Recording and read-out apparatus

A radiation image recording and read-out apparatus comprises a system for circulating and conveying many stimulable phosphor sheets, a section for recording a radiation image on the stimulable phosphor sheets, a section for scanning the respective stimulable phosphor sheets with stimulating rays and reading out the radiation image stored thereon, and a section for erasing radiation energy remaining on the stimulable phosphor sheets. The scanning size is adjusted based on a scanning size designation signal. A control section is provided for storing combinations of image recording menus with scanning sizes and sending the scanning size designation signal corresponding to a designated image recording menu to the image read-out section. The image recording section may be provided with a device for adjusting an irradiation field to a region on the stimulable phosphor sheet, where the scanning is conducted, based on the scanning size designation signal.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a radiation image recording and read-out 
apparatus for exposing individual stimulable phosphor sheets to a 
radiation passing through an object to have a radiation image of the 
object stored thereon, exposing the individual stimulable phosphor sheets 
to stimulating rays which cause them to emit light in proportion to the 
stored radiation energy, and detecting and converting the emitted light 
into electric signals. This invention particularly relates to a radiation 
image recording and readout apparatus in which the stimulable phosphor 
sheets are circulated and reused for recording radiation images. 
2. Description of the Prior Art 
When certain kinds of phosphors are exposed to a radiation such as X-rays, 
.alpha.-rays, .beta.-rays, .gamma.-rays, cathode rays or ultraviolet rays, 
they store a part of the energy of the radiation. Then, when the phosphor 
which has been exposed to the radiation is exposed to stimulating rays 
such as visible light, light is emitted by the phosphor in proportion to 
the stored energy of the radiation. A phosphor exhibiting such properties 
is referred to as a stimulable phosphor. 
As disclosed in U.S. Pat. Nos. 4,258,264, 4,276,473, 4,315,318 and 
4,387,428 and Japanese Unexamined Patent Publication No. 56(1981)-11395, 
it has been proposed to use a stimulable phosphor in a radiation image 
recording and reproducing system. Specifically, a sheet comprising the 
stimulable phosphor (hereinafter referred to as a stimulable phosphor 
sheet or simply as a sheet) is first exposed to a radiation passing 
through an object to have a radiation image stored thereon, and is then 
scanned with stimulating rays which cause it to emit light in proportion 
to the radiation energy stored. The light emitted by the stimulable 
phosphor sheet when the sheet is exposed to the stimulating rays is 
photoelectrically detected and converted into an electric image signal, 
which is processed as desired to reproduce a visible image having an 
improved image quality, particularly a high diagnostic efficiency and 
accuracy. The finally obtained visible image may be reproduced in the form 
of a hard copy or may be displayed on a cathode ray tube (CRT). In this 
radiation image recording and reproducing system, the stimulable phosphor 
sheet is used to temporarily store the radiation image in order to 
reproduce the final visible image therefrom on a final recording medium. 
For economical reasons, therefore, it is desirable that the stimulable 
phosphor sheet be used repeatedly. 
Further, in a mobile X-ray diagnostic station such as a traveling X-ray 
diagnostic station in the form of a vehicle like a bus which is provided 
with a radiation image recording and read-out apparatus for use in the 
aforesaid radiation image recording and reproducing system and moves from 
place to place to record radiation images for mass medical examinations, 
it is disadvantageous to load the mobile X-ray diagnostic station with a 
large number of stimulable phosphor sheets, and the number of the 
stimulable phosphor sheets which can be loaded on the mobile X-ray 
diagnostic station is limited. Therefore, it is desired to load the mobile 
X-ray diagnostic station with stimulable phosphor sheets which can be used 
repeatedly, once store the radiation images of the objects respectively on 
the stimulable phosphor sheets, transfer the electric image signals read 
out from the stimulable phosphor sheets to a recording medium having a 
large storage capacity, such as a magnetic tape, and circulate and reuse 
the stimulable phosphor sheets for further image recording and read-out 
operations, thereby to obtain the radiation image signals of many objects. 
Further, when image recording is conducted continuously by circulating and 
reusing the stimulable phosphor sheets, it becomes possible to increase 
the image recording speed in mass medical examination. This is very 
advantageous in practical use. 
