JPH0516575B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention accumulates and records radiation image information of a subject on a stimulable phosphor sheet, and then irradiates this with excitation light to produce stimulated luminescence according to the accumulated and recorded image information. The present invention relates to a radiation image information recording/reading device capable of detecting light to read image information and convert it into an electrical signal, and more specifically, it is configured to circulate and reuse a stimulable phosphor sheet within the device, and When high-dose radiation image information is recorded on a specific stimulable phosphor sheet, this is detected and multiple images are displayed corresponding to the amount without recording new image information or reading the image information. The present invention relates to a radiographic image information recording/reading device configured so that residual images are almost completely erased after multiple erasing steps.

Certain types of fluorophores are exposed to radiation (X-rays, α-rays, β-rays,
When irradiated with γ-rays, electron beams, ultraviolet rays, etc., part of the energy of this radiation is accumulated in the phosphor, and when the phosphor is then irradiated with excitation light such as visible light, the accumulated energy is In response to this, the phosphor exhibits stimulated luminescence. A phosphor exhibiting such properties is called a storage phosphor.

Using this type of stimulable phosphor, radiographic image information of subjects such as the human body can be stored on a sheet made of a stimulable phosphor (hereinafter referred to as a ``stimulable phosphor sheet'' or simply a ``sheet''). This stimulated luminescence is produced by irradiating it with excitation light, and this stimulated luminescence light is read photoelectrically to obtain image information, and this image signal is electrically processed to provide a method suitable for diagnosis. A radiation image information recording and reproducing method for obtaining a radiation image of a subject has been proposed (for example, Japanese Patent Application Laid-open No. 12429/1983;
No. 55-116340, No. 55-163472, No. 56-11395
No. 56-104645, etc.). In this way, the final image obtained can be reproduced as a hard copy, reproduced on a display device such as a CRT, or recorded on a recording medium such as a magnetic tape for long-term storage. . In any case,
In the radiation image information recording and reproducing method, the stimulable phosphor sheet is not used to ultimately record image information, but is used to provide an image to a different recording medium as described above. , it only temporarily records image information, and for this purpose, the stimulable phosphor sheet may be used repeatedly, and it is extremely economical and convenient to use it repeatedly in this way. . Furthermore, for example, a mobile station such as an X-ray imaging vehicle may be equipped with a radiation image information recording/reading device that uses a stimulable phosphor sheet, and the mobile station may be used to travel to various locations for group examinations and take X-ray images. In such cases, it is inconvenient to load a large number of stimulable phosphor sheets into a car.
Furthermore, there is a limit to the number of seats that can be loaded onto a moving vehicle. Therefore, a stimulable phosphor sheet is loaded onto a moving vehicle so that it can be used repeatedly, and radiographic image information for each subject is recorded on it. By reading this out, limited image signals can be converted to magnetic fields. If the stimulable phosphor sheet is stored on a recording medium with a large recording capacity such as a tape, and the stimulable phosphor sheet is erased once to obtain the next image information and then reused, it can be stored in a large number of images by moving vehicles. This is extremely practical because it allows radiographic images of a subject to be captured without being restricted by location. moreover,
By cyclically reusing it in this way, it becomes possible to perform continuous imaging, which increases the speed at which image information can be captured in mass medical examinations, making it possible to obtain image information in a short time and efficiently. .

By the way, in order to recycle and 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 out is No. 56-12599, the remaining radiation image is erased by irradiating the sheet with light or heat, and the stimulable phosphor sheet is used again to record the radiation image. Just use it.

Based on this knowledge, the present applicant proposed a circulating conveyance means for conveying a stimulable phosphor sheet capable of accumulatively recording radiation images along a predetermined circulation path, and a circulating means for conveying a stimulable phosphor sheet capable of accumulating and recording radiation images, and a method for conveying radiation through the sheet through a subject in the circulation path. an image recording section that accumulates and records radiographic image information of a subject on the sheet by irradiating the image with the radiation image; an image reading section comprising an excitation light source and photoelectric reading means for reading stimulated luminescence light emitted from a sheet scanned by the excitation light to obtain an image signal; and an erasing section for emitting radiation energy remaining on the sheet prior to recording an image on the sheet after the stimulable phosphor sheet is incorporated into one device, and the stimulable phosphor sheet is circulated between the respective sections. We have already proposed and applied for a patent on a so-called built-in type radiation image information recording/reading device that is configured to be used repeatedly.
58-66730).

The radiographic image information recording/reading device having such a structure has the advantage of being able to continuously and efficiently record and read radiographic image information.

