Note: Descriptions are shown in the official language in which they were submitted.
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STIMULABLE PHOSPHOR SHEET,
AND METHOD AND DEVICE OF COMVEYING THE SAME
BACKGROUND OF THE INVE~ITION
Field of the Invention
.
The present invention relates to a stimulable phos-
phor sheet employable in a radiation image recording and
reproducing method utilizing a stimulable phosphor, and a
method and a device of conveying a stimulable phos~hor
sheet.
10 Description of Prior Arts
For obtaining a radiation image, there has been con-
ventionally employed a radiography utilizing a combina-
tion of a radiographic film having a sensitive silver
salt material l~ayer and an intensifying screen.
As a method replacing the above-mentioned conven-
tional radiography, a radiation image recording and
reproducing method utilizing a stimulable phosphor as
described, for instance, in U.S. Patent No. 4,239,968,
has been developed and paid much attention. The method
20 involves steps of causing a stimulable phosphor to absorb
a radiation having passed through an object or having
radiated from an object; sequentially exciting (or scan-
ning) the phosphor with an electromagnetic wave such as
visible light or infrared rays (stimulating rays) to
25 release the radiation energy stored in the phosphor as
light emission (stimulated emission); photoelectrically
detecting the emit-ted light to obtain electric signals;
and reproducing the radiation image of the ob~ect as a
visible image, numerals, symbols, etc. from the electric
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signals.
In the radiatlon image recording and reproducing
method, a radiation image is ob-tainable with a sufficient
amount of information by applying a radiation to the ob-
5 ject at a considerably smaller dose, as compared with theconventional radiography. Accordingly J the radiation
image recording and reproducing method is of great value,
especially when the method is used for medical diagnosis.
In performing the radiation image recording and
10 reproducing method, a stimulable phosphor is generally
employed in the form of a stimulable phosphor sheet (also
referred to as a radiation image storage panel, and gene-
rally in the form of a sheet of rectangle, square, etc.)
which comprises a support and a phosphor layer provided
15 thereon. The phosphor layer comprises a stimulable phos-
phor and a binder. Further, a protective film made of a
transparent plastic film is provided on a surface of the
phosphor layer to protect the phosphor layer from physi-
cal and chemical deterioration.
The stimulable phosphor sheet does not serve to
finally record image information, but only stores the
information temporarily to provide the image or the like
on an independently prepared final recording medium as
described above. Accordingly, the stimulable phosphor
25 sheet can be repeatedly used and such repeated use brings
about economical advantage.
The repeated use of the stimulable phosphor sheet is
particularly advantageous, for instance, in the case that
a radiation image information recording and reading de-
30 vice employing the stimulable phosphor sheet is mountedon a traveling station such as a radiographic apparatus-
carryig car to conduct mass radiographic examination in
various places. More in detail, it ls inconvenient to
carry a great number of stimulable phosphor sheets on a
35 traveling station, and there is a limitation on the num-
ber of sheets capable of being carried on a car such as a
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radiographic apparatus-carrying car. Accordingly, it i5
practically useful that the stimulablé phosphor sheets
are mounted on a radiographic car under such conditions
that the stimulable phosphor sheets are repeatedly used;
5 radiation image information of an object is recorded on
each stimulable phosphor sheet and read out to obtain
image information as a signal; and the obtained signal is
transferred to a recording medium having a great record-
ing capacity such as a magnetic tape so as to repeatedly
10 use the stimulable phosphor sheet in cycle. This means
that radiation images of a number of objects can be ob-
tained by the use of a small number of stimulable phos-
phor sheets. Further, the combination of the repeated
uses of the stimulable phosphor sheets with a continuous
15 radiographic process enables to perform rapid radiography
in the mass radiographic examinations. This combination
is of great value in practical use.