In order to reuse stimulable phosphor sheets as described above, the 
radiation energy remaining on the stimulable phosphor sheet after it is 
scanned with stimulating rays to read out the radiation image stored 
thereon should be erased by exposure to light or heat as described, for 
example, in U.S. Pat. No. 4,400,619 or Japanese Unexamined Patent 
Publication No. 56(1981)-12599. The stimulable phosphor sheet should then 
be used again for radiation image recording. 
From the aforesaid viewpoint, the applicant proposed in Japanese Unexamined 
Patent Publication No. 59(1984)-192240 a built-in type radiation image 
recording and read-out apparatus comprising: 
(i) a circulation and conveyance means for conveying at least one 
stimulable phosphor sheet for recording a radiation image thereon along a 
predetermined circulation path, 
(ii) an image recording section positioned on said circulation path for 
recording a radiation image of an object on said stimulable phosphor sheet 
by exposing said stimulable phosphor sheet to a radiation passing through 
said object, 
(iii) an image read-out section positioned on said circulation path and 
provided with a stimulating ray source for emitting stimulating rays for 
scanning said stimulable phosphor sheet carrying said radiation image 
stored thereon at said image recording section, and a photoelectric 
read-out means for detecting light emitted by said stimulable phosphor 
sheet scanned with said stimulating rays to obtain an electric image 
signal, and 
(iv) an erasing section positioned on said circulation path for, prior to 
the next image recording on said stimulable phosphor sheet for which the 
image read-out has been conducted at said image read-out section, having 
said stimulable phosphor sheet release the radiation energy remaining on 
said stimulable phosphor sheet, whereby said stimulable phosphor sheet is 
circulated through said image recording section, said image read-out 
section and said erasing section and reused for radiation image recording. 
In the aforesaid radiation image recording and readout apparatus, recording 
and read-out of radiation images can be conducted continuously and 
efficiently. 
However, in the aforesaid radiation image recording and read-out apparatus, 
since stimulable phosphor sheets of a fixed size are circulated and reused 
in the apparatus, it is normally impossible to select the sheet size in 
accordance with the image recording portion of the object and/or the image 
recording method. Therefore, it occurs that an image of a small image 
recording portion is recorded at a part of a stimulable phosphor sheet of 
a large size and a markedly broad background portion (a direct radiation 
impingement region) is recorded around the image of the small image 
recording portion, or an object portion not related to diagnosis is 
broadly recorded around an object portion related to diagnosis. When the 
image read-out is conducted also for the background portion or the portion 
not related to diagnosis, the time required for the image read-out becomes 
unnecessarily long. 
Accordingly, the operator of the apparatus is required to store the type of 
image recording conducted on each stimulable phosphor sheet in the memory, 
and adjust the image read-out size to an appropriate value based on the 
memory at the time of the image read-out. However, such work is very 
troublesome, and becomes a great burden to the operator of the apparatus. 
SUMMARY OF THE INVENTION 
The primary object of the present invention is to provide a radiation image 
read-out apparatus wherein image read-out size can be adjusted to the 
minimum size necessary in accordance with the image recording portion of 
the object of the like by a simple operation. 
Another object of the present invention is to provide a radiation image 
recording and read-out apparatus which shortens the time required for 
image read-out. 
The specific object of the present invention is to provide a radiation 
image recording and read-out apparatus which eliminates unnecessary 
exposure of an object to a radiation. 