By the way, as described above, the erasing section of the radiation image information recording/reading device irradiates the stimulable phosphor sheet with light or heat, thereby releasing the residual radiation energy of the stimulable phosphor sheet. However, in order to make a stimulable phosphor sheet reusable, it is necessary to irradiate the sheet with a larger amount of light or heat as the residual radiation energy increases (i.e., to reduce the residual radiation energy). The amount emitted increases as the amount of light and heat irradiation increases).
Therefore, if the amount of light or heat irradiation in the erasing section is kept constant, it will almost completely eliminate the maximum residual radiation energy of the stimulable phosphor sheet (i.e., the next image It is set so that it can be released (to the extent that it does not interfere with recording). Furthermore, when controlling the amount of light or heat applied to the erasing section depending on the residual radiation energy of the stimulable phosphor sheet in order to reduce the energy and time required for image erasing, the amount of control is The maximum value is set to a value at which the normally assumed maximum residual radiation energy of the stimulable phosphor sheet can be almost completely emitted.

However, during special radiography, the stimulable phosphor sheet may be exposed to a much larger amount of radiation than usual, and the stimulable phosphor sheet that has been exposed to a large amount of radiation may In many cases, the residual energy after image reading also exceeds the maximum value that is normally expected. Therefore, when such a special stimulable phosphor sheet is sent to the erasing section, it is desirable to irradiate it with light or heat for a particularly long period of time, so that the sheet that has been exposed to a large amount of radiation will be removed. can also be reused for image recording.

However, if the erasing section takes a particularly long time to erase the image on the stimulable phosphor sheet that has been exposed to a large amount of radiation as described above, the erasing section will erase the image of the stimulable phosphor sheet. The flow becomes congested, and image recording and reading processes have to be interrupted.

On the other hand, if the remaining image information is erased without taking a particularly long time, the unerased image information will be superimposed on the newly recorded image information when the next image recording is performed on the stimulable phosphor sheet. Accurate image information of the subject cannot be secured. Moreover, for this reason, for example, when the subject is a patient, it cannot be denied that there is a possibility that the doctor may misdiagnose the subject.

Therefore, the object of the present invention is to treat a stimulable phosphor sheet that is cyclically reused when it is irradiated with an extremely larger amount of radiation than usual and the afterimage energy after image reading of this sheet exceeds a predetermined value. , the stimulable phosphor sheet is subjected to the erasing process multiple times without recording a new image or reading the image, almost completely erasing the remaining image, thereby recording, reading, and erasing the image. An object of the present invention is to provide a radiographic image information recording/reading device that can sufficiently increase the processing speed and accurately obtain radiographic image information of a subject.

In order to achieve the above-mentioned object, the present invention includes a circulation conveyance means for conveying a stimulable phosphor sheet capable of accumulating and recording radiographic image information along a predetermined circulation path, and a circulation means for conveying a stimulable phosphor sheet capable of accumulating and recording radiation image information, and a an image recording section that accumulates and records radiographic image information of a subject on the sheet by irradiating radiation through the subject; and a sheet that is interposed in the circulation path and on which radiographic image information is accumulated and recorded in the image recording section. an image reading section having an excitation light source that emits excitation light that scans the sheet; and a photoelectric reading section that obtains an image signal by reading the stimulated luminescence light emitted from the sheet scanned by the excitation light; an erasing section that releases radiation energy remaining on the sheet prior to recording an image on the sheet after the image reading is performed in the image reading section; a selection means for selecting the radiation dose from the radiation source for the radiation source; a storage means for specifying and storing the number of times of erasing of the sheet passing through the erasing section based on the image signal obtained by the photoelectric reading means; control means for causing the sheet to pass through an image recording section and an image reading section without image recording and image reading, respectively, according to a signal sent from a sheet position detection means disposed at a predetermined location and an output signal from the storage means; It is characterized by providing.

Next, preferred embodiments of the radiation image information recording/reading apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

First, the basic configuration of the radiation image information recording/reading apparatus according to the present invention is as shown in FIG. That is, an image recording section 2 for recording radiographic image information on the stimulable phosphor sheet A is provided on the way of the circulating conveyance means 1 for conveying a plurality of stimulable phosphor sheets A, and an image recording section 2 for recording radiation image information on the stimulable phosphor sheet A; The stimulable phosphor sheet A is irradiated with excitation light such as a laser beam to obtain stimulated luminescence light, and an image reading section 3 converts this into an electrical signal to read image information, and the image information is read. an erasing unit 4 that irradiates the stimulable phosphor sheet A with erasing light to release radiation energy remaining in the sheet;
and in this order. Then, the image recording section 4
A selection means 6 is provided for adjusting the radiation dose from the radiation source 5 for the subject in , and the accumulation property of passing through the erasing section 4 from the output signal of the image reading section 3 that changes based on the radiation dose selected by the selection means 6 is provided. It includes a storage means 7 for specifying the number of times the phosphor sheet A has been erased. Sheet position detection means 8a to 8c are disposed at appropriate positions along the circulation conveyance means 1,
On the other hand, the stimulable phosphor sheet A is detected by the signals from the sheet position detection means 8a to 8c and the storage means
It has a control means 9 that temporarily stops the functions of the image recording section 2 and the image reading section 3 without subjecting the image recording section 2 to the image recording step and the image reading section 3 to the image reading step.

