JPH043144A - Mechanism for erasing accumulating fluorescent material sheet - Google Patents

Abstract

PURPOSE:To allow the erasing over the entire surface of an accumulating fluorescent material sheet in a short period of time with the small-sized erasing mechanism by disposing a light source for erasing in a transporting path of the fluorescent material sheet in the position where this transporting path is turned back in an approximately opposite direction. CONSTITUTION:The fluorescent material sheet in an erasing section 16 is carried into this mechanism from above by a transporting roller pair 76 and is transported by repeating the transportation of a prescribed length and stoppage in the approximately U-shaped transporting path on both sides of an erasing light source unit 90 where the sheet is turned back via the upper part of a roller 78, is changed backward in the transporting direction and is transported downward. The erasing light source 90 is so disposed in the position having the approximate U shape as to be sandwiched by the accumulating fluorescent material sheet. The accumulating fluorescent material sheet is, therefore, transported for a prescribed distance and thereafter, the transportation is stopped or while the accumulating fluorescent material sheet is transported, the turn back parts of the accumulating fluorescent material sheet existing on both sides of the erasing light source are simultaneously erased. The erasing over the entire surface of the accumulating fluorescent material sheet is executed in this way in a short period of time by the small-sized erasing mechanism.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a stimulable phosphor sheet erasing mechanism that erases radiation image information remaining on the stimulable phosphor sheet etc. after radiation image information has been read. .

<Prior Art> Recently, radiation image information recording and reproducing systems using stimulable phosphors have been attracting attention.

Here, stimulable phosphor refers to radiation (X-rays, α-rays, β-rays,
When irradiated with γ-rays, electron beams, ultraviolet rays, etc., some of that radiation energy is accumulated, and when it is later irradiated with excitation light such as visible light, photosynthesis occurs according to the accumulated energy. A phosphor that emits light.

The radiation image information recording and reproducing system utilizes this stimulable phosphor, and uses a sheet (hereinafter referred to as a phosphor) having a layer of stimulable phosphor to absorb radiation emitted from a subject or transmitted through the subject. This phosphor sheet is first stored and recorded on a sheet (referred to as a sheet), and this phosphor sheet is scanned with excitation light such as a laser to generate stimulated luminescent light, and the resulting stimulated luminescent light is read photoelectrically to obtain an image signal. Based on this image signal, a radiation image of the subject or subject is output as a visible image to a recording material such as a photographic light-sensitive material or a CRT.

The radiation image information recording and reproducing system described above is based on the conventional XJ
Compared to radiography using i1 film, this method is becoming widespread because it allows radiographic images with a rich amount of information to be obtained with a much lower radiation exposure dose.

Here, the phosphor sheet is not for ultimately recording image information, but only for temporarily holding radiation image information in order to give an image to the recording medium as described above. After reading is performed by irradiation with light, the remaining radiation energy in the phosphor sheet is released by irradiation with light, erasing the remaining radiation image information, and this phosphor sheet can be used repeatedly. It is economical and convenient.

Such residual radiation image information (hereinafter referred to as residual image) can be erased by stopping the stimulable phosphor sheet after image reading in an erasing device equipped with a plurality of erasing light sources such as fluorescent lamps, and Alternatively, this is carried out by irradiating erasing light for a predetermined period of time while being transported.

Furthermore, in Japanese Patent Application Laid-Open No. 63-226632, the present applicant proposed a phosphor sheet erasing mechanism in which an erasing light source is disposed inside a housing and the phosphor sheet is bent or curved and conveyed inside the housing. ing. According to this mechanism, it is possible to use only one erasing light source, the erasing device can be downsized, and the residual image can be erased reliably and efficiently.

Incidentally, in recent years, there has been a demand for using this radiation image information recording and reproducing system to record and reproduce radiation images of long objects, such as the entire vertebrae of a human being. For this reason, diagnosis of long affected areas such as vertebrae is performed by recording images on multiple phosphor sheets, processing the images, and stitching them together. However, this method lacks speed because it takes a lot of effort to record the images and also takes time to stitch together the obtained images.

