JPH07234465A - Radiation image photographing and reading device - Google Patents

Abstract

PURPOSE:To deal with various kinds of objects by turning a radiation image converting panel. CONSTITUTION:The whole of a device 3 is rotatably attached to a support 92 by an arm 91. By such a constitution, the radiation image converting panel in the device 3 can be rotated in accordance with the object. In other words, the radiation image converting panel can be rotated around a line perpendicular to the surface of the panel as the center of the rotation in an image recording part. Moreover, at this time, the radiation image converting panel is provided so as to rotate around the line extended from a shaft supporting member 93 as the center of the rotation, so that the radiation image converting panel is turned according to the object, to obtain a proper photographing position. In other words, photographing onto the radiation image converting panel can be executed in accordance with the object.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation image in which radiation image information is recorded on an image conversion panel having a stimulable phosphor layer, and the recorded image information is excited and scanned to photoelectrically read the radiation image. The present invention relates to a photographing and reading device.

[0002]

2. Description of the Related Art For example, when a stimulable phosphor is irradiated with radiation such as X-rays or ultraviolet rays, a part of the energy of this radiation is stored and recorded in the phosphor, and then the phosphor is irradiated with excitation light. The phosphor emits stimulated light according to the stored energy.

The radiation image conversion panel is a rigid panel having a stimulable phosphor layer having such characteristics (hereinafter, simply referred to as "panel" except for special cases), and the stimulable fluorescence is used. A body can record a radiation image such as an X-ray of a human body as a latent image. When this latent image portion is irradiated with excitation light such as laser light, stimulated emission of intensity corresponding to the density of the latent image is generated. It happens. Therefore, if the stimulated emission light is detected by a photodetector such as a photomultiplier (photomultiplier tube) and appropriately processed,
It is possible to obtain the recorded radiation image.

FIG. 16 is a diagram schematically showing a conventional scanning portion of an image reading apparatus using such a panel 4.
In this image reading apparatus, the panel 4 is supported so as to be conveyed and moved in the Y direction to be sub-scanned, and at the same time as the sub-scanning, the excitation light 81 is swept so that the panel 4 is main-scanned in the X direction. Irradiation, and the stimulated emission light generated thereby is two-dimensionally read by a photodetector (not shown).
Reference numeral 80 denotes a scanning line on the surface of the panel 4 which is scanned by the excitation light 81.

[0005]

However, in the conventional radiographic image capturing and reading apparatus, the panel 4 is vertically long according to the maximum film size, and the orientation of the panel 4 with respect to the subject is fixed. However, depending on the subject, there may be a problem in shooting. That is, when shooting a fat body object,
There is a problem in that the width of the projection is out of the panel 4, and it is not possible to take a picture of the projection.

The present invention has been made in view of the above points, and an object thereof is to provide a radiographic image capturing and reading apparatus which can deal with various subjects.

[0007]

According to the present invention, a radiation image conversion panel having a stimulable phosphor layer on which a radiation image of an object is accumulated and recorded by radiation, and the accumulation and recording are performed by scanning with excitation light. Exciting / reading means for photoelectrically reading radiation image information, and erasing means for erasing the afterimage of the radiation image conversion panel after the reading of the radiation image information is completed. A radiographic image capturing and reading apparatus that repeatedly performs reading and erasing of the residual image, and is configured such that the radiation image conversion panel is rotatable.

[0008]

In the present invention, since the radiation image conversion panel can be rotated, the panel can be set not only in portrait orientation but also in landscape orientation.

[0009]

The present invention will be described below. FIG. 3 is a block diagram showing the configuration of an embodiment of the radiographic image capturing and reading apparatus according to the present invention, and shows an example of the case applied to chest radiography.

The radiation source 1 is controlled by the radiation control device 2 and irradiates the subject (human chest or the like) M with radiation. The radiation image information recording / reading device 3 is provided with the above-mentioned panel 4 on the surface facing the radiation source 1 with the subject M sandwiched therebetween, and the panel 4 is the radiation transmittance of the subject M with respect to the radiation dose from the radiation source 1. By accumulating energy according to the distribution in the stimulable phosphor layer, a latent image of the subject M is formed there.

A light beam generator 5 (gas laser, solid-state laser, semiconductor laser, etc.) generates a light beam whose emission intensity is controlled, and the light beam passes through various optical systems to be described later and enters a scanner 6. The light beam arrives, is deflected there, is further changed in its optical path by the reflecting mirror 7, and is guided to the panel 4 as excitation scanning light.

The light collector 8 is a panel 4 on which the excitation light is scanned.
A condensing end made of an optical fiber is located in close proximity to and receives the stimulated emission light which is almost proportional to the latent image energy from the panel 4 scanned by the light beam. Reference numeral 9 is a filter that passes only the light in the stimulated emission wavelength range from the light introduced from the light collector 8, and the light passing therethrough is incident on the photomultiplier 10 and converted into a current signal corresponding to the incident light. To be converted.

