JPH0685046B2 - Radiation image information reader - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a radiation image information reading apparatus used in a radiation image information recording / reproducing system, and more particularly to radiation that combines a reading unit and an erasing unit integrally. The present invention relates to an image information reading device.

(Technical background and prior art of the invention) When a certain kind of phosphor is irradiated with radiation (X-rays, α-rays, β-rays, γ-rays, electron beams, ultraviolet rays, etc.), a part of this radiation energy is in the phosphor. It is known that when the phosphor is irradiated with excitation light such as visible light, the phosphor emits stimulated luminescence according to the accumulated energy. It is called a luminescent phosphor (stimulable phosphor).

Using this stimulable phosphor, the radiation image information of a subject such as a human body is once recorded in a sheet-shaped stimulable phosphor, and this stimulable phosphor sheet (hereinafter, simply referred to as a sheet) is used for laser light or the like. Scan with excitation light to generate stimulated emission light, obtain the image signal by photoelectrically reading the resulting stimulated emission light,
The applicant has already proposed a radiation image information recording / reproducing system for outputting a radiation image of a subject on the basis of this image signal as a visible image on a recording material such as a photographic photosensitive material or a CRT. (JP-A-55-12429, JP-A-56-11395,
55-163472, 56-104645, 55-116340, etc. ) The stimulable phosphor sheet in the above system stores and records radiation image information and temporarily holds the recorded image information until it is read by the excitation light scanning. After finishing, it is desirable to erase the image information remaining on the sheet and reuse the sheet.

Based on such a request, a radiation image information reading apparatus has been proposed which includes a reading unit for reading image information recorded on a sheet and an erasing unit for erasing the image information remaining on the sheet. .

In the radiation image information reading apparatus, a cassette containing a stimulable phosphor sheet that has been photographed by an external imaging device is loaded in a cassette holding unit, and the stimulable phosphor sheet is taken out of the cassette and read by the reading unit. To read the image information, and further erase the image information remaining on the sheet after the reading is completed by the erasing unit. The erased sheets are in a state in which they can be taken out of the reading device to record the image information again, but these erased sheets are once accumulated in the accumulating tray in the reading device. Generally, the whole tray in which sheets are accumulated is taken out of the apparatus. The sheets accumulated in the accumulating tray need to be accommodated in the cassette as described above when a new photographing is performed, and thus it is necessary to load the sheets one by one into the cassette before photographing.
For this reason, it takes a lot of time before the sheets that can be photographed are stored again in the cassette and photographing is performed, and there is a problem that the sheets cannot be efficiently recycled and reused. Also, this loading is performed by a dedicated loader or by manual work. However, when a dedicated loader is used, the cost of the entire system increases, and when manual loading is performed, the stimulable phosphor is used. Since the sheet is directly touched, there is a disadvantage that it is not preferable in handling the sheet.

(Object of the Invention) In view of the above problems, the present applicant loads a cassette containing a stimulable phosphor sheet that has been photographed in an external photographing device into a cassette holder and removes the cassette from the cassette. After reading and erasing the stored stimulable phosphor sheet, the reader is proposed to carry it back into the original empty cassette and store it (Japanese Patent Application No. 60-
232029).

The present invention aims at further downsizing of such a reading device.

(Structure of the Invention) The radiographic image information reading device of the present invention comprises:
A cassette holding unit that detachably holds a cassette that can store a stimulable phosphor sheet together with an erasing unit, and has a take-out unit that takes out the sheet from the cassette, and
In order to receive the sheet carried out from the cassette holding section, convey the sheet to the reading section and the erasing section in this order, and to further convey the sheet passing through the erasing section to the cassette in the cassette holding section, the sheet is omitted. It is characterized in that it comprises a sheet conveying means for conveying in an annular shape, and the cassette holding portion is provided inside a substantially annular conveying path by the sheet conveying means.

