JPS61242167A - Radiation image information reader - Google Patents

Abstract

PURPOSE:To obtain initially recorded information through rereads by protecting the information recorded on cumulative fluorescent substance sheets whenever it is impossible to read the recorded information. CONSTITUTION:When it is impossible to read images because of an interruption to services and the like during its reading of the images, the images are detected by detection means 5 and secondary scanning positions of sheets where images reads is carried out are stored by a storage means 6. When an electric service is reopened, the images are detected by the detection means 5. Receiving outputs of the detecting means 5, a control means 7 carry the cumulative fluorescent substance sheets which are being read during its interruption of the images reads as far as an outside of a image reading part 3 so as to control the images. And its control means 7 permit the rereads to start again from the first stage by taking control measures of carrying the above sheets in the images reading part 3 and so on. During these rereads, as long as the secondary scanning positions are stored by storage means 6, read gains will be extended by gain adjustment means 8.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention irradiates excitation light onto a stimulable phosphor sheet on which radiation image information of a subject is accumulated and recorded, and detects stimulated light emitted according to the accumulated and recorded image information. Regarding a radiation image information reading device that is capable of reading image information and converting it into an electrical signal, more specifically, while reading image information from a stimulable phosphor sheet, image reading becomes temporarily impossible. The present invention relates to a radiation image information reading device configured to be able to reread image information even in cases where the image information is read out again.

When certain phosphors are irradiated with radiation (X-rays, alpha-rays, beta-rays, gamma-rays, electron beams, ultraviolet light, etc.), some of the energy of this radiation is stored in the phosphor and 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 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 is then irradiated with excitation light to cause stimulated luminescence, 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 Laid-Open No. 55-12429,
55-116340, 55-163472, 56-[395, 56-104645, etc.). The image finally obtained in this way 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 and stored for a long period of time. I can do it. In any case, in the radiation image information recording and reproducing method, the stimulable phosphor sheet is not for ultimately recording image information;
Since it is intended to provide an image to a different recording medium as mentioned above, the image information is only temporarily recorded, and for this reason, the stimulable phosphor sheet is designed to be used repeatedly. Moreover, repeated use in this way is extremely economical and convenient.

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 is read is used, for example, as described in Japanese Patent Laid-Open No. 5
As disclosed in Japanese Patent No. 6-11392, the remaining radiation image may be erased by irradiating the sheet with light, and the stimulable phosphor sheet may be used again for recording radiation images.

Based on such knowledge, the applicant is a circulatory transportation means to transport the accumulation of radiation images along the predetermined circulating passage, and the subject is radiated through the sheet in the earlier sheet. an image recording section that accumulates and records radiographic image information of the subject on the sheet by irradiating the image with an excitation light that is located in the circulation path and scans the sheet on which the radiographic image information has been accumulated and recorded in the image recording section; an image reading section comprising an excitation light source and a 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 that releases radiation energy remaining on the sheet prior to image recording on the sheet after image recording, and the stimulable phosphor sheet is circulated between the respective sections. I have already proposed a so-called built-in radiation image information recording/reading device configured to be repeatedly used, and I have filed a patent application for it in 1982-66'7.
No. 30).

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, in the above-mentioned radiation image information recording/reading apparatus, etc., an accident such as a power outage may occur while reading image information from a sheet, and reading the recorded information may become impossible. Even if such a situation occurs, it is desirable to be able to continue reading the remaining part when it becomes possible to read the recorded information again.For this reason, it is desirable to have an image memory such as a magnetic disk and read it first. There is also a method of electronically combining the information stored in the image memory with the information that can be read again and newly read.
However, due to the nature of stimulable phosphor sheets, even if the accumulated and recorded image information is extracted as stimulated luminescence light by irradiation with excitation light, the information level will decrease. However, since the image information still remains, can it be reread without using image memory? You can obtain the original recorded information.

The present invention has been made in view of the above, and it protects the image information recorded on the stimulable fluorescent material and restores the original record by re-reading when the recorded information becomes unreadable. An object of the present invention is to provide a radiation image information reading device that can obtain information.

According to the present invention, in a radiation image information reading device, a detection means for detecting when image reading becomes impossible and when image reading becomes possible; storage means for storing a sub-scanning position during image reading when it is detected that the image has become readable; Achieved by comprising a control means for controlling re-reading of the sheet image from the beginning, and an image signal adjustment means for increasing the image signal obtained by the photoelectric reading means up to the storage sub-scanning position of the storage means during re-reading. be done.