Therefore, it has been proposed to use a long phosphor sheet to record images of long affected areas such as vertebrae using a single phosphor sheet.

However, when erasing the residual image on such a long phosphor sheet, the conventional mechanism that erases while transporting the phosphor sheet takes time, and it is also necessary to stop the phosphor sheet and erase it. The problem with the erasing mechanism that uses this method is that it is unavoidable to increase the size of the mechanism.

<Problems to be Solved by the Invention> As described above, in the conventional erasing mechanism, residual images are erased while stopping or transporting the phosphor sheet.

In order to stop the phosphor sheet and erase the remaining images at once, an erasing mechanism having an erasing area corresponding to the size of the phosphor sheet is required. For example, a phosphor sheet that can photograph vertebrae is 377011QX 940mm.
However, the erasing mechanism corresponding to this needs to be extremely large, resulting in a large radiation image information reading device, which does not meet the demands of users who wish to downsize the device.

Therefore, a method is used in which the entire surface of the phosphor sheet is erased by erasing the window area multiple times from one side of the phosphor sheet. Moreover, in order to shorten the time, a large-sized erasing mechanism with a long erasing area that can be erased at one time is required.

In addition, even in the method of erasing while transporting a long phosphor sheet, it naturally takes time to erase due to the length of the phosphor sheet, and in order to erase in a short time, it is necessary to avoid increasing the size of the erasing mechanism. I can't.

Therefore, there is a desire for a compact erasing mechanism that can reliably erase residual images in a short time even if the phosphor sheet is long.

An object of the present invention is to solve the problems of the prior art, and even when erasing a residual image on a long stimulable phosphor sheet, it can be done reliably in a short time. Moreover, it is an object of the present invention to provide a compact erasing mechanism for a stimulable phosphor sheet.

Means for Solving the Problems> In order to achieve the above object, the present invention is provided at a folding portion of a conveyance path for conveying a stimulable phosphor sheet by folding it in the direction described above, and for conveying a stimulable phosphor sheet along the conveyance path. A mechanism for erasing a stimulable phosphor sheet is provided, characterized in that erasing light is irradiated onto both sides of the stimulable phosphor sheet folded back to erase remaining radiation energy.

<Operation of the Invention> The stimulable phosphor sheet erasing mechanism of the present invention having the above-mentioned predetermined configuration erases the stimulable phosphor sheet at a position where the transport path of the stimulable phosphor sheet is folded in a substantially opposite direction to form a substantially U-shape. The erasing light source is arranged so as to be sandwiched between the stimulable phosphor sheets. The folded portions of the stimulable phosphor sheet located on both sides of the erasing light source are simultaneously erased.

Therefore, according to the erasing mechanism for a stimulable phosphor sheet of the present invention, it is possible to erase two areas in a normal erasing mechanism, even when dealing with a long stimulable phosphor sheet. The compact erasing mechanism can erase the entire surface of the phosphor sheet in a short time, and when applied to radiation image information recording and reading devices, radiation image information reading devices, etc., the entire device can be significantly miniaturized. , and records and/
Alternatively, it is possible to realize a device with high reading efficiency.

<Embodiments> Hereinafter, the erasing mechanism of the stimulable phosphor sheet according to the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

FIG. 1 shows an example of a radiation image information recording/reading device that uses the stimulable phosphor sheet erasing mechanism (hereinafter referred to as "erasing mechanism") of the present invention.

