JPH0526181B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an erasing unit for a stimulable phosphor sheet, and more specifically, in a radiation image information reading device incorporating an image reading section and an erasing section, the erasing unit is disposed close to the reading section. The erase section is made into a unit,
The present invention relates to an erasing unit for a stimulable phosphor sheet that is constructed to simplify the construction of the radiation image information reading device itself and to be suitable for downsizing.

2. Description of the Related Art Recently, a radiographic image information recording and reproducing system that obtains a radiographic image of a subject using a stimulable phosphor has been attracting attention. Here, stimulable phosphors are irradiated with radiation (X-rays, α-rays, β-rays, γ-rays, ultraviolet rays, etc.) and store a portion of this radiation energy. A phosphor that emits stimulated luminescent light in response to stored energy. The radiation image information recording and reproducing system described above utilizes this stimulable phosphor, and once the radiation image information of a subject such as a human body is recorded on a sheet having a layer made of the stimulable phosphor (hereinafter referred to as stimulable phosphor sheet), The stimulable phosphor sheet is scanned with excitation light such as a laser beam to generate stimulated luminescence, and the resulting stimulated luminescence is read photoelectrically. An image signal is obtained, and based on this image signal, it is output as a visible image to a recording material such as a photographic light-sensitive material or a CRT. Regarding this type of technology, please refer to Japanese Patent Application Laid-open No.
-12429, No. 56-11395, etc.

By the way, this system uses a conventional intensifying screen and
It has the practical advantage that images can be recorded over a much wider range of radiation exposure compared to radiographic systems using line film. That is, in a stimulable phosphor, it is recognized that the amount of emitted light that is stimulated to emit light due to excitation after accumulation is proportional to the amount of radiation exposure over an extremely wide range. Therefore, even if the amount of radiation exposure varies considerably due to various imaging conditions, the amount of emitted light is read by the photoelectric conversion means with the reading gain set to an appropriate value and converted into an electrical signal. Recording materials such as photographic materials using
If the image is output as a visible image on a display device such as a CRT, a radiation image that is not affected by fluctuations in radiation exposure can be obtained.

In addition, according to this system, after converting the radiation image information stored in the stimulable phosphor into an electrical signal, appropriate signal processing is performed, and this electrical signal is used to display on recording materials such as photographic light-sensitive materials, CRTs, etc. It also has the extremely great effect of outputting it as a visible image to the apparatus, thereby providing a radiographic image with excellent suitability for observation and interpretation (diagnosis). In such a radiation image information recording and reproducing system, the stimulable phosphor sheet does not ultimately record the image information, but temporarily holds the radiation image information in order to provide the image to the recording medium as described above. Since this stimulable phosphor sheet is unique, it may be used repeatedly, and such repeated use is extremely economical and convenient. In this case, in order to reuse the stimulable phosphor sheet, the radiation energy remaining in the stimulable phosphor sheet after reading has been performed by irradiation with excitation light is released by irradiation with light, and the residual radiation image is imaged. This stimulable phosphor sheet can be used again for recording radiation images. Techniques for removing radiation energy remaining in the stimulable phosphor sheet after reading are described, for example, in JP-A-56-11392 and JP-A-56-11392.
No. 12599.

That is, a radiation image information reading device that meets the above purpose generally includes an image reading section that reads an image stored and recorded by irradiating radiation through a subject onto a reusable sheet made of a stimulable phosphor; The stimulable phosphor sheet is provided with an erasing section for releasing the radiation energy remaining in the Takese phosphor sheet after reading to make the stimulable phosphor sheet usable for the next image recording.

In such a configuration, if the image reading section and the image erasing section are combined into one device, the device itself can be made compact and a narrow space can be effectively utilized, which can be said to be extremely practical and convenient.

Therefore, when assuming a radiation image information reading device that meets the above requirements, it is preferable that the image material reading section and the image erasing section incorporated therein be arranged as close together as possible. This is because it is only possible to make the device more compact by covering it and bringing it closer together.

However, if the image reading section and the image erasing section are disposed with no spacing from each other, the following disadvantages arise. In other words, when reading an image, excitation light is irradiated to generate stimulated luminescence light related to a radiation image on the stimulable phosphor sheet, so the inside of the image reading section should be as dark as possible. On the other hand, since it is necessary to release all the radiation energy stored in the stimulable phosphor sheet inside the erasing section, an erasing irradiation light source with as much luminosity as possible is placed, and this irradiation light is Based on this, the afterimage must be erased in a short time. Therefore, if the erasing light from the erasing section leaks to the image reading section disposed in close proximity, the accuracy of image reading deteriorates, resulting in the inconvenience that a precise radiation image cannot be obtained.