The output current from the Photomul 10 is current /
It is converted into a voltage signal by the voltage converter 11, amplified by the amplifier 12, and then converted into digital data by the A / D converter 13. The digital data is stored in the image memory 14
Are sequentially stored in. Reference numeral 15 denotes a CPU, which performs various image processing (for example, on the image information stored in the memory 14).
Gradation processing, frequency processing, movement, rotation, statistical processing, etc.), and the image information as the processing result is displayed on the image display device 1.
Displayed at 6. Reference numeral 17 is an interface for transmitting the image information in the memory 14 to the outside or receiving similar information from the outside. Reference numeral 18 denotes a read gain adjusting circuit. With this circuit, the light beam intensity adjustment of the light beam generator 5, the photomal gain adjustment by adjusting the power source voltage of the high voltage power source 19 for photomul, the current / voltage converter 11 and the amplifier 12 are performed. Gain adjustment and A / D converter 13
The input dynamic range is adjusted, and the read gain of the radiation image information is adjusted comprehensively.

FIG. 4 is a view showing a mechanical portion in which the panel 4 is fixedly arranged and the excitation / reading unit 30 is movably provided. Reference numeral 21 is a frame forming an outer frame of the main body of the device 3. The entire excitation / reading unit 30 is a moving plate 3.
It is configured in a fixed state. A female screw body (not shown) is fixed to the moving plate 31, and the female screw body is screwed onto a male screw rod 26 rotated by a motor 25 attached to the frame 21. 27 is a guide rod. Therefore,
By driving the motor 25, the moving plate 31 moves in the direction of the arrow Y.
It can be moved in or out of the direction.

The above-mentioned light beam generator 5 is mounted on this moving plate 31 (not shown in FIG. 4), and the beam from there is an optical system such as a beam expander for shaping (expanding) the beam diameter (see FIG. 4). (Not shown) via a galvanometer mirror, a polygon mirror, etc. (The galvanometer mirror is shown in the figure.)
Is reflected by the scanner 6 to become scanning light, passes through the condenser lens 32 such as an fθ lens for focus adjustment, and is reflected by the reflecting mirrors 71 to 71.
The optical path is changed at 73 to become the excitation light 81.

The panel 4 is fixed to the left of the moving range of the excitation / reading unit 30 in FIG. 4, and the excitation light 81 is scanned on the panel 4 as a scanning line 80.

Here, from the light beam generator 5 to the reflecting mirror 71.
The pumping light paths up to are on the same plane, and the panel 4
Although it is configured so as to be parallel to, it is possible to easily assemble the device and perform optical path adjustment work of the light beam that requires positional accuracy, and further downsize the device. It is also possible.

The photomul 10 is fixed to the moving plate 31,
The condensing end surface 8a of the condensing body 8 that transmits the stimulated emission light is located in the vicinity of the scanning line 80 and arranged in parallel with the scanning line 80.

In the apparatus 3, in the main scanning in the X direction on the panel 4 (direction perpendicular to the paper surface of the drawing of FIG. 4), the beam emitted from the light beam generator 5 is swung by the scanner 6 ( (Scanned) and is focused on the surface of the panel 4 by the condenser lens 32, which is the same as the conventional one. On the other hand, the sub-scanning in the Y direction is performed by moving the moving plate 31 in the Y direction, that is, the excitation / reading unit 30 itself, with the panel 4 fixed in this embodiment.

Therefore, the panel 4 can be two-dimensionally scanned with the excitation light 81, and when the stimulated emission light corresponding to the density of the latent image is generated in the portion scanned with the excitation light 81, the emission is generated. Is collected by the light collector 8 and the photomultiplier 10
And is detected there to become an electric signal. Then, by processing this electric signal in synchronization with the main scanning and the sub-scanning, the image recorded as a latent image on the panel 4 can be reproduced.

In the apparatus of this embodiment, the excitation / excitation is performed as described above.
Since the reading unit 30 is integrally configured, the positional deviation (misalignment) between the respective parts is reduced, and more stable image reading is possible.

Further, since the panel 4 is fixed to the frame 21 as described above, the possibility of damaging the panel 4 can be minimized. Further, unlike the conventional case, the space required for moving the panel 4 is not required. Further, in the sub-scanning in the Y direction, the excitation / reading unit 30 itself moves, and the moving range is sufficient for the length of the panel 4 in the Y direction, so that the entire apparatus can be downsized.

Further, since a space required for moving the panel itself is not required and a driving member for the panel is not required, the distance between the panel 4 and the subject can be greatly reduced, and scattered rays generated from the subject or the like can be obtained. Can be significantly reduced, and deterioration of the quality of image information can be prevented.

FIG. 5 shows details of the panel fixing portion. The panel 4 is integrated with the panel fixing plate 22 with an adhesive or the like, and a part of the exterior 23 attached to the frame 21 including the radiation irradiating portion is cut out, and the panel fixing plate 22 including the panel 4 is attached and detached thereto. It is installed freely and has an exterior 23
Form part of the. Reference numeral 24 is a mounting plate for the panel fixing plate 22. By integrally mounting the panel 4 on the frame 21 as described above, the distance between the panel 4 and the subject can be greatly reduced.