In order to achieve the above object, the present invention relatively moves a stimulable phosphor sheet on which radiographic image information is stored and excitation light from an excitation light source in two directions in the main scanning direction and the sub-scanning direction. a scanning means for dimensional scanning; a photoelectric reading means for reading stimulated luminescent light emitted from the stimulable phosphor sheet scanned by the excitation light to obtain an image signal; and image reading by the photoelectric reading means is disabled. and a storage means for storing a sub-scanning position during image reading when the detection means detects that image reading has become impossible during image reading. and a control means for controlling the image of the stimulable phosphor sheet, which was being read when the image could not be read, to be readable again from the beginning when the detection means detects that the image can be read. During the re-reading, the image signal adjusting means is provided for increasing the image signal level obtained by the photoelectric reading means up to the storage sub-scanning position of the storage means.

In the present invention, the image signal adjustment means for increasing the image signal level obtained by the photoelectric reading means includes gain adjustment means for increasing the reading gain of the photoelectric reading means, means for increasing the intensity of excitation light, or two-dimensional shall mean means for reducing the scanning speed of the scan.

Next, the so-called radiation image information reading device according to the present invention is incorporated into one device together with an image recording section and an image erasing section.
Embodiments of the present invention will be described in detail by taking a built-in radiographic image information recording/reading device as an example.

First, the basic configuration of a radiation image information recording/reading apparatus related 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, and an image recording section 2 for recording radiation image information on the stimulable phosphor sheet A are provided on the way of the circulating conveyance means 1 for conveying a plurality of stimulable phosphor sheets A. An image reading section 3 that irradiates excitation light such as a laser beam onto the stimulable phosphor sheet A) to obtain stimulated luminescence light, converts it into an electrical signal and reads image information; An erasing section 4 that irradiates the read stimulable phosphor sheet A with erasing light to emit radiation energy remaining in the sheet is provided in this order. Furthermore, a detecting means 5 detects when image reading becomes impossible and becomes possible, and when the detecting means 5 detects that image reading becomes impossible during image reading, it detects when image reading becomes impossible. A storage means 6 for storing the sub-scanning position; a control means 7 for controlling reading from the beginning of the sheet whose image was being read when the image cannot be read when the detection means 5 detects that the image can be read; , a gain adjustment means 8 for increasing the reading gain of the photoelectric conversion means up to a sub-scanning position stored in the storage means 6.

Therefore, during image reading, when image reading becomes impossible due to a power outage, etc., the detection means 5 detects this, and the sub-scanning position on the sheet where the image reading was performed is stored in the storage means 6. When it becomes possible to read the image, for example, when the power supply is restarted, the detection means 5 detects this, and the control means 7 receives the output from the detection means 5 and controls the storage capacity that was being read when the image could not be read. Re-reading is performed from the beginning by controlling the conveyance of the phosphor sheet to the outside of the image reading section 3 and carrying it into the image reading section again.

During this rereading, the reading gain is increased by the gain adjustment means 8 until the sub-scanning position is stored in the storage means 6. As a result, the images obtained by re-reading are almost the same as those obtained by normal reading, and do not affect diagnosis or the like.

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 1
0 includes a first housing 12 extending in the vertical direction and a second housing 14 extending in the horizontal direction, and above the front surface of the first housing 12 is a recorder for recording a radiation image of the subject. A section (image recording section) 16 is disposed, and an operation section 1B is disposed above the side wall section.

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

A bending belt conveyor 20 is disposed at the top of the first housing 12, and a first roller group 22 rotatably slides on the bending portion of the belt conveyor 20, and a first guide member 24 is in close proximity to 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 3Qa 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.