The present invention provides a radiation image recording and read-out 
apparatus provided with: 
(i) a circulation and conveyance means for conveying a plurality of 
stimulable phosphor sheets for recording a radiation image thereon along a 
predetermined circulation path, 
(ii) an image recording section positioned on said circulation path for 
recording a radiation image of an object on each of said stimulable 
phosphor sheets by exposing said stimulable phosphor sheet to a radiation 
passing through said object, 
(iii) an image read-out section positioned on said circulation path and 
provided with a stimulating ray source for emitting stimulating rays for 
scanning said stimulable phosphor sheet carrying said radiation image 
stored thereon at said image recording section, and a photoelectric 
read-out means for detecting light emitted by said stimulable phosphor 
sheet scanned by said stimulating rays to obtain an electric image signal, 
and 
(iv) an erasing section positioned on said circulation path for, prior to 
the next image recording on said stimulable phosphor sheet for which the 
image read-out has been conducted at said image read-out section, having 
said stimulable phosphor sheet release the radiation energy remaining on 
said stimulable phosphor sheet, 
wherein the improvement comprises: 
(v) constituting said image read-out section so that a stimulating ray 
scanning size with respect to said stimulable phosphor sheet is 
changeable, and said image readout section receives a scanning size 
designation signal and adjusts said stimulating ray scanning size to a 
scanning size represented by said scanning size designation signal, and 
(vi) providing a control section for storing combinations of image 
recording menus with stimulating ray scanning sizes in a storage means, 
receiving a signal representing one of said image recording menus, reading 
the scanning size corresponding to said image recording menu represented 
by said signal from said storage means, and sending a signal representing 
said scanning size as said scanning size designation signal to said image 
read-out section. 
The present invention also provides a radiation image recording and 
read-out apparatus provided with the circulation and conveyance means, the 
image recording section, the image read-out section, and the erasing 
section as mentioned above, 
wherein the improvement comprises: 
constituting said image read-out section so that a stimulating ray scanning 
size with respect to said stimulable phosphor sheet is changeable, and 
said image readout section receives a scanning size designation signal and 
adjusts said stimulating ray scanning size to a scanning size represented 
by said scanning size designation signal, 
providing said image recording section with an irradiation field adjusting 
means for adjusting an irradiation field to a region on said stimulable 
phosphor sheet where said scanning with said stimulating rays is 
conducted, and 
providing a control section for storing combinations of image recording 
menus with stimulating ray scanning sizes in a storage means, receiving a 
signal representing one of said image recording menus, reading the 
scanning size corresponding to said image recording menu represented by 
said signal from said storage means, and sending a signal representing 
said scanning size as said scanning size designation signal to said image 
read-out section. 
Normally, the object image recording range on the stimulable phosphor sheet 
is approximately fixed by an image recording menu such as the image 
recording portion of the object and an image recording method. Therefore, 
it becomes possible to adjust the image read-out size to the minimum 
required size suitable for respective radiation images when combinations 
of image recording menus with stimulating ray scanning sizes (i.e. the 
image read-out sizes) suitable for the respective image recording menus 
are stored in the storage means and the stimulating ray scanning size 
corresponding to an image recording menu specified for a stimulable 
phosphor sheet is read from the storage means and adjusted. In this case, 
it is only necessary for the operator of the apparatus to enter 
information on the image recording menu to the control section, for 
example, by operating keys on an operating console. 
In the present invention, the start point of scanning may be adjusted at 
the same position for all stimulating ray scanning sizes, or may be 
adjusted at different positions in accordance with the respective 
stimulating ray scanning sizes. In the latter case, it becomes possible to 
adjust the image recording position on the stimulable phosphor sheet as 
desired for each image recording menu. Specifically, it becomes possible, 
for example, to make the center of the image recording area (which 
coincides with the center of a scanning surface in the image read-out 
carried out later) coincide with the center of the stimulable phosphor 
sheet for all image recording menus. As a result, positioning of the 
object in the image recording step is facilitated. 
In the radiation image recording and read-out apparatus of the present 
invention mentioned last, it is possible to adjust the irradiation field 
at the region, where scanning with stimulating rays is carried out, by use 
of the irradiation field adjusting means. In this case, there is no risk 
of the stimulable phosphor sheet being exposed to a radiation over an area 
larger than the region where the radiation image is actually read out. As 
a result, it becomes possible to decrease the radiation dose to the 
object. 
With the radiation image recording and read-out apparatus in accordance 
with the present invention, since there is no risk of unnecessary image 
read-out being carried out, it is possible to shorten the time required 
for the image read-out. Further, in order to obtain the effects of the 
radiation image recording and read-out apparatus in accordance with the 
present invention, since it is only necessary for the operator of the 
apparatus to enter the image recording menu, the burden to the operator is 
relieved markedly as compared with the case where the image read-out 
region is changed manually. 
