JPH0690419B2 - Image reading and playback method - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention stores and records radiation image information on a stimulable phosphor sheet, and then irradiates it with excitation light to stimulate irradiation according to the image information stored and recorded. The present invention relates to an image reading / reproducing method for detecting emitted light and converting the light into an electric signal to obtain image information, particularly in industrial small object inspection, X-ray local inspection, etc.
The present invention relates to an image reading and reproducing method used when a stimulable phosphor sheet having a relatively small size is used.

(Prior Art) When a certain kind of phosphor is irradiated with radiation (X-ray, α-ray, β-ray, γ-ray, electron beam, ultraviolet ray, etc.), a part of this radiation energy is accumulated in the phosphor, It is known that when a phosphor is irradiated with excitation light such as visible light, the phosphor exhibits stimulated emission depending on the stored energy, and a phosphor having such a property is a stimulable phosphor (luminescent material). Exhaustible phosphor).

A stimulable phosphor sheet is obtained by molding a stimulable phosphor having such features into a sheet, and the stimulable phosphor sheet can be used for reading image information for various purposes.

For example, as an example of its application, radiation image information of a subject such as a human body is temporarily stored and recorded on a sheet of stimulable phosphor,
This stimulable phosphor sheet is irradiated with excitation light such as laser light to generate stimulated emission light, and the obtained stimulated emission light is photoelectrically read by a photodetector to obtain an image signal. Based on this, a radiation image information recording / reproducing system for outputting a radiation image of a subject as a visible image on a recording material such as a photographic light-sensitive material or a display device such as a CRT is known and put into practical use. (JP-A-55-12429, JP-A-56-11395, etc.) (Problems to be solved by the invention) However, in the above-mentioned conventional system, image information over a wide range on the stimulable phosphor sheet is read. Therefore, the excitation light to the sheet is raster-scanned.Therefore, in the irradiation of the excitation light to the sheet and the reading of the stimulated emission light generated from the sheet by the irradiation of the excitation light, complicated main scanning and sub-scanning are performed. Need to scan,
As a result, the system becomes large and complicated.

However, on the other hand, the above-mentioned system is mainly used for medical diagnosis, and in recent years, there has been a demand to make the entire system as small as possible, simple, and inexpensive. That is, downsizing the system,
By simplifying and reducing the cost, not only a large hospital but also a practitioner or the like can be installed in each diagnostic room.

In addition, if the system handles only local parts of the human body, it is not always necessary to use a large stimulable phosphor sheet, and it is sufficient to use a small stimulable phosphor sheet. , It is more convenient to make it easier to turn around.

Furthermore, for example, when the above-mentioned stimulable phosphor sheet is used for non-destructive inspection of small industrial products, autoradiography such as DNA colony hybridization or protein electrophoresis pattern, the area required for the sheet is considerably large. It may be small. Therefore, the image reading / reproducing system should be of a scale corresponding to the size of the stimulable phosphor sheet.
Along with the miniaturization of the system scale, there is an increasing demand for easier system operation, easier adjustment, and lower system manufacturing cost.

Under such a request, the inventors of the present invention stacked the stimulable phosphor sheet and the recording medium on the rotating plate in such a state that the respective recording surfaces are in the opposite directions, and the excitation light was also applied to the recording medium on the sheet. The recording light is irradiated, and the excitation light and the recording light are main-scanned by the rotation of the rotary plate, and the excitation light and the recording light are sub-scanned by the movement of the rotary plate in the radial direction of the rotary plate. A method for recording the read radiation images on the above-mentioned recording medium at the same time as reading the read radiation images has been developed.

By the way, the stimulated emission light, which is a carrier of radiation image information, varies in amount depending on the illuminance on the stimulable phosphor sheet due to the excitation light and the size of the irradiation beam diameter. It is desirable that the excitation light is accurately focused on the stimulable phosphor sheet. Also,
In order to record a radiation image on a recording medium and reproduce a good visible image, it is desirable that the recording light is accurately focused on the recording medium.

However, in the method of reading and recording the radiation image using the rotating plate as described above, it is difficult to avoid the surface wobbling of the rotating plate during reading and recording, and therefore, the excitation accompanying the rotation of the rotating plate is difficult. The distance between the optical focus lens and the stimulable phosphor sheet and the distance between the recording light focus lens and the recording medium change to change the illuminance and the beam irradiation diameter due to the excitation light, which deteriorates the reading accuracy and recording accuracy of the radiation image information. There is a problem.