Bent belt conveyor 32 is arranged further below these belt conveyors 3Qa, 30b, and a second roller group 34 is arranged at the bending portion. Said 20th-
A second guide member 36 is disposed above the group 34 and close to the belt conveyor 32. A further bending belt conveyor 40 is disposed on the exit side of the bending belt conveyor 32 via a guide member 3B, and in this case, a third roller group 42 rotatably slides into the bending portion of the belt conveyor 40. ing. A laser light source 50 is installed above the belt conveyors 46 and 48 that constitute a part of the image reading unit 44, and the output laser light 58 is scanned in the width direction onto the sheet 26 on the belt conveyors 46 and 48. A mirror 52 and a galvanometer mirror 56 are provided. By this reciprocating movement of the galvanometer mirror 56, the laser beam 58 is main-scanned over the sheet 26 on which the radiation image has been accumulated and recorded. Note that, after a radiation image is recorded on the sheet 26 in the image recording section 16, the sheet 26 is conveyed to the image reading section 44 by driving the sheet circulating conveyance means. At the scanning position of the laser beam 58 on the sheet 26, a condensing optical element 60 is arranged along the main scanning line. Stimulated luminescent light emitted from the sheet 26 irradiated with the laser beam 58 is collected by the condensing optical element 60
The light enters the condensing optical element 60 from the incident end face of the light, is guided through the condensing optical element 60 by total reflection, and is received by the photomultiplier 62 connected to the exit end face of the element 60, where the stimulated luminescent light is read out photoelectrically. It will be done. As mentioned above, the laser beam 58
At the same time as the main scanning of the sheet 26 is performed, the sheet 26 is conveyed by 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) to perform the sub-scanning of the sheet 26. Accumulated radiation image information is read over the entire surface. As will be described later, the image signal read by the photo multiplier 62 is sent to the image processing device 1 via the image signal input/output circuit 117 (see FIG. 4).
16 (see Figure 4), the necessary image processing is performed, and the display device! 114 (see FIG. 4), and the radiation image is reproduced. Further, the radiation image may be reproduced by performing optical scanning recording on a photosensitive film, or may be temporarily recorded on a storage device such as a magnetic tape for this purpose.

By the way, a slightly bent belt conveyor 64 is disposed on the exit side of the belt conveyor 48 arranged in series as described above, and a fourth roller group 66 is rotatably in sliding contact with the bent portion. A third guide member 68 is provided on the exit side of the 40th 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 the exit side of the fourth guide member 72 faces an erasing section 74. There is also a nip roller 76b surrounded by the housing. The exit side of the nip roller 76b faces the fifth guide member 7, and the exit side of the fifth guide member 78 faces the nip roller 80. The nip roller 80 is provided adjacent to a relatively long sixth guide member 82, and this sixth guide member 82 is provided opposite to the first bending conveyor belt conveyor 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. provided.

In this embodiment, first, the first position detection sensor 100a is a pair of belt conveyors 28a128b and a belt conveyor 30a disposed below the belt conveyors 28a128b.

30b, the second position detection sensor 1
00b is arranged near the end portion of the belt conveyor 32 that bends. Further, the third position detection sensor 100c is disposed just before the bending part of the belt conveyor 40 that is connected to the bending belt conveyor 32, and the fourth position detection sensor 100d is arranged on the belt conveyor 48 that extends in the horizontal direction. Arranged just before the terminal part. Furthermore, the position detection sensor 100e is disposed at a portion separated from the guide member 68 and the nip roller 70, and the position detection sensor 100f is disposed at a portion separated from the guide member 78 and the nip roller 80.

Finally, the position detection sensor 100g is disposed at a portion separated from the guide member 82 and the belt conveyor 20.

Therefore, as described above, the position detection sensors 100a to 10
See Figure 4 for a control circuit for controlling the belt conveyor that constitutes the conveyance system to drive or stop in response to the position detection signal of the stimulable phosphor sheet from 0g, and for controlling the reading. This will be explained in detail below.

The output side of the position detection sensors 100a to 100g is a control circuit 1 that is substantially composed of a microcomputer.
02, and this control circuit 102 has an input device 10.
8 is connected to this control circuit 102, and a radiation source 10 is connected to the control circuit 102.
4 is connected to a controller 106 that sends an imaging signal, that is, a shot signal S, and also controls the radiation dose of the radiation source 104. Note that the controller 106 is pressed by the operator to move the subject 11 from the radiation source 104.
A switch 112 for irradiating radiation to 0 is connected. The control circuit 102 is also supplied with the output of a power-off detection circuit 149, so that the control circuit 102 can detect whether the power is turned off or turned on. This control circuit 102 also includes an image signal input/output circuit 117.
is connected.