Therefore, the mechanical structure of the radiation image information recording/reading apparatus having the above-mentioned basic structure is shown in FIGS. 2 and 3.

In FIG. 2, reference numeral 10 indicates a standing type (chest type) radiation image information recording/reading device, and the device 10 has a first casing 12 extending in the vertical direction and extending in the horizontal direction. and a second housing 14. A recording section (image recording section) for recording a radiation image of a subject is located above the front part of the first housing 12.
16 is arranged, and on the other hand, an operation section 1 is arranged above the side wall part.
8 are arranged.

Next, the internal configurations of the first casing 12 and the second casing 14 will be described with reference to FIG. 3.

A bending belt conveyor 20 is disposed at the top of the first casing 12 , and a first roller group 22 rotatably slides on the bending portion of the belt conveyor 20 , and a first guide member 24 approaches this roller group 22 . will be placed. Inside the image recording section 16, a pair of belt conveyors 28a and 28b for sandwiching and positioning the stimulable phosphor sheet 26 are disposed so as to be movable horizontally in the figure. Belt conveyors 30a and 30b are further disposed on the exit side of the belt conveyors 28a and 28b, and in this case, the belt conveyor 30b extends slightly downward than the belt conveyor 30a that is paired with it. These belt conveyors 30a, 30b
A bending belt conveyor 32 is disposed further below, and a second roller group 34 is provided at the bending part.
will be placed. A second guide member 36 is disposed above the second roller group 34 and close to the belt conveyor 32 . Bendable belt conveyor 3
A belt conveyor 40 which is further bent via a guide member 38 is disposed on the exit side of the belt conveyor 2. In this case, a third roller group 42 is rotatably in sliding contact with the bent portion of the belt conveyor 40. Belt conveyor 4 forming a part of this image reading section 44
A laser light source 50 is installed above 6 and 48, and a mirror 52 and a galvanometer mirror 56 are provided for scanning the output laser beam 58 onto the sheet 26 on the belt conveyors 46 and 48 in the width direction thereof. There is. This reciprocating movement of the galvanometer mirror 56 causes the laser beam 58 to
is main-scanned onto the sheet 26 on which radiographic images have been accumulated and recorded. Note that this sheet 26 is used after the radiation image is recorded in the image recording section 16.
The sheet is conveyed to the image reading section 44 by driving the sheet circulation conveyance means. Sheet 2 of laser light 58
At the scanning position above 6, a condensing optical element 60 is arranged along the main scanning line. Stimulated luminescence light emitted from the sheet 26 irradiated with the laser beam 58 is transmitted from the incident end face of the condensing optical element 60 to the condensing optical element 6.
0, the light is guided therein by total reflection and received by a photomultiplier 62 connected to the exit end face of the element 60, and the stimulated luminescence light is read photoelectrically. At the same time as the main scanning of the laser beam 58 is performed as described above, the sheet 26 is conveyed by the belt conveyors 46 and 48 in the direction of arrow A in the figure (that is, the direction substantially perpendicular to the main scanning direction) and is subjected to the sub-scanning. The stored radiation image information is read over the entire surface of the sheet 26. The image signal read by the photo multiplier 62 is transmitted to the image processing circuit 116 (see FIG. 4) via the image signal input/output circuit 117 (see FIG. 4), where it is subjected to necessary image processing. , and is sent to the display device 114 (see FIG. 4), where the radiation image is reproduced. Furthermore, this radiation image may be reproduced by performing optical scanning recording on a photosensitive film, or by performing optical scanning recording on a photosensitive film.
Alternatively, for that purpose, the information may be temporarily recorded on a storage device such as a magnetic tape.

