JPH0666027B2 - Radiation image eraser - Google Patents

Description

TECHNICAL FIELD The present invention relates to a radiation image erasing apparatus for erasing a radiation image recorded on a stimulable phosphor.

(Prior Art) So-called radiography using a silver salt to obtain a radiographic image has been conventionally used, but in recent years, a method for obtaining a radiographic image without using a silver salt has been proposed due to problems such as reduction of silver resources. It came to be desired. Therefore, as an alternative to the conventional photographic method for obtaining a radiation image using a silver salt, as shown in FIG. 1, the radiation (generally X-rays) emitted from the radiation source S and transmitted through the object OBJ is converted into a plate-like shape. A stimulable phosphor (usually prepared by mixing a stimulable phosphor powder with a suitable binder and applying it to a base to finish into a plate. Hereinafter, this stimulable phosphor will be referred to simply as a phosphor. (Note) It is made to absorb in SP, and then it is excited by this kind of energy which is the fluorescent substance recorded in radiation, and the radiation energy accumulated in the fluorescent substance is emitted as fluorescent light, and this fluorescent light is detected. A method of obtaining a radiation image by doing so has been considered (see, for example, JP-A-55-12429).

FIG. 2 is an explanatory diagram showing a configuration example of a radiation image reading device for reading a radiation image recorded on such a fluorescent body. In this figure, the power of the laser beam emitted from the laser light source 1 is made constant by the light quantity control unit 2.
After being focused in one direction by the cylindrical lens 3, it is incident on the reflecting surface of a rotary polygon mirror 6 as an optical deflector via a beam expander 4 and a mirror 5. The rotary polygon mirror 6 is rotated at a constant speed in the direction of the arrow in the drawing in order to scan the X laser beam in the main scanning direction. The sub-scanning is performed by moving the fluorescent body SP in the Y direction. The laser beam deflected by the rotary polygon mirror 6 is reflected by the f · θ lens 7
After being reflected by the mirror 8 through the mirror 8, the fluorescent body SP is irradiated through a cylindrical lens 9 arranged in the vicinity of the fluorescent body SP. Therefore, fluorescent light is generated from the fluorescent body SP. This fluorescent light enters the end surface (linear shape) of the light guide path 10 formed by a method of bundling optical fibers into a sheet shape, and then the other end surface (circular shape).
It comes out of and enters the first photodetector 11 such as a photomultiplier tube. The second photodetector 12 detects the laser beam at the scanning start end and obtains a synchronizing signal in the main scanning direction X of the reading scanning. Upon receiving this output, the control unit 13 performs signal processing on the timing signal. It is sent to the section 14. Based on this timing signal, the signal processing unit 14 processes the output signal of the first photodetector 11 and reproduces the radiation image recorded in the fluorescent body SP. The cylindrical lenses 3 and 9 correct the tilt angle error of the reflecting surface of the rotary polygon mirror 6 and may not be used when there is no problem in accuracy.

By the way, when such a fluorescent body SP is strongly irradiated with light or heat, the radiation image is erased and can be used for photographing again.

3 and 4 are schematic configuration diagrams of a conventional radiographic image erasing device, respectively. FIG. 3 shows an example of illuminating a fluorescent body SP with a light source 15, and FIG. In FIGS. 3 and 4, which show an example of irradiating the body SP,
HL is a support. The heater 16 is not actively used because it may cause serious deterioration of the fluorescent body SP, and the light source 15 is generally used.

However, in the erasing device using the conventional light source 15, the characteristics of the light source 15 deteriorate due to the life, or even if the wire breaks at worst, it is not possible to detect or confirm the abnormal state of these light sources 15, In some cases, the radiographic image of the fluorescent substance SP was not erased sufficiently or was not erased at all.
It is necessary to erase millions of lux in order to erase the radiation image of the fluorescent substance SP so that it can be used without any problem in practical use.
・ Light irradiation for more than sec is required, and in order to erase it in several tens of seconds, a light source 15 with light intensity of several hundred thousand lux or more must be used, and eyeballs are hurt when the inside of the device is opened and viewed. It depends. When a photograph is taken again using a fluorescent material SP in which such a radiation image has not been erased sufficiently or not at all, the recorded image becomes double and the image quality is significantly impaired. Has to be redone, resulting in unnecessary man-hours. In addition, the operator's psychological burden on whether or not the fluorescent body SP can be reused increases, which is not preferable.