That is, according to the apparatus of the present invention, the cassette holding portion is provided inside the substantially circular sheet conveying path, so that the space of the cassette holding portion is almost absorbed in the inner space of the conveying path. Therefore, the cassette holding portion does not project outside the device, and the entire device can be downsized. It should be noted that here the transport path is substantially annular means that the main transport paths are connected in an annular shape, and its specific shape is not necessarily limited to a circle, and transport by switchback is It may be included in part.

Embodiments Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic side view showing the outline of a radiation image information reading apparatus according to an embodiment of the present invention.

The reading device of the present invention includes a cassette holding unit 10 that detachably holds a cassette 2 that can hold a stimulable phosphor sheet (hereinafter, simply referred to as a sheet) 1, a reading that reads image information accumulated and recorded on the sheet. The unit 20, an erasing unit 30 for erasing the image information remaining on the sheet after the reading is completed,
Further, the sheet 1 taken out from the cassette 2 is provided in the apparatus.
A sheet conveying means 50 that receives the sheet 1 and conveys it to the reading unit 20 and the erasing unit 30 in this order, and conveys the sheet 1 that has been erased in the erasing unit 30 to the cassette holding unit 10 in a substantially annular shape. It is provided. Further, the cassette holder 10 is arranged inside the substantially annular conveying path by the sheet conveying means 50.

The cassette 2 photographed on the sheet 1 held inside by an external photographing device (not shown) is loaded into the cassette holding unit 10. The cassette 2 has a light-shielding property in order to prevent the sheet from being exposed to external light when recording (imaging) image information by irradiating the sheet with radiation, and the cassette body that holds the sheet 1 It consists of 2A and a lid part 2B that can be opened and closed. In addition, the sheet 1
Is housed in the cassette 2 with the surface having the stimulable phosphor layer facing down. The opening / closing of the cassette in the cassette holding unit 10 will be described below with reference to FIG.

The lid 2B of the cassette 2 is urged by a spring and the lid 2B
Lock part 2b that locks the cassette body 2A with the cover closed
Is provided. Inside the cassette holder 10, there is provided a lock release claw 11 which is driven by a rotary solenoid or the like and rotates so that it can take a first position shown by a broken line in the drawing and a second position shown by a solid line in the drawing. When the cassette 2 is loaded into the cassette holding portion 10 with the lid portion 2B locked, the unlocking claw 11 rotates from the first position to the second position to press the lock portion 2b. , Unlock the lid 2B.

Further, in the cassette holding portion 10, there are provided a biasing means 15 for biasing the lid portion 2B toward the closed position and a lid portion opening / closing means 14 including a swing arm 12 and a suction means 13, as described above. When the lock of the lid portion 2B is released,
And the swing arm 12 moves from the position shown by the broken line in the figure to the position shown by the solid line in the figure, and opens the lid 2B against the biasing force of the biasing means 15. When the lid 2B is opened in this way,
As shown in FIG. 1, a suction plate 16 which is a sheet take-out means enters the cassette to suck the sheet 1, and the sheet 1 is taken out of the cassette 2 and delivered to a sheet conveying means 50 in the vicinity. As will be described later, when the erased sheet is carried into the cassette 2 and the cassette 2 is taken out from the cassette holding portion, the lid opening / closing means 14 is moved to the position shown by the broken line in FIG. 2 again. The lid portion 2B is closed, and the lid portion 2B is the biasing means.
By being biased by 15, the lock portion 2b engages with the protrusion 2a of the cassette body 2A and is locked in the closed position.