The present invention has been made in view of the above circumstances, and photoelectrically reads the image information by irradiating a stimulable phosphor sheet on which a radiation image is stored and recorded with excitation light, and an image signal obtained by this reading When recording and reproducing a radiation image as a visible image on a recording medium by recording light based on the above, without lowering the reading accuracy of the image information and the recording accuracy of the image information for visualizing the image, An object of the present invention is to provide an image reading / reproducing method capable of downsizing the system, simplifying the operation and adjustment, and reducing the manufacturing cost.

(Means for Solving Problems) An image reading / reproducing method of the present invention includes a stimulable phosphor sheet on which a radiation image is stored and recorded, and a recording medium capable of recording and reproducing the radiation image as a visible image. Each recording surface is placed on a rotating plate so as to be opposite to each other, and the excitation light beam is irradiated onto the sheet at the same time, and the excitation light irradiation position on the sheet and the direction from the rotation axis and The recording light beam is irradiated onto the recording medium at the same distance, and when the excitation light and the recording light beam are irradiated, the rotation of the rotary plate causes the main scanning of the excitation light and the recording light, and the rotation plate and the above excitation light. Sub-scanning of the excitation light and the recording light by relative movement of the light and the recording light in the radial direction of the rotating plate, further measuring the amount of surface blurring accompanying the rotation of the rotating plate, based on the measurement result, the excitation light and Recording light Focusing of the excitation light and the recording light is adjusted so that the excitation light forms an image on the sheet and the recording light forms an image on the recording medium during scanning. Is.

Further, the beam irradiation positions of the excitation light and the recording light are arranged so as not to move relative to each other.

Further, both the stimulable phosphor sheet and the recording medium may be mounted on one surface of the rotary plate, or one may be mounted on one surface of the rotary plate and the other on the other surface of the rotary plate. It may be installed.

Here, any method may be used as a method for measuring the amount of surface blur regardless of contact or non-contact, but in order to eliminate friction between the rotating plate and the measurement probe, stable optical measurement can be performed. It is desirable to use a physical, electrical or magnetic non-contact measurement method.

Further, the focus adjustment of the excitation light and the recording light is achieved by moving an optical system such as a focus lens or a light source in the optical axis direction.

Further, the "rotating plate radial direction" means a linear direction passing through the excitation light beam irradiation position or the recording light beam irradiation position and the rotation center of the rotating plate, and the excitation light beam or the recording light beam moves on this straight line. .