In the case of performing repeated uses of the sti-
mulable phosphor sheets in cycle, after the radiation
20 energy stored in the stimulable phosphor sheet is read
out and aimed image information is obtained, the remain-
ing energy in the sheet is released and erased in a man-
ner as disclosed, for instance, in Japanese Patent Provi-
sional Publications No. 56(1981)-11392 and 56(1981)-
25 12599. By employing such manner, the stimulable phosphorsheet can be efficiently and repeatedly used in cycle.
Thus, 'he radiation image information recording and
reading device, in one aspect, is desirably mounted on a
traveling station such as a radiographic apparatus-carry-
30 ing car in the form of a united built-in device which
comprises an image recording means for exposing a stimu-
lable phosphor sheet to a radiation having passed through
an object so as to record and store a radiation image in
the stimulable phosphor sheet, a read-out means for read-
35 ing out the radiation image stored in the stimulablephosphor sheet, an erasure means for releasing and eras-
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ing radiation energy remaining in the stimulable phosphorsheet for the next use of the stimulable phosphor sheet,
and a conveyance means for moving the stimulable phosphor
sheet in cycle to each of the above-mentioned means. The
5 radiation image information recording and reading device
having the above-mentioned constitution have various
advantages not only in mounting in the traveling station
such as a radiographic apparatus-carrying car but also in
setting in hospitals, so that the above device is conve-
10 nient in practical use.
The radiation image information recording and read-
ing device utilizing the above-mentioned system of re-
peatedly and cyclically using the stimulable phosphor
sheet is disclosed in Japanese Patent Application No.
15 58(1983)-66730 filed in the present applicant (assignee).
In the device, the stimulable phosphor sheet is occasion-
ally conveyed vertically or almost vertically for the
purpose of making the device compact.
If a stimulable phosphor sheet has physical deterio-
20 ration such as a scratch on a surface thereof (a phosphorlayer-side surface of the sheet), the quality of image or
the accuracy of image information provided by the phos-
phor sheet tends to decrease markedly. For this reason,
it is necessary to select the means for conveying a sti-
25 mulable phosphor sheet with such a careful considerationthat the surface of the stimulable phosphor sheet is not
damaged. From this viewpoint, as a means for conveying a
stimulable phosphor sheet, a belt conveyor made of a soft
sheet-material is generally employed. However, while the
30 belt conveyor is suitable for conveying the stimulable
phosphor sheet horizontally, it is unsuitable for convey-
ing the stimulable phosphor sheet in the direation other
than the horizontal direction, particularly in the verti-
cal or almost vertical direction. More in detail, in the
35 process for conveying a stimulable phosphor sheet verti-
cally or almost vertically using a belt conveyor, it is
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necessary to arrange a pair of belt conveyors in such a
manner that the belt conveyors are in face to face con-
tact with each other so as to convey the stimulable phos-
phor sheet under the condition that the stimulable phos-
5 phor sheet is sandwiched between that pair of belt con-
veyors. However, said conveying device is complicated in
structure, and it is difficult to make the device com-
pact. Further, there are other problems such that the
surface of the stimulable phosphor sheet tends to suffer
10 scratches when the rate of one belt conveyor is made dif-
ferent from that of the other, even if the difference
therebetween is very small.
SU~ARY OF THE INVENTION
The present invention provides a method suitable for
15 conveying a stimulable phosphor sheet, particularly suit-
able for conveying a stimulable phosphor sheet in the
vertical or almost vertical direction which is highly
required in the radiation image information recording and
reading device in which the stimulable phosphor sheet is
20 repeatedly used in cycle, and further provides a device
employed for the method.
In another aspect, the present inventi,on provides a
stimilable phosphor sheet preferably employable in the
conveying method.
The method of conveying a stimulable phosphor sheet
of the present invention comprises applying a driving
force to a surface of the stimulable phosphor sheet by
means of a driving member, keeping both side of said
phosphor sheet by means of a guiding member to move the
30 stimulable phosphor sheet in a given direction.