Therefore, as a result of extensive research and efforts, the inventor of the present invention made the erasing section located close to the image reading section into a box shape, and introduced a stimulable phosphor sheet from the reading section into one end of the box. An extremely narrow opening is provided, and a set of nip rollers is provided corresponding to the opening, whereby the stimulable phosphor sheet fed from the image reading section is passed through the opening. If the erasing irradiation light from the erasing light source is introduced into the inside of the box, it is possible to efficiently erase the afterimage of the stimulable phosphor sheet without leaking the erasing irradiation light from the erasing light source to the reading section. Furthermore, since it is a box type, it is easy to incorporate it into the device itself, and since it occupies only a small space, an erasing unit that is more effective in making the entire device more compact can be obtained, and the above-mentioned disadvantages can be avoided. It turned out that it was going to be wiped out.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a radiation image information reading apparatus that can prevent afterimage erasing light from entering the image reading section from an erasing light source and that can further reduce the overall size of the apparatus. The purpose of the present invention is to provide an erasing unit for body sheets.

In order to achieve the above object, the present invention irradiates a stimulable phosphor sheet placed inside a casing and on which a radiation image is stored and recorded with excitation light to emit the radiation image as stimulated luminescence light, an image reading section that reads this stimulated luminescence light using an optical element and converts it into an electrical signal; and an image reading section that is located inside the casing and close to the image reading section and that remains on the stimulable phosphor sheet after reading. In the radiation image information reading device, the erasing section has a narrow opening for receiving a stimulable phosphor sheet sent out from the reading section. an eraser box, and an erasing light source disposed inside the eraser box, and further includes a stimulable phosphor sheet placed opposite to the opening and introduced into the eraser box, and the storage device from which residual images are erased. a first pair of rollers made of an elastic material for leading out the stimulable phosphor sheet from inside the erasing box; a second roller pair arranged to The stimulable phosphor sheet
The remaining image is erased within the erase box by being held between a pair of rollers.

Next, regarding the erasing unit for stimulable phosphor sheets according to the present invention, a radiographic image information recording/reading device in which an image recording section is incorporated together with an image reading section and an erasing section will be listed as a preferred embodiment, and reference will be made to the attached drawings. This will be explained in detail below.

First, a radiation image information recording/reading apparatus incorporating an erasing unit according to the present invention will be described with reference to FIGS. 1 and 2.

In FIG. 1, reference numeral 10 indicates an upright type radiation image information recording/reading device, and the device 10 has a first casing 12 extending in the vertical direction and a second casing 14 extending in the horizontal direction. including.
Above the front part of the first casing 12 is an imaging section (image recording section) for recording a radiation image of a subject.
16 is arranged, and on the other hand, an operation section 1 is arranged above the side wall part.
8 are arranged.

Next, the first casing 12 and the second casing 1
The internal configuration of 4 will be explained with reference to FIG.

A pair of sheet receiving rollers 20 for receiving photographed sheets is disposed in the lower part of the interior of the photographing section 16.
A first guide member 22 is provided below this roller pair 20.
A second guide member 24 corresponding to the first guide member 22 and extending in the vertical direction is provided. The first and second guide members 22, 24
A third guide member 26 is further disposed below the roller pair 20 via the roller pair 20 . Said third guide member 2
6 and a fourth guide member 28 provided below it.
A pair of rollers 20 is pivotally supported between. Furthermore, an endless first conveyor belt 30 that is bent at an internal corner of the first casing 12 is provided corresponding to the fourth guide member 28 . The conveyor belt 30 terminates at the lower central portion of the second casing 14 . Next, an endless second conveyor belt 32 is disposed at a slight distance from the terminal end of the first conveyor belt 30. This second conveyor belt 3
2 is bent upward at a corner of the second casing 14, and a roller group 34 is provided at the inner bent part.
will be placed. An endless third conveyor belt 36 and a fourth conveyor belt 38 extend horizontally at a distance from the terminal end of the second conveyor belt 32. An endless fifth conveyor belt 40 is provided close to the terminal end of the fourth conveyor belt 38 and bent further upward. A roller group 42 is provided on one surface of the fifth conveyor belt 40 . Fifth
A pair of opposing guide members 44 is further disposed above the conveyor belt 40 and the roller group 42, and a guide member 46 is disposed above the guide member 44 via a pair of rollers. . An erasing unit according to the present invention is incorporated above the guide member 46. Note that details of this erasing unit will be described later. A shorter guide member 48 is disposed above the erasing unit, and a guide member 50 is further disposed above the guide member 48. An endless bent conveyor belt 52 is provided at the end of the guide member 50 . This conveyor belt 52 is located approximately at the top of the first casing 12, as can be understood from the figure. Since the conveyor belt 52 is bent as described above, a roller group 54 is provided inside the conveyor belt 52. Furthermore, the conveyor belt 5
A pair of rollers 56 and 58 is provided below the roller group 54 and the roller group 54, and supplies the stimulable phosphor sheet to the photographing section 16.