The panel 4 and the excitation / reading unit 30
If the parallelism between the and changes, the reading accuracy will deteriorate, so it is important to select a material of the panel fixing plate 22 that is rigid and has good flatness. It is also necessary to select the panel fixing plate 22 that absorbs as little radiation as possible.

As the material of the panel fixing plate 22, various polymer materials, glass, metal and the like can be used as will be described in detail later, but a rigid carbon material is used because of its small radiation absorption amount. Is preferred. The panel 4 is composed of the support 4a, the phosphor layer 4b, and the protective layer 4c, but it is even more preferable if the panel fixing plate 22 also serves as the support 4a.

In the above-mentioned FIG. 4, in the sub-scanning in the direction of the arrow Y, it is required to stabilize the moving operation of the moving plate 31, but this is achieved by appropriately providing the guide mechanism such as the guide rod 27 or the rail. can do.

Further, the moving mechanism of the excitation / reading unit 30 can be constituted by a wire, a roller or the like, or a belt or the like, but a mechanism using a ball screw or a roller screw is more preferable. .

In this case, the nut plate of the ball screw and the roller screw and the moving plate are generally firmly fixed, but the ball screw, the screw shaft of the roller screw and the slide shaft, and the mounting position of the rail require accuracy. In addition, vibration caused by rotation of ball screw, roller screw shaft, etc. is excited / reading unit 3
Therefore, it is preferable that the nut plate and the moving plate be finely movable via a rotating material such as a bearing, since they may be transmitted to 0 and adversely affect the reading.

In the present embodiment, since the moving body is the moving plate 31 on which the excitation / reading unit 30 is mounted, a rapid change in speed is not preferable, and the range that does not affect reading at the start and stop of the sub-scanning. It is necessary to adjust the speed with. Figure 6
Indicates a change in the sub-scanning speed during the series of operations. If the speed changes rapidly as shown in (a), the optical system may be impacted, but as shown in (b) the movement starts. If you adjust the speed when stopped, it is difficult to give a shock. Furthermore,
It is more preferable to adjust so that the speed change becomes slow as in (c). If a shock absorbing structure is adopted at both ends of the stroke of the moving plate 31 in addition to the speed change as shown in (b) or (c), the shock to the excitation / reading unit 30 mounted on the moving plate 31 will be reduced. Relaxation becomes more preferable.

Further, although the optical path is bent by the reflecting mirrors 71 to 73 in the above embodiment, the scanner 6 can be constructed in this way.
Since the space occupied by the fan-shaped scanning light can be reduced without changing the substantial optical path length between the scanning line 80 on the panel 4 and the scanning line 80 on the panel 4, if a plurality of such reflecting mirrors are inserted in the optical path. , Greatly contributes to downsizing of the device.

In FIG. 4, the excitation light 81 is incident on the panel 4 obliquely from below. If the excitation light is incident on the panel 4 from the vertical direction, the excitation light may directly return to the light beam generation unit 5 due to reflection on the surface of the panel 4, which may lead to fluctuations in the light beam power. In the mechanism for moving the excitation / reading unit 30, it is preferable to use a laser light source, particularly a semiconductor laser, as the light beam generator 5 in terms of compactness, light weight, and low cost. However, reflected light is generated in the active region of the semiconductor laser. Upon incidence, the laser oscillation mode changes and the light beam power fluctuates greatly, which adversely affects image reading. Therefore, in the present embodiment, as described above, the excitation light 81
Was incident on the panel 4 from an oblique direction.

Further, in this embodiment, the incident end face of the light collector 8 is arranged substantially parallel to the panel 4 in FIG. With such a configuration, the efficiency of collecting stimulated emission light generated on the panel 4 is maximized, and read image information with a high S / N ratio can be obtained.

FIG. 7 is a view showing a structure in which the light collecting end face of the light collecting body 8 is obliquely attached to the surface of the panel 4. l is the distance between the light emitting point s on the surface of the panel 4 and the end surface 8a of the light collector 8, W is the width of the light collector 8, and θ is the perpendicular to the surface of the panel 4 and the perpendicular to the light collecting end surface 8a. It is an angle.

The case where an optical fiber assembly as shown in FIG. 8 is used as the light collector 8 will be described below. However, as the light collector 8, a stack of photoconductive sheets or the like may be used. Yes, and in that case, the following theories and effects are the same. The condensing end face 8a is composed of a cut end face of the optical fiber group, and the periphery thereof is fixed by a frame 28. FIG. 9 shows a cross section of the optical fiber a forming the light collector 8, p ₁ represents an angle at which the optical fiber a can receive and transmit, and the relationship with the numerical aperture (NA) is N. A. = Sin p ₁ .