By the way, a slightly bent belt conveyor 64 is arranged on the exit side of the belt conveyor 48 arranged in series as described above, and a third belt conveyor 64 is provided at the bent part.
A group of rollers 66 are rotatably in sliding contact with each other. A third guide member 68 is provided on the exit side of the third roller group 66 and the belt conveyor 64, and a nip roller 70 is provided above the guide member 68. A fourth guide member 72 is provided on the exit side of the nip roller 70, and further faces the erasing section 74 on the exit side. The erasing section 74 has a nip roller 76a surrounded by a casing at one end and a nip roller 76b also surrounded by a casing at the other end. The exit side of the nip roller 76b faces the fifth guide member 78, and the exit side of the fifth guide member 78 faces the nip roller 80. The nip roller 80 is provided next to a relatively long sixth guide member 82, and this sixth guide member 82 is provided opposite to the first bending conveyor belt 20.

In the above configuration, the apparatus of the present invention includes a position detection sensor at a predetermined position in order to grasp the positional relationship of the plurality of stimulable phosphor sheets 26a to 26d that are cyclically conveyed by the belt conveyor. is provided.

In this embodiment, first, the first position detection sensor 100a is connected to a pair of belt conveyors 28.
a, 28b and the belt conveyors 30a, 30b disposed below them, and the second position detection sensor 100b is disposed near the terminal end of the belt conveyor 32 that bends. Also, the third
The fourth position detection sensor 100c is disposed just before the bending part of the belt conveyor 40 connected to the bending belt conveyor 32, and the fourth position detection sensor 100c
00d is a belt conveyor 48 extending in the horizontal direction
It is placed just before the terminal part of. Furthermore, the position detection sensor 100e is arranged at a spaced part between the guide member 68 and the nip roller 70, and the position detection sensor 100f is arranged between the guide member 78 and the nip roller 8.
It is arranged in the spaced part of 0. Finally, the position detection sensor 100g is connected to the guide member 82 and the belt conveyor 2.
It is arranged in the spaced part of 0.

Therefore, as described above, the position detection sensor 100a
Refer to FIG. 4 for a control circuit for driving or stopping the belt conveyor constituting the conveyance system in response to the position detection signal of the stimulable phosphor sheet from the position detection sensor 100g. This will be explained in detail below.

The output sides of the position detection sensors 100a to 100g are connected to a control circuit 102 that is substantially composed of a microcomputer.
02 is connected to an input device 108, and this control circuit 102 includes a controller 1 that sends an imaging signal, that is, a shot signal S, to the radiation source 104 and controls the radiation dose of the radiation source 104.
06 is connected. Note that a switch 112 is connected to the controller 106, which is pressed by the operator to irradiate the subject 110 with radiation from the radiation source 104.

Further, an image signal input/output circuit 117 is connected to this control circuit 102. On the other hand, the image reading section 44
The radiation image information signal of the subject 110 detected by the photo multiplier 62 provided in 114, and the radiation image is displayed on this display device 114 in real time. Furthermore, the output side of the control circuit 102 is a rotational drive source for the belt conveyor constituting the conveyance system, that is, a motor M1 that drives the belt conveyor 28b, a motor M2 that drives the belt conveyor 32, and a motor M3 that drives the belt conveyor 40. , a motor M4 that drives the belt conveyor 46, and a motor M that drives the belt conveyor 48.
5. The drive circuits 118a to 118g of the motor M6 that drives the nip roller 70 and the motor M7 that drives the nip roller 80 are connected.

Furthermore, the output side of the control circuit 102 is a photo multiplier 6 constituting the image reading section 44.
It is connected to the input side of this photo multiplier 62 so as to perform the energization control of 2.