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

FIG. 1 is a schematic view showing a radiation image information reading / reproducing apparatus for performing image reading / reproduction by a method according to an embodiment of the present invention.
This radiation image information reading / reproducing apparatus has a stimulable phosphor sheet (hereinafter referred to as IP) 1 mounted thereon, performs a predetermined CLV (constant linear velocity) rotation in the direction of arrow A, and is in a direction perpendicular to the rotation axis. A rotating disc 2 that is a transparent rotating plate that linearly moves in the direction of arrow B, a reading light source 3 for irradiating a laser beam as excitation light from below in the drawing on an IP1 mounted on this rotating disc 2, and focusing. The lens 4 and the half mirror 5, the photoelectric conversion means 6 for receiving the stimulated emission light generated from the IP1 by the excitation light irradiation through the half mirror 5 and converting it into an electric signal, and the surface deviation of the rotating disk 2. In order to measure the amount, a measurement light source 8 and a focusing lens for irradiating a laser beam on the lower surface of the rotating disk 2 in the figure, which is a straight line connecting the excitation light irradiation position and the rotation center of the rotating disk 2. 9. Irradiate the rotating disc 2 from the measuring light source 8. A cylindrical lens 10 and quadrant photodiode 11 for measuring defocus amount detected and Kakaru laser beam reflected return light of the laser light,
A half mirror 12 for causing the returning light of the laser light to enter the four-photo-division diode 11, and a calculation means 13 for calculating the amount of surface deviation of the rotating disk 2 based on the defocus amount measured by the four-division photodiode 11. Focusing lens moving means 14 for moving the focusing lens 9 in the direction of arrow C so that the measuring light from the measuring light source 8 is accurately imaged on the rotating disc 2 based on the calculation result of the calculating means 13; Calculation means
The reading light from the reading light source 3 is IP based on the calculation result of 13.
Focusing lens moving means 15 for moving the focusing lens 4 in the direction of arrow D so as to accurately form an image on the recording medium 21 mounted on the IP1 for visualizing and recording a radiation image. Based on the calculation result of the recording light source 23, the focusing lens 24, and the calculating means 13 for irradiating the laser light modulated by the electric signal output from the converting means 6 as recording light, Recording light is a recording medium
The focusing lens 24 is moved to the arrow E so that the image is accurately formed on 21.
It comprises a focusing lens moving means 25 for moving in the direction. A cut filter 7 is provided between the half mirror 5 and the photoelectric conversion means 6 so as to cut the excitation light and the like and allow only the photostimulated emission light to be received by the photoelectric conversion means 6 so that only the light of a certain wavelength range is transmitted. Has been inserted. The rotating disc 2 is made of a material transparent to excitation light and stimulated emission light and has a length of 1 m.
Form to a thickness of at least m. In addition, the IP1 has already been used for image capturing in a radiation image capturing unit ((not shown). That is, in this radiation image capturing unit, for example, a radiation source such as an X-ray tube is used as a subject. It is designed to irradiate radiation toward and also to arrange the IP1 for accumulating radiation energy at the position where the radiation transmitted through this subject is irradiated, and to accumulate and record the transmitted radiation image information in such IP1. According to the present embodiment, the image information stored and recorded in the IP1 can be obtained by placing and reading the IP1 used for image capturing on the rotating disk 2. Further, as the photoelectric conversion means 6, a photomultiplier is used. A photodetector such as pliers may be used, and the photoelectric conversion means 6
Generally, an amplifier and an A / D converter are appropriately provided in the subsequent stage. Further, in general, when the recording light source 23 is an internal modulation type semiconductor laser, the output power is modulated by an oscillation output control electronic circuit that modulates the oscillation output power, and it is difficult to perform internal modulation at high speed. (Example: He-Ne
In the case of a laser), the recording light is modulated by an external modulator such as an acousto-optic modulator (AOM) or an electro-optic modulator (EOM) that modulates the laser light emitted from the laser. Further, as the recording light source 18, an internal modulation type light emitting diode may be used. The reading light source 3 is not necessarily a laser, and may be a light emitting diode or the like.

The recording medium 21 may be a latent image forming recording medium such as a silver salt sensitive material, but is preferably a thermal recording type recording medium capable of forming a visible image simultaneously with recording.

Further, both the reading light source 3 and the recording light source 23 are fixedly provided, and the excitation light beam irradiation position and the recording light irradiation position are set so as to be always opposite to each other with the rotary disc 2 interposed therebetween.

When reading the IP1 using this embodiment, the IP1 is placed on the rotating disc 2 so that the laser beam from the reading light source 3 is focused on the IP1 via the rotating disc 2. The focusing lens 4 and the half mirror 5 are adjusted in position to rotate the rotating disc 2 in the direction of arrow A at a constant linear velocity, and to rotate the rotating disc 2 in the linear direction connecting the rotation center and the beam irradiation position. That is, the beam is moved at a predetermined speed according to the distance from the rotation center of the predetermined position of the beam in the direction of arrow B which is the radial direction of the rotary disc 2. As a result, the laser beam is scanned on IP1 so as to draw a spiral locus at equal intervals, and the laser beam is rotated so that the laser beam is irradiated from the outer edge of the disc to the inner edge of the disc. If the plate 2 is moved linearly, the entire surface of IP1 can be scanned.

In this way, the laser beam irradiated on IP1 acts as excitation light for obtaining the image information stored and recorded in IP1,
From the portion irradiated with this laser beam, stimulated emission light carrying image information accumulated and recorded in that portion is generated, and this stimulated emission light is photoelectrically converted through the half mirror 5 and the cut filter 7. It is incident on the light receiving portion of the means 6.
Therefore, the stimulated emission light which carries the image information at the position where the excitation light is irradiated is sequentially incident on the photoelectric conversion means 6 in correspondence with the scanning of the excitation light, and thereafter the stimulated emission light is the photoelectric conversion means. Is converted into the form of an electric signal in sequence by 6,
It is sent to a radiation image recording unit for reproducing a visible image of radiation image information.

