JPH0193731A - Radiophotograph information recorder and reader - Google Patents

Abstract

PURPOSE:To speed up a processing and to ensure erasure by allowing a reading and erasing unit to move at speed suitable for reading out of a going-out route, reading and erasing information, and allowing said unit to move at speed suitable for erasure at an incoming route, by thereby erasing information. CONSTITUTION:On the going-out route where an image reading means 40 reads image information, and simultaneously an erasing means 50 erases in the part where the read of an accumulating phosphor sheet 2 is ended the reading and erasing unit 4 moves in a direction A in a time t1 required for reading. Where the time required for erasure is t2, the required time at the incoming route that the erasing means 50 erases residual radiograph goes to (t2-t1). Accordingly, the required time at the outgoing route that the reading and erasing unit 4 needs to be reciplocated goes to t1+(t2-t1)=t2. In the time t2 required only for erasure, reading and erasing are performed surely.

Description

Detailed Description of the Invention (Field of the Invention) The present invention involves accumulating and recording radiation image information on a stimulable phosphor sheet, then irradiating this with excitation light, and performing photostimulation according to the accumulated and recorded image information. The present invention relates to a radiation image information recording/reading device that detects emitted light, reads image information, and converts it into an electrical signal, and in particular, it relates to a radiation image information recording/reading device that can be miniaturized as a whole.

(Conventional technology) Certain types of phosphors are exposed to radiation (X-rays, α-rays, β-rays.

When irradiated with γ-rays, electron beams, ultraviolet rays, etc., a part of this radiation energy is accumulated in the phosphor, and when this phosphor is irradiated with excitation light such as visible light, the phosphor changes depending on the accumulated energy. is known to exhibit stimulated luminescence, and phosphors exhibiting this property are called stimulable phosphors (stimulable phosphors).

Using this stimulable phosphor, radiation image information of a subject such as a human body is temporarily recorded on a stimulable phosphor sheet, and the stimulable phosphor sheet is irradiated with excitation light such as a laser beam to emit stimulated light. Light is generated, and the resulting stimulated luminescent light is photoelectrically read by a photodetector to obtain an image signal, and based on this image signal, a radiation image of the subject is displayed on a recording material such as a photographic light-sensitive material or a display device such as a CRT. The applicant has already proposed a radiation image information recording and reproducing system that outputs radiation images as visible images. (Unexamined Japanese Patent Publication No. 55-12429, 5B-11
No. 395 etc. ) This system has the practical advantage of recording images over a much wider range of radiation exposure compared to conventional radiographic systems using silver halide photography. In other words, in a stimulable phosphor, it is recognized that the amount of emitted light that is stimulated to emit light due to excitation after accumulation is proportional to the amount of radiation exposure over an extremely wide range.
Therefore, even if the amount of radiation exposure varies considerably due to various imaging conditions, the amount of stimulated luminescence emitted from the stimulable phosphor sheet can be read by the photoelectric conversion means by setting the reading gain to an appropriate value. This electric signal is converted into an electric signal,
By using the signal to output a radiation image as a visible image to a recording material such as a photographic material or a display device such as a CRT, a radiation image that is not affected by fluctuations in radiation exposure can be obtained.

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

Therefore, the present applicant has proposed an optical radiation image information recording/reading device that realizes efficient cyclical reuse of stimulable phosphors (
For example, Japanese Patent Publication No. 58-200289).

The above-mentioned apparatus comprises a support, a recording body consisting of a stimulable phosphor layer that stores and records a radiographic image fixed on the support, and a recording body that irradiates the recording body with radiation through a subject. an image recording section that stores and records a radiographic image of a subject; an excitation light source that emits excitation light that scans the recording medium on which the radiation image is cumulatively recorded; and an excitation light source that emits excitation light that scans the recording medium that is scanned by the excitation light an image reading section having a photoelectric reading means for reading stimulated luminescence light to obtain an image signal; and the recording medium on the support is read by repeatedly moving the support and the image reading section relative to each other. a means for circulating the image relative to the image reading section; and a means for releasing the residual radiation energy on the recording medium prior to recording an image on the recording medium after the image reading is performed in the image reading section. The erasing section is incorporated into one device,
The recording medium is efficiently circulated and reused.