The above-described method of conveying a stimulable
phosphor sheet is effectively performed by utilizing a
device comprising a guiding member for keeping both sides
of said stimulable phosphor sheet and two or more driving
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members arranged along the conveying direc-tion for apply-
ing a driving force to a surface of said phosphor sheet,
the distance between two driving members adjoining each
other along the conveying direction being smaller than
5 the length of said stimulable phosphor sheet measured in
the conveying direction.
The stimulable phosphor sheet of the invention com-
prises, in one aspect, a support, a phosphor layer con-
taining a stimulable phosphor and a binder, and a protec-
10 tive film superposed in this order, which is character-
ized in that at least both sides of the phosphor layer
along the direction to be conveyed are retracted from the
corresponding side edges of the support, and both of said
sides of the phosphor layer and support are protected by
15 a polymer coating layer or a polymer film.
The stimulable phosphor sheet of -the invention com-
prises, in another aspect, comprises a support, a phos-
phor layer containing a stimulable phosphor and a binder,
and a protective film superposed in this order, which is
20 characterized in that at least both sides of the phosphor
layer along the direction to be conveyed are retracted
from the corresponding side edges of the support, and
both of said retracted sides of the phosphor layer are
protected by a solid material fixedly placed in the area
25 formed by the retraction of the side of phosphor layer.
The stimulable phosphor sheet of the invention, in a
further aspect, comprises a substrate, a support, a phos-
phor layer containing a stimulable phosphor and a binder,
and a protective film superposed in this order, which is
30 characterized in that at least both sides of the phosphor
layer and support along the direction to be conveyed are
retracted from the corresponding side edges of the sub-
strate, and both of said sides of the sheet are protected
by a polymer coating layer or a polymer film.
The stimulable phosphor sheet of the invention, in a
still further aspect, comprises a substrate, a support, a
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phosphor layer containing a stimulable phosphor and a
binder, and a protective film superposed in this order,
which is characterized in -that at least both sides of the
phosphor layer and support along the direction to be con-
5 veyed are retracted from the corresponding side edges ofthe substrate, and both of said retracted sides of the
phosphor layer and support are protected by a solid mate-
rial fixedly placed in the area formed by the retraction
of the side of phosphor layer.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a schematic view illustrating the consti-
tution of a conventional stimulable phosphor sheet, and
Fig. 2 is a schematic view illustrating the consti-
tution of the device preferably employed in the method of
15 conveying a stimulable phosphor sheet according to the
present invention.
Fig. 3-(1) is a schematic view illustrating the con-
stitution of another device preferably employed in the
conveying method. Fig. 3-(2) is a side view of the
20 device of Fig. 3-(1) seen along the indicated arrow A.
Figs. 4a, 4b and 4c are schematic views illustrating
the constitutions of embodiments of the stimulable phos-
phor sheet.
Figs. 5a and 5b are schematic views illustrating the
25 constitutions of embodiments of the stimulable phosphor
sheet.
Figs. 6a and 6b are schematic views illustrating the
constitutions of embodiments of the stimulable phosphor
sheet.
Figs. 7a and 7b are schematic views illustrating the
constitutions of embodiments of the stimulable phosphor
sheet. ~c
Figs. 8a, 8b and ~ are schematic views illustrating
the constitutions of embodiments of the stimulable phos-
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phor sheet.
DETAILED DESCRIPTIOM OF THE INVENTION
The present invention will be described more in
detail hereinafter referring to the accompanying draw-
5 ings.
The general constitution of the conventional stimu-
lable phosphor sheet which is an object of the conveyance
in the present invention is well known. The stimulable
phosphor sheet is generally employed, as described above,
10 in the form of a sheet comprising a support and a phos-
phor layer provided thereon which comprises a stimulable
phosphor and a binder. On the surface of the phosphor
layer is provided a protective film of a transparent
plastic material, because the phosphor layer is easily
15 affected by physical shocksO
Fig. 1 schematically illustrates the constitution of
the conventional stimulable phosphor sheet.