Radiographic image information shown in FIG. 1! Reading device 10
(hereinafter referred to as the recording/reading device 10) is a device that records radiation image information of a subject on a stimulable phosphor sheet (hereinafter referred to as a phosphor sheet) and reads this. There is an imaging unit 12 that records radiation image information on the phosphor sheet, a reading unit 14 that photoelectrically reads the radiation image information recorded on the phosphor sheet, and a radiation image information that remains on the phosphor sheet after reading is completed. an erasing section 16 that erases the phosphor sheet, a special section 18 where the phosphor sheet after erasing is on standby, a control section 2o that controls the operation of the entire device, and a conveyance means that conveys the phosphor sheet along a predetermined path. It is formed.
Here, the erasing section 16 can be used as the erasing mechanism of the present invention.

In such a recording/reading device 10, normally three phosphor sheets are loaded, and the recording/reading device 10 is loaded with three phosphor sheets at predetermined intervals.
It is used for recording and reading radiographic image information.

Note that the phosphor sheet is conveyed with its elongated direction aligned with the conveyance direction.

In the illustrated example recording/reading device 10, the imaging unit 12 includes an imaging stage 22, a support base 24 that supports a phosphor sheet, and a pressing member made of a radiolucent material that can be moved into and out of contact with the support base 24. It has a member 26, a pair of transport rollers 28 and 3o, and a radiation source (not shown).

In the photographing section 12, the phosphor sheet is conveyed from above by a pair of conveyance rollers 28 (30), stopped at a predetermined position, and then fixed at a predetermined position by a support base 24 and a pressing member 26. Next, radiation is irradiated from the radiation source to the phosphor sheet through the subject placed at a predetermined position on the imaging table 22, and radiation image information of the subject is stored and recorded on the phosphor sheet. .

Note that the photographing section 12 may be configured to be movable in the vertical direction in the figure, if necessary.

After photographing, the phosphor sheet is guided by a conveyance guide 32 and conveyed downward by a pair of conveyance rollers 28 and 30, and then passed through rollers 34, 36, an endless belt 38, and four tensioners that stretch this endless belt 38. It is conveyed to the left in the figure by a conveyor means constituted by a belt conveyor made up of rack rollers 40 and a conveyance guide 44. Next, the phosphor sheet is transferred to a belt conveyor consisting of a roller 46, an endless belt 48.5 tension rollers 50, and a nip roller 52, and an endless belt 56.
, and a belt conveyor consisting of two bow-length rollers 58, the conveyor is conveyed upward in the figure, and then the conveyance direction is changed downward by the roller 46, and guided by the conveyor guide 2 to the reading unit. It will be brought in on the 14th.

The reading section 14 includes an optical unit 64 that includes an excitation light source, a light deflector, etc., and emits excitation light deflected in the main scanning direction perpendicular to the plane of the paper, and an optical unit 64 that directs the carried phosphor sheet in the main scanning direction. A pair of sub-scanning rollers 66 and 68 that transport in the sub-scanning direction indicated by orthogonal arrow a, and a transport guide 70;
A condensing optical system 7 that includes a condensing guide, a photodetector, etc., condenses stimulated luminescence light generated by irradiation with excitation light, and performs photoelectric conversion.
2.

The phosphor sheet that has been carried into the reading section 14 is conveyed in the direction of arrow a by a pair of sub-scanning rollers 66 and 68.
Two-dimensional scanning is performed by excitation light deflected in the main scanning direction. From the excitation light irradiation position of the phosphor sheet,
Stimulated luminescence light corresponding to the accumulated and recorded radiation image information is emitted.

This stimulated luminescent light is collected by a focusing optical system 72, photometered, photoelectrically converted, and sent as an electrical signal to the control unit 20 for image processing.

The phosphor sheet whose image has been read is guided by a transport guide 74 and transported upward by a pair of sub-scanning rollers 66 and 68, and further transported upward by a pair of transport rollers 76 to be carried into the erasing section 16.

The erasing unit 16 applies the erasing mechanism of the present invention, and includes a first belt conveyor composed of a roller 78, an endless belt 80, and four tension rollers 82;
An endless belt 84, a second belt conveyor included below the first belt conveyor consisting of five tension rollers 86, an erasing light source unit 90, and phosphor sheets above and below the erasing light source unit 90. It has a pair of rollers 92 and 94 and nip rollers 96 and 98 to assist in the conveyance of the paper.