On the other hand, the radiation image information signal of the subject 110 detected by the photomultiplier 62 provided in the image reading unit 44 passes through the reading gain adjustment circuit 150 and then is sent to the image processing device 116 via the image signal input/output circuit 117. After being subjected to appropriate image processing, the radiation image is sent to the display device 114, and the radiation image is displayed on the 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 Mz that drives the belt conveyor 32, and a motor Mi that drives the belt conveyor 40. ,
Drive circuits 118a to 118g are connected to motor M4 that drives belt conveyor 46, motor M6 that drives belt conveyor 48, motor M that drives nip roller 70, and motor M that drives nip roller 80, respectively.

Further, the rotation of the motor M4 is configured to be detected by an encoder 151, and the output pulses of the encoder 151 are supplied to a counter 152 for counting. Here, the encoder 151 is designed to generate, for example, one pulse for one sub-scanning line. Further, several pulses may be generated for one sub-scanning line.

The count value of the counter 152 corresponds to the number of sub-scanning lines, and is configured to be supplied to the control circuit 102. In addition, the control circuit 10
2 is a latch circuit 153 that stores the counted value of the counter 152 when a power outage is detected by the power outage detection circuit 149.
and latches it.

The latch output of the latch circuit 153 and the count value of the counter 152 are compared by a digital comparator 154, and the gain of the read gain adjustment circuit 150 is changed before and after the re-input of the digital comparator 154 matches. Normally, the former gain is set to several times the latter gain.This gain ratio is used when reading the same information after reading the same information from the stimulable phosphor sheet. The magnification is determined in advance through experiments or the like so that the level is sufficiently readable, and this magnification is changed depending on the characteristics of the sheet, the intensity of the laser beam, the scanning speed, etc. Furthermore, the control circuit 102 On the output side, there is a photomultiplier 62 that constitutes the image reading section 44.
This photomultiplier 62
Connect it to the input side of the

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 consists of an input/output port 131, an input port 132:, a CPU 134,
, ROM 136, RAM 13B, nonvolatile RAM 146, output port 140, timer 142, and a timer counter and register (not shown).
The output signal of 0g, the output signal of the power-off detection circuit 149, and the count value of the counter 152 are introduced, and on the other hand, the output port 140 energizes the drive circuits 118a to 118g to rotate the motors M1 to M. The latch circuit 153 is configured to output latch data at the same time as the drive control signal is output. When the stimulable phosphor sheets 26a to 26d are carried into the blocks B1 to B7 divided by the position detection sensors 100a to long into the RAM 138,
Each position and the sheet number of the phosphor sheet are always checked by the CPU.
table 14 so that it can be looked up by 134
4 is formed. Furthermore, the nonvolatile RAM 146 includes a flag area 147 and a sub-scanning line, that is,
Count value storage area 1 that stores the count value of the counter 152
48 is formed. In addition, the ROM136 has CPU1
A program is stored for controlling the stimulable phosphor sheet 34 to have 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, the radiation image information recording/reading device 1
Storage phosphor sheets 26 a, 26 b, 26 inside 0
Assume that c and 26d are waiting for circular reuse. Then, as described above, each of the sensors 100a to 100
It is divided into blocks B to B7 corresponding to g. That is, the positional information of the stimulable phosphor sheet in block B is detected by the position detection sensor 100g during its conveyance, and the positional information of the stimulable phosphor sheet in block BZ is detected by the position detection sensor 100g. sensor 100
detected by a. On the other hand, block B.

The position information of the stimulable phosphor sheet in block B is detected by a position detection sensor 1oob, and the position detection function of the sheet in block B is detected by a position detection sensor 100c.
This is done by Block B.

The positional information of the stimulable phosphor sheet is obtained by the position detection sensor 100d, and the positional information of the stimulable phosphor sheet derived from the erasing section 74 is obtained by the position detection sensor 100e.
This is done by Finally, the position information of the sheet in block B is detected by the position detection sensor 100r.