Also, when the radiation image recording and readout apparatus in 
accordance with the present invention is constituted so that the starting 
point of scanning with stimulating rays is changeable for respective image 
recording menus, it becomes possible to adjust the center of the image 
recording area on the stimulable phosphor sheet as desired for the 
respective image recording menus, and to facilitate positioning of the 
object in the image recording step. Further, with the radiation image 
recording and read-out apparatus in accordance with the present invention 
mentioned last, since in the image recording step the stimulable phosphor 
sheet is exposed to a radiation only at the region where image read-out is 
to be carried out, it becomes possible to prevent unnecessary exposure of 
the object such as the human body to a radiation.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The present invention will hereinbelow be described in further detail with 
reference to the accompanying drawings. 
Referring to FIG. 1, an embodiment of the radiation image recording and 
read-out apparatus in accordance with the present invention is provided 
with a sheet conveyance circulation path 26 constituted by endless belts 
1, 2, 3, 4, 5, 6, 7, 8, 9 and 10, guide rollers 11, 12, 13 and 14 which 
are rotated respectively by the endless belts 1, 6, 7 and 10, guide plates 
15, 16, 17, 18, 19, 20 and 21, and nip rollers 22, 23, 24 and 25. A 
plurality of (by way of example, five) stimulable phosphor sheets 30, 30, 
. . . are positioned in spaced relation to each other on the circulation 
path 26 and are conveyed in the direction as indicated by the arrow A by 
the endless belts 1 to 10 and nip rollers 22, 23, 24 and 25 as the sheet 
circulation and conveyance means. 
The endless belts 2 and 3 are positioned to vertically hold the stimulable 
phosphor sheet 30 therebetween. An image recording section 40 is 
constituted by an image recording stand 41 positioned on the left side of 
the endless belts 2 and 3, and a radiation source 42, e.g. an X-ray 
source, spaced from the image recording stand 41 to stand face to face 
with the endless belts 2 and 3. When a radiation image of an object 43 is 
recorded on the sheet 30, the sheet 30 is held between the endless belts 2 
and 3 as shown, and the radiation source 42 is activated with the object 
43 standing in front of the image recording stand 41. In this manner, the 
sheet 30 is exposed to a radiation passing through the object 43 to have a 
radiation image of the object 43 stored on the sheet 30. 
An image read-out section 50 is positioned at the lower section of the 
circulation path 26. At the image read-out section 50, a laser beam source 
51 is positioned above the endless belt 8 constituting a part of the image 
read-out section 50, and a mirror 53 and a galvanometer mirror 54 are 
positioned for scanning a laser beam 52 emitted by the laser beam source 
51 in the width direction of the sheet 30 placed on the endless belt 8. 
The galvanometer mirror 54 is swung in both ways to scan the laser beam 52 
in the main scanning direction on the sheet 30 carrying the radiation 
image stored thereon. The sheet 30 which has been subjected to image 
recording at the image recording section 40 is then conveyed by the sheet 
circulation and conveyance means to the image read-out section 50. A light 
guiding reflection mirror 55 and a light guide member 56 are positioned 
along the main scanning line at the scanning portion of the laser beam 52 
on the sheet 30. When the sheet 30 is exposed to the laser beam 52, the 
sheet 30 emits light in proportion to the stored radiation energy. The 
light emitted by the sheet 30 directly towards the light guide member 56 
and the light emitted by the sheet 30 and reflected by the light guiding 
reflection mirror 55 enter the light guide member 56 from a light input 
face 56A thereof, and is guided inside of the light guide member 56 
through total reflection to a light output face 56B thereof. The light is 
thus detected by a photomultiplier 57 connected to the light output face 
56B of the light guide member 56. Simultaneously with the scanning of the 
sheet 30 by the laser beam 52 in the main scanning direction, the sheet 30 
is moved by the endless belt 8 in the sub-scanning direction as indicated 
by the arrow A approximately normal to the main scanning direction, so 
that the radiation image is read out over the whole surface of the sheet 
30. The electric image signal S1 generated by the photomultiplier 57 is 
sent to an image processing circuit 60 for processing the electric image 
signal S1. The image signal S1 thus processed is then sent to an image 
reproducing apparatus 61. The image reproducing apparatus 61 may be a 
display device such as a CRT, or a device for recording a visible image by 
point-by-point scanning on a photographic film. Or, the image signal may 
be stored on a storage means such as a magnetic tape (not shown). 