In Fig. 1, the stimulable phosphor sheet comprises a
support 11, a phosphor layer 12 and a protective film 13.
20 Examples of the support material include plastic films
such as films of cellulose acetate and polyethylene tere-
phthalate, metal sheets such as aluminum foil, ordinary
papers, baryta paper, and resin-coated papers. On the
surface of the support (phosphor layer-side surface of
25 the support) may be provided other functional layers such
as an adhesive layer, a light-reflecting layer and a
light-absorbing layer.
The phosphor layer essentially comprises stimulable
phosphor particles dispersed in a binder. A great numher
30 of stimulable phosphors are known. The stimulable phos-
phor employed in the invention can be selected from the
known stimulable phosphors. Examples of the known stimu-
lable phosphor include a divalent europium activated
alkaline earth metal fluorohalide phosphor (MIIFX:E~2+,
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6in which MII is at least one alkaline earth rnetal
selected from the group consisting of Mg, Ca and Ba; and
X is at least one halogen selected from the group con-
sisting of C~, Br, and I); an europium and samarium
5 activated strontium sulfide phosphor (SrS:Eu,Sm~; an
europium and samarium activated lanthanum oxysulfide
phosphor (La202S:Eu,Sm); an europium activated barium
aluminate phosphor (BaO A~203:Eu); an europium activated
alkaline earth metal silicate phosphor (M2+0-SiO2:Eu, in
10 which M2+ is at least one alkaline earth metal selected
from the group consisting of Mg, Ca and Ba); a cerium
activated rare earth oxyhalide phosphor (LnOX:Ce, in
which Ln is at least one rare earth element seletected
from the group consisting of La, Y, Gd and Lu; and X is
15 at least one halogen selected from the group consisting
of C~, Br and I) and the like.
A transparent protective film is then provided on
the surface of the phosphor layer to physically and che-
mically protect the phosphor layer. Examples of the
20 material employable for the preparation of the transpar-
ent protective film include cellulose acetate, polymethyl
methacrylate, polyethylene terephthalate and polyethyl-
ene. The transparent protective film generally has a
thickness within the range of approx. 0.1 - 20 ~m.
The stimulable phosphor sheet can be colored with an
appropriate colorant as described in U.S. Patent No.
4,394,581 and U.S. Patent Application No. 326,642. Fur-
ther, white powder may be dispersed in the phosphor layer
as described in U.S. Patent No. 4,350,893.
Figs. 2 and 3 [(1) and (2)] are schematic views of
the conveying device which are preferably employed in the
method of conveying a stimulable phosphor sheet according
to the present invention. The method of conveying a sti-
mulable phosphor sheet of the invention is described
35 hereinafter, by referring to an embodiment employing the
conveying devices shown in Figs. 2 and 3.
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The conveying device preferably employed in the
method of conveying a stimulable phosphor sheet according
to the inven-tion is a device basically comprising guiding
members 22 and 23 (22a, 23a, 22b, 23b, ...)[32 and 33
5 (32a, 33a, 32b, 33b, ...)] for keeping both sides of a
stimulable phosphor sheet 21[31], and two or more driving
members 24 (24a, 24b, 24c, ...)[34 (34a, 34b, 34c, ...)]
arranged along the conveying direction (direction along
the indicated arrow) for providing a driving force on
10 both surfaces of the stimulab~e phosphor sheet 21[31], in
which the distance between said two driving members which
adjoin each other along the conveying direction (e.g.,
24b and 24c)[e.g., 34b and 34c] is smaller than the
length of the stimulable phosphor sheet measured in the
15 conveying direction.