On the other hand, the light intensity distribution of stimulated emission has extremely strong diffusivity and can be regarded as completely diffused light. Figure 1
0 indicates the light intensity distribution of the completely diffused light, and when the light intensity in the direction perpendicular to the panel 4 surface is I ₀ , the panel 4
The light intensity in the direction forming an angle of θ with respect to the direction perpendicular to the surface is I ₀ × cos θ. A calculation of the light collection efficiency when collecting this light by the light collection end surface 8a of the light collector 8 will be performed.

As shown in FIG. 11, the incident surface of the light collector 8 is indicated by a broken line, and the stimulated emission point is set to point 0. The small area on the incident surface is represented by dS, the distance from the point 0 is r, and the points 0 and dS
The angle formed by the line connecting the lines with the Z axis is θ, the angle formed by the line connecting the point 0 and dS with the y axis when projected on the xy plane is p,
Assuming that the angle q formed by the incident surface and the xy plane is dF = Io (cos θ / r ² ) (sin θ cosp sinq + cos
θ cosp) dS. However, Io represents the light intensity in the Z-axis direction. This d
If F is integrated over the entire range of the light collecting end face 8a of the light collecting body 8, the light collecting efficiency can be calculated. However, in this integration, light incident at an angle larger than the light receiving angle is ignored.

The results of the above calculation performed under the conditions shown in FIG. 7 are shown in FIGS. Curves I and II in FIG. 12 are NA = 0.5, W = 5 mm, and 1 = 5 m, respectively.
m and NA = 0.5, W = 8 mm, l = 8 mm,
It shows the light collection rate when θ is changed. θ =
It shows that the light collection efficiency is maximum when the panel 4 and the light collection end face 8a are arranged in parallel at 0 degree. Therefore, it has been clarified that by arranging the light collector 8 in this way, stimulated emission light can be efficiently captured.

Curves I and II in FIG. 13 are N.
A. = 0.5, W = 5 mm, θ = 0 degree, and NA = 0.5, W =
It shows the light collection rate when the distance l between the light emitting point s and the light collection end face 8a is changed under the condition of 8 mm and θ = 0 degree. It takes the maximum value when l = 4.3, and l when it decreases by about 10% is l = 3 and l = 6.
It has been clarified that the stimulated emission light can be efficiently collected by arranging the light collection end face 8a.

Further, as can be seen from FIG. 9, the light receiving angle p ₁ of the optical fiber is symmetrical with respect to its center line, and therefore the light receiving angle of the light collecting end face 8a which is an assembly of the optical fibers has the width W. It becomes symmetrical with respect to the center line A (FIG. 8) of the direction. Therefore, the light-collecting end face 8a should be positioned so that the line where the plane perpendicular to the light-collecting end face including the center line in the width W direction intersects the panel 4 is substantially coincident with the excitation light scanning line 80 on the panel. Is found to be the most preferable.

By the way, as described with reference to FIG. 5, the panel 4 is used.
In order to be able to use it repeatedly without removing it from the frame 21, it is necessary to erase the latent image remaining after the reading. This erasing can be performed by irradiating the panel 4 with strong light.
As shown in FIG. 3, the erasing lamp 33 may be provided on the side opposite to the sub-scanning direction (arrow Y direction) of the light collector 8 substantially parallel to the light collector 8, and the lamp 33 may be fixed to the moving plate 31. Further, the lamp 33 is covered with a reflection plate 34 in order to efficiently irradiate the panel 4 with light from the lamp 33.

The erasing lamp 33 and the reflecting plate 34 form an erasing unit. If the mounting position of the erasing lamp 33 is close to the panel 4, the power consumption is small, and the lamp 33 itself can be made small and lightweight. Further, as shown in FIG. 4, by passing the excitation light 81 between the light collector 8 and the erasing unit, the dead space is reduced, and the device 3 itself can be significantly downsized. As the erasing lamp 33 used here, a tungsten lamp, a halogen lamp,
There are fluorescent lights and so on.

Since the condenser 8 and the lamp 33 are integrated, it is possible to sequentially erase the read-completed portions while the image is being read. When incident on or incident on the scanning line 80 which is currently being read, a large noise occurs, which causes a problem of being detected by the photomultiplier 10.

Therefore, in order to prevent this, it is preferable to adopt a process in which reading is performed during sub-scanning in the direction of arrow Y and erasing is performed when returning in the opposite direction.

Further, in order to prevent the photocathode of the photomultiplier 10 from being deteriorated by the light at the time of erasing by the lamp 33, an optical path from the scanning line 80 to the photomultiplier 10 is provided.
It is preferable to provide a light shielding means 35 (FIG. 4) that can be inserted and removed. By doing so, the lamp light to the photomultiplier 10 can be blocked, the life of the photomultiplier 10 can be extended, and the hindrance of the next reading can be reduced.