The sheet 1 taken out from the cassette 2 as described above
Is indicated by the arrow A ₁ by the sheet conveying means 50 as shown in FIG.
Sent in the direction. In the apparatus of the present embodiment, between the cassette holding unit 10 and the reading unit 20 of the sheet conveying means 50,
A first stacker 40, which has a plurality of sheet accommodating portions 41 for accommodating sheets one by one and temporarily accommodates the sheet 1 carried out from the cassette holding portion 10, is provided. In the first stacker 40, as shown in FIG. 3, a plurality of trays 43 each capable of holding one sheet 1 are held in parallel in a housing 42 composed of four side walls at equal intervals. The trays 43 are each inclined obliquely upward. Each of the trays 43 has an L-shaped cross section, and the space formed by the trays 43 serves as the sheet storage portion 41. The housing 42 holding the plurality of trays 43 is driven by a driving mechanism such as a motor (not shown),
The wheel 44 attached to the lower end moves in the direction of arrow B by being moved on the rail 45. The movement of the housing 42 in the direction of the arrow B causes a predetermined tray 43 to be positioned below the transport rollers 51A and 51B for loading the sheet 1 into the stacker 40, and the tray 43 is at the position indicated by the broken line as shown in the drawing. To the position indicated by the solid line, the space at the upper end of the sheet is widened so that the sheet 1 can be easily carried in. The sheet 1 is carried into the tray 43 whose inclination is changed as described above by the carrying rollers 51A and 51B. When the loading of the sheet is completed, the tray 43 is returned to the original inclination, and the housing 42 is further moved in the arrow B direction to prepare for the loading of the sheet to the next tray 43. When the sheet 1 is unloaded from the stacker, the housing 42 moves in the direction of arrow B, and the unloaded sheet 1 is unloaded.
The predetermined tray 43 holding the trays is positioned above the transport rollers 52A and 52B provided below the stacker, and the bottom plate 43a of the tray 43 is drawn from the position shown by the broken line in the figure as shown in FIG. The sheet 1 is rotated from the position indicated by the solid line to drop the sheet 1 from the inside of the tray 43, and the conveying rollers 52A and 52B grip the leading end of the sheet 1 to convey the sheet 1 to the outside of the stacker 40. The sheet 1 is further conveyed in the direction of arrow A ₂ by the sheet conveying means 50 and carried into the reading unit 20.

The reading unit 20 scans the sheet 1 on which image information is accumulated and recorded with excitation light 21 such as a laser beam, and stimulated emission light emitted from the sheet 1 by the scanning is detected by a photoelectric reading unit 22 such as a photomultiplier. It is photoelectrically read to obtain an electric image signal for outputting a visible image. In the figure, 23 is an excitation light source, 24 is an optical deflector such as a galvanometer mirror, and 26 is a light guide 22a of photoelectric reading means for the stimulated emission light emitted from the sheet 1 (the light guide 22a totally reflects the stimulated emission light. It is a reflection mirror that reflects the light toward a photodetector 22b such as a photomultiplier while guiding it).

The sheet 1 carried into the reading section 20 is conveyed in the direction of the arrow A ₃ by the sheet conveying means 50, and the entire surface of the sheet is two-dimensionally scanned by the exciting light 21 deflected substantially perpendicular to the conveying direction, and stimulated emission of light. Light is generated, and this stimulated emission light is detected by the photodetector 22b via the light guide 22a to read the image information.

Incidentally, in reading the radiation image information, reading for obtaining the image signal for visible image output described above (main reading)
Prior to the above, pre-reading for reading the outline of the radiation image information accumulated and recorded on the sheet 1 in advance is performed, and the reading conditions and the like for the main reading are determined based on the image information obtained by this pre-reading. A method of performing the main reading according to the reading conditions is known.

As a method of performing such pre-reading, for example, the sheet 1 is scanned using excitation light having an energy lower than that of the excitation light used for the main reading, and the stimulated emission light emitted by this scanning is also photoelectrically read by the photoelectric reading means. There is a method of reading (see, for example, JP-A-58-67240).

The reading unit in the present invention may be a unit that performs both main reading and pre-reading, in addition to the above-described part that performs only main reading. For example, the sheet 1 is conveyed in the direction of the arrow A ₃ and pre-reading is first performed. Then, the sheet is switched back by the switch back in the direction of the arrow A ₄ and returned to the reading start position, and the main reading is performed again in the direction of the arrow A _3. You can do it. Each optical member arranged in the reading unit is not limited to the above-mentioned one. For example, as a photoelectric reading unit, it is long along the main scanning line as in Japanese Patent Application No. 60-156255 filed by the applicant of the present application. The photomultiplier may be arranged to detect the stimulated emission light without passing through the light guide sheet 22a.