Therefore, when the subject 110 waits for radiography and keeps his or her chest in contact with the recording section 16 of the radiation image emotion recording/reading device, the belt conveyor is driven and the housing 12 is
The first sheet 26a of the four stimulable phosphor sheets housed in the belt conveyor 28
It is positioned while being sandwiched between a 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, and the radiation source 104 irradiates the subject 110 with a predetermined radiation. A radiographic image of the subject 110 is recorded in the form of a bridge on the sheet 26a. The stimulable phosphor sheet 26a, which has been photographed, is transferred to the third belt conveyor 30a, 30b and belt conveyor 32 under the biasing action of the belt conveyors 28a, 28b.
It will be transported to a position directly below the sensor 100b shown in the figure. At this time, the position detection sensor 100a detects the passage of the stimulable phosphor sheet 26a, and the control circuit 1
Send to 02. At the same time, the stimulable phosphor sheet 26d, 2 located before the stimulable phosphor sheet 26a
6c and 26b are motors M+ to M? Normally, the stimulable phosphor sheet 26c, which passes through the block B3 and is transported by the belt conveyors 46 and 48, is transported by the image reading section 44 and the laser light source. The laser beam 58 from 50 performs main scanning on the sheet surface under the swinging action of the galvanometer mirror 56, and also performs sub-scanning by conveying the stimulable phosphor sheet 26c by belt conveyors 46 and 48. is done. Stimulated luminescence light corresponding to radiation image information emitted by the stimulable phosphor sheet 26c by the scan nip is collected by the condensing optical element 60 and sent to the photomultiplier 62. The photomultiplier 62 converts the stimulated luminescent light into an electrical signal, and this signal is transmitted to the image signal input/output circuit 11? The image is sent to the image processing device 116 via the image processor 116, subjected to image processing, and then reproduced as a visible image on the display device 114. 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 and processed to eliminate its afterimage under the lighting action of the erasing light source.
Block B from 6.

The image is then led out again to the image recording unit 16, that is, block B.

Next, the process of circulating one stimulable phosphor sheet through the transport system will be described below with reference to the flowchart of FIG.

The radiation image information reading device 10 is started by a start switch (not shown). As a result, the motors that drive the belt conveyor and nip rollers that make up the conveyance system perform constant speed operation (STPI).
6 (hereinafter, the stimulable phosphor sheet is referred to as rlPJ in the flow chart) is read and stored (SrF2), that is, the table 144 is created. In this case, the image reading section 44 may be used to read a barcode affixed to the back surface of the phosphor sheet 26 to obtain information on the position and sheet number.

Next, while the radiation image information reading device IO is operating, an interrupt operation is performed under the action of the timer 142 of the microcomputer 130 (SrF3). Position detection sensors 100a to 10 related to stimulable phosphor sheets 26
This is done to read the bit pattern of 0g (Sr
F2) The read bit pattern causes the RAM 13B to relatively store the block position and sheet number in the P area via the bit pattern as shown in the table 144 shown in the figure (SrF2). In this way, RAM13B
When the focus pattern is stored in the computer 130
The computer 130 then returns to the main routine operation (STP6), whereby 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, an interrupt operation is performed again under the action of the timer 142 (STP7), a bit pattern is read from the input port 132 (STP8), and this is stored in the RAM 13.
Store it in the Q area of 8 (STP9), and once,
After returning (STPlo) to the main routine, compare the bit pattern stored in the P area and the focus pattern stored in the Q area.5TPII)
, a phosphor sheet 2 corresponding to a predetermined position on the table 144
In this way, the phosphor sheets 26 in blocks B1 to B are updated (STP12).
The identification number will be specified in relation to the location.

In this state, the CPU 134
A drive signal is sent from 40 to the drive circuits 118a to 118g, and the drive circuits 118a to 118g drive the belt conveyors constituting the respective conveyance systems. As a result, for example, the stimulable phosphor sheet existing in block B is fed to block B3, and the stimulable phosphor sheet existing in block Bt is fed to block B3. Similarly, the stimulable phosphor sheet present in block B4 is fed to block B, and is further present inside the erasing section 74, that is, inside the erasing box, where it is subjected to erasing action. The stored stimulable phosphor sheet is fed to the next block, B.

In this way, by driving the conveyance system, the position detection sensors 100a to 100g send a signal to the CPU 13 indicating whether or not a stimulable phosphor sheet is present in each block.
It will be sent to 4.

First, it is determined via the table 144 whether or not the stimulable phosphor sheet 26a exists in the block Bl (STP).
13) If the stimulable phosphor sheet is present, the microcomputer 130 basically checks whether or not the stimulable phosphor sheet is present in the block Bt using the output signal of the position detection sensor 100b (STP14). If there is no stimulable phosphor sheet in B3, the device will
The dy state is displayed on the display device 114 (STP15), and the operator who emits X-rays displays this Re.
After confirming the ady state, the switch 112 is pressed to take an X-ray image (STP16). When this X-ray shot is achieved, the device must be released from the Ready state to prevent the next shot until the next one is ready.
TP17), the stimulable phosphor sheet of block B is fed to block Bt (STP18). on the other hand,
If xl sit is not achieved with 5TP16,
The phosphor sheet 26 of block B1 will proceed to the next step as it is.