The light-shielding plate used as the light-shielding means 35 in this case may be replaced with a filter for transmitting stimulated emission light and attenuating excitation light. A liquid crystal shutter can also be used as the light blocking means 35. Further, it is preferable that the light shielding means 35 shields not only the erasing lamp light but also radiation during photographing, and in this case, a material such as a lead plate is preferably added as a material.

FIG. 15 is a diagram showing the operation timing of each part in image recording and reading. When the photographing (radiation irradiation) switch is turned on, radiation irradiation is performed, a radiation image is recorded on the panel 4 according to the amount of radiation that has passed through the subject M, and after a certain period of time elapses, the excitation / reading unit 30.
The reading operation is started by moving the. This fixed time is
It is the time until the momentary light emission and the momentary afterglow of the panel 4 due to radiation irradiation are sufficiently attenuated, and the energy recorded and accumulated in the panel 4 is not significantly spontaneously released. Specifically, 0.01 to 60 seconds is preferable, but 0.01 to 10 seconds is preferable.
Seconds are good. In reading, after the moving speed of the moving plate 31 is stabilized, the light beam generator 5, the scanner 6, and the photomultiplier 10 are turned on for a predetermined time to be active, and the light shielding means 35 transmits light for a predetermined time. It will be open to let you. Reading is performed during this predetermined time. In this way, operating each part only for the required time is effective for prolonging the life. Then, when the movable plate 31 returns in the direction opposite to the arrow Y direction, the erasing lamp 33 is turned on and the latent image remaining on the panel 4 is erased.

By the way, the excitation / reading unit 30 is moved as described above, and by moving the unit 30 to a specified place in the irradiation field at the time of irradiation of radiation,
There is no need to newly provide a radiation detector, and there is no need to perform pre-reading prior to the original reading.

That is, the photodetector such as the photomultiplier 10 in the excitation / reading unit 30 can also be used as a radiation detector, and radiation generated during irradiation of radiation, instantaneous light emission,
Using the instantaneous afterglow, etc., (1) When the radiation dose reaches a specified dose, a signal to stop the radiation irradiation is generated to prevent the radiation dose fluctuation to the panel 4 and stabilize the image recording condition. (2) The amount of radiation received by the panel 4 can be accurately detected and measured, and the read gain of stimulated emission can be adjusted.

On the moving excitation / reading unit 30, the current / voltage converter 11 and the amplifier 1 shown in FIG.
2, and it is preferable to mount the A / D converter 13 from the viewpoint that a digital signal can be output from the analog signal rather than an analog signal that is easily affected by noise.

Further, by moving the excitation / reading unit 30 with the ball screw and the slide shaft, the positional relationship with the radiation image conversion panel 4 is not changed and the apparatus becomes compact.

An embodiment of the present invention is shown in FIGS. As shown in the figure, in this embodiment, the entire apparatus 3 is rotatably attached to a support base 92 by an arm 91. With this configuration, the radiation image conversion panel 4 in the device 3 can be rotated according to the subject M. Therefore, by rotating the radiation image conversion panel 4 in accordance with the subject M, an appropriate photographing position can be taken. That is, it is possible to capture an image on an appropriate radiation image conversion panel according to the subject M. FIG. 1 shows an example of horizontal arrangement, and FIG. 2 shows an example of vertical arrangement.

Further, in the above embodiment, the recording and reading apparatus for standing is shown in which the panel 4 is vertically arranged vertically, but the same configuration is also used for so-called "depression" in which the panel 4 is laid horizontally. Of course, it can be realized with.

The stimulable phosphor in the panel 4 described above means a stimulus (stimulation) such as optical, thermal, mechanical, chemical or electrical after the first irradiation of light or high energy radiation. Excitation, it means a phosphor that shows stimulated emission corresponding to the first irradiation of light or high-energy radiation. From a practical point of view, it is preferable that the fluorescent substance shows stimulated emission by stimulated excitation light of 500 nm or more. It is the body.

The photostimulable phosphor used in the panel 4 of the present invention is, for example, BaSO ₄ : Ax described in JP-A-48-80487 (where A is at least one of Dy, Tb and Tm). And x is 0.001 ≤ x <1 mol%), M described in JP-A-48-80488.
A phosphor represented by gSO ₄ : Ax (where A is either Ho or Dy, and x is 0.001 ≦ x ≦ 1 mol%), which is described in JP-A-48-80489. Sr
SO ₄ : Ax (provided that A is at least one of Dy, Tb and Tm, and x is 0.001 ≦ x <1 mol%).

In addition, Mn and D can be added to Na ₂ SO ₄ , CaSO _4, BaSO _{4 and the} like described in JP-A-51-29889.
Phosphors containing at least one of y and Tb, BeO, LiF, Mg described in JP-A-52-30487
Phosphors such as SO ₄ and CaF ₂ , phosphors such as Li ₂ B ₄ O ₇ : Cu and Ag described in JP-A-53-39277,
Li ₂ O. (B ₂ O described in JP-A-54-47883
₂ ) x: Cu (where x is 2 <x ≦ 3), and Li ₂ O.
(B ₂ O ₂ ) x: phosphor such as Cu and Ag (where x is 2 <x ≦ 3), Sr described in US Pat. No. 3,859,527
S: Ce, Sm, SrS: Eu, Sm, La ₂ O ₂ S:
Examples include phosphors represented by Eu, Sm, and (Zn, Cd) S: Mn, X (where X is a halogen).