The rotation speed of the rotary disk 2 in the direction of arrow A, that is, the main scanning speed of the laser beam is determined in consideration of the desired pixel pitch when reproducing a visible image and the reading speed of the photoelectric conversion means 6. . It is desirable to use a spindle motor to drive the rotation of the rotary disk 2 and to stabilize the rotation by using a spindle servo. Further, the moving speed of the rotating disk 2 in the direction of arrow B, that is, the sub-scanning speed of the laser beam is determined in consideration of the desired pixel pitch when forming a visible image.

By the way, in this embodiment, as described above, one or a plurality of IP1s are mounted on the rotary disc 2.
One IP to improve the rotation balance of the rotating disk 2.
In the case of, the shape of IP1a
It is desirable to make it rotationally symmetrical as shown in Fig. 2A, and in the case of a plurality of IPs, as shown in Fig. 2B, the position where the composite center of gravity of IP1b to 1e coincides with the center of rotation of the rotating disk 2. It is desirable to arrange the Further, when the IP1 is arranged at such a position, it is convenient if it is provided with a positioning recess, a marker, or the like at the position in advance as a mark when the IP1 is mounted.

Next, a case of recording the read image information on the recording medium will be described. First, on IP1 on the rotating disk 2,
The recording medium 21 is placed so that the recording layer faces upward in the figure, and the recording light, which is a laser beam from the recording light source 23 and modulated by the electric signal sent from the photoelectric conversion means 6, is used for the recording. The position of the focusing lens 24 is adjusted so as to focus on the medium 21 at a position facing the irradiation position of the excitation light beam. When the rotating disk 2 is rotated and linearly moved for scanning the excitation light in this state, the recording medium 21
The main scanning and the sub scanning of the recording light are performed on the top. That is, the main scanning of the recording light is performed by the rotation of the rotating disc 2 in the direction of the arrow A, and in the linear direction connecting the rotation center of the rotating disc 2 and the recording light irradiation position, that is, in the direction of the arrow B which is the radial direction of the disc 2. The recording light is sub-scanned by moving the rotating disk 2 at a predetermined speed. Here, since the recording light beam irradiation position is arranged to face the excitation light beam irradiation position across the rotating disk 2, the recording light beam is applied to the recording medium 21.
The scanning is performed so that the same scanning locus as that of the excitation light on IP1 is drawn. However, the visible image of the radiographic image drawn on the recording medium 21 has a left-right inverse relationship with the radiographic image on the IP1.

As described above, in the present embodiment, the image information is recorded, at the same time as the image information is read, the main scanning of the laser beam is performed by the rotation of the rotating disc 2, and the laser beam is produced by the linear movement of the rotating disc 2 in the direction perpendicular to the rotation axis. The sub-scan is performed. Therefore, in this type of conventional device,
An optical system such as a galvanometer mirror and a polygon mirror used for raster-scanning the beam becomes unnecessary, and the device can be downsized, simplified, and inexpensive.

Further, as described above, the scanning of the image information and the scanning of the image information are performed by using the single rotating disc 2, so that the scanning system can be made compact and the operation and the adjustment can be simplified.

Further, the size of the recording medium 21 may be determined in consideration of the size of the visible image to be reproduced, and its shape is the same as that of the IP1 described with reference to FIGS. 2A and 2B. It is desirable to stabilize the rotational balance of the plate 2.

