JPH03221940A - Radiograph information recorder/reader - Google Patents

Abstract

PURPOSE:To significantly facilitate picture photographing and reproduction and to miniaturize a device by at the time of reading radiograph information by cylindrically scanning a stimulable phosphor sheet with excitating light after the sheet is wound around a drum-like platen, drawing the sheet and stretching only at the time of recording radiograph information. CONSTITUTION:Radiograph information is read by winding the stimulable phosphor sheet 14 around the drum-like platen 11. When a radiograph is recorded on the sheet 14, it is drawn from the platen 11 and is stretched. Thus, the device can be miniaturized substantially. Specifically, one end of the sheet 14 is supported by the drum-like platen 11, and the sheet 14 drawn therefrom and stretched is irradiated with radial rays, thereby recording radiograph information onto a picture recording part; when the record is read, a reading unit 22 is moved, and a laser beam having a wavelength in the excitating wavelength band of the sheet 14 is emitted from a laser light source.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention records radiographic image information on a stimulable phosphor sheet, then irradiates the sheet with excitation light, thereby increasing the luminance emitted from the sheet. Regarding a radiation image information recording/reading device that detects exhaustion light and reads the radiation image information,
In particular, the present invention relates to a radiation image information recording/reading device that can use a stimulable phosphor sheet repeatedly and is miniaturized.

(Prior art) When a certain type of phosphor is irradiated with radiation (X-rays, α-rays, β-rays, γ-rays, ultraviolet rays, electron beams, etc.), part of the energy of this radiation is accumulated in the phosphor. Then, when the phosphor is irradiated with excitation light such as visible light, the phosphor exhibits stimulated luminescence depending on the accumulated energy. A phosphor exhibiting such properties is called a stimulable phosphor (stimulable phosphor).

Using this stimulable phosphor, radiation image information of a subject such as a human body is recorded on a sheet with a stimulable phosphor layer (hereinafter referred to as a stimulable phosphor sheet), which is then scanned with excitation light. A method has been proposed in which the stimulated luminescent light is photoelectrically read to obtain an image signal, and the image signal is processed to obtain a radiation image of a subject with good diagnostic suitability (for example, Kaisho 55-12429, Kaisho 55-11
No. 6340, No. 55-163472, No. 56-113
No. 95, No. 56-104645, etc.). This final image can be played back as a hard copy or on a CRT.
You can play on it.

In such radiation image information recording and reproducing methods, the stimulable phosphor sheet does not ultimately record image information, but temporarily carries image information in order to provide the image to the final recording medium as described above. Therefore, this stimulable phosphor sheet may be used repeatedly, and such repeated use is extremely economical.

In order to reuse the stimulable phosphor sheet as described above, the radiation energy remaining in the stimulable phosphor sheet after the stimulated luminescence light has been read can be absorbed by, for example,
As shown in No. 2, No. 56-12599, residual radiation images may be erased by irradiating the sheet with light or heat, and the stimulable phosphor sheet may be used again for recording radiation images.

Therefore, the present applicant proposed a circulating conveyance means for conveying a stimulable phosphor sheet capable of storing and recording radiation images along a predetermined circulation path, and a means for irradiating the sheet with radiation through a subject in the circulation path. an image recording unit that accumulates and records radiation image information of the subject on this sheet;
An excitation light source that is located in the circulation path and emits excitation light to scan a sheet on which radiation image information is stored and recorded in the image recording section, and reads stimulated luminescence light emitted from the sheet scanned by the excitation light. an image reading section comprising a photoelectric reading means for obtaining an image signal; and an image reading section which is located in the circulation path and remains on the sheet after the image reading is performed in the image reading section before an image is recorded on the sheet. We have previously proposed a radiation image information recording/reading device in which a stimulable phosphor sheet is repeatedly used by circulating the stimulable phosphor sheet between the various parts, and an erasing part that emits radiation energy. Showa 59-1
92240 etc.). According to the radiographic image information recording/reading device having such a structure, radiographic image information can be recorded and read continuously and efficiently.

Furthermore, as shown in, for example, Japanese Unexamined Patent Publication No. 1-178956, a stimulable phosphor sheet is formed into a flexible endless belt, and the sheet is stretched between, for example, a pair of rollers. Radiographic image information in which radiographic image information is recorded (photographed) on a stretched portion of the sheet, and then the stimulable phosphor sheet is rotated to sequentially send the radiographic image information recording portion to an image reading section and an erasing section. Record reading devices have also been proposed.