(Object of the Invention) The present invention has been made in view of the above circumstances, and an object thereof is to realize a radiation image erasing apparatus capable of visually confirming a light emitting state of a light source even during an erasing operation. is there.

(Structure of the Invention) The present invention to achieve this object, in a radiation image erasing apparatus in which a light source for irradiating a stimulable phosphor on which a radiation image is recorded to erase the radiation image is arranged inside the case,
An output light extraction means for extracting a part of the output light of the light source to the outside of the case is provided.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 5 is a block diagram showing an embodiment of the present invention. In FIG. 5, an insertion port IN and a discharge port OUT of the fluorescent body SP are provided on both opposite side surfaces of the case 17. Inside the case 17, the plurality of rod-shaped light sources 18 are arranged at a position orthogonal to the moving direction of the fluorescent bodies SP of the light source 18, and are turned on in a state where the fluorescent bodies SP are completely inserted inside. , When the erasing is completed for a certain period of time, it goes out. Incidentally, the fluorescent body SP is gradually moved during the erasing so as to reduce the unevenness of the erasing due to the variation of the emission intensity between the light sources 18, but the fluorescent body SP is fixed and the light source 18 is fixed. You may move it. Such a light source 18
For example, a halogen lamp is used. A reflection member 19 for increasing the erasing efficiency is provided on the upper part of each light source 18,
An infrared cut filter (20) is provided between each light source (18) and the fluorescent body (SP) to prevent the fluorescent body (SP) from being deformed or discolored by heat generated from the light source (18). A cooling fan 21 is provided on the inner side surface.

By the way, a hole 22 is provided in a part of each reflection member 19, and a window 23 is provided in a part of the upper surface of the case 17, and the window 23
An ND filter 24 is fitted in. Further, a lid 25 having a light shielding property is provided on the window 23 so as to be openable and closable.

In such a configuration, by opening the lid 25, the window 23
The light emitting state of the light source can be directly confirmed through the hole 22 provided in the reflection member 19. On the other hand, by closing the lid 25, it is possible to prevent the filter 24 fitted in the window 23 from being damaged and prevent stray light from entering the inside when the erasing device and the reading device are connected.
When the erasing device and the reading device are connected in this way, the light source may be turned off during the reading operation, and a light may be displayed to indicate that opening of the lid is prohibited.

According to the above-mentioned configuration, even during the erasing operation, the lid 25 can be opened as necessary to visually confirm the light emitting state of the light source 18, and the reliability of erasing the radiation image can be improved. .

In addition, in the above-described embodiment, the example in which the halogen lamp is used as the light source has been described, but a tungsten lamp or a fluorescent lamp may be used, or these may be mixed and used.

Further, an optical fiber may be used as the output light extraction means for extracting a part of the output light of the light source to the outside of the case. As a result, the structure can be simplified.

(Effects of the Invention) As described above, according to the present invention, it is possible to realize a radiation image erasing apparatus capable of visually confirming the light emitting state of a light source even during an erasing operation.

[Brief description of drawings]

FIG. 1 is an explanatory view showing recording of a radiation image on a fluorescent body, and FIG. 2 is an explanatory view showing a configuration example of a radiation image reading device for reading a radiation image recorded on the fluorescent body, FIGS. FIG. 4 is a schematic configuration diagram of a conventional radiation image erasing device, and FIG. 5 is a configuration diagram showing an embodiment of the present invention. 17 …… Case, 18 …… Light source 19 …… Reflecting member 20 …… Infrared cut filter 21 …… Cooling fan, 22 …… Hole 23 …… Window, 24 …… ND filter 25 …… Lid, SP …… Storage Fluorescent substance HL ... Support

Claims (5)

[Claims] 1. A radiographic image erasing device in which a light source for irradiating a stimulable phosphor on which a radiographic image is recorded to erase the radiographic image is arranged inside a case. A radiation image erasing device, characterized in that output light extracting means for extracting the light to the outside of the case is provided. 2. A window as a part of the case is provided as the output light extraction means.
The radiation image erasing device according to the item. 3. The radiation image erasing device according to claim 2, wherein a filter for limiting light transmission is fitted in the window. 4. The radiation image erasing device according to claim 2, wherein a lid having a light shielding property is provided on the window so as to be openable and closable. 5. The radiation image erasing apparatus according to claim 1, wherein an optical fiber is provided as the output light extracting means.