By the way, the radiation image information recording/reading device described above is extremely suitable for use mainly for medical diagnosis.
In recent years, there has been an increasing demand to make the entire device as small as possible. In other words, if the device is large,
The device can only be used by being installed in the central part of a relatively large hospital, but if the device is made smaller, it can be installed and used in each diagnostic room by a medical practitioner, for example, so the scope of use of the device will be reduced. will expand greatly.

Such a recording/reading device aimed at miniaturization is designed to hold a stimulable phosphor sheet facing a radiation source, and to integrate an image reading means and an erasing means to this stimulable phosphor sheet. An apparatus has been proposed in which a reading/erasing unit formed as a unit is moved back and forth, and the stimulable phosphor sheet after imaging is read on the outward trip and erased on the return trip.
115148, No. 62-119537). According to such an apparatus, since the erasing means erases the stimulable phosphor sheet while moving, the erasing means, which conventionally required a size larger than one stimulable phosphor sheet, can be made small. Since the reading/erasing unit is compact, the entire device can be downsized.

(Problems to be Solved by the Invention) However, in the above device, the reading/erasing unit performs reading on the outward path and erases on the returning path, so that the stimulable phosphor sheet that has been photographed is It is necessary to reciprocate the reading/erasing unit until the next photographing is possible, and the time required for this is the reading time plus the erasing time, which is disadvantageous in that the processing takes time.

Furthermore, in order to eliminate the above-mentioned disadvantages, the apparatus disclosed in Japanese Patent Application No. 62-94548, which was previously proposed by the present applicant, has erasing means provided on both sides of the image reading means in the reading and erasing unit. By using erasing means upstream of the reading means in each of the outward and return passes, reading and erasing can be performed simultaneously in both the outward and return passes. However, in the above device, the reading speed and the erasing speed are always the same, so if the moving speed of the unit is set to a speed suitable for reading, there is a problem that erasing cannot be performed satisfactorily.

The present invention has been made in view of the above-mentioned problems, and by moving a reading/erasing unit relative to a stimulable phosphor sheet to perform reading and erasing, it is possible to miniaturize the device, and also reduce the stimulable phosphor sheet. Reading of phosphor sheet,
It is an object of the present invention to provide a radiation image information recording/reading apparatus that can reduce the time required for erasing as much as possible and can sufficiently perform both reading and erasing.

(Means for Solving the Problems) The radiation image information recording/reading device of the present invention has a reading/erasing unit that can reciprocate with respect to the stimulable phosphor sheet, and an excitation light source that irradiates the stimulable phosphor sheet with excitation light. An image reading means consisting of a light irradiation means and a photoelectric reading means, and an erasing means provided at a position upstream of the image reading means and adjacent to the image reading means in the forward direction are integrated into a unit, and the image reading means and the image reading means are integrated into a unit. A light shielding means is provided between the erasing means, and an accumulation amount detection means is provided for detecting the amount of accumulated energy of the radiation image accumulated and recorded on the stimulable phosphor sheet by the image recording means, and the reading and erasing unit While moving the reading/erasing unit at a speed suitable for reading image information, the image reading means reads the image information, and the erasing means erases the information, and on the return trip, the image information is erased based on the output from the accumulation amount detecting means. It is characterized in that the erasing means performs erasing while moving the reading and erasing unit at a speed suitable for erasing.

Note that the reading and erasing unit moves at a speed suitable for erasing on the return trip means that the unit moves at a speed suitable for erasing the radiation image remaining on the stimulable phosphor sheet after the erasure is performed by the erasing means on the outward trip. It means to move. Further, the accumulation amount detection means may be the phototimer when the radiation source of the image recording means is controlled to have an appropriate amount of radiation by a phototimer, or the accumulation amount detection means may be the phototimer when the radiation source of the image recording means is controlled to an appropriate amount by a phototimer, or the radiation amount detected by the image reading means may be the phototimer. Since the accumulated amount can be determined from the image data, an image information reading circuit within the image reading means may be used as the accumulated amount detecting means.