The above is the basic configuration of the stimulable phosphor sheet conveyance system in the radiation image information recording/reading apparatus 10.

Next, a reading section arranged in relation to the transport system will be explained.

The reading unit 62 basically includes a scanning optical system (not shown) including a laser light source 64 and a galvanometer mirror for scanning a sheet with the laser light derived from the laser light source 64, and a condensing reflection mirror 6.
6, a portion of the stimulated luminescent light emitted from the sheet by the scanning laser beam, and the reflecting mirror 6.
It includes a condensing optical element 68 that efficiently condenses the stimulated luminescence light reflected by 6. Note that a photomal 70 is attached to the top of the condensing optical element 68.

Therefore, an erasing unit according to the present invention is shown in FIGS. 3 and subsequent figures. That is, in FIG.
00 indicates an erasing unit for the stimulable phosphor sheet, and this erasing unit 100 basically consists of an erasing box 102, transport means 104 and 106 disposed at the upper and lower ends of the erasing box 102, respectively, and the erasing box 102. First to fourth light sources 108a to 108 for irradiating erasing light inside
It has d. An angle member 110 is fixed to the lower end of the erase box 102, and as the angle member 110 is engaged with a part of the first casing 12, the erase box 102 is
It will be positioned in the casing 12. On the other hand, openings 112a and 1 are provided at positions corresponding to the transport means 104 and 106 of the erase box 102.
12b are respectively formed, and the erase box 102 extends from the opening 112a to the opening 112b.
Guide members 114a and 114b are arranged in parallel inside (see FIG. 4). A set of nip rollers 11 constituting the conveying means 104 is provided outside the opening 112a.
6a and 116b are arranged so as to be surrounded by the first cover member 117a so as to be in sliding contact with each other;
Similarly, nip rollers 118a and 118b constituting the conveying means 104 are disposed in the opening 112b so as to be in sliding contact with each other and surrounded by the second cover member 117b. Elastic members, ie, coil springs 120a and 120b, are suspended on the nip rollers 116b and 118b using pin members implanted in the cover members 117a and 117b, respectively. 118b is configured to forcibly come into sliding contact with the nip roller 118a. The cover members 117a and 117b surrounding the conveying means 104 and the conveying means 106 formed in this way have the openings 1
Holes 122a and 122b corresponding to 12a are formed. Furthermore, the Nitz roller 116b
The detecting section 128 of the micro switch 126 is in sliding contact with.

On the other hand, a motor 130 is fixed close to the angle member 110 that holds the erase box 102, and a first sprocket 134 is fixed to the rotating shaft 132 of this motor 130. A chain 136 suspended from the first sprocket 134 meshes with a second sprocket 138 coaxially supported by the nip roller 116a, and further extends upward and engages with a second sprocket 138 coaxially supported by the nip roller 118a. It also meshes with sprocket 140 of No. 3. The chain 136 further engages with a fourth tension sprocket 142 disposed on the side wall of the erase box 102, and then returns to the first sprocket 134.

A shaft 144 holding the fourth sprocket 142 is attached to the holding member 1 fixed to the erase box 102.
The chain 13 is displaced within the elongated hole 148 of 46.
6 at an optimum tensile strength.

The erasing unit for a stimulable phosphor sheet according to the present invention is basically constructed as described above, and its operation and effects will now be explained.