By the way, the stimulable phosphor sheet is sent to block Bt in this way, but here block B! Whether or not there is a stimulable phosphor sheet is determined based on the output of the position detection sensor 100b. If there is a stimulable phosphor sheet in block B (STP19), then if it is determined that there is no stimulable phosphor sheet in block B based on the output signal of the position detection sensor 100c (STP20) , the stimulable phosphor sheet of block B2 is used as block B.

(STP21). When a stimulable phosphor sheet is fed to block B and there is a stimulable phosphor sheet in block B (STP22), the stimulable phosphor sheet that reaches block B1 proceeds to the next step. Then, it is checked whether there is a stimulable phosphor sheet in block B4 (STP23), and if there is no stimulable phosphor sheet in block B4, the stimulable phosphor sheet in block B is checked (STP23). At the same time as driving the conveyance system, the image reading section 44 is activated, and the excitation light is irradiated from the laser light source 50 onto the stimulable phosphor sheet that has reached the block B4 to read its image information (STP24). That is, the stimulated luminescence light generated by the excitation light is converted into an electrical signal by the photomultiplier 62. However, position detection sensor 1
When the stimulable phosphor sheet is detected by 00c, the counter 152 is cleared, and when the stimulable sheet is fed by the motor M4, the encoder 151 generates a pulse according to the rotation of the motor M4, and this pulse is counted by the counter 152. Ru.

By the way, when the stimulable phosphor sheet is present in block B4 (STP25), when feeding the stimulable phosphor sheet in block B4, the stimulable phosphor sheet is first placed in block B. Determine whether there is (
STP26).

When the stimulable phosphor sheet is present in block B, the microcomputer 130 and the CPU 134 do not substantially output a drive signal to the drive circuit 118f. If it is confirmed that there is no fluorescent phosphor sheet, the block B4
The stimulable phosphor sheet is fed to block B (ST
P27), and if there is a stimulable phosphor sheet in block B (STP28), when feeding this stimulable phosphor sheet to the next block B,
, determine whether a stimulable phosphor sheet is present in (
STP29), and 7, if it is determined that there is no stimulable phosphor sheet in block B-, the stimulable phosphor sheet of block BS is sent to block B6 STP2O), CPU U134 is a timer 142
Therefore, within the time set in the timer 142, the erasing unit 74 irradiates the stimulable phosphor sheet with erasing light from the erasing light source disposed inside the erasing unit 74 to erase the remaining image. Furthermore, block B performs processing.
, if there is a stimulable phosphor sheet in (STP3
2) Wait for the time set by the timer 142 to elapse (STP33) and determine whether a stimulable phosphor sheet exists in block B (STP34).
), if the time has not passed, proceed to the next step 0
Next, it is determined by 5TP34 whether or not there is a stimulable phosphor sheet in block B7, and if block B? If there is no stimulable phosphor sheet, the stimulable phosphor sheet is sent to block B7 (STP3).
5).

By the way, block B? If there is no stimulable phosphor sheet in block B (STP36), return to 5TP13 and repeat the same flow; on the other hand, if there is a stimulable phosphor sheet in block B, then block B 5TP to determine whether or not a stimulable phosphor sheet is present in .
37), feed the stimulable phosphor sheet of block B to the block B+ only when it is determined that there is no stimulable phosphor sheet in block B5TP38), and further S
It is executed from T P 13.

As mentioned above, the stimulable phosphor sheet circulates and images are read and erased sequentially, but if a power outage occurs during this time, it is detected by the power outage detection circuit 149, an interrupt is generated, and the required data is saved. etc. are processed. When an image is being read when a power outage occurs, in addition to normal interrupt processing, the laser light source 5 is activated as shown in FIG. 7(a).
0 is turned off and the motors M, ~M are stopped to interrupt image reading (STP50), and then a flag is set in the flag area 147 (STP51).
, Incidentally, at 5TP51, only the motor M4 may be stopped.Subsequently, the count value of the counter 152 is read and stored in the count value storage area 148 (STP52).
. Therefore, when a power outage occurs and an image is being read, the position where the image was being read is stored in the count value storage area 148.