(Problems to be Solved by the Invention) However, in the radiation image information recording/reading device that transports the stimulable phosphor sheet along the circulation path as described above, the circulation path takes up space and the device is It is recognized that the problem is that it is easy to increase the size.

On the other hand, a radiation image information recording/reading device using a stimulable phosphor sheet in the form of an endless belt does not require a large sheet circulation path as described above, but it is still possible to use a stimulable phosphor sheet with a size at least larger than the image recording size. In other words, it is necessary to extend the structure three-dimensionally, making it difficult to significantly reduce the size.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a radiation image information recording/reading device that can be formed particularly compact.

(Means and effects for solving the problems) A radiation image information recording/reading device according to the present invention reads radiation image information by cylindrical scanning of excitation light by winding a stimulable phosphor sheet around a drum-shaped platen. This stimulable phosphor sheet is pulled out from the platen for radiation image information recording and stretched, thereby achieving significant miniaturization.Specifically, the stimulable phosphor sheet has flexibility. A phosphor sheet, a drum-shaped platen that holds one end of the stimulable phosphor sheet and can wind the sheet around the circumferential surface from the one end side; an image recording section that irradiates a stimulable phosphor sheet with radiation having image information to accumulate and record radiation image information; a main scanning drive means that rotates the platen around its central axis; An excitation light irradiation means for irradiating excitation light onto the stimulable phosphor sheet wound up on its circumferential surface, and a photoelectronic device that emits stimulated luminescent light emitted from a portion of the stimulable phosphor sheet that has been irradiated with the excitation light. a sub-scanning drive means for moving the light detection means and the excitation light irradiation means relative to the platen in a direction parallel to its central axis; The stimulable phosphor sheet is composed of an erasing means for releasing the radiation energy remaining in the stimulable phosphor sheet after being irradiated.

(Example) Hereinafter, the present invention will be described in detail based on Example 1 shown in the drawings.

FIGS. 1 and 2 show the state of a radiation image information recording/reading apparatus according to an embodiment of the present invention when recording (photographing) radiation image information. A drum-shaped platen is held rotatably around its central axis 12 within the light-shielding casing IO. The platen 11 can be rotated in forward and reverse directions by a motor 13 serving as a main scanning drive means.

On the circumferential surface 11a of the platen 11, one end 14a of a stimulable phosphor sheet 14, which is formed by supporting a layer of stimulable phosphor as described above on a flexible support, is held. Therefore, this stimulable phosphor sheet 14 has one end 14
platen circumferential surface 1] from side a, and is wound onto a. Further, a hanging hole 14b is provided near the other end of the stimulable phosphor sheet 14.

A slit-shaped opening 10a is provided at the top of the square housing 10. This opening 10a is closed and opened by a light-shielding door 15 that is moved in the left-right direction in FIG.

When taking a radiographic image, the light-shielding door 15 is moved to the position shown in FIG. 2, and the opening 10a is opened. The stimulable phosphor sheet 14 is then pulled out from the platen 11 and extended to the outside of the housing 10 through the opening IDa. Then, the hook hole 14b of the stimulable phosphor sheet 14 is hung on a hook-shaped hook member 16, and the sheet 1
4 maintains the tensioned state.

The subject 17 is the stimulable phosphor sheet 1 in this state.
It is placed in a position facing 4. A radiation source 18 such as an X-ray tube constituting the image recording unit then
Radiation 19 is irradiated toward. As a result, the radiation 19 transmitted through the subject 17 is transmitted to the stimulable phosphor sheet I.14.
The transmitted radiation image information of the subject 17 is accumulated and recorded on the sheet 14.

Next, the motor 13 is driven and the platen 11 is rotated in the direction of arrow A in FIG. 2, so that the stimulable phosphor sheet 14 is wound onto the circumferential surface of the platen 11 ], ], a. After winding up the stimulable phosphor sheet 14, the end of the sheet on the side where the latching hole 14b is installed is held on the platen circumferential surface 11a by a known magnetic chuck means or a manually operated chuck means. The sheet 14 is wound and held around the platen 11. Thereafter, the light shielding door 15 is operated, and the opening 10a is closed (the state shown in FIG. 3).

Note that in order to achieve significant miniaturization, the device of this example has the following features:
A light-shielding cover that covers the stimulable phosphor sheet 14 pulled out of the housing 10 is not provided. Therefore, the above-described operations from pulling out the stimulable phosphor sheet 14 through the opening 10a to closing the opening 10a are performed in a dark room. Of course, if a light-shielding cover as described above is provided, it is also possible to perform radiographic imaging in a bright room.