In addition, it is desirable to use the above-mentioned image reading means as compact as possible in order to miniaturize the reading/erasing unit and downsize the entire device. For example, as the photoelectric reading means, a long photo multiplier, etc., which will be described later, is used. Moreover, the irradiation of the excitation light is not limited to the scanning of the excitation light as described above, but it is also possible to irradiate the striped emitted light in a line and collect the stimulated luminescence light emitted from this irradiation position using a line sensor. A reading method may also be used. This method is particularly preferable in terms of downsizing the image reading means.

(Function) According to this device, the stimulable phosphor sheet is held at the photographing position, and the reading and erasing unit is reciprocated with respect to the stimulable phosphor sheet to perform reading and erasing. can be downsized to make the entire device compact. In addition, according to the apparatus of the present invention, reading and erasing are performed simultaneously on the forward pass of the reading/erasing unit, and only erasing is performed on the return pass to compensate for the lack of erasure. If the required time is tz, the time required for the outward journey is tl, the time required for the return journey is tz-tl, and the time required for the round trip is t.
z + (tz tx ) - tz. Therefore, both reading and erasing can be carried out sufficiently, and the round trip time is equal to the time required for erasing, so that the processing speed of the stimulable phosphor sheet can be increased. Furthermore, since the erasing time is controlled for each stimulable phosphor sheet by the accumulation amount detecting means, erasing on the stimulable phosphor sheet can be carried out reliably without waste.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIGS. 1(a) and 1(b) are side views showing an outline of a radiation image information recording/reading apparatus according to an embodiment of the present invention.

This apparatus consists of a main body 1 and a radiation source 12 such as an X-ray source placed above the imaging table 11 which is the top surface of the main body 1. The stimulable phosphor sheet 2 is fixedly held by a holding means (not shown). The stimulable phosphor sheet 2 has a stimulable phosphor layer 2B formed on the underside of a substrate 2A that transmits X-rays, and the photographing table 11 is transparent to radiation. A grid 13 that covers the entire surface of the stimulable phosphor sheet 2 is provided below the photographing platform 11 . When imaging areas with large body thickness, such as the chest, the scattered radiation emitted from the subject during imaging may cause deterioration in image quality, so grid 1 is used.
3 is disposed between the photographing table 11 and the stimulable phosphor sheet 2, so that the scattered radiation is absorbed by the grid. Note that this grid is not necessary when photographing areas with thin body thickness, so
It does not necessarily have to be provided, and may be detachable depending on the region to be imaged. In this apparatus, an image recording means 10 is constituted by the above-mentioned radiation source 12, photographing stage 11, grid 13, and phototimer 14, which will be described later. In addition, in FIG. 1, what is arranged between the grid 13 and the stimulable phosphor sheet 2 is a fluorescent screen 14a that constitutes a part of the phototimer 14, and this fluorescent screen 14a has radiation transparency. It has become.

Below the stimulable phosphor sheet 2, an image reading means 40 comprising an excitation light irradiation means 20 and a photoelectric reading means 30 is provided in the casing 3, and an image reading means 40 is disposed adjacent to the image reading means. A reading/erasing unit 4 in which erasing means 50 is housed is provided. This reading/erasing unit 4 is shown in FIG.
) from the right end position (first position) shown by the solid line in Figure 1 (
It is possible to reciprocate while facing the stimulable phosphor sheet 2 up to the left end position (second position) shown by the solid line in b).

In this embodiment, the movement path in the direction of arrow A from the first position to the second position is the outward path, and the movement path from the second position to the first position is the forward path.
The path of movement in the direction of arrow A' to the position is defined as the return path. The unit moving means 60 for reciprocating the reading/erasing unit 4 includes, for example, a screw rod 61 extending in the moving direction of the unit. A unit support portion 62 that fits into this screw rod 61, a gear 63 that is pivotally supported on the screw rod, a gear 64 that meshes with this gear 63, this gear 6
The screw rod 61 is rotated by the motor 65 via gears 63 and 64, so that the unit support part 62 is rotated in both forward and reverse directions.
The unit 4 is moved back and forth by moving the unit 4.