Here, as described above, the control circuit 102 actually utilizes a microcomputer. As shown in FIG. 5, the microcomputer 130 that substantially constitutes the control circuit 102 is of a well-known type, and basically includes an input/output port 131, an input port 132, a CPU 134, a ROM 136,
RAM138, output port 140, timer 14
2 and a counter (not shown), that is, a register. Output signals from the position detection sensors 100a to 100g are introduced to the input port 132, while drive control signals for energizing the drive circuits 118a to 118g to rotate the motors M1 to M7 are introduced from the output port 140. It is configured to be issued. When the stimulable phosphor sheets 26a to 26d are carried into the blocks B1 to B7 divided by the position detection sensors 100a to 100g, the RAM 138 stores the respective positions and phosphor sheets. A table 144 is included so that the sheet number and sheet number can be looked up by the CPU 134 at any time. Furthermore, this RAM 138 is a photo multiplier 6
Depending on the amount of light detected from the stimulable phosphor sheet by 2, for example, when it is 0 to 10, the number of erasing steps required for the stimulable phosphor sheet is 1. It has a table 146 that associates 62 detection signals with the required number of times of erasure. Note that information can be stored in this table 146 by the following method. For example, so-called solid imaging (uniform exposure) is performed on a stimulable phosphor sheet by varying the amount of radiation applied. Next, the image reading unit 44 reads this sheet, that is, reads the signal level (for example, the maximum value) detected by the photo multiplier 62.
Next, the eraser 74 erases the afterimage of the sheet that has been read. Note that this erasing section 74
The afterimage radiation energy of the stimulable phosphor sheet after normal imaging is almost completely released, so that the sheet is irradiated with a sufficient amount of light to enable the sheet to be reused for image recording. It is constructed. Next, in the erasing section 74, the image reading section 44 again reads the afterimage of the sheet from which the afterimage has been erased, and confirms the signal level of the remaining image. If this level is sufficiently small, the number of times the sheet must be erased is one, and if it is above a certain level, the afterimage of the sheet is erased again in the erasing unit 74. In this way, erasing is repeated several times until the signal level of the remaining image becomes sufficiently low. Therefore, depending on the signal level detected by the photo multiplier 62, it is possible to determine how many times a sheet on which an image of that level has been photographed needs to be erased. As described above, a table in which the detection signal of the photo multiplier 62 corresponds to the required number of times of erasure can be obtained experimentally in advance. In addition, the RAM
138 includes a table 148 that defines the correspondence between the required number of erasures read out by the table 146 and the identification number of the stimulable phosphor sheet. The ROM 136 stores a program that controls the CPU 134 to make the stimulable phosphor sheet 26 stand by when it reaches a predetermined position, or to feed it to the next block. .

The radiation image information recording/reading apparatus according to the present invention is basically constructed as described above, and its operation and effects will be explained next.

First, in this embodiment, a stimulable phosphor sheet 26a,
Assume that 26b, 26c and 26d are waiting for circular reuse. Then, as described above, the blocks are divided into blocks B1 to B7 corresponding to the respective sensors 100a to 100g. That is, the positional information of the stimulable phosphor sheet in block B1 is detected by the position detection sensor 100g during its conveyance, and the positional information of the stimulable phosphor sheet in block B2 is detected by the position detection sensor 100g. It is detected by the detection sensor 100a. On the other hand, the position information of the stimulable phosphor sheet in block B3 is detected by a position detection sensor 100b, and the position of the sheet in block B4 is detected by a position detection sensor 100c. The position information of the stimulable phosphor sheet in block B5 is obtained by the position detection sensor 100d, and the eraser 74
The position information of the stimulable phosphor sheet derived from the stimulable phosphor sheet is detected by the position detection sensor 100e. Finally, the position information of the sheet in block B7 is detected by the position detection sensor 100f.

Therefore, when the subject 110 waits for radiography and keeps his or her chest in contact with the recording unit 16 of the radiographic image information recording/reading device, the belt conveyor is driven and the 4 A first sheet 26a of the stimulable phosphor sheets is positioned between the belt conveyors 28a and 28b.

Therefore, when the operator presses the switch 112, the imaging signal S from the controller 106 is sent to the radiation source 104, from which the subject 110 is irradiated with a predetermined radiation, and the stimulable phosphor is The subject 110 is placed on the sheet 26a.
radiographic images are captured and recorded. The stimulable phosphor sheet 26a that has been photographed is transferred to the belt conveyor 28.
Under the biasing action of elements a and 28b, it is conveyed via belt conveyors 30a and 30b and belt conveyor 32 to a position directly below sensor 100b shown in FIG. 3. At this time, the position detection sensor 100a detects the passage of the stimulable phosphor sheet 26a and sends it to the control circuit 102. At the same time, stimulable phosphor sheets 26d, 26c located before and after the stimulable phosphor sheet 26a,
26b is conveyed by a conveyor belt under the rotation of motors M1 to M7. Normally, the stimulable phosphor sheet 26c, which is conveyed by the belt conveyors 46 and 48 after passing through the block B3, is passed through the image reading device 44 and the laser beam 58 from the laser light source 50 is applied to the sheet under the swinging action of the galvanometer mirror 56. scanned onto the surface.
As a result of the scan, stimulated luminescence light corresponding to radiation image information emitted by the stimulable phosphor sheet 26c is collected by the light guide sheet 60 and sent to the photomultiplier 62. The photomultiplier 62 converts the stimulated luminescent light into an electrical signal, and this signal is sent to the image processing device 116 via the image signal input/output circuit 117, where it is subjected to image processing and then displayed on the display device. 114 as a visible image. This radiographic image will be checked by a doctor.

After the image information has been read, the stimulable phosphor sheet is introduced into the erasing section 74, processed to eliminate the afterimage under the lighting action of the erasing light source, and then passed from block B6 to block B7. The image is again output to the image recording section 16, that is, block B1.

