The irradiation pattern of 7 can be, for example, as follows.

As shown in FIG. 3, the front of the cassette 1 outside the cassette 1
The light source 12 is installed at a predetermined position on the 10 side, and the erasing light 17 emitted from the light source 12 directly strikes almost the entire surface of the light reflecting surface 11 inside the lid, and the image recording area of the reflective stimulable phosphor sheet 14 is recorded. The whole 151 is irradiated.

As shown in FIG. 4, the front of the cassette 1 outside the cassette 1
The light source 12, the lens 131 and the mirror 132 are installed on the 10 side in a predetermined arrangement, and the erasing light 17 emitted from the light source 12 is generated by the lens 13
The light is reflected on almost the entire light reflection surface 11 on the inner surface of the lid via 1 and the mirror 132, and is reflected and irradiated to the entire image recording area 151 of the stimulable phosphor sheet 14.

As shown in FIG. 5, the cassette front surface 10 outside the cassette 1
The light source 12 is installed at a predetermined position on the side, and the erasing light 17 emitted from the light source 12 directly hits a part of the light reflecting surface 11 on the inner surface of the lid, and is reflected and image-recording area 15 of the stimulable phosphor sheet 14.
A part of 1 is irradiated. The image recording area 151 (phosphor layer b) of the stimulable phosphor sheet 14 is white or the like, and a part of the irradiated light is reflected, hits the light reflecting surface 11 again, and returns to the image recording area 151. . In this way, the erasing light 17 is repeatedly reflected between the light reflecting surface 11 and the image recording area 151, and the erasing light 17 is applied to the entire image recording area 151.

As shown in FIG. 6, the front side of the cassette 1 outside the cassette 1.
The light source 12 is installed at a predetermined position on the 10 side, and the erasing light 17 emitted from the light source 12 is directly on the light reflecting surface 11 inside the lid (in this case, the light reflecting surface 11 has a property of diffusing light). The light is diffused (diffusely reflected) and its diffusivity is applied to the entire image recording area 151 of the stimulable phosphor sheet 14.

As shown in FIG. 7, the front of the cassette outside the cassette 1
A light source 12 and a variable angle mirror 132 are installed on the 10 side in a predetermined arrangement. The erasing light 17 emitted from the light source 12 is reflected by the mirror.
The light is reflected in a certain direction by 132, and the light reflection surface 11 on the inner surface of the lid 11
Is reflected and irradiated to a part of the image recording area 151 of the stimulable phosphor sheet 14, the mirror 132 is rotated at an appropriate cycle to change the reflection angle of the erasing light 17 from the light source 12. , The erasing light 17 is swung in the range of the angle α,
Irradiation is performed over the entire image recording area 151 of the stimulable phosphor sheet 14.

Needless to say, the present invention is not limited to the irradiation pattern of the erasing light as shown in FIG. 3 to FIG.

As described above, the image recording area of the stimulable phosphor sheet 14
Irradiating 151 with the erasing light 17 erases unnecessary images due to natural radiation or the like.

The irradiation time of the erasing light may be appropriately adjusted and determined by the lighting time of the light source 12.

In this way, after the erasing is completed, the stimulable phosphor sheet 14 in the cassette 1 is used again.

Although the cassette of the present invention is suitable for performing secondary erasing of the stimulable phosphor sheet 14, it increases the amount of the erasing light 17 to be emitted by selecting the light source 12 and / or irradiates the erasing light. If the time is extended, it can be applied to the primary erase. In this case, there is no need to provide an erasing section in the reading device, and there is an advantage that the reading device can be made compact.

<Effects of the Invention> According to the cassette for a stimulable phosphor sheet of the present invention, the cassette that stores and holds the stimulable phosphor sheet also has the erasing function, so that the following effects are exhibited.

Conventionally, in the secondary erasing, the stimulable phosphor sheet is conveyed to the erasing device for primary erasing built in the image reading device by circulating it along the same line as the reading, or the erasing is performed, or the outside of the image reading device. Alternatively, the erasing was carried out by an erasing device separately provided near the loader part for inserting the stimulable phosphor sheet into the cassette, but if the cassette of the present invention is used, the lid is removed before the stimulable phosphor sheet is used. Open your body,
Since it is only necessary to directly apply the erasing light to the sheet that is already stored in the cassette, there is no need to circulate or convey the stimulable phosphor sheet as in the above-mentioned conventional method, and the time and labor are required. Since it is omitted, and it is not necessary to separately provide an erasing device dedicated to the secondary erasing, the system can be made compact. Even if the cassette of the present invention is used for primary erasing, it is not necessary to install an erasing device in the image reading device, and the device can be made compact.

Further, in the cassette of the present invention, the cassette lid is opened immediately before the stimulable phosphor sheet is used for erasing (primary or secondary erasing), so that even if the cassette is stored for a long time, It is possible to completely eliminate the noise caused by the exposed X-rays and the like, and it is possible to obtain accurate image information when the stimulable phosphor sheet is reused.

[Brief description of drawings]

FIG. 1 is a perspective view showing a structural example of a cassette for a stimulable phosphor sheet of the present invention. FIG. 2 is a partial sectional side view of the cassette shown in FIG. 3 to 7 are side views each schematically showing a state in which the stimulable phosphor sheet is erased using the cassette for the stimulable phosphor sheet of the present invention. FIG. 8 is a perspective view of the stimulable phosphor sheet. Explanation of reference numerals 1 ... Cassette, 2 ... Casing, 21 ... Bottom, 3 ... Lid, 31 ... Locking part, 32 ... Opening, 32 ... Inner surface, 4 ... Internal space, 5 ... … Hinges, 6 …… Lock mechanism, 7 …… Claw member, 71 …… Lever part, 72 …… Claw part, 8 …… Guide member, 9 …… Spring, 10 …… Cassette front, 101 …… Hole, 11 …… Light-reflecting surface, 111 …… White coating, 12 …… Light source, 13 …… Optical system, 131 …… Lens, 132 …… Mirror, 14 …… Storing phosphor sheet, 15 …… Surface, 151… … Image recording area, 16 …… Back surface, 17 …… Erasing light

Claims (2)

[Claims] 1. A cassette comprising a housing for accommodating a stimulable phosphor sheet and a lid body which is rotatably attached to the housing and which can be opened and closed, and which is introduced into the inside from the outside of the cassette. A cassette for a stimulable phosphor sheet, comprising: a light reflecting means capable of reflecting or diffusing the reflected light and irradiating the image recording area of the stimulable phosphor sheet. 2. The cassette for a stimulable phosphor sheet according to claim 1, wherein the light reflecting means has a light reflecting surface for reflecting or diffusing light formed on the inner surface of the lid.