Next, a case where the power outage is restored will be explained.

When the power outage is restored, the state of the flag in the flag area 147 is checked as shown in FIG.
STP53), when the flag is set in 5TP53, the laser light source 50 is turned on (STP54).
), however, the laser beam is controlled so that it scans the surface of the phosphor sheet until image reading is started (CTP60).

The motor M until the position detection sensor 100c turns off.
4 is driven in reverse (STP55.56). 5TP55
．． 56, the stimulable phosphor sheet which was in the process of image reading at the time of power outage is temporarily moved to the position before image reading even if it is outside the image reading section. In this state, the motor M4 rotates in the forward direction until the position detection sensor 100c is turned off (STP57.58). According to 5TP57.58, the stimulable phosphor sheet that was in the process of image reading at the time of power failure is unable to start image reading. It is set to the position immediately before it is made. In this state, the state of the table 144 is corrected (STP58), and then the stored contents of the count value storage area 148 are output to the latch circuit 153 and latched (STP59). From this state, image reading is started again (STP60).

The counter 152 sequentially counts the output pulses from the encoder 151 from the start of reading by the 5TP60, and the latched data of the latch circuit 153 and the counted value of the counter 152 are compared by the digital comparator 154, and the counted value of the counter 152 is latched. Until the data is reached, the digital comparator 154 is, for example, producing a high potential output. The read gain adjustment circuit 150 is a digital comparator 154.
The image signal read from the stimulable phosphor sheet is amplified with high gain and supplied to the image signal input/output circuit 117. When the count value of the counter 152 and the latch data of the latch circuit 153 fail, it is the sub-scanning position where reading was being performed at the time of the power outage.

When the count value of the counter 152 exceeds the latch data of the latch circuit 153, the digital comparator 154 generates a low potential output, the read gain adjustment circuit 150 is set to a low gain, and the read image signal from the stimulable phosphor sheet is output. is amplified at a low gain and supplied to the image signal input/output circuit 117, and the gain is returned to the normal state.

As described above, the information stored in the stimulable phosphor sheet that was being read at the time of the power outage is read, and following 5TP59, the normal circulation operation shown in FIG. 6 is performed, and the image information is Each operation of recording, reading image information, and erasing is performed.

In addition, when the flag is not set in 5TP53, the laser light source 50 is turned on (5TP61), and then,
The normal operation shown in FIG. 6 is performed.

Note that FIG. 8 is a timing chart for explaining the operation when re-reading after recovering from the power outage, and FIG. 8(a) shows the timing of starting reading, and FIG. 8(b)
1 is the output of the position detection sensor 100c, and particularly indicates the timing at which the counter 152 is reset. FIG. 8(0) shows the output pulses of the encoder 151, and FIG.
) schematically shows the count value of the counter 152, and FIG.

8(f) shows the output of the digital comparator 154; FIG. 8(11) shows the gain of the reading gain adjustment circuit 150; FIG. The reading signal is shown.The description of the reading operation with respect to FIG. 8 is the same as the reading operation description before the power outage,
Detailed explanation will be omitted.

In addition, in FIG. 8(h), for example, if one pulse of the encoder output is one line in the sub-scanning, then at the 7th sub-scanning line, there is a temporary power outage in the middle of the 7th pulse. Although the read signal level is not flat within this one scanning line, it can be suppressed to a level that does not cause problems in image diagnosis, etc.

In one embodiment of the present invention described above, the stimulable phosphor sheet whose stored information was being read at the time of a power outage is temporarily removed.
Although the case where the stimulable phosphor sheet is returned and read again is illustrated, the stimulable phosphor sheet may be once conveyed through the erasing section 74 and the image recording section 16 to the image reading section 44 again. In this case, the erasing section 7
The radiation source 104 is controlled to temporarily prevent the erasing action by illuminating the erasing light of 4, and to prevent new image information from being accidentally recorded in the image recording unit 16.
It is only necessary to control the projection so as to temporarily prohibit the projection of the image.