When a subject 15 is placed on the photographing table 11 of the image recording means 10 with the reading/erasing unit 4 in the first position, the radiation source 12 is activated, and the transmitted radiation image of the subject 15 is converted into a stimulable fluorescence image. The radiation image information of the subject is projected onto the body sheet 2 and stored and recorded in the phosphor layer 2B of the stimulable phosphor sheet 2.

Further, the image recording unit IO of the embodiment apparatus is configured such that the dose of radiation applied to the stimulable phosphor sheet 2 is controlled to an appropriate amount by the phototimer 14 when performing the above-mentioned photographing.

As shown in FIG. 2, the phototimer 14 includes the fluorescent screen 14 placed at a position that receives radiation transmitted through the subject.
a, and a photodetector 14 such as a photomultiplier.
b, the light receiving surface of this photodetector 14b and the fluorescent screen 14a.
and a control section 14d to which the output S1 of the photodetector 14b is input. As shown in FIG. 1, the fluorescent screen 14a is arranged between the subject 15 and the stimulable phosphor sheet 2.

Therefore, when recording the transmitted radiation image of the subject 15 on the stimulable phosphor sheet 2 as described above, the phosphor plate 1
4a is irradiated with radiation that has passed through the subject 15, thereby emitting fluorescence. This fluorescence is transmitted to the photodetector 14b via the condensing optical element 14c, and is photoelectrically detected by the photodetector 14b. The control unit 14d receives the output S1 of the photodetector 14b indicating the level of the fluorescence, and outputs a radiation source stop signal S2 when the amount of light of the fluorescence (integrated amount of light) reaches the set amount of light. This stop signal S2 is sent to the drive circuit 16 of the radiation source 12, and this drive circuit 16 stops the operation of the radiation source 12 upon receiving the stop signal S2.

By doing this, the dose of radiation applied to the stimulable phosphor sheet 2 is controlled to an appropriate predetermined amount. The above-mentioned set amount of fluorescence is desirably changed in accordance with the reading gain when reading the stimulable phosphor sheet, which is selected as appropriate depending on the part to be imaged and the purpose of imaging. from the control section 14
It is also possible to adjust the set light amount by sending an instruction signal S3 to d. When the above-mentioned photographing is completed, the unit 4
The image reading means 40 reads the image information accumulated on the stimulable phosphor sheet 2.

This reading starts from the first position where the excitation light from the image reading means can enter the end of the stimulable phosphor sheet 2.

Excitation light irradiation means 2 in the image reading means 40 of this embodiment
0 is an excitation light source 21 such as a semiconductor laser, a condenser lens 22 provided on the optical path of excitation light 2LA emitted from this excitation light source, and excitation light 21A that has passed through the condenser lens 22.
A rotating polygon mirror 2 is an optical deflector that deflects the light in a direction perpendicular to the plane of the paper in FIG.
3 and mirrors 24A and 24 that change the optical path of the excitation light.
B and 24C, and the excitation light 21A is caused to repeatedly main-scan the stimulable phosphor sheet 2 by this excitation light irradiation means.

On the other hand, along with the main scanning of the excitation light 21A described above, the unit 4 is transported in the direction of the arrow A by the unit moving means 60 at a constant speed suitable for image reading, so that the scanning position of the excitation light 21A is moved in the direction of the arrow A. The stimulable phosphor sheet 2 is moved and sub-scanned, and the excitation light 2LA is irradiated over almost the entire surface of the stimulable phosphor sheet 2. Stimulated luminescence light corresponding to the accumulated radiation energy level (that is, carries accumulated radiation image information) is emitted from the portion of the stimulable phosphor sheet that is irradiated with this excitation light. This stimulated luminescence light is detected by the photoelectric reading means 30 within the image reading means 40.