Therefore, in order to perform special radiography on the stimulable phosphor sheet that is reused as described above,
When trying to irradiate a larger amount of radiation than usual,
A signal to increase the exposure dose is sent from the input device 108 to the controller 106 via the control circuit 102. As a result, the controller 106 causes the radiation source 104 to emit radiation at a dose based on the input signal from the input device 108 to the subject 110 by pressing the switch 112 . In this case,
It is preferable that the RAM 138 includes a table for determining the radiation dose using the input device 108.

A process in which one stimulable phosphor sheet circulates through the transport system, including a process in which a specific stimulable phosphor sheet is subjected to an erasing process multiple times when a large amount of radiation is radiated to the specific stimulable phosphor sheet. This will be explained below with reference to the flowchart of FIG.

Therefore, the radiation image information recording/reading apparatus 10 is started using a start switch (not shown).
As a result, the motors that drive the belt conveyor and nip rollers that make up the conveyance system operate at a constant speed (STP1). This results in table 14
4 shows the position existing at that time and the phosphor sheet 2
6 (hereinafter, the stimulable phosphor sheet is referred to as "IP" in the flow chart) is read and stored (STP2). That is, table 144 will be created. In this case, the image reading section 44 is used to scan the phosphor sheet 2.
You may also read the barcode affixed to the back of the sheet 6 to obtain information on the position and sheet number.

Next, while the radiation image information recording/reading device 10 is operating, the microcomputer 130
An interrupt operation is performed under the action of the timer 142 (STP3). This interrupt operation is performed to read the bit patterns related to the four stimulable phosphor sheets 26 from the input port 132 (STP4). The read bit pattern is stored in RAM
At 138, the block position and sheet number are relatively stored in the P area via the bit pattern as shown in the table 144 (STP5). After the bit pattern is stored in the RAM 138 in this manner, the computer 130 returns to the main routine operation (STP6). Thereby, the computer 130 performs other operations, such as controlling the conveyance system and feeding the phosphor sheet to the next belt conveyor.

After a predetermined period of time has elapsed, the interrupt operation is performed again under the action of the timer 142 (STP7), and the input port 132
The bit pattern is read from (STP8) and stored in the Q area of RAM 138 (STP9).
After returning to the main routine (STP10), the bit pattern stored in the P area is compared with the bit pattern stored in the Q area (STP11), and the bit pattern is placed in a predetermined position in the table 144. The position information of the corresponding phosphor sheet 26 is updated (STP12). In this way, the identification numbers of the phosphor sheets 26 in blocks B1 to B7 are identified in relation to their positions. In this state, the CPU 134 outputs the drive circuits 118a to 1 from the output port 140.
Send a drive signal to 18g and drive circuit 118
A to 118g drive belt conveyors constituting the respective conveyance systems. As a result, for example, the stimulable phosphor sheet present in block B1 is fed to block B2, and the stimulable phosphor sheet present in block B2 is fed to block B3. Similarly, the stimulable phosphor sheet present in block B4 is fed to block B5, and is also present inside the erasing section 74, that is, inside the erasing box, where it is subjected to the erasing action. The stimulable phosphor sheet is fed to the next block, B7.

By driving the conveyance system in this way, the position detection sensors 100a to 100g send information to the CPU 134 as to whether or not a stimulable phosphor sheet is present in each block.

Therefore, first, when the device 10 is initially driven, the number of times the table 148 constituting the RAM 138 is erased is set to 0 in relation to the stimulable phosphor sheets 26a to 26d (STP13).

Under such conditions, first, it is determined via the table 144 whether or not the stimulable phosphor sheet 26a exists in the block B1 (STP14), and if it exists, the microcomputer 13 basically
0 then confirms whether or not a stimulable phosphor sheet exists in block B2 using the output signal of the position detection sensor 100b (STP15). This block B
If there is no stimulable phosphor sheet in 2,
Furthermore, the stimulable phosphor sheet 26a of block B1
Table 14: Is the required number of erasures 0?
8 and make a judgment (STP16). If the required number of times of erasing of the phosphor sheet of block B1 is not 0, the phosphor sheet of block B1 is directly fed to block B2 without photographing a radiographic image (STP17). On the other hand, if it is determined that the required number of times of erasure is 0, it is determined that the radiation image information recording/reading device 10 is sufficient for imaging (STP18), and the device is set to Ready.
This state is displayed on the CRT 114, and the operator who emits the X-rays confirms the Ready state and presses the switch 112 to take an X-ray image (STP19). When this X-ray shot is achieved, the device is released from the Ready state (STP20) in order to prevent the next shot until the next preparation is completed, and the accumulative fire in block B1 is activated in the same way as above. The light sheet will be fed to block B2. On the other hand, if the X-ray shot is not achieved in STP19, the phosphor sheet 26 of block B1
will continue to the next step.