Furthermore, in the embodiment described above, the reading gain adjustment circuit 150 that adjusts the reading gain of the photomultiplier 62 is provided as an image signal adjusting means for increasing the image signal level obtained by the photoelectric reading means.
As other image signal adjustment means, means for increasing the intensity of excitation light irradiated onto the stimulable phosphor sheet can be used. Specifically, the path of the light beam from the excitation light source is A.
Insert the OM and, for example, normally read at 80% illuminance, and when rereading, control the AOM to set it to 100%.
It is possible to use a device configured to perform reading at an illuminance of . Further, it is also possible to use means for adjusting the scanning speed during two-dimensional scanning by moving the stimulable phosphor sheet and the excitation light relative to each other to slow down the scanning speed. In this case, the scanning speed is reduced, - the amount of excitation light irradiated per pixel is increased, and the resulting image signal level is therefore increased.

As described above, according to the present invention, when image reading becomes impossible during image reading, reading is performed again from the beginning. In addition, in this rereading, the image signal level obtained by the photoelectric reading means is increased up to the sub-scanning position where image reading becomes impossible, so the image obtained by rereading is inferior to the image obtained by normal reading. It does not interfere with image diagnosis, etc.

The embodiments of the present invention have been described above using a built-in radiation image information recording/reading device as an example.
The present invention is not limited to this embodiment, and it goes without saying that various improvements and changes in design can be made without departing from the gist of the present invention.

[Brief explanation of the drawing]

Fig. 1 is a block diagram explaining the present invention in detail, Fig. 2 is a perspective view of a radiographic image information recording/reading device incorporating the radiographic image information reading device according to the present invention, and Fig. 3 is shown in Fig. 2. 4 is an explanatory diagram showing the control system of the radiographic image information recording/reading device, and FIG. 5 shows the control circuit of the control system shown in FIG. 4. A block diagram showing the internal configuration, FIGS. 6A to 6C are flowcharts for conveying the stimulable phosphor sheet based on the control circuit shown in FIG. 5, and FIGS. FIG. 8 is a flowchart illustrating the operation at the time of power outage and restart of energization during operation based on the control circuit shown in FIG. 1. Circulating conveyance means 2. Image recording section 3. Image reading section 4. Erasing section 5. Detection means
6...Storage means 7...Control means 8...Gain adjustment means 10...Radiation image information recording/reading device 12.14...Housing 16...Image recording section 18
・・Operation unit 20 ・・Belt conveyor 22 ・・Roller group 24 ・・Guide member 26 ・
- Accumulative phosphor sheets 28a, 28b, 30a, 30b, 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 parts 76a, 76b...-1-7 propeller 78...Guide member 80...Nip roller 82...Guide member 1008 to 100g...Position detection sensor 102...Control circuit 104 ... Radiation source 106 ... Controller 10B ... Input device 110 ... Subject 112゛ ... Switch 116 ... Image processing device 1188 to 118g ... Drive circuit 130 ... Microcomputer 131 ... Input/output port 132 ... Input Port 134...CPU 136...
・ROM138 ・・RAM 140
...Output boat 142 ...Timer 144
...Table 146 ...Nonvolatile RAM 14
7... Flag area 148... Count value storage area 149... Power failure detection circuit 150... Reading gain adjustment circuit 151... Encoder 152... Counter 153... Latch circuit 154... Digital comparator procedure correction stamp button Showa May 28, 1960 1, Display of case 1985 Patent application No. 084
032 No. 2, Title of the invention: Radiographic image information reading device 3, Person making the amendment Relationship to the case Patent applicant Address: 210 Nakanuma, Minamiashigara City, Kanagawa Prefecture Name: Fuji Photo Film Co., Ltd. 4: Agent: 5: Amendment order date spontaneous

Claims (1)

[Claims] (1) a scanning means for two-dimensionally scanning in the main scanning direction and the sub-scanning direction by relatively moving a stimulable phosphor sheet on which radiation image information is stored and excitation light from an excitation light source; A photoelectric reading means for obtaining an image signal by reading stimulated luminescence light emitted from a stimulable phosphor sheet scanned by light, and the fact that image reading by the photoelectric reading means became impossible and became possible. a detection means for detecting image reading; a storage means for storing a sub-scanning position during image reading when the detection means detects that image reading is disabled during image reading; control means for re-reading the image of the stimulable phosphor sheet which was being read when the image became unreadable from the beginning when it is detected that the image has become readable; and the storage means during the re-reading. and an image signal adjustment means for increasing the image signal level obtained by the photoelectric reading means up to the storage sub-scanning position.