The photoelectric reading means 30 in this device is
The photomultiplier 31 is equipped with a long photomultiplier 31 as disclosed in No. a filter 32 that selectively transmits only the excitation light and cuts off the excitation light reflected on the sheet surface from entering the photomultiplier;
The photomultiplier 31 is attached to the light-receiving end surface of the photomultiplier 31 via the
A light guide 33 is integrally attached to provide good transmission of light to the light source. In addition, 34 in the figure is a light guide of the stimulated luminescence light.

This is a reflecting mirror that reflects the light emitted to the opposite side to the light guide 33 and allows it to enter the light guide 33 in a good manner. The long photomultiplier 31 extends in the main scanning direction over the length of the main scanning line, and is disposed with its light receiving surface facing the main scanning line. blind type,
It was created by extending a photomultiplier equipped with a multiplier section consisting of various electrodes such as a box type.

The stimulated luminescent light generated from the stimulable phosphor sheet 2 by the scanning of the excitation light 2LA is well transmitted by the light guide 33 and made to enter the photomultiplier 31, and the photomultiplier 31 The exhaustion light is read photoelectrically to generate an image signal for outputting a visible image, and this image signal is sent to an image information reading circuit 35 where necessary image processing and the like are performed.

On the other hand, the image reading means 40 is provided in the reading/erasing unit 4.
Erasing means 50 is provided adjacent to.

This erasing means 50 is located upstream of the image reading means in the above-mentioned outward path, and the reading erasing unit 4 is located at the arrow A.
At the same time as the image reading means 40 reads the image information while moving in the direction, the erasing means 50 sequentially erases the portions of the stimulable phosphor sheet 2 that have been read.

The erasing means 50 includes: - As an example, the stimulable phosphor sheet 2
The eraser includes an erasing light source 51 such as a fluorescent lamp extending in the width direction of the erasing light source 51, and a reflecting plate 52 that reflects downward light emitted from the erasing light source 51 toward the stimulable phosphor sheet. Further, a light shielding means 53 made of velvet or the like is extended above the portion of the reflecting plate 52 facing the image reading means 40 to prevent erasing light from leaking into the image reading means 40. The erasing light source 51 moves as the unit 4 moves in the six directions of the arrow, and when the light shielding means 53 reaches the end of the stimulable phosphor sheet, the erasing light source 51 is turned on and the stimulable phosphor sheet 2 Immediately after the image information is read by the image reading means 40, erasing light is irradiated,
As the erasing means 50 moves, the entire surface thereof is irradiated with erasing light. The erasing light source 51 mainly emits light in the excitation wavelength range of the stimulable phosphor sheet, and the radiation energy remaining in the stimulable phosphor sheet 2 after reading the image is transferred to the stimulable phosphor sheet 2 in this way. It is emitted from the sheet by being irradiated with light.

When the reading/erasing unit 4 moves to the second position shown by the solid line in FIG. 1(b), the image information has been read over the entire stimulable phosphor sheet and erasing has also been done to some extent. becomes.

However, the moving speed of the reading/erasing unit 4 on the outward journey is set to be suitable for reading image information.
At this moving speed, the irradiation of the erasing light onto the stimulable phosphor sheet 2 becomes insufficient. Therefore, the above unit is shown in Figure 1 (
The erasing light source 51 is turned on on the return path in the direction of arrow A' shown in b), and is moved at a speed suitable for erasing the radiation image remaining on the stimulable phosphor sheet after erasing on the outward path. The body sheet is now fully erased.

The appropriate moving speed of the unit 4 on the return trip changes depending on the amount of radiation energy remaining in the stimulable phosphor sheet 2, and the larger the amount of radiation energy, the slower the unit 4 moves and the more erasing light is accumulated. It is necessary to irradiate the fluorescent phosphor sheet.

Assuming that the transport speed of the unit, the intensity of the excitation light, and the intensity of the erasing light are constant on the outward path, the stimulable phosphor sheet 2
The amount of radiation energy remaining in the stimulable phosphor sheet is determined by how much radiation energy was accumulated in the stimulable phosphor sheet during imaging. Therefore, in this embodiment, information on the amount of radiation energy accumulated in the stimulable phosphor sheet at the time of photographing is obtained from the phototimer 14 to determine the moving speed of the reading/erasing unit 4 on the return trip.