Next, reading of radiation image information stored and recorded on the stimulable phosphor sheet 14 will be explained. Inside the housing 10,
A guide rod 20 and a screw rod 21 extending parallel to the central axis 12 of the platen 11 are arranged. A reading unit 22 is held on these rods 20,21. That is, as shown in detail in FIG. 4, the reading unit 22 is movable along the guide rod 20, and the screw rod 21 is screwed into a female threaded portion 23 fixed to the unit 22. This screw rod 21 is rotated forward and backward by a sub-scanning motor 24, whereby the reading unit 22 reciprocates along the guide rod 20, that is, in a direction parallel to the central axis 12 of the platen 11.

The reading unit 22 receives a laser beam R25 and a laser beam 26 as excitation light created by this laser light source 25.
a mirror 2 that reflects the light toward the stimulable phosphor sheet 14;
7, a condensing lens 28 that converges the laser beam 26 on the stimulable phosphor sheet ↓4, a condensing guide 29, a filter 30 connected to the condensing guide 29, and a photomultiplier tube (photomultiplier tube). A photodetector 31 such as pliers is mounted. The laser light source 25 emits a laser beam 26 having a wavelength included in the excitation wavelength range of the stimulable phosphor sheet 14. The condensing guide 29 is approximately cylindrical and has a reflective coating on its inner surface, and has an excitation light input opening 29a and an excitation light output opening 29b.

When reading radiation image information from the stimulable phosphor sheet 14, the laser beam 26 is irradiated onto the stimulable phosphor sheet 14 through the opening 29a, and then the platen 1
1 is rotated in the direction of arrow A, and the reading unit 2
2 is moved in the direction of arrow B in FIG. 1.4. Stimulated luminescent light 32 of an amount corresponding to the radiographic image information stored and recorded there is emitted from the location of the stimulable phosphor sheet 14 irradiated with the laser beam 26 . This stimulated luminescent light 3
2 is reflected by the inner surface of the condensing guide 29 or directly enters the filter 30, passes through the filter 30, and is received by the photodetector 31. The photodetector 31 emits an output S corresponding to the detected amount of the stimulated luminescence light 32. Note that most of the laser beam 2B reflected on the stimulable phosphor sheet 14 passes through the opening 29b and reaches the condensing guide 29.
Emit outside. Also, a part of this reflected laser beam 26 travels toward the photodetector 3L, but the filter 3
Cut by 0.

When the platen 11 is rotated as described above, the stimulable phosphor sheet 14 is scanned (main scanned) by the laser beam 26 along a line extending in the circumferential direction of the platen 11. Further, as the reading unit 22 is moved along with this, the laser beam 26 is sub-scanned on the stimulable phosphor sheet 4, so that the sheet 14 is two-dimensionally scanned by the laser beam 26.

Therefore, the output S continuously emitted by the photodetector 31 is
The radiation image information stored and recorded on the stimulable phosphor sheet 14 is exported. The output S of this photodetector 31 is subjected to processing such as amplification and logarithmic conversion in a reading circuit 33 shown in FIG. 3, and then digitized by an A/D converter 34. The digital read image signal Sd thus obtained is subjected to signal processing (image processing) such as gradation processing and frequency processing in an image processing circuit 40 as shown in FIG. The image is input to an image reproducing device 41 such as a recording device. This image reproducing device 4
1, the radiation image stored and recorded on the stimulable phosphor sheet 14 is displayed or recorded based on the image signal Sd.

Note that the image processing circuit 40 may be housed within the housing IO. Further, the read image signal Sd may be recorded on a recording medium such as an optical disc or a magneto-optical disc before being input to the image reproducing device 41.

After the radiation image information has been read as described above, the sub-scanning motor 24 is rotated in the opposite direction to that in the above case. Thereby, the reading unit 22 is moved in the direction opposite to the direction of arrow B and returned to the sub-scanning start position. On the other hand, the platen 11 continues to be rotated several times, and at the same time the erasing light source 35 is turned on. The erasing light source 35 is composed of, for example, a fluorescent lamp, a halogen lamp, or the like, and irradiates the entire width of the stimulable phosphor sheet 14 with erasing light 36 having a wavelength included in the excitation wavelength region of the stimulable phosphor sheet 14 . The radiation energy remaining in the stimulable phosphor sheet 14 even after reading the radiation image information is emitted from the sheet 1-14 by the illumination of the erasing light 36. In this way, the stimulable phosphor sheet 14 becomes in a state in which radiation image information can be stored and recorded again.