By the way, although the stimulable phosphor sheet is sent to block B2 in this manner, whether or not there is a stimulable phosphor sheet in block B2 is determined based on the output of the position detection sensor 100b. If there is a stimulable phosphor sheet in block B2 (STP21), then if it is determined from the output signal of the position detection sensor 100c that there is no stimulable phosphor sheet in block B3 (STP22), the block B
The second stimulable phosphor sheet can be fed to block B3 (STP23). When a stimulable phosphor sheet is fed to block B3 and there is a stimulable phosphor sheet in block B3 (STP24), the stimulable phosphor sheet that has reached block B3 is sent to the next step. Check whether there is a stimulable phosphor sheet in block B4 (STP25). If there is no stimulable phosphor sheet in block B4, look up from table 148 whether or not the required number of times of erasing of the stimulable phosphor sheet that has reached block B3 is 0 (STP26); If it is determined that the required number of times of erasure has not reached 0, the stimulable phosphor sheet of block B3 is quickly fed to the rear end of block B4 by driving the belt conveyors 46 and 48 faster than in the normal state. become (STP27). i.e. CPU
134 receives information from the table 148 that as a result of receiving a high dose of stimulable phosphor sheet in block B3, it will not be possible to wait for image recording again until a predetermined number of times of erasing is performed. A signal for faster feeding than the normal state is sent to the drive circuits 118d and 118e, and the drive circuits 118d and 118e
48 predetermined motors are driven at high speed. On the other hand, if it is determined that the required number of times of erasing of the stimulable phosphor sheet in block B3 is 0 (STP26), the transport system is driven for the stimulable phosphor sheet in block B3 in the normal state. The image reading unit 44 is energized, and the excitation light from the laser light source 50 is irradiated onto the stimulable phosphor sheet that has reached the block B4 to read the image information (STP28). At this time, the stimulated luminescent light generated by the excitation light is converted into an electrical signal by the photo multiplier 62, and the CPU 134 uses the maximum value of this electrical signal (for example, current value) to 146 to determine the required number of erasures. Then, it is written and recorded in the table 148 together with the identification number of the stimulable phosphor sheet (STP29).

By the way, when the stimulable phosphor sheet is present in block B4 (STP30), when feeding the stimulable phosphor sheet in block B4, first the stimulable phosphor sheet is placed in block B5. Determine whether it exists (STP31). Block B5
If a stimulable phosphor sheet is present in the microcomputer 130, i.e., substantially
No drive signal is issued from the CPU 134 to the drive circuit 118f. On the other hand, if it is confirmed that there is no stimulable phosphor sheet in block B5, the stimulable phosphor sheet in block B4 is fed to block B5 (STP32). Also, block B
If there is a stimulable phosphor sheet in block B6 (STP33), when feeding this stimulable phosphor sheet to the next block B6, it is checked whether or not there is a stimulable phosphor sheet in the block B6. Judgment (STP34). If it is determined that there is no stimulable phosphor sheet in block B6, the stimulable phosphor sheet in block B5 is fed to block B6 (STP35), and the CPU 134 controls the timer 142 to emit the stimulable phosphor sheet. Configure settings (STP36). Therefore, within the time set by the timer 142, the erasing section 74 processes the remaining image by irradiating the stimulable phosphor sheet with erasing light from the erasing light source disposed therein. Furthermore, if there is a stimulable phosphor sheet in block B6 (STP37), the system waits for the time set by the timer 142 to elapse (STP38) and then sets the stimulable phosphor sheet in block B7. Determine whether it exists (STP39). If the time has not elapsed, proceed to the next step. Next, it is determined by STP38 whether or not there is a stimulable phosphor sheet in block B7, and if there is no stimulable phosphor sheet in block B7, the stimulable phosphor sheet is removed. It will be sent to block B7 (STP49). As a result of feeding the stimulable phosphor sheet to block B7, 1 is subtracted from the number of times the stimulable phosphor sheet is erased in the table 148 (STP41).

By the way, if there is no stimulable phosphor sheet in block B7 (STP42), the process returns to STP14,
Repeat the same flow. On the other hand, if a stimulable phosphor sheet is present in block B7, then:
It is determined whether or not a stimulable phosphor sheet exists in block B1 (STP43), and only when it is determined that there is no stimulable phosphor sheet in block B1, the stimulable phosphor sheet in block B7 is replaced with the stimulable phosphor sheet described above. Block B
1 (STP44), returns to STP14, and repeats the same flow indefinitely while the device is operating.