The guiding members of the device according to the
invention keep the stimulable phosphor sheet at the both
sides thereof. The guiding members prevent the sheet
from bending in the vertical direction against the sur-
20 face plane of the sheet (namely, flexure) and from movinglaterally. The guiding member is, for instance, U shaped
in the section. Accordingly, the guiding member is not
necessarily in contact with the stimulable phosphor sheet
to keep it. As is evident from Figs. 2 and 3, between
25 the two driving members 24[34], the surface of the sheet
on which the radiation image is stored and recorded is
kept being from contact with members of the device, since
the stimulable phosphor sheet 21 is kept by the guiding
members 22 and 23[32 and 33] at both sides of khe sheet
30 which do not participate in storing and recording the
radiation image. Accordingly, the surface o~' the sheet
is hardly damaged. The shape of the guiding member is
not restricted to one as shown in Figs. 2 and 3, and any
shape can be optionally used, as far as the guiding mem-
35 ber has the above-described *unctions. Further, there is
no specific limitation on the material of the guiding
member. The guiding member is not necessa~ employed
in the form of individually separated member as shown in
Figs. 2 and 3, and a united guiding member, for instance,
a member in which one guiding member 22[32] is combined
5 with another guiding member 23[33] on the back surface-
side of the stimulable phosphor sheet 21[31] (support
side-surface of the sheet) in Figs. 2 and 3, can be em-
ployed with appropriate selection of the driving members
as described hereinafter.
The driving members of the conveying device of the
present invention apply a driving force to the surface(s)
of the stimulable phosphor sheet, and make it possible to
convey (i.e., move) the stimulable phosphor sheet in a
given direction. The driving members comprises at least
15 two members, and the distance (Q) between the two driving
members which are adjacent to each other along the con-
veying direction is smaller than the length (m) of the
stimulable phosphor sheet in the conveying direction.
Two or more driving members having the above-described
20 constitution can convey the stimulable phosphor sheet
with little error.
Representative examples of the driving member for
providing a driving force on the surfaces of the stimu-
lable phosphor sheet are a driving member comprising a
25 pair of rollers as shown in Figs. 2 and 3. The length of
the roller is preferably as almost the same as width of
the stimulable phosphor sheet (length measured in the
lateral direction, but the length of the roller is not
restricted to the above-mentioned length. The roller may
30 comprise a plurality of short rollers. The driving mem-
ber may not consist of a pair of rollers, and for exam-
ple, a driving member comprising a driving roller and a
fixed supporting member which is associated with the
roller is employable. Further, other driving members
35 than the above-mentioned rollers can be employed in the
invention.
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The surface of the driving rnember, especially the
surface thereof which are to be in contact with the sur-
face of the stimulable phosphor sheet, are preferably
formed by a soft and elastic material such as rubber. By
5 employing a driving member having a surface of such mate-
rial, the surface of the stimulable phosphor sheet can be
protected from physical shock so as not to be damaged.
The driving force is generally supplied to the driv-
ing members 24 (24a, 24b, 24c, ...)t24 (34a, 34b, 34c,
10 ...)] from a means 26[37] such as a motor through a driv-
ing power-transmitting means 25[36] such as a chain and a
belt. This driving force is then supplied to the stimu-
lable phosphor sheet 21[31] under rotation via surfaces
thereof.
The guiding member and driving members are supported
by an appropriate means such as a fixing means or a sup-
porting means so as to fulfill each function in the area.
In the method of conveying a stimulable phosphor
sheet according to the present invention, the stimulable
20 phosphor sheet can be easily and reliably conveyed in di-
rections other than horizontal direction, particularly in
the vertical or almost vertical direction (upward and/or
downward conveying), ~ithout damaging the surfaces of the
sheet. The vertical or almost vertical conveyance giving
25 no damage to the surface of stimulable phosphor sheet has
been hardly attained in the conventional method using a
belt conveyor. The method of conveying the stimulable
phosphor sheet of the invention can be effectively used
not only in the conveyance of a stimulable phosphor sheet
30 in the vertical or almost vertical direction but also in
the conveyance with alteration of the direction (e.g. L-
turn and U-turn). Further, the method of the invention
can be effectively employed in the conveyance of a stimu-
lable phosphor sheet in the horizontal direction. A bel-t
35 conveyor is conventionally used in the conveyance thereof
in such direction. Furthermore, the method of the pre-
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sent invention can be employed in combination with a con-
ventional method using a belt conveyor in conveying the
stimulable phosphor sheet in a radiation image informa-
tion recording and reading device.