In such an erasing unit 16, the phosphor sheet is carried upward by a pair of conveying rollers 76, is folded back through the upper part of a roller 78, and the conveying direction is changed to the opposite direction, and an erasing light source unit 90 is conveyed downward. The material is conveyed through an inverted U-shaped conveyance path sandwiching the two sides, repeatedly conveying a predetermined length and stopping.

Further, the erasing light source unit 90 has a width slightly larger than the lateral direction of the phosphor sheet (in the direction perpendicular to the plane of the paper in FIG. 1), and the surface facing the phosphor sheet is inside the housing 100 through which light can pass. It has six erasing light sources 88 on both sides of the housing 100 (in the left-right direction in the figure).
That is, it is configured to be able to irradiate erasing light onto both sides of the phosphor sheet located at the folded portion.

In other words, in the illustrated erasing mechanism, the phosphor sheet is stopped and transported in the inverted U-shaped transport path sandwiching the erasing light source unit 90, and the region sandwiching the erasing light source unit 90 when the transport is stopped. are erased on both sides of the erase light source unit 90.

2a, 2b and 2c are diagrams conceptually showing the operation of erasing the residual image of the phosphor sheet A in the erasing section 16, and FIG. A conceptual diagram of each surface is shown. In addition, Figure 2a~
In FIG. 2C, for ease of explanation, only the phosphor sheet A, the roller 78, the erasing light source unit 90, the pair of rollers 92, 94, the nip rollers 96, 98, and the tension roller 86 corresponding to both nip rollers are shown. , and other members are omitted.

The phosphor sheet A carried into the erasing section 16 is conveyed upward by the first belt conveyor and the second belt conveyor, and further changes its path downward at the upper part of the roller 78.

This conveyance stops when the phosphor sheet A is conveyed to the position shown in FIG. Image information remaining in areas 102a and 102b is erased. As the erasing light source that can be used in the present invention, any light source that is commonly used as erasing light for stimulable phosphor sheets, such as a fluorescent lamp, can be used.

After stopping the conveyance of the phosphor sheet A, when a predetermined erasing time set to ensure that the remaining image is completely erased has elapsed, the conveyance is started again, and then the conveyance is continued at the position shown in FIG. 2b. Stop, then area 1 of phosphor sheet A
04a and 104b are erased. Note that while the phosphor sheet A is being transported, the erasing light source 88 may be turned off or may be turned on all the time.

When the conveyance of the phosphor sheet A is stopped and a predetermined erasing time has elapsed, the conveyance is started again and stopped at the position shown in FIG. 2c, and the areas 106a and 10 of the phosphor sheet A are
6b is performed, and erasing of the remaining image on the entire surface of the phosphor sheet A is completed.

That is, in the erasing mechanism of the present invention represented by the erasing section 16 in the illustrated example, the erasing light source unit 90 is disposed inside the transportation path of the phosphor sheet at a position where the transportation path of the phosphor sheet is approximately U-shaped. Therefore, it is possible to erase two areas in one go, which would otherwise be erased in one go with a normal erasing mechanism.

Therefore, the device can be significantly downsized, and
It is possible to quickly erase residual images with high efficiency.

Note that the control of conveyance and stopping of the phosphor sheet A described above is performed by the control section 2o of the recording/reading device 10.

In the illustrated example, a belt conveyor is used as the main conveyance means, but the present invention is not limited to this, and a pair of conveyance rollers, a nip roller, etc. may be applied as the conveyance means. .

The number of erasing light sources 88 is not limited to six as shown in the illustrated example, and may be set as appropriate according to the size of the erasing mechanism.
Also, one piece is sufficient as long as it has a sufficient amount of light.
Furthermore, instead of arranging the light sources in two rows according to the surfaces to be erased as in the illustrated example, the light sources may be arranged in one row to erase both sides. Furthermore, the method is not limited to one in which the phosphor sheet is repeatedly stopped and transported, but may be one in which erasing is performed while the phosphor sheet is transported.