Further, a ZnS: Cu, Pb phosphor described in JP-A-55-12142, whose general formula is BaO.xAl ₂
O ₃ : Eu (provided that 0.8 ≦ x ≦ 10) and a barium aluminate phosphor represented by the general formula M ^II O.xSiO ₂ : A
(However, M ^II is Mg, Ca, Sr, Zn, Cd or Ba.
And A is Ce, Tb, Eu, Tm, Pb, Tl, B
At least one of i and Mn, and x is 0.5 ≦ x
<2.5. ) Alkaline earth metal silicate-based phosphors represented by.

Further, the general formula described in JP-A-55-12143 is as follows: (Ba _1-xy Mg _x Ca _y ) FX: eEu ²⁺ (where X is at least one of Br and Cl). Yes,
x, y and e are numbers satisfying the conditions of 0 <x + y <0.6, xy ≠ 0 and 10 ⁻⁶ ≦ e ≦ 5 × 10 ⁻² , respectively. ) Is represented by the general formula described in JP-A-55-12144, LnOX: xA (where Ln is at least one of La, Y, Gd and Lu). , X represents Cl and / or Br, A represents Ce and / or Tb, and x represents a number satisfying 0 <x <0.1.).

The general formula described in JP-A-55-12145 is as follows: (Ba _1-x M ^II _x ) FX: yA (where M ^II is Mg, Ca, Sr, Zn or Cd) At least one of X, Cl is at least one of Cl, Br and I, and A is Eu, Tb, Ce, Tm, Dy,
At least one of Pr, Ho, Nd, Yb and Er
On the other hand, x and y represent numbers satisfying the conditions of 0 <x≤0.6 and 0≤y≤0.2. ), A phosphor represented by JP-A-55-8
No. 4389 has the general formula of BaFX: xCe, yA (where X is at least one of Cl, Br and I,
A is at least one of In, Tl, Gd, Sm, and Zr, and x and y are 0 <x ≦ 2 × 10 ^{−1, respectively.}
And 0 <y ≦ 5 × 10 ⁻² . ) The fluorescent substance represented by this is mentioned.

[0060] Also the general formulas described in JP ,, JP 55-160078 ^{is, M II FX · xA: yLn} ( where M ^II is Mg, Ca, Ba, Sr, at least one of Zn and Cd , A is BeO, MgO, CaO, S
rO, BaO, ZnO, Al ₂ O ₃ , Y ₂ O ₃ , La ₂
O ₃ , In ₂ O ₃ , SiO ₂ , TiO ₂ , ZrO ₂ , G
eO ₂ , SnO ₂ , Nb ₂ O ₅ , Ta ₂ O ₅ and ThO ₂
At least one of Ln is Eu, Tb, Ce,
At least one of Tm, Dy, Pr, Ho, Nd, Yb, Er, Sm, and Gd, X is at least one of Cl, Br, and I, and x and y are 5 × 10 5, respectively. It is a number that satisfies the conditions of ^-5 ≤ x ≤ 0.5 and 0 <y ≤ 0.2. ) A divalent metal fluorohalide phosphor activated with a rare earth element represented by the general formula: ZnS: A, Cd
S: A, (Zn, Cd) S: A, ZnS: A, X and C
A phosphor represented by dS: A, X (wherein A is Cu, Ag, Au or Mn and X is a halogen) is exemplified.

Further, one of the following general formulas described in JP-A-57-148285 xM ₃ (PO ₄ ) ₂ .NX ₂ : yA M ₃ (PO ₄ ) ₂ : yA (wherein M and N is Mg, Ca, Sr, Ba,
At least one of Zn and Cd, X is F, Cl,
At least one of Br and I, A is Eu, Tb, C
e, Tm, Dy, Pr, Ho, Nd, Yb, Er, S
It represents at least one of b, Tl, Mn and Sn. Further, x and y are numbers satisfying the conditions of 0 <x ≦ 6 and 0 ≦ y ≦ 1. ), A phosphor represented by any one of the following general formulas: nReX ₃ · max ′ ₂ : xEu nReX ₃ · max ′ ₂ : xEu, ySm (wherein Re is at least one of La, Gd, Y and Lu). Species, A is an alkaline earth metal, at least one of Ba, Sr, and Ca, X and X ′ are at least one of F, Cl, and Br, and x and y are 1 × 10.
^-4 <x <3 × 10 ⁻¹ , 1 × 10 ⁻⁴ <y <1 × 10 ⁻¹ , and n / m is 1 × 10 ⁻³ <n / m <
It is a number satisfying the condition of 7 × 10 ⁻¹ . ) The fluorescent substance represented by this is mentioned.