The device illustrared in the Fig. 3 is further pro-
vided with a guiding means 35 (35a, 35b, 35c, ...) for
guiding the front end of the stimulable phosphor sheet.
The guiding means 35 is arranged in the vicinlty of the
driving means 34, for instance, just in front of the
10 driving means 34. The guiding means 35 serves to smooth-
ly engage the coming stimulable phosphor sheet with the
driving means. Although the stimulable phosphor sheet
essentially comprising a support and a phosphor layer is
considerably rigid, flexure may occasionally happen on
15 most of the conventional stimulable phosphor sheet used
in a relatively thin plate having a width of approx. 30 -
60 cm at the front end. If flexure takes place at the
front end of the stimulable phosphor sheet, the front end
sometimes suffers damage, or in the worst case, the con-
20 veying action is stopped by unsuitable engagement between
the sheet and the driving means. The guiding means 35
for guiding the front end of the stimulable phosphor
sheet is very effective to enable smooth engagement bet-
ween the stimulable phosphor sheet and the driving means.
There is no specific limitation on the shape, size,
and location of the front end-guiding means, as far as it
serves to enable the smooth engagement. Otherwise, the
front end-guiding m0ans can be in the form of a roller
arranged in the vicinity of the driving means. The front
30 end-guiding means can be arrange merely on one side of
the conveyor. The front end-guiding means is generally
made of plastic material, metal, or a composite material
of plastic material and metal.
As described above, the method of the invention is
35 suitable for conveying a stimulable phosphor sheet in the
vertical or almost vertical direction. Accordingly, from
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the viewpoint of making the device compact, the method of
the invention can be preferably and practically employed
in the radiation image information recording and reading
device in which the stimulable phosphor sheet is required
5 to be conveyed in such direction so as to be repeatedly
used in cycle.
Both sides of the stimulable phosphor sheet to be
employed in the conveying method of the invention are
preferably formed or processed to have enhanced protec-
10 tion against the physical (mechanical) shock given tothese sides by the side-guiding means in the course of
the conveying stage, as well as enhanced protection
against chemical deterioration.
For instance, at least both sides of the phosphor
15 layer along the direction to be conveyed are retracted
from the corresponding side edges of the support, as
illustrated in Fig. 4a in which the support, phosphor
layer and protective layer are indicated by 41, 42 and
43, respectively. Alternatively, at least both sides of
20 the phosphor layer and support are protected by a polymer
coating layer, as illustrated in Fig. 4b in which the
support, phosphor layer, protective layer and polymer
coating layer are indicated by 41, 42, 43 and 44, respec-
tively. Alternatively, at least both sides of the phos-
25 phor layer and support are protected by a polymer film,
as illustrated in Fig. 4c in which the support, phosphor
layer, protective layer and polymer film are indicated by
41, 42, 43 and 45, respectively. The polymer film 45 is
fixed to the side by an adhesive layer 46.
In other aspects, at least both sides of the phos-
phor layer along the direction to be conveyed are re-
tracted from the corresponding side edges of the support,
and both of said sides of the phosphor layer and support
are protected by a polymer coating layer, as illustrated
35 in Fig. 5a in which the support, phosphor layer, protec-
tive layer and polymer coating layer are indicated by 51,
52, 53 and 54, respectively. The side edges on the bot-
tom surface of the support can be chamferred, as illus-
trated in Fig. 5b.
In other aspects, at least both sides of the phos-
5 phor layer along the direction to be conveyed are re-
tracted from the corresponding side edges of the support,
and both of said sides of the phosphor layer and support
are protected by a polymer film, as illustrated in Fig.