The reading of the image information by the reading unit 20 takes a relatively long time, but since the first stacker 40 is provided in the apparatus of the present embodiment as described above, one sheet can be read. The sheets 1 that have been photographed can be sequentially loaded into the stacker 40 while the sheets are being read, and the sheets 1 can be processed very efficiently. Further, it is possible to preferentially send a specific sheet out of the sheets 1 accommodated in the stacker 40 to the reading section for reading. Note that the cassette 2 containing a new sheet is always loaded into the cassette holding unit 10 after the reading unit 20 has finished reading one sheet, and the sheet taken out from the cassette 2 is not sent to the reading unit 20. The stacker 40 does not necessarily have to be provided when it is not necessary to wait.

As described above, the sheet 1 whose image information has been read in the reading section 20 is conveyed in the directions of arrows A ₅ and A ₆ by the sheet conveying means 50 and is conveyed toward the erasing section 30.

The erasing unit 30 is for erasing the radiation image information remaining on the sheet 1 after the reading is completed (releasing the radiation energy remaining in the stimulable phosphor).
That is, a part of the radiation image information accumulated and recorded on the sheet 1 is still left on the sheet after reading, and the erasing portion of the remaining image information is erased in order to reuse the sheet 1.
Conducted at 30. Any erasing method in the erasing unit 30 may be used. The erasing unit 30 in the present embodiment includes an erasing light source such as a fluorescent lamp, a tungsten lamp, a sodium lamp, a xenon lamp, an iodine lamp.
A plurality of sheets 31 are provided, and the sheet 1 is conveyed in the direction of the arrow A _{7 and} is irradiated with light from these erasing light sources 31 to release the residual radiation energy on the sheet.

The sheet 1 which has been erased in the erasing section 30 is indicated by an arrow A ₈
After being conveyed in the direction, it is further conveyed to arrows A ₉ and A ₁₀ . When the sheet 1 is conveyed in the direction of arrow A ₁₀ and reaches the position indicated by the broken line in the figure, the sheet 1 is switched back by the arrow.
It is sent back in the A ₁₁ direction. The sheet sent back is further indicated by arrow A.
_The sheet is conveyed in ₁₂ directions and is loaded into the second stacker 60 provided in the conveying direction. The second stacker has a structure similar to that of the first stacker 40 described above, and a plurality of trays form a sheet storage portion 61 for holding the sheets 1 one by one, and move in the direction of arrow C to erase. The sheet 1 sent from the unit is received in any one of the sheet storage units 61. A plurality of sheets are already stored in the stacker 60 before the sheet 1 is loaded.

As described above, the sheets 1 accommodated in the respective sheet accommodating portions 61 of the second stacker 60 are selected one by one and taken out,
It is conveyed into the empty cassette 2 held in the cassette holding section 10. The sheet is carried into the cassette 2 immediately after the sheet suitable for the cassette is selected from the sheets accommodated in the stacker 60 and the above-mentioned sheet 1 is taken out from the cassette 2. At the lower end of the stacker 60, as shown in FIG. 1, a pair of transport rollers 54A, 54B for receiving the sheet 1 discharged from the second stacker 60 and transporting it to the outside of the stacker are provided, and each tray is selected. Sheet storage portion 61 that holds the opened sheet 1
Is moved in the direction of arrow C so as to be positioned above the transport rollers 54A and 54B, and when the movement is completed, the lower end of the sheet storage portion 61 that holds the selected sheet is held open. Sheet 1 drops. The dropped sheet 1 is gripped by the transport rollers 54A and 54B, and is discharged to the outside of the stacker 60 by the rotation of the transport rollers.