Through the above flow, if a specific stimulable phosphor sheet contains high-dose radiation image information, blocks B1 and B4 are directly skipped to ensure that the stimulable phosphor sheet is fully covered. This state continues until the remaining image is erased.

In the present embodiment, when the stimulable phosphor sheet is passed through without the image reading unit reading the image, scanning of the galvanometer mirror 56 is stopped and the photomultiplier 62 is stopped.
Although it is possible to de-energize the stimulable phosphor sheet, it is better to use the image reading function as is and rapidly feed the stimulable phosphor sheet as in normal reading, without having to start and stop an extra device. The corner is nice.

As explained in detail above, in the radiation image information recording/reading device of the present invention, the stimulable phosphor sheet circulates through the image recording, reading, and erasing sections, so that the sheet can be used repeatedly. Since the overall structure is compact, it is particularly suitable for use while being loaded onto a vehicle. In the radiation image information recording/reading apparatus of the present invention, no matter how high the level of residual radiation energy remains in the stimulable phosphor sheet, the sheet will not become jammed in the erasing section. Therefore, recording and reading of radiation image information can be performed continuously and at high speed without interruption.

Although the present invention has been described above with reference to preferred embodiments, the present invention is not limited to these embodiments, and various improvements and changes in design are possible without departing from the gist of the present invention. Of course.

[Brief explanation of the drawing]

FIG. 1 is a block diagram explaining the gist of the present invention;
FIG. 2 is a perspective view of the radiation image information recording/reading device according to the present invention, FIG. 3 is a partially omitted longitudinal sectional view of the radiation image information recording/reading device shown in FIG. 2, and FIG. 4 is the radiation image information recording device. An explanatory diagram showing the control system of the reading device, FIG. 5 is a block diagram showing the internal configuration of the control circuit in the control system shown in FIG. 4, and FIGS. 6A to C are based on the control circuit shown in FIG. 5. FIG. 2 is a flowchart for conveying a stimulable phosphor sheet. 1... Circulating conveyance means, 2... Image recording section, 3...
...Image reading unit, 4...Erasing unit, 5...Radiation source,
6...Selection means, 7...Storage means, 8c-8c...
... Seat position detection means, 9... Control means, 10...
...Radiation image information recording and reading device, 12...First housing, 14...Second housing, 16...Image recording unit, 1
8...Operation unit, 20...Belt conveyor, 22...
... Roller group, 24 ... Guide member, 26 ... Storable phosphor sheet, 28a, 28b, 30a, 30
b, 32... Belt conveyor, 34... Roller group, 36, 38... Guide member, 40... Belt conveyor, 42... Roller group, 44... Image reading unit, 46, 48... Belt conveyor, 50 ... Laser light source, 52 ... Mirror, 56 ... Galvanometer mirror, 58 ... Laser light, 60 ... Condensing optical element, 62 ... Photo multiplier, 64 ...
...Belt conveyor, 66...Roller group, 68...
Guide member, 70...Nip roller, 72...Guide member, 74...Erasing section, 76a, 76b...
Nitz roller, 78... Guide member, 80... Nitz roller, 82... Guide member, 100a-1
00g... Position detection sensor, 102... Control circuit, 104... Radiation source, 106... Controller, 108... Input device, 110... Subject, 1
12...Switch, 116...Image processing device, 1
18...drive circuit, 130...microcomputer, 131...input/output port, 132...
Input port, 134... CPU, 136...
ROM, 138... RAM, 140... Output port, 142... Timer, 144, 146, 14
8...table.

Claims (1)

[Claims] 1. Circulating transport means for transporting a stimulable phosphor sheet capable of accumulating and recording radiation image information along a predetermined circulation path; an image recording section that accumulates and records radiographic image information of a subject on a sheet; an excitation light source that is interposed in the circulation path and emits excitation light that scans the sheet on which radiographic image information is accumulated and recorded in the image recording section; an image reading section having a photoelectric reading means for reading stimulated luminescence light emitted from a sheet scanned by excitation light to obtain an image signal; and an image reading section interposed in the circulation passage and performing image reading in the image reading section. an erasing unit that releases radiation energy remaining on the sheet prior to recording an image on the sheet after the image is recorded; and a selection that is attached to the image recording unit and that selects the radiation dose from the radiation source to the subject. storage means for specifying and storing the number of erasures of the sheet passing through the erasing section based on the image signal obtained by the photoelectric reading means; and sheet position detection means disposed at a predetermined location of the conveyance means. A radiation image information recording/reading device characterized in that a control means is provided for causing the sheet to pass through an image recording section and an image reading section without image recording or image reading, respectively, according to a signal sent from the storage means and an output signal of the storage means. Device.