As described above, the control section 14d of the phototimer 14 monitors the amount of radiation energy accumulated in the stimulable phosphor sheet based on the amount of fluorescence emitted from the fluorescent screen 14a, and adjusts the amount of radiation energy to a predetermined amount. It is something that is controlled by Al.

Therefore, as shown in FIG. 2, a signal S4 indicating the predetermined amount of radiation energy is obtained from the control section 14d, and this signal is transmitted to the driver 6 of the motor 65 of the unit moving means 60.
6, and the higher the amount of radiation energy, the more
By moving the stimulable phosphor sheet in the backward direction at a low speed, it is possible to perform erasing that sufficiently compensates for the insufficiency of erasing on the forward path, depending on the amount of radiation energy remaining in the stimulable phosphor sheet.

In addition to the phototimer 14, the image information reading circuit 35 can also be used as an accumulation amount detection means for detecting the amount of radiation energy accumulated in the elastogenic phosphor sheet during photographing. In other words, when the level of the image signal sent to the image information reading circuit is high (the amount of stimulated luminescence light emitted from the stimulable phosphor sheet is large), the radiation energy accumulated in the stimulable phosphor sheet at the time of imaging is It is thought that the amount of radiation energy remaining in the stimulable phosphor sheet after erasing on the forward pass is also large. Therefore, a signal indicating the total amount of image signals is obtained from the image reading circuit 35, and the motor 65 By controlling the drive of the unit, it is possible to move the unit at an appropriate speed and perform erasing on the return trip.

In this way, according to the present device, reading and erasing are performed simultaneously while moving the reading/erasing unit at a speed suitable for reading on the outward pass, and only erasing is performed on the return pass to compensate for the lack of erasure on the outward pass. The time required to complete reading and erasing can be reduced,
In addition, erasing can be performed satisfactorily. Furthermore, since the moving speed of the unit on the return trip is controlled by the storage amount detection means, erasing on the stimulable phosphor sheet is performed reliably without waste.

The image reading means of the apparatus of the present invention scans the excitation light two-dimensionally against the stimulable phosphor sheet to generate stimulated luminescent light as described above, and photomultiplies this stimulated luminescent light. It is not limited to detection using a photodetector such as pliers, but it is also possible to irradiate excitation light in a linear manner and divide the stimulated luminescence light emitted from the linear excitation light irradiation position into pixels using a line sensor. It may be something that can be read.

Next, an apparatus using a method of linearly irradiating excitation light will be described with reference to FIG. 3 and the subsequent drawings.

Note that the same parts as in the embodiment shown in FIG. 1 are given the same numbers, and their explanations will be omitted.

In the apparatus shown in FIG. 3, the excitation light irradiation means 120 of the image reading means 140 irradiates the stimulable phosphor sheet 2 with excitation light in a line substantially perpendicular to the moving direction of the reading and erasing unit 4'. As an example, the fluorescent light-condensing sheet disclosed in Japanese Patent Application No. 1983-21957 previously filed by the present applicant is used. Further, the photoelectric reading means of the image reading means 140 is the excitation light irradiation means L.
It consists of a line sensor 130 provided at a position facing 2Q with a stimulable phosphor sheet 2 in between. As shown in FIG. 4, this line sensor is fixed to the casing 3' of the unit 4' by support means 3A, and is movable together with the casing 3'.