The sheet 1 discharged from the stacker 60 is a sheet conveying unit.
After being conveyed in the direction of arrow A ₁₃ by 50, and after passing through the auxiliary erasing section 70 provided in the conveying path, it is further conveyed in the direction of arrow A ₁₄ and carried into the cassette 2. After the trailing end of the sheet 1 carried in the cassette 2 in the carrying-in direction is separated from the sheet conveying means 50, the suction plate 16 sucks the sheet to completely carry it into the cassette 2. Good. In addition, the sheet 1 carried into the cassette 2
Is the erasing unit that has been held in the second stacker 60 before the cassette 2 was loaded in the cassette holding unit 10.
Since the elapsed time after erasing by 30 may be long, light is emitted from the erasing light source 71 in the auxiliary erasing section 70 described above. That is, the stimulable phosphor sheet 1 has a property that, even if the erasing is performed once, when a certain time or more elapses, the radiation emitted from a radioisotope such as ²²⁶ Ra or ⁴⁰ K which is contained in the stimulable phosphor in a trace amount is Radiation energy may be accumulated by environmental radiation such as cosmic rays and X-rays from other X-ray sources, and this radiation energy may become noise for the next captured image. In order to prevent the generation of this noise, the sheet 1 is made to pass through the auxiliary erasing unit 70, and the sheet 1 is made to release the radiation energy accumulated in the sheet during the waiting time in the second stacker 60. Erasing (so-called secondary erasing) is performed. Therefore, the sheet 1 carried into the cassette 2 can be taken out of the apparatus while being held in the cassette 2 and immediately photographed. In this way, when the sheet conveying means 50 is provided with the second stacker 60, the stacker 60 is immediately held after the cassette 2 is held in the cassette holding portion 10 and the photographed sheet is taken out from the cassette 2. It is possible to take out a sheet corresponding to the cassette 2 from the inside and carry it into the cassette 2. Therefore, in a short time after the cassette holding the photographed sheet is loaded into the cassette holding unit 10, the cassette 2 into which a new sheet has been loaded is taken out from the cassette holding unit 10 and carried to an external photographing device. You can take a picture. Further, even when the size of the sheet held in the cassette 2 is different for each cassette, various sheets are held in advance in the stacker 60, and the stacker is loaded in accordance with the size of the cassette loaded in the cassette holding portion. Since it suffices to select and carry out the sheet from within 60, the sheet can be efficiently reused regardless of the size of the sheet. In order to hold various sheets in the stacker 60 in advance, the sheets may be collected in the stacker 60 without taking out the sheets from the stacker 60 for a while after starting the use of the apparatus. Before use of the apparatus, unused sheets of various sizes may be stored in the stacker in advance. In order to take out a sheet of a desired size from the stacker 60 according to the cassette loaded in the cassette holder 10, the stacker 60
The control means for storing the size of the sheet accommodated in each of the sheet accommodating portions 61 and controlling the work of selecting and extracting the sheet of a desired size according to the cassette loaded in the cassette holding portion 10 is provided. It is necessary, and the apparatus of the present embodiment is provided with a control unit 80 above the reading unit 20 for performing the above control.

Note that the apparatus of the present invention uses the sheet 1 carried out from the erasing unit 30.
May be directly carried into the cassette 2, and the second stacker 60 and the auxiliary erasing section 70 may be eliminated to further downsize the apparatus.

By the way, this apparatus takes out the sheet 1 from the cassette 2 and conveys it to the reading unit 20 and the erasing unit 30, as described above.
After reading and erasing sheet 1 again,
The sheet conveying means 50 for carrying in the sheet conveys the sheet 1 in a substantially annular shape, and the cassette holding portion 10 for detachably holding the cassette 2 is arranged inside the substantially annular conveying path. . Therefore, the cassette holder does not project to the outside of the sheet conveying means, and the entire apparatus is compact. Further, in the apparatus of this embodiment, since the cassette holding portion is arranged inside the sheet conveying path as described above, the cassette is arranged in the lateral direction of the substantially annular conveying path (in FIG. It is designed to be loaded in the cassette holder so that it does not cross the transport path from the direction (perpendicular to). An example of attachment / detachment of the cassette to / from the cassette holding portion will be described below with reference to FIGS. 5 and 6.