6a in which the support, phosphor layer, protective layer
10 and polymer film are indicated by 61, 62, 63 and 65, res-
pectively. The polymer film 65 is fixed to the side by
an adhesive layer 64. The side edges on -the bottom sur-
face of the support can be chamferred, as illustrated in
Fig. 6b.
In other aspect, at least both sides of the phosphor
layer along the direction to be conveyed are retracted
from the corresponding side edges of the support, and
both of said retracted sides of the phosphor layer are
protected by a solid material fixedly placed in the area
20 formed by the retraction of the phosphor layer, as illu-
strated in Fig. 7a in which the support, phosphor layer,
protective layer and solid material are indicated by 71,
72, 73 and 74, respectively. The side edges on the bot-
tom surface of the support can be chamferred, as illus-
25 trated in Fig. 7b.
In other aspect, a stimulable phosphor sheet maycomprise a substrate, a support, a phosphor layer and a
protective film superposed in this order, in which at
least both sides of the phosphor layer and support along
30 the direction to be conveyed are retracted from the cor-
responding side edges of the substrate, and both of said
sides of the sheet are protected by a po]ymer coating
layer. This embodiment is illustrated in Fig. 8a, in
which the substrate, support, phosphor layer, protective
35 layer and polymer coating layer are indicated by 81, 82,
83, 84, and 85, respectively. The protection can be made
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by means of an adhesive layer 86 and a polymer filM 87,
as illustrated in Fig. 8b. The protection can 'oe made by
means of a solid material 88, as illustrated in Fig. 8c.
There is no specific limitation on the mate-rial of
5 the substrate. For instance, the substrate can be pro-
duced from any material employable for the production of
the support.
The above-described protections can be given to the
front and/or rear ends of the stimulable phosphor sheets,
lO to protect the phosphor layer against physical shocks, as
well as to keep the phosphor layer from chemical deterio-
ration. The front and/or rear ends can be chamferred on
the bottom surface.
In the above-described embodiments, the sides of the
15 protruded support or substrate can effectively keep the
phosphor layer from physical shock, friction, and the
like applied to the sides of the stimulable phosphor
sheet.
The polymer coating layer can be provided to the
20 side of the stimulable phosphor sheet, for instance, by
applying a solution of a fllm-forming polymer in a sol-
vent to the side and then drying to remove the solvent,
or applying reactive material(s) to form a polymer mate-
rial to the side and causing the reaction to form in-situ
25 the polymer coating film. There is no specific limita-
tion on the film-forming polymer employed in the above
process. For instance, a polyurethane-acrylic resin and
a mixture of an acrylic resin and vinyl chloride-vinyl
acetate copolymer (which is disclosed in Japanese Patent
30 Provisional Publication 58(1983)-68746) can be used.
The polymer film can be produced from the same mate-
rial as that employed for the production of the protec-
tive material. For instance, cellulose acetate, poly-
methyl methacrylate, polyethylene terephthalate, and
35 polyethylene can be mentioned. The polymer film employed
for this purpose may be transparent or not. The film can
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be fixed to the side, for instance, by an adhesive or
other sticky material.
There is no specific limitation on the solid materi-
al to be arranged adjacent to the side of the phosphor
5 layer. For instance, a solid polymer material and a
metal can be employed. The solid polymer material can be
that menioned hereinbefore as the material for production
of the surface protective film or a polymer film for pro-
tection of the side. The solid material can be provided
10 adjacent to the side of the phosphor layer by placing it.
Otherwise, a polymer material solution can be introduced
in the area and the solid polymer can be formed in-situ
after removal of the solvent. Otherwise, a solid polymer
material can be formed in-situ by a reaction of reactive
lS compound(s). The solid material can be fixed to the side
of the phosphor layer and/or the upper surface of the
support or substrate.
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