Further, the following general formula M ^I X.aM ^II X ' ₂ .bM ^III X " ₃ : cA (where M ^I is at least one alkali metal selected from Li, Na, K, Rb and Cs) is used. Yes, M ^II is B
e, Mg, Ca, Sr, Ba, Zn, Cd, Cu and N
It is at least one divalent metal selected from i. M
^III is Sc, Y, La, Ce, Pr, Nd, Pm, S
m, Eu, Gd, Tb, Dy, Ho, Er, Tm, Y
It is at least one trivalent metal selected from b, Lu, Al, Ga and In. X, X'and X "are F, C
It is at least one halogen selected from l, Br and I. A is Eu, Tb, Ce, Tm, Dy, Pr, H
o, Nd, Yb, Er, Gd, Lu, Sm, Y, Tl,
It is at least one metal selected from Na, Ag, Cu and Mg. a is a numerical value in the range of 0 ≦ a <0.5, b is a numerical value in the range of 0 ≦ b <0.5, and c is 0 <c.
It is a numerical value in the range of ≤0.2. ) Alkali halide phosphors represented by). In particular, the alkali halide phosphor is preferable because it facilitates the formation of a stimulable phosphor layer by a method such as vapor deposition and sputtering.

However, the stimulable phosphor used in the panel of the present invention is not limited to the above-mentioned phosphor, but it exhibits stimulated emission when irradiated with radiation and then irradiated with excitation light. Any phosphor can be applied as long as it is a phosphor.

The panel of the present invention may be a stimulable phosphor layer group containing at least one kind of the above-described stimulable phosphor or composed of two or more stimulable phosphor layers. Also,
The stimulable phosphors contained in each stimulable phosphor layer may be the same or different.

In the radiation conversion panel of the present invention, a support for supporting the stimulable phosphor layer is provided when the stimulable phosphor layer has no self-supporting ability. As the support, various polymer materials, glass, metal, etc. are used as described above, and plastic films such as cellulose acetate film, polyester film, polyethylene terephthalate film, polyamide film, polyimide film, triacetate film, and polycarbonate film. A metal sheet such as an aluminum sheet, an iron sheet, a copper sheet, or a metal sheet having a coating layer of the metal oxide is preferable.

The surface of these supports may be a smooth surface or may be a matte surface for the purpose of improving the adhesiveness with the stimulable phosphor layer. Further, these supports may be provided with an undercoat layer on the surface on which the stimulable phosphor layer is provided for the same purpose. The layer thickness of these supports varies depending on the material of the support used, etc., but is generally 50 to 2,000 μm, and more preferably 80 to 1,000 μm from the viewpoint of handling.
Is good.

In the radiation image conversion panel of the present invention, a stimulable phosphor layer is physically or chemically formed on the surface of the stimulable phosphor layer opposite to the surface on which the support is provided. A protective layer for protection may be provided. This protective layer may be formed by directly applying a protective layer coating solution onto the stimulable phosphor layer, or a separately formed protective layer may be adhered onto the stimulable phosphor layer. . Alternatively, a procedure of forming a stimulable phosphor layer on a separately formed protective layer may be taken. Materials for the protective layer include cellulose acetate, nitrocellulose, polymethylmethacrylate, polyvinyl butyral, polyvinyl formal, polycarbonate, polyester, polyethylene terephthalate, polyethylene, polyvinylidene chloride, nylon, polytetrafluoroethylene, polytrifluoride-chloride. Usual protective layer materials such as ethylene, tetrafluoroethylene-hexafluoropropylene copolymer, vinylidene chloride-vinyl chloride copolymer, vinylidene chloride-acrylonitrile copolymer and the like are used. In addition, this protective layer is formed of SiC, by a vapor deposition method, a sputtering method, or the like.
It may be formed by stacking inorganic substances such as SiO ₂ , SiN, and Al ₂ O ₃ . The thickness of these protective layers is generally 0.1-100 μm.
About m is preferable.

[0068]

As described above, according to the present invention, since the radiation image conversion panel can be rotated, the panel can be set not only in the portrait orientation but also in the landscape orientation. For this reason, it is possible to take appropriate shooting positions for various subjects, and it is possible to appropriately deal with various subjects.

[Brief description of drawings]

FIG. 1 is a diagram of a radiographic image capturing and reading apparatus according to an embodiment of the present invention in a horizontally used state, in which (a) is a top view and (b) is a side view.

FIG. 2 is a diagram of a radiographic image capturing and reading apparatus according to an embodiment of the present invention in a vertically used state, in which (a) is a top view and (b) is a side view.

FIG. 3 is a block diagram of a configuration of a radiographic image capturing and reading apparatus according to an embodiment of the present invention.

FIG. 4 is a side view showing an internal mechanism of the apparatus.

FIG. 5 is a side view showing a panel mounting structure.

FIG. 6 is a movement characteristic diagram of the excitation / reading unit.