Radiation is applied to a subject (not shown) on the imaging surface 60 of the imaging unit 16, and the stimulable phosphor sheet 15
When a radiographic image of the subject is recorded on the stimulable phosphor sheet 150, the stimulable phosphor sheet 150
0, 32, and 36 to the reading section 62. The reading unit 62 scans the laser light sent from the laser light source 64 on the sheet 150, and thereby the stimulated luminescence light emitted from the sheet 150 is reflected directly or by the reflecting mirror 66 to collect the light into a condensing optical system. The light is made incident on the element 68, converted into an electrical signal by the photomultiplier 70, and sent to a reproducing device (not shown).

After the reading operation of the stimulable phosphor sheet 150 on which the image signal has been read in this way is completed, the stimulable phosphor sheet 150 reaches the guide member 44 via the conveyor belts 38 and 40, and further passes through the guide member 46 to form the apparatus of the present invention. Nitz rollers 116a, 116b
leading to. In other words, the sheet 150 introduced from the opening 112a is transferred to the nip rollers 116a, 1.
16b to guide member 114a.
When the sheet 150 is sandwiched between the nip rollers 116a and 116b in this way, the nip roller 116b is held by the coil spring 120a due to its thickness.
Lift this nip roller 116b against the tensile force of
detects this. This detection signal causes motor 1 to
30 rotates, the chain 136 moves, and this movement of the chain 136 causes the second sprocket 1 to move.
Rotate 38. As mentioned above, since the second sprocket 138 is disposed coaxially with the rotating shaft of the nip roller 116a, this sprocket 1
The nip roller 116 rotates under the rotational action of 38.
a simultaneously rotates the nip roller 116b that is in sliding contact with it, and guides the sheet 150 introduced during this time toward the guide members 114a and 114b.

The micro switch 126, whose tip end contacts the nip roller 116b, is connected to the sheet 1 as described above.
50 is fed from the reading section 62 side, the micro switch 126 is energized, and this energizing signal rotates the motor 130. In this way, when the seat 150 passes through the guide members 114a and 114b and reaches the nip rollers 118a and 118b, which rotate under the action of the third sprocket 140, the seat 150 is separated from the nip rollers 116b and 116a, so that it is moved under the action of the coil spring 120a. Then, the nip roller 116b is displaced in the direction of arrow A in FIG. As a result, the detection section 128 of the microswitch 126 is also displaced in the same direction. Therefore, the displacement signal is sent to motor 130, causing it to rotate in the opposite direction. That is, the sheet 150 held by the nip rollers 118a and 118b is
When the sheet 150 returns to the directions a and 116b and is again held by the nip rollers 116a and 116b, the detection section 1 of the micro switch 126
28 is again displaced due to its thickness and this displacement signal causes motor 130 to stop. In this way, the sheet 150 is transferred to the nip rollers 116a, 116b.
and the nip rollers 118a, 118b.

Therefore, when the light sources 108a, 108b, 108c and 108d are turned on, the irradiated light completely erases the radiation image remaining on the stimulable phosphor sheet 150 inside the erasing box 102.
In this case, the light sources 108a to 108d
Of course, erasing light in the excitation wavelength region of the stimulable phosphor of the sheet 150 is emitted from the phosphor.

After the light sources 108a to 108d have been energized for a predetermined period of time, the motor 130 is driven again to move the chain 136, and the sheet 150 is held by the nip rollers 118a and 118b and moved to the guide member 4.
It is transported in eight directions. Since the afterimage of the stimulable phosphor sheet 150 that has reached the guide member 48 has been completely erased, the conveyor belt 52 and roller pair 5
6 and 58 to the imaging unit 16 and waits for the next radiographic image to be taken.

According to the present invention, the erasing unit for a stimulable phosphor sheet is configured in a box shape as described above, and a pair of nip rollers are disposed in an extremely small opening of the box, and a pair of nip rollers are disposed inside the box. Since the erasing light source is arranged, it is possible to efficiently erase the radiation image remaining on the stimulable phosphor sheet either directly inside the box or by reflected light, which will cause trouble in the next image recording. Furthermore, since the stimulable phosphor sheet is held between a pair of rollers to erase the remaining image, the surface of the stimulable phosphor sheet can be evenly irradiated with the erasing light. I can do it. Moreover,
Since the present device itself has a completely light shielding structure for the reading section, there is no concern that noise will be generated in the reading operation in the reading section.
Furthermore, since the erasing unit is configured in a box shape, it is easy to incorporate it into the radiation image information recording/reading device, and furthermore, since it occupies only a small space, it can be easily incorporated into the radiation image information recording/reading device itself. can be made extremely compact. Here, the box shape is not limited to a simple rectangular parallelepiped shape, but also includes an elliptical shape and a polygonal shape.