Next, the excitation light focus adjustment system of this apparatus will be described. This adjusting system is substantially the same as that used for optical discs, but differs from that used for ordinary optical discs in that the optical system is not shared with the optical system of the signal reading system. That is, first, the laser light generated from the measurement light source 8 is set to go straight through the half mirror 12 and focused by the focusing lens 9 on the lower surface of the rotating disk 2 in the figure. At this time, the rotary disc 2 to which the laser light from the measuring light source 8 is applied is set at the standard position. The laser light reflected by the rotating disk 2 is reflected by the half mirror 12 in the direction perpendicular to the laser beam and is applied to the four-division photodiode 11 via the cylindrical lens 10. The position of the cylindrical lens 10 and the four-division photodiode 11 is adjusted so that the beam image on the four-division photodiode 11 becomes circular when the rotating disk 2 is in the standard position. Further, the electric signal output of the 4-division photodiode 11 at this time is set to be zero. By the way, when the rotating disk 2 starts to rotate in the direction of arrow A due to the excitation light scanning, the rotating disk vertically oscillates with the rotation, so-called surface wobbling phenomenon occurs. If the image forming position of the excitation light or the recording light is kept constant in this state, a periodic defocus occurs, and accurate reading or recording of image information cannot be performed. In view of this, in the present embodiment, the astigmatism of the cylindrical lens 10 is used when the surface of the rotating disk 2 is deviated, and the surface of the four-divided photodiode 11 is reflected by the reflected light of the measurement light source 8. An elliptical beam image corresponding to the amount of blur is formed, and an electric signal corresponding to this elliptical beam image is output from the four-division photodiode 11. The beam image is set to be circular when the rotating disk 2 is in the standard position.
Since the output electric signal of 11 is set to zero, when some non-zero electric signal is output from the four-division photodiode 11, the beam of the measurement light is based on the output electric signal of the rotating disc 2 in the figure. A correction signal for moving the focusing lens 9 in the direction of arrow C to focus on the lower surface is output from the calculating means 13, and the focusing lens moving means 14 moves the focusing lens 9 in the direction of arrow C based on this correction signal. In addition, the beam of excitation light is the IP1 phosphor layer 1f in the figure.
A correction signal for moving the focusing lens 4 in the arrow D direction so as to focus on the lower surface of the lens is output from the calculating means 13, and the focusing lens moving means 15 moves the focusing lens 4 in the arrow D direction based on this correction signal. I am trying to move. Further, based on the output electric signal, a correction signal for moving the focusing lens 24 in the arrow E direction so that the beam of the recording light is focused on the upper surface of the recording medium 21 in the figure is also output from the calculating means 13. The focusing lens moving means 25 moves the focusing lens 24 in the arrow E direction based on the correction signal. The correction signal in the calculating means 13 is output as follows. That is, the amount of surface deviation at the measurement laser beam irradiation position (vertical position from the standard position) is δ ₁ , and the distance from the rotation center of the rotary disc 2 to the measurement laser beam irradiation position in the radial direction of the disc. Let L _{1 be} the distance in the radial direction of the disc from the center of rotation of the rotating disc 2 to the excitation light irradiation position, and let L _{2 be} the vertical movement amount δ ₂ of the excitation light irradiation position. Then, an electric signal corresponding to this movement amount is sent to the focusing lens moving means 15 as a first correction signal. Further, the vertical movement amount δ ₃ of the recording light irradiation position due to the surface wobbling of the rotating disc 2 is −δ ₂ , and therefore, The electric signal calculated according to the moving amount is sent to the focusing lens moving means 25 as a second correction signal. In addition,
In order for both of the above expressions to be satisfied, the measurement laser beam irradiation position needs to be set on a straight line that passes through the rotation center of the rotating disk 2 and the excitation light irradiation position. The measurement laser light is
Even if the rotating disk 2 is moved in the direction of arrow B by the excitation light sub-scan, it must be set so that the rotating disk 2 is always illuminated. Further, in order to improve the accuracy of focus adjustment, it is desirable to set the measurement laser light irradiation position as close to the excitation light irradiation position as possible.

In the method of this embodiment, the focus adjustment described above is performed by IP.
Since it is designed to be performed over the entire reading scanning period of
The so-called out-of-focus phenomenon of the excitation light and the recording light due to the surface deviation of the rotating disk 2 can be reduced or prevented, and accurate image information reading and image information recording can be performed.

In the above embodiment, the sub-scanning of the laser beam is performed by moving the rotary disc 2 in the direction of arrow B, but instead of this, the rotary disc 2 is fixed, and 2 for reading and recording. Two optical systems (light source 3,23, focusing lens 4,24
The half mirror 5) may be moved in the direction of arrow B. In this case, it is desirable that the two optical systems be fixed to a common base or the like so that they can move integrally. Further, both the rotary disc 2 and the optical system for irradiating the laser beam may be relatively moved in the direction of the arrow B to perform sub-scanning of the laser beam. In this case, it is desirable that the optical system for irradiating the measuring laser beam is moved integrally with the optical system for irradiating the excitation light and the recording light in the arrow B direction.

In the above embodiment, the case where the two rotary plates are in contact with each other has been described, but the two rotary plates may be separated from each other as long as they share the rotary shaft.

The optical system and the photoelectric conversion means for irradiating the laser beam are not necessarily limited to those in the above-mentioned embodiment, and for example, the beam incident angle of the excitation light incident on the IP1 or the recording medium 21 is not 0 ° and is constant. The angle may be set so that the beam incident direction of the excitation light and the maximum light amount emission direction of the stimulated emission light do not overlap with each other, and the device may be configured without using the half mirror.