FIG. 7 is an explanatory diagram of condensing stimulated emission light by excitation light.

FIG. 8 is a diagram showing a light collecting end surface of a light collecting body.

FIG. 9 is a cross-sectional view of an end portion of an optical fiber.

FIG. 10 is a diagram showing an intensity distribution of completely diffused light of stimulated emission light.

FIG. 11 is a diagram for explaining light collection efficiency.

FIG. 12 is a light collection rate characteristic diagram.

FIG. 13 is a light collection rate characteristic diagram.

FIG. 14 is an explanatory diagram of an erase lamp portion.

FIG. 15 is a time chart showing the operation timing of the device.

FIG. 16 is an explanatory diagram of image reading of a conventional panel.

[Explanation of symbols]

1: Radiation source, 2: Radiation control device, 3: Radiation image capturing / reading device, 4: Radiation image conversion panel, 5: Light beam generator, 6: Scanner, 7: Reflector, 8: Condenser,
9: Filter, 10: Photomul, 11: Current / voltage converter, 12: Amplifier, 13: A / D converter, 14: Image memory, 15: CPU, 16: Display, 17: Interface, 18: Gain Adjustment circuit, 19: high-voltage power supply, 2
1: Frame, 22: Panel fixing plate, 23: Mounting plate for panel fixing plate, 24: Exterior, 25: Motor, 26: Male screw rod, 27: Guide rod, 28: Frame, 30: Excitation / reading unit, 31 : Moving plate, 32: condenser lens, 33: erasing lamp, 34: reflecting plate, 71-73: reflecting mirror, 80: scanning line, 81: excitation light, 91: arm, 92: support base.

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] January 27, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 1

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

According to the present invention, a radiation image conversion panel having a stimulable phosphor layer, an image recording section for irradiating the radiation image conversion panel with radiation that has passed through an object to store and record a radiation image, and the radiation are described. Excitation / electrically reading the radiation image information stored / recorded by scanning the radiation image conversion panel for which the image storage / recording is completed with excitation light.
It has a reading means and an erasing means for erasing the afterimage of the radiation image conversion panel that has finished reading the radiation image information, and repeats accumulation and recording of the radiation image on the radiation image conversion panel, excitation / reading, and afterimage elimination. A radiation image capturing / reading device for performing the radiation image conversion panel, wherein the radiation image conversion panel is rotatably provided in the image reading unit with a line perpendicular to the panel surface as a rotation center.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

The radiation source 1 is controlled by the radiation control device 2 and irradiates the subject (human chest or the like) M with radiation. The radiation image information recording / reading device 3 is provided with the above-mentioned panel 4 on the surface facing the radiation source 1 with the subject M sandwiched therebetween, and the panel 4 is the radiation transmittance of the subject M with respect to the radiation dose from the radiation source 1. By accumulating energy according to the distribution in the stimulable phosphor layer, a latent image of the subject M is formed there. As described above, the panel 4 is arranged in the image recording unit when the radiation transmitted through the subject is irradiated and the radiation image is accumulated and recorded.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0052

[Correction method] Change

[Correction content]

An embodiment of the present invention is shown in FIGS. As shown in the figure, in this embodiment, the entire apparatus 3 is rotatably attached to a support base 92 by an arm 91. As described above, the device 3 has the configuration shown in FIG.
It is configured as in FIG. 4 and its description. Therefore, with such a configuration, according to the subject M,
The radiation image conversion panel 4 in the device 3 can be rotated. That is, the radiation image conversion panel 4 is
The panel 4 can be rotated about a line perpendicular to the plane of the panel 4. In the present embodiment, the radiation image conversion panel 4 is rotatably provided with the line extending from the shaft support portion 93 as the center of rotation. Therefore, the radiation image conversion panel 4
By rotating the camera according to the subject, it is possible to take an appropriate shooting position. That is, the radiographic image conversion panel 4 can be imaged according to the subject M. FIG. 1 shows an example of horizontal arrangement, and FIG. 2 shows an example of vertical arrangement.

[Procedure Amendment 5]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

[Procedure correction 6]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 2

[Correction method] Change

[Correction content]

[Fig. 2]

Front page continuation (72) Inventor Mikio Takeuchi 1st Sakura-cho, Hino-shi, Tokyo Konica stock company (72) Inventor Mitsuru Ishii 1st Sakura-cho, Hino-shi, Tokyo Konica stock company

Claims (1)

[Claims] 1. A radiation image conversion panel having a stimulable phosphor layer for storing and recording a radiation image of a subject by radiation, and photoelectrically reading the stored and recorded radiation image information by scanning with excitation light. Excitation / reading means and erasing means for erasing the afterimage of the radiation image conversion panel after the reading of the radiation image information is completed, and the accumulation / recording of the radiation image, the excitation / reading, and the afterimage erasing are repeated. A radiographic image capturing and reading apparatus for performing the above, wherein the radiation image converting panel is rotatable.