When image read-out is conducted as mentioned above, the reciprocal 
swinging width and the number of swings of the galvanometer mirror 54, and 
the sub-scanning movement length of the endless belt 8 corresponding to 
the number of swings (i.e. the scanning size of the laser beam 52 with 
respect to the stimulable phosphor sheet 30) are changeable by a drive 
control circuit 64 which will be described later. 
After image read-out is finished, the stimulable phosphor sheet 30 is 
conveyed by the endless belts 9 and 10 via the guide plate 18, the nip 
rollers 22, the guide plate 19 and the nip rollers 23 to an erasing 
section 70 comprising a case 71 and many erasing light sources 72, 72, . . 
. , constituted by fluorescent lamps, arranged within the case 71. After a 
shutter 73 is opened, the sheet 30 is conveyed into the case 71 by the nip 
rollers 23. Then, the shutter 73 is closed, and the erasing light sources 
72, 72, . . . are turned on. The erasing light sources 72, 72, . . . 
mainly emit light having a wavelength within the stimulation wavelength 
range for the stimulable phosphor constituting the sheet 30. When the 
sheet 30 is exposed to the erasing light, the radiation energy remaining 
on the sheet 30 after the image read-out is conducted is released. At this 
time, since the shutter 73 is closed, no erasing light leaks into the 
image read-out section 50 and accordingly no noise is generated in the 
read-out image signal. 
After the radiation energy remaining on the stimulable phosphor sheet 30 is 
erased to such an extent that another image recording on the sheet 30 is 
possible, the nip rollers 24 are rotated and the sheet 30 is conveyed out 
of the erasing section 70. Then, the sheet 30 is sent via the guide plate 
20 to the nip rollers 25, and then conveyed by the nip rollers 25 along 
the guide plate 21 onto the endless belt 1 and to the image recording 
section 40 at which the sheet 30 is reused for image recording. 
Adjustment of the scanning size of the laser beam 52, i.e. the image 
read-out size, by the control section 62 will now be described below. An 
image recording menu signal S2 is entered, for example, from an operating 
console 63, into the control section 62. The image recording menu signal 
S2 represents a combination of the image recording portion of the object 
with the image recording method or the like, for example, general image 
recording of the chest or general image recording of the cranium. As 
mentioned above, the recording range of the object 43 on the stimulable 
phosphor sheet 30 is approximately fixed by the image recording menu. The 
control section 62 stores the combinations of the image recording menus 
with the minimum necessary scanning sizes for the respective image 
recording menus in a storage means 62A. The image recording menu signal S2 
is entered to a read means 62B of the control section 62. Upon receiving 
the image recording menu signal S2, the read means 62B reads the scanning 
size corresponding to the image recording menu signal S2 from the storage 
means 62A, and sends a scanning size designation signal S3 representing 
the scanning size to the drive control circuit 64 for the galvanometer 
mirror 54 and the endless belt 8. Upon receiving the scanning size 
designation signal S3, the drive control circuit 64 controls operations of 
the galvanometer mirror 54 and the endless belt 8 so that the laser beam 
52 scans the stimulable phosphor sheet 30 over the scanning size 
represented by the scanning size designation signal S3. In this 
embodiment, the starting point of scanning is maintained constant even 
though the scanning size of the laser beam 52 is changed. 