The optical system for irradiating the measuring laser beam, and the optical system and the electrical system for reading the return beam of the measuring laser beam and outputting the laser beam image forming position correction signal are not necessarily those of the above embodiment. Is not limited to
Other various autofocus devices can be used.

It is also possible to irradiate the measurement laser beam on the upper surface of the rotary plate surface in FIG. 1 to perform the same focus adjustment as described above, but in this case, a focusing lens is used to correct the excitation light imaging position. The correction amount input to the moving means has the opposite sign to that in the above embodiment, and the correction amount input to the focusing lens moving means for correcting the recording light image forming position has the opposite sign to that in the above embodiment. You have to be careful.

(Effects of the Invention) As described in detail above, according to the image reading / reproducing method of the present invention, the main scanning of the excitation light and the recording light is performed by the rotation of the rotating disk, and the raster of the galvanometer mirror, the polygon mirror, etc. Since the optical system for scanning is unnecessary, the scanning system can be formed compactly and easily,
It is possible to downsize the device and simplify the operation and adjustment. Also, since the scanning system can be manufactured at low cost,
At the same time, the manufacturing cost can be reduced.

Further, during such reading and recording scanning, the amount of surface deviation of the rotating disk is measured by a focus measurement system separate from the excitation light irradiation system or the recording light irradiation system, and the excitation light and recording are measured based on the measurement results. Since the focus adjustment of light is performed, so-called out-of-focus phenomenon of excitation light and recording light is reduced or prevented, and accurate reading and recording of image information can be performed.

Further, the excitation light reading scan and the recording light recording scan are performed by a single rotating plate, and the sharing of the scanning drive system facilitates downsizing of the device, simplification of operation and adjustment, and reduction of manufacturing cost. be able to.

The method of the present invention is particularly useful for image reading / reproduction using a small size IP in which the driving force of the rotating plate does not become too large, that is, the diameter of the rotating plate does not need to be too large. Of course, it can also be used for image reading and reproduction.

The method of the present invention can also be applied to image reading / reproduction of a system in which concentric loci are drawn.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an apparatus for carrying out an embodiment of an image reading / reproducing method according to the present invention.
FIG. 2B shows an example of placing the stimulable phosphor sheet shown in FIG. 1 on a rotating plate. 1, 1a to 1e ... Accumulative phosphor sheet (IP) 2 ... Rotating disc (rotating plate), 3 ... Reading light source 4, 9, 24 ... Focusing lens, 5 ... Half mirror 6 ... Photoelectric conversion means, 8 ... Measurement light source 10 ... Cylindrical lens 11 ... Quadrant photodiode 13 ... Calculation means 14,15, 25 ... Focusing lens moving means 21 ... Recording medium, 23 ... Recording light source

Claims (1)

[Claims] 1. A stimulable phosphor sheet on which a radiation image is stored and recorded, and a recording medium capable of reproducing the radiation image as a visible image on a rotating plate such that their recording surfaces are opposite to each other. At the same time, the excitation light beam is radiated onto the sheet, and at the same time, the recording light is radiated onto the recording medium at a position where the excitation light irradiation position on the sheet and the direction and distance from the rotation axis of the rotary plate are equal. Beam irradiation, and during irradiation of the excitation light beam and the recording light beam, the rotation plate is rotated to perform main scanning of the excitation light beam and the recording light beam, and the rotation plate is rotated to the excitation light beam and the recording light beam. With respect to the sub scanning of the excitation light and the recording light by relatively moving in the radial direction of the rotary plate, when the rotary plate is rotated, to measure the amount of surface deviation of the rotary plate, Its measurement Based on the result, while the excitation light and the recording light are being scanned, the excitation light and the recording light are so formed that the excitation light forms an image on the sheet and the recording light forms an image on the recording medium, respectively. Focus is adjusted, at the same time photoelectrically reading the stimulated emission light emitted from the sheet by this excitation light irradiation by photoelectric conversion means,
Recording light modulated based on the image signal obtained by this reading is beam-irradiated onto the recording medium, whereby reading of the radiation image stored and recorded on the stimulable phosphor sheet is performed simultaneously and sequentially. An image reading / reproducing method comprising recording the radiation image on a recording medium.