Next, a second embodiment of the present invention will be described with reference to FIG. Note that in FIG. 5, elements equivalent to those in FIG. 2 are given the same numbers, and a description thereof will be omitted (the same applies hereinafter).

In the apparatus of this second embodiment, a light-shielding cover 5 covers the stimulable phosphor sheet 14 pulled out from the platen 11.
0 is set. Therefore, the apparatus of this second embodiment is capable of radiographic imaging even in a bright room.

Since this light-shielding cover 50 only needs to house the stimulable phosphor sheet 14, it can be made extremely thin, and thus this radiation image information recording/reading apparatus can also be made compact overall.

When providing the light-shielding cover 50 as described above, when taking a radiographic image, for example, the platen 11 is rotated at low speed in the direction of arrow C (the opposite direction to the reading direction), and the tip of the stimulable phosphor sheet 14 is rotated in the direction of the arrow C. When the tip reaches the position shown, the hook 6 between the tip and the platen 11 is automatically released, and the tip is guided by the guide portion 51 and fed into the light shielding cover 50.

In addition, instead of the light-shielding cover 50, a flexible bag-shaped light-shielding cover 60 as shown in FIG. 6 is provided, and this cover 60 is folded except when radiographic images are being taken, thereby reducing the size of the apparatus. You can also try it out.

Furthermore, as shown in FIG. 7, a plurality of cover members 70a
It is also possible to reduce the size of the device by providing an extendable light-shielding cover 70 made up of s 70b, 70c.

(Effects of the Invention) As described above in detail, the radiation image information recording/reading device of the present invention reads radiation image information by cylindrical scanning of excitation light by winding a stimulable phosphor sheet around a drum-shaped platen. Since the stimulable phosphor sheet is configured to be pulled out from the platen and stretched only when recording radiation image information, it is possible to circulate the stimulable phosphor sheet or form the stimulable phosphor sheet into an endless belt. Compared to conventional devices, it is possible to significantly downsize the device.

Therefore, the present device can be easily moved, and has the effect of significantly facilitating the work of radiographic imaging and reproduction in the fields of medical diagnosis and research.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an apparatus according to a first embodiment of the present invention; FIGS. 2 and 3 are side sectional views showing the state of the apparatus according to the first embodiment when recording and reading radiation image information, respectively; FIG. 4 is a side view showing the reading unit of the device of the first embodiment, and FIGS. 5.6 and 7 are side sectional views showing the devices of the 2.3 and 4th embodiments of the present invention, respectively. 10... Housing 11... Platen 11
a...Platen circumferential surface 13...Main scanning motor 1
4...Stimulable phosphor sheet 14a...One end of the stimulable phosphor sheet 15...Light-shielding door 18...Radiation source 19...Radiation 21...Screw rod 23...Femally threaded portion 25 ... Laser light source 27 ... Mirror 3 ... Photodetector 33 ... Reading circuit 35 ... Erasing light source 50.60.70 ... Light-shielding cover 20 ... Guide rod 22 ...・Reading unit 24... Sub-scanning motor 26... Laser beam 29... Focusing guide 32... Stimulated luminescence light 34... A/D converter 86... Erasing light 5 11a 5 11a

Claims (1)

[Scope of Claims] A stimulable phosphor sheet having flexibility; and a drum-shaped drum capable of holding one end of the stimulable phosphor sheet and winding the sheet around its circumferential surface from the one end side. a platen; an image recording section that irradiates the stimulable phosphor sheet stretched out from the platen with radiation having image information to accumulate and record radiation image information; a main scanning drive means for rotating the stimulable phosphor sheet around the platen; an excitation light irradiation means for irradiating excitation light onto the stimulable phosphor sheet wound on the peripheral surface of the platen; and a stimulable phosphor sheet irradiated with the excitation light. a photodetection means for photoelectrically detecting stimulated luminescence light emitted from a portion of the body sheet; and a photodetection means and the excitation light irradiation means relative to the platen in a direction parallel to its central axis. A radiation image information recording/reading device comprising: a sub-scanning driving means for moving the stimulable phosphor sheet; and an erasing means for emitting radiation energy remaining in the stimulable phosphor sheet after being irradiated with the excitation light.