After the residual image has been erased in this way, the phosphor sheet is conveyed downward by the first belt conveyor and the second belt conveyor, and the surface is cleaned by the cleaning device 108, and the special It is carried into the section 18.

The special equipment section 18 includes a roller 110 and an endless heald 112.
, a belt conveyor composed of four tension rollers 114, an endless belt 116, and two tension rollers 118, and a belt conveyor composed of an endless belt 116 and two tension rollers 118. The phosphor sheet is conveyed upward and stopped at a predetermined position sandwiched between both belt conveyors, where the phosphor sheet is held until it is used for the next photographing.

When the phosphor sheet held in the special equipment section 18 is used for photographing, the phosphor sheet held in the special equipment section 18 is conveyed upward by both belt conveyors of the holding section, and then transferred to the rollers 120.
122, an endless belt 124, and four tension rollers 126, and a conveyance means having a conveyance guide 128. It will be brought in.

The above explanation has been made using an example in which the erasing mechanism of the present invention is applied to a radiographic image information recording/reading device, but the present invention is not limited to this, and may be applied to a radiographic image information reading device. Alternatively, the erasing mechanism of the present invention may be integrated into a single device.

Although the erasing mechanism of the stimulable phosphor sheet of the present invention has been described in detail above, the present invention is not limited thereto, and various changes and improvements can be made without departing from the gist of the present invention. Of course, it is also good.

<Effects of the Invention> As explained in detail above, according to the stimulable phosphor sheet erasing mechanism of the present invention, the stimulable phosphor sheet is erased at a position where the stimulable phosphor sheet transport path is turned back in substantially the opposite direction. By arranging an erasing light source inside, it is possible to erase twice the area that can be erased by a normal device.

Therefore, even when dealing with a long stimulable phosphor sheet, it is possible to erase the entire surface of the phosphor sheet in a short time using a small erasing mechanism. When applied to a device or the like, it is possible to significantly downsize the entire device and realize a device with high recording and/or reading efficiency.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing an example of a radiation image information recording/reading device to which the stimulable phosphor sheet erasing mechanism of the present invention is applied. 2a, 2b, and 2c are diagrams conceptually showing the operation of the radiation image information recording/reading apparatus shown in FIG. 1. FIG. 3 is a diagram conceptually showing the surface of the stimulable phosphor sheet subjected to erasing. Explanation of symbols 10... Radiographic image information recording/reading device, 12... Imaging section, 14... Reading section, 16... Erasing section, 18... Special equipment section, 20... Control section, 22... Shooting stand, 24... Support stand, 26... Pressing member, 28.30.76... Conveyance roller pair, 32 44.6
2,70.74 128...Conveyance guide, 34, 36. 46. 78. 1 10°120
．． 122...roller, 3g, 48. 56. 80. 84, 11
2116.124...Endless belt, 40.50
,58,82.86゜114.118.126...Long bow roller 52.96
．． 98... Nip roller, 64... Light source unit, 86. 68... Sub-scanning roller pair, 72... Condensing optical system, 88... Erasing light source, 90... Erasing light source unit, 92. 94...Roller pair, 100...Housing, 102a, 102b, 104a. 104b, 106a, 106b--area, 108...
・Cleaning device, L...excitation light, A...stimulable phosphor sheet

Claims (1)

[Claims] (1) The stimulable phosphor sheet is disposed at a folded portion of a conveyance path that is folded in substantially the opposite direction to convey the stimulable phosphor sheet, and irradiates erasing light onto both sides of the stimulable phosphor sheet that has been folded back along the conveyance path. An erasing mechanism for a stimulable phosphor sheet, characterized in that it erases residual radiation energy.