As shown in FIG. 2, in the case where the stimulable phosphor sheet 30 is 
of the 356 mm.times.432 mm size, the scanning size is adjusted to the 
overall area of the sheet 30, i.e. to the 356 mm.times.432 mm size, the 
356mm.times.356mm size as indicated by F1 smaller than the size of the 
sheet 30, the 254 mm.times.305 mm size as indicated by F2, or to some 
other size. The starting point of scanning is adjusted to a point M at the 
corner of each size. As mentioned above, combinations of the scanning 
sizes thus adjusted with the image recording menus like chest general 
image recording/356mm.times.356mm, and head general image 
recording/254mm.times.305mm are stored in the storage means 62A of the 
control section 62. The minimum necessary scanning size for an image 
recording menu is equal to the image recording size optimal for the image 
recording menu. For example, as indicated by the combination of head 
general image recording/254mm.times.305mm, the head general image 
recording is carried out generally exactly over the 254mm.times.305mm size 
as shown in FIG. 2. However, since the stimulable phosphor sheet 30 is 
larger than the 254mm.times.305mm size, an image of an object portion 
outside of the head is also recorded on the sheet 30. 
However, when image recording is conducted on the stimulable phosphor sheet 
30 carrying an image recorded thereon by the head general image recording, 
the image recording menu signal S2 representing the head general image 
recording is entered to the control section 62, and the scanning size 
designation signal S3 representing the corresponding scanning size, i.e. 
the 254mm.times.305mm size, is generated by the control section 62. 
Therefore, image readout is conducted only over the 254mm.times.305mm 
size. Thus, as shown in FIG. 2, even though an image of an object portion 
outside of the head is stored on the stimulable phosphor sheet 30, said 
image which need not be reproduced into a visible image is not read out, 
and the image read-out processing speed becomes high. 
The image recording stand 41 should be provided with marks respectively 
corresponding to a plurality of the scanning sizes as mentioned above, so 
that the image of an object portion is recorded exactly within each size. 
In the aforesaid embodiment, the starting point of scanning is maintained 
constant even though the scanning size of the laser beam 52 is changed. 
However, the starting point of scanning may be changed when the scanning 
size is changed. As will be described in detail below, changing of the 
starting point of scanning facilitates positioning of the object in the 
image recording step. 
Another embodiment of the radiation image recording and read-out apparatus 
in accordance with the present invention will now be described with 
reference to FIG. 3. In FIG. 3, similar elements are numbered with the 
same reference numerals with respect to FIG. 1. In this embodiment, a 
radiation source moving means 65 is provided for moving the radiation 
source 42 vertically and horizontally in a plane parallel with the image 
recording stand 41, and an irradiation field adjusting means 66 is 
positioned between the radiation source 42 and the image recording stand 
41 for adjusting the irradiation field on the stimulable phosphor sheet 30 
positioned at the image recording section 40. The irradiation field 
adjusting means 66 is constituted by a movable stop plate or the like and 
adjusts the size and position of the irradiation field on the sheet 30. 
Like the embodiment of FIG. 1, the galvanometer mirror 54 and the endless 
belt 8 at the image read-out section 50 are constituted so that the 
scanning size of the laser beam 52 on the sheet 30 is changeable. However, 
unlike the embodiment of FIG. 1, they are constituted so that the starting 
point of scanning may be changed. 
In the embodiment of FIG. 3, when image recording is conducted on the 
stimulable phosphor sheet 30 at the image recording section 40, the image 
recording menu signal S2 is entered to the control section 62. Upon 
receiving the image recording menu signal S2, the control section 62 sends 
a scanning size designation signal S3' representing the scanning size, 
which is stored in the storage means 62A in combination with the image 
recording menu represented by the image recording menu signal S2, to the 
radiation source moving means 65 and the irradiation field adjusting means 
66, and stores the scanning size designation signal S3' in a storage means 
62C. Upon receiving the scanning size designation signal S3', the 
irradiation field adjusting means 66 operates to adjust the irradiation 
field to the scanning size on the stimulable phosphor sheet 30 as shown in 
FIG. 4. At this time, the adjustment of the irradiation field is effected 
so that, for example, centers of the irradiation fields in the horizontal 
direction in FIG. 4 align with each other and the upper sides or the lower 
sides of the respective irradiation fields coincide with each other. 