Although the present invention has been described above with reference to preferred embodiments, the present invention is not limited to this embodiment. It goes without saying that various improvements and design changes can be made without departing from the gist of the present invention, such as that these can also be used in a so-called radiation image information reading device configured separately from the image recording section.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a radiation image information recording/reading device incorporating the stimulable phosphor sheet erasing unit according to the present invention, and FIG. 2 is an internal explanatory diagram of the radiation image information recording/reading device shown in FIG. 3 is a side view of the erasing unit of the invention, FIG. 4 is a front view of the erasing unit of the invention, and FIG. 5 is a perspective view of the erasing unit of the invention. 10...radiation image information recording/reading device, 12,
14...Casing, 16...Imaging unit, 18...
Operation unit, 20...Roller pair, 22, 24, 26,
28... Guide member, 30, 32... Conveyor belt, 34... Roller group, 44, 46, 48, 50
... Guide member, 52 ... Conveyor belt, 54 ...
Roller group, 56, 58...Roller pair, 60...Photographing surface, 62...Reading section, 64...Laser light source, 6
6... Reflection mirror, 68... Condensing optical element, 70
... Photomal, 100 ... Erase unit for stimulable phosphor sheet, 102 ... Erase box, 10
4,106...transporting means, 108a to 108d...
...Light source, 110...Angle member, 112a, 1
12b...opening, 114a, 114b...guide member, 116a, 116b...nip roller,
117a, 117b...Cover member, 118a,
118b...Nippon roller, 120a, 120b
... Coil spring, 126 ... Micro switch, 128 ... Detection section, 130 ... Motor, 1
32... Rotating shaft, 134... Sprocket, 13
6... Chain, 138, 140, 142... Sprocket, 144... Shaft, 146... Holding member, 148... Elongated hole, 150... Stimulable phosphor sheet.

Claims (1)

[Claims] 1. A stimulable phosphor sheet disposed inside a casing on which a radiation image is stored and recorded is irradiated with excitation light to emit the radiation image as stimulated luminescence light;
an image reading section that reads this stimulated luminescence light using an optical element and converts it into an electrical signal; and an image reading section that is located inside the casing and close to the image reading section and that remains on the stimulable phosphor sheet after reading. In the radiation image information reading device, the erasing section has a narrow opening for receiving a stimulable phosphor sheet sent out from the reading section. an eraser box, and an erasing light source disposed inside the eraser box, and further includes a stimulable phosphor sheet placed opposite to the opening and introduced into the eraser box, and the storage device from which residual images are erased. a first pair of rollers made of an elastic material for leading out the stimulable phosphor sheet from inside the erasing box; a second roller pair arranged to An erasing unit for a stimulable phosphor sheet, characterized in that the stimulable phosphor sheet is held between the first and second pair of rollers, and residual images are erased within the erasing box. 2. The erasing unit for a stimulable phosphor sheet according to claim 1, wherein the elastic member is a coil spring that engages with the rotating shaft of the rollers constituting the first roller pair. 3. In the erasing unit according to claim 1 or 2, a rotational drive source is attached to the erasing box, a sprocket is attached to the drive shaft of the rotational drive source, and the first pair of rollers is configured. a sprocket is attached to the rotating shaft of one of the rollers, and a chain is suspended between the sprocket of the drive shaft and the sprocket of the first pair of rollers to rotate the rollers of the first pair of rollers. Erasing unit for fluorescent phosphor sheets. 4. An erasing unit for a stimulable phosphor sheet according to claim 3, comprising a tension sprocket movably disposed between the sprocket of the drive shaft and the sprocket of the first pair of rollers. 5. In the erasing unit according to claim 3, a detector constituting a limit switch is engaged with one roller of the first pair of rollers, and under the action of this detector, the rotational drive source is drive-controlled and the storage is performed. An erasing unit for a stimulable phosphor sheet, which is configured to introduce, position and deliver a stimulable phosphor sheet.