The fluorescent light-concentrating sheet is a sheet-like molded product containing phosphor, and when the surface thereof is irradiated with light, the phosphor inside the fluorescent light-concentrating sheet is excited and fluorescence is generated. , this fluorescence undergoes repeated total internal reflection and travels toward the end surface. Therefore, as shown in FIG.
1. A fluorescent light-concentrating sheet 122 formed to surround the entire circumference of the fluorescent lamp 12, 1, and a cylindrical lens 1 provided on one end surface of this fluorescent light-concentrating sheet.
23, and a fluorescent lamp 121 when irradiating with excitation light.
is turned on, the light emitted from the fluorescent lamp 121 causes fluorescence in the fluorescent light-condensing sheet 122, and this fluorescence is emitted from one end surface of the fluorescent light-concentrating sheet through the cylindrical lens 128. This fluorescence is used as linear excitation light. Note that the fluorescent light-condensing sheet may be selected from one that emits fluorescence in the excitation wavelength range of the stimulable phosphor sheet by light emitted from a fluorescent lamp. Further, instead of a fluorescent lamp, a sodium lamp, a mercury lamp, an electroluminescent panel, etc. can be used. In this embodiment, the excitation light irradiation means 120 excites the phosphor surface of the stimulable phosphor sheet 2, and the stimulated luminescence light emitted by the excitation light is transmitted to the line sensor 130.
Detected by

In the device of this embodiment, the substrate 2A of the stimulable phosphor sheet 2 and the fluorescent screen 14a of the phototimer are transparent.

As shown in FIG. 5, the line sensor 130 is made up of a support 131 extending in the width direction of the stimulable phosphor sheet 2 and a pixel-divided light receiving element array 132 fixed thereto. Further, on the light receiving element array 132, a filter 133 is disposed that transmits the stimulated luminescence light emitted from the stimulable phosphor sheet 2 and absorbs the excitation light transmitted through the stimulable phosphor sheet 2. The stimulated luminescence light is received by the light receiving element array 132 of the line sensor 130 via this filter 133.

The light-receiving element array 132 has a large number of solid-state photoelectric conversion elements 132a arranged in a row in the width direction of the stimulable phosphor sheet 2 and each corresponding to one pixel. The light is simultaneously received by the conversion element 132a. Each element 132a that receives light generates photocarriers and temporarily stores signals obtained thereby. The accumulated signals are sequentially read out by the scanning circuit 134, and reading of information from one linear irradiation section (corresponding to a scanning line) is completed.

Next, the reading/erasing unit 4' is transported by one scanning line in the forward direction indicated by arrow A in FIG. 3 relative to the stimulable phosphor sheet 2 by the unit moving means 60, and the above reading steps are repeated. By repeating this step for the entire surface of the stimulable phosphor sheet 2, the radiation image information recorded on the entire surface of the stimulable phosphor sheet 2 is read out.

Next, the scanning circuit 134 following the line sensor 130 will be explained. FIG. 6 is an equivalent circuit of a line sensor and a scanning circuit using a photoconductor. A signal from a photocarrier generated when the stimulated luminescence light hits a solid-state photoelectric conversion element 132a using a photoconductor is transferred to a capacitor C1 (1-1°2, . . . n ). The accumulated photocarrier signal is transferred to a switch section 134A controlled by a shift register 134B.
are sequentially read out by sequentially opening and closing, thereby obtaining time-series image signals. The image signal is then amplified by an amplifier 135 and output from its output terminal 136. Using this image signal, it is possible to display the radiation image on a CRT, for example, or to obtain a hard copy of the radiation image using a scanning recording device or the like. Note that the switch section 134A and the shift register 1
The MO8 section 134 consisting of 34 B may be replaced with a CCD. Furthermore, the erasing means 50 in this embodiment has a structure similar to that of the erasing means of the apparatus shown in FIG. It is done in the same way.

Furthermore, as an excitation light irradiation means for linearly irradiating excitation light, in addition to the one using the fluorescent light-concentrating sheet mentioned above, the ordinary L
ED arrays can also be used.

FIG. 7 shows an example in which this LED array is used as excitation light irradiation means.

In the apparatus shown in FIG. 7, the reading/erasing unit 4'' is movable between the imaging platform 11 and the stimulable phosphor sheet 2, and the unit moving means 180 is configured to move the unit as shown in FIG. It consists of two rails tet extending in the moving direction and four wheels 163 that are attached to the side of the unit 4' and are driven by a motor 162 to run on the rails in a reciprocating direction.

Excitation light irradiation means 2 in the image reading means 240 of this device
20 is provided on an LED array 221 in which light emitting diodes are connected in the width direction of the stimulable phosphor sheet, and on the excitation light exit surface of the LED array 221, and focuses the excitation light only in the moving direction of the reading/erasing unit 4'. It consists of a cylindrical lens 222.