The cassette 2 is inserted into the cassette holder 10 along the guide portion 18A of the holder 18 from the direction of arrow D. The holding table 18 is formed with a step portion 18B whose position is lower than that of the guide portion 18A, and a spring 17a is formed on the step portion 18B.
There is provided a width-shifting plate 17 that is biased in the direction opposite to the insertion direction of the cassette 2 and is slidable on the step portion 18B. The cassette 2 moves onto the holding table 18 while moving the positioning plate 17 in the insertion direction against the biasing force of the spring 17a,
When the rear end in the insertion direction reaches the stepped portion 18B, it falls onto the stepped portion 18B and is urged by the width-shifting plate 17 to perform positioning in the insertion direction. Moreover, the cassette 2 is provided on the step portion 18B.
Is provided with a plurality of slits 18a and 18b extending in the inserting direction, and below each slit, as shown in FIG. 6 which is a sectional view taken along the line AA of FIG. 5, it projects above the slit. Positioning plates 19A and 19B are provided so as to rotate so as to be able to take a first position and a second position that retreats below the slit. These slits 18a, 18b and positioning plates 19A, 19B
Is provided at a position corresponding to each width of the cassettes of a plurality of sizes that may be loaded in the cassette holder 10, and a predetermined positioning plate is selectively provided according to the size of the cassette to be loaded. The cassette is moved to the first position to position the cassette. When the cassette 2 is two-dimensionally positioned on the step portion 18B in this way, the cassette is opened and the sheets stored inside are taken out as described above. On the other hand, a hole portion 18C is provided in the step portion 18B in the vicinity of the guide portion 18A, and when the cassette 2 is taken out from the cassette holding portion 10, a pin 19C is inserted into the hole portion 18C and the cassette 2 is inserted. Push up the end of. When the end portion of the cassette 2 is pushed up to the height of the guide portion 18A, the cassette 2 is pushed out of the cassette holding portion by the biasing force of the width-shifting plate 17.

Needless to say, the cassette attaching / detaching mechanism described above is an example, and the cassette may be attached / detached to / from the cassette holding portion by various other means. Further, the cassette may be loaded in a slightly oblique direction as long as it does not cross the transport path. Furthermore, regarding the entire reading device, the shape of the conveyance path of the sheet conveying means, the reading unit,
The arrangement and structure of the erasing portion and the like are not limited to those shown in the above embodiment.

(Effects of the Invention) As described above, according to the radiation image information reading apparatus of the present invention, the cassette holding unit is arranged inside the substantially annular conveying path of the sheet by the sheet conveying unit, so that the cassette holding unit is provided. A compact reading device can be realized without projecting outside the device.

[Brief description of drawings]

1 is a schematic side view showing a radiation image information reading apparatus according to an embodiment of the present invention, FIG. 2 is a schematic view showing an opening / closing mechanism of a cassette, FIG. 3 is a side view showing a structure of a stacker of the apparatus, FIG. 4 is a schematic view for explaining the taking out of the sheets from the stacker, FIG. 5 is a perspective view showing the structure of the cassette holder, and FIG. 6 is a sectional view taken along the line AA of FIG. 1 ... Accumulable phosphor sheet, 2 ... Cassette 10 ... Cassette holding section, 20 ... Reading section, 30 ... Erase section, 50 ... Sheet conveying means

Claims (1)

[Claims] 1. A reading unit for reading radiation image information accumulated and recorded on a stimulable phosphor sheet, an erasing unit for erasing the radiation image information remaining on the sheet after the reading is completed, and the sheet can be accommodated. Removably holds a simple cassette,
A cassette holding unit having a take-out unit that takes out the sheet from the cassette, receives the sheet carried out from the cassette holding unit, conveys the sheet in this order to the reading unit and the erasing unit, and further passes the sheet passing through the erasing unit. The cassette holding unit is composed of a sheet conveying unit that conveys the sheet in a substantially annular shape so as to be carried into the cassette, and the cassette holding unit is provided inside the substantially annular conveying path by the sheet conveying unit. A characteristic radiation image information reading device.