Therefore, centers 01, 02, 03 of the respective recording regions deviate 
vertically in FIG. 4. When the radiation source moving means 65 receives 
scanning size designation signal S3', it moves the radiation source 42 to 
the center 01, 02 or 03 of the recording region adjusted by the scanning 
size designation signal S3'. Therefore, for example, the head general 
image recording is conducted over the region of the 254mm.times.305mm size 
as indicated by F2 in FIG. 4. In this case, since the irradiation field is 
adjusted as described above, no image of the object portion outside of the 
head region is recorded on the stimulable phosphor sheet 30. 
The control section 62 detects the sheet conveyance condition, for example, 
by receiving a signal representing conveyance of the stimulable phosphor 
sheet 30 from a sheet conveyance control circuit (not shown) for 
controlling the conveyance and circulation of the sheet 30. When the sheet 
carrying a radiation image stored thereon as described above is sent to 
the image read-out section 50 and subjected to image recording, the 
control section 62 reads the scanning size designation signal S3' stored 
in the storage means 62C, and sends the signal S3' to the drive control 
circuit 64 for the galvanometer mirror 54 and the endless belt 8. Upon 
receiving the scanning size designation signal S3', the drive control 
circuit 64 controls operations of the galvanometer mirror 54 and the 
endless belt 8 so that scanning of the sheet 30 with the laser beam 52 is 
conducted over the scanning size represented by the signal S3' as in the 
embodiment of FIG. 1. Also, the drive control circuit 64 adjusts the 
starting point of scanning to Ml, M2 or M3 depending on the scanning size 
so that the scanning with the laser beam 52 is conducted over the 
recording region positioned as shown in FIG. 4. 
Also in this embodiment, unnecessary read-out is eliminated, and the image 
read-out processing speed becomes high. Further, since image recording is 
carried out only over the region where image read-out is conducted by the 
operation of the irradiation field adjusting means 66, it is possible to 
avoid unnecessary exposure of the object 43 to the radiation. Since the 
radiation source 42 is positioned to face the center 01, 02 or 03 of the 
recording region, it is also possible to prevent distortion from arising 
at the marginal portions of the recorded image. Further, since the 
starting point of scanning is changed when the size of scanning with 
stimulating rays is changed, it is possible to adjust the irradiation 
field as desired by the irradiation field adjusting means 66 and to 
facilitate positioning of the object 43 in the image recording step. For 
example, besides the adjustment of the irradiation field as shown in FIG. 
4, it is also possible to adjust the irradiation field so that the centers 
01, 02 and 03 of the respective recording regions coincide with each other 
as shown in FIG. 5. In this case, since the center of image recording 
region is fixed, for example, at the center of the image recording stand 
41 for every recording size, it becomes easier to adjust the position of 
the object 43. 
The starting point of scanning need not necessarily be changed when the 
size of scanning with stimulating rays is changed. Thus as mentioned with 
reference to FIG. 1, the starting point of scanning may be maintained 
constant when the size of scanning with stimulating rays is changed. 
In the embodiment of FIG. 1, it is also possible to enter the image 
recording menu signal S2 to the control section 62 at the time of image 
recording, store the scanning size designation signal S3 generated thereby 
in the storage means 62A, read the scanning size designation signal S3 
from the storage means 62A when the stimulable phosphor sheet 30 carrying 
a radiation image stored thereon at the image recording section 40 is then 
subjected to the image read-out, and send the scanning size designation 
signal S3 to the drive control circuit 64. Alternatively, the storage 
means 62A may be omitted, the operator of the apparatus may remember the 
image recording menu for the stimulable phosphor sheet 30 when image 
recording is conducted on the sheet 30, and enter the image recording menu 
signal S2 based on his memory into the control section 62 when the sheet 
30 is subjected to the image read-out. 
In the embodiments of FIGS. 1 and 3, it may occur that image recording of a 
type different from the image recording menus stored in the storage means 
62A of the control section 62 is carried out, or a radiation image is 
recorded to a specific size different from general sizes even though the 
type of image recording comes under the image recording menus stored in 
the storage means 62A. For the stimulable phosphor sheet 30 on which such 
image recording is conducted, the image recording menu signal S2 should 
not be entered to the control section 62. The apparatus should preferably 
be constituted so that, in this case, image read-out is conducted 
automatically over the entire area of the stimulable phosphor sheet 30, or 
conducted over a region adjusted manually.