The LED array 221 emits light from the excitation and emission region of the phosphor layer of the stimulable phosphor sheet 2, and this light (
Stimulated luminescence light is emitted from the part of the stimulable phosphor sheet that has been irradiated with the excitation light. This stimulated luminescence light is detected by a line sensor 130 disposed within both reading means at a position looking into the irradiation position of the excitation light. Furthermore, in this device, since the line sensor 130 is arranged a little apart from the stimulable phosphor sheet 2, there is space between the stimulable phosphor sheet 2 and the line sensor 130 corresponding to each light receiving element of the line sensor 130. A microlens array 137 is provided in which a plurality of microlenses are integrally connected, and the stimulated luminescent light emitted from the stimulable phosphor sheet 2 is efficiently made incident on the line sensor 130. .

(Effects of the Invention) As described above in detail, according to the radiation image information recording/reading device of the present invention, the stimulable phosphor sheet is fixed and the reading/erasing unit is reciprocated with respect to the stimulable phosphor sheet. By performing reading and erasing, the erasing means can be downsized and the entire device can be downsized. At the same time, according to this device, the sum of time required for reading and erasing can be shortened by performing erasing in parallel on the forward pass when reading image information, and furthermore, only erasing is performed on the return pass to make up for the lack of erasure. This allows for sufficient erasing.

[Brief explanation of the drawing]

1(a) and 1(b) are side views of a radiation image information recording/reading device according to an embodiment of the present invention, FIG. 2 is a schematic diagram illustrating control of a radiation source by a phototimer, and FIGS. FIG. 7 is a side view of an apparatus according to another embodiment of the present invention, FIG. 4 is a perspective view of an image reading means equipped with a fluorescent light-condensing sheet, FIG. 5 is a schematic perspective view of a line sensor, and FIG. The scanning circuit diagram following the line sensor, Figure 8 is the 7th
FIG. 3 is a perspective view showing the reading/erasing unit and its moving means in the apparatus shown in the figure. 2...Stimulative phosphor sheet 4.4', 4'...Reading/erasing unit lO...Image recording section 12...Radiation source 14...Phototimer 20.120.220. ...Excitation light irradiation means 30...
...Photoelectric reading means 35...Image information reading circuit 40
, 140, 240... Image reading means 50...
- Erasing means 60, 160...Unit moving means 130...Line sensor

Claims (1)

[Scope of Claims] A stimulable phosphor sheet; an image recording means for accumulating and recording a radiation image of a subject on the stimulable phosphor sheet by irradiating the stimulable phosphor sheet with radiation through the subject; excitation light irradiation means for irradiating excitation light in a fixed direction onto a stimulable phosphor sheet on which stimulable phosphor is stored and recorded, and photoelectrically reading stimulated luminescence light emitted from the sheet by irradiation with this excitation light to output an image signal. an image reading means comprising a photoelectric reading means, and an image reading means provided adjacent to the image reading means in a direction perpendicular to the irradiation direction of the excitation light, and emitting radiation energy remaining in the stimulable phosphor sheet after reading. a reading/erasing unit, the reading/erasing unit being integrally formed with erasing means for erasing the image, and having a light shielding means between the image reading means and the erasing means; a forward direction in which the image reading means is downstream of the erasing means; a unit moving means for moving the image reading means in a backward direction opposite to the forward direction; and a unit moving means for moving the image reading means in a backward direction opposite to the forward direction; It comprises an accumulated amount detecting means for detecting the amount of accumulated energy of the accumulated and recorded radiation image, the stimulable phosphor sheet is held at a photographing position facing the image recording means, and the reading and erasing unit is held at the photographing position. the reading/erasing unit is moved at a speed suitable for reading the image information while the image reading means reads the image information, and the erasing means erases the image information; A radiation image information recording/reading apparatus characterized in that, on a return trip, the erasing means performs erasing while moving the reading/erasing unit at a speed suitable for erasing based on the output from the accumulation amount detecting means.