JP2013101131A - Method for cutting radiation image conversion plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for cutting a radiation image conversion plate in which a crack is not generated and which has successful productivity even to a radiation image conversion plate generated by using a vapor phase deposition method.SOLUTION: In this cutting method, when a radiation image conversion plate of multilayer structure including: a support formed by a high polymer material; and a phosphor layer formed on the support by a vapor phase deposition method is cut, cutting size and the number of radiation image conversion plates are input in a cutting device, and the radiation image conversion plate is cut into a plurality of radiation image conversion panels having desired size.

Description

  The present invention relates to a method for cutting a radiation image conversion plate, and more particularly to a method for cutting a radiation image conversion plate for cutting a radiation image conversion plate formed by a vapor deposition method using a laser beam.

  Conventionally, radiographic images represented by X-ray images have been used for the purpose of disease diagnosis and the like. As a method for obtaining this radiation image, in recent years, a radiation image reading method employing a phosphor such as a stimulable phosphor has been proposed and put into practical use. For example, when using a photostimulable phosphor, specifically, using the properties of the photostimulable phosphor, the radiation energy corresponding to the radiation transmittance of each part of the subject is accumulated in the photostimulable phosphor layer, and photostimulable excitation is performed. Radiation energy accumulated by scanning with light is emitted as stimulated light emission, and this stimulated light emission is converted into an image signal using a photoelectric conversion means to obtain a radiation image as digital image data.

In general, a radiation image conversion plate used in such a radiation image reading method is formed by applying a phosphor layer containing a phosphor such as a stimulable phosphor on a support. As a processing method of the radiation image conversion plate, a cutting method of forming a radiation image conversion panel having a predetermined size using a punching blade is known (for example, see Patent Documents 1 and 2). Moreover, the processing method which patterns an organic film using a laser as a general processing method is known (for example, refer patent document 3).
By the way, the radiation image conversion panel is desired to be as sensitive as possible to the radiation in view of the purpose of use, and to provide an image with good image quality depending on sharpness and graininess. However, the coating-type radiation image conversion panel has a problem that it is difficult to obtain sensitivity and image quality exceeding a certain level because the coating material contains a component such as a binder that does not contribute to light emission.

  Therefore, in order to solve such a problem, a method of manufacturing a radiation image conversion plate by a vapor deposition method is disclosed. In vapor phase deposition, the phosphor material is evaporated and vaporized, and crystals that adhere to the support are grown to form a phosphor panel with a structure in which crystals are arranged in an orderly manner, such as columnar crystals on the support surface. Since the material does not contain a component that does not contribute to light emission, high sensitivity to radiation can be obtained.

JP-A-11-223891 JP 2004-154913 A JP 2004-226903 A

However, while the radiation image conversion plate produced by using the vapor deposition method gives an image with high sensitivity to radiation and good image quality, the phosphor itself does not contain a binder resin, so that the crystal itself is very high. It is brittle and has a problem of low productivity due to cracking of crystals when a product is cut out using a punching blade.
In addition, when cutting with a single scan using a laser, the area around the laser processing area is excessively melted by thermal interaction, and the effective image area of the product portion becomes narrow. Have.

  The present invention has been made in view of the above points, and a method for cutting a radiation image conversion plate with good productivity without causing cracks even for a radiation image conversion plate generated by using a vapor deposition method. It is intended to provide.

In order to achieve the object, the cutting method of the radiation image conversion plate according to claim 1,
A radiation image conversion plate having a multilayer structure having a support formed of a polymer material and a phosphor layer formed on the support by a vapor deposition method. It is characterized by cutting into panels.

The invention according to claim 2 is the method for cutting a radiation image conversion plate according to claim 1,
The cutting is performed by laser light.

The invention according to claim 3 is the method for cutting a radiation image conversion plate according to claim 2,
The radiation image conversion plate is cut by the laser beam scanning the same scanning line a plurality of times.

The invention according to claim 4 is the method for cutting a radiation image conversion plate according to any one of claims 1 to 3,
The phosphor layer is characterized by being either an instantaneous light-emitting phosphor or a photostimulable phosphor containing Cs in the composition.

The invention according to claim 5 is the cutting method of the radiation image conversion plate according to claim 4,
The phosphor layer is a mixed crystal in which at least two of CsI, CsBr, and CsCl are formed at an arbitrary mixing ratio.

  The invention according to claim 6 is the method for cutting a radiation image conversion plate according to claim 4, wherein the instantaneous light emitting phosphor is made of CsI containing at least one activator. It is characterized by being.

The invention according to claim 7 is the method for cutting a radiation image conversion plate according to claim 4,
The photostimulable phosphor is CsBr containing Eu as an activator.

  ADVANTAGE OF THE INVENTION According to this invention, the cutting method of the radiographic image conversion plate with sufficient productivity is provided, without generating a crack also with respect to the radiographic image conversion plate produced | generated using the vapor deposition method.

It is a schematic block diagram which shows the cutting apparatus which concerns on this invention. It is the schematic which shows the laser generator mounted in the cutting apparatus which concerns on this invention. It is a block diagram which shows the control mechanism of the cutting apparatus shown in FIG. It is sectional drawing of the base material plate which concerns on this invention. It is a principal part enlarged view of the base material plate shown in FIG. It is the schematic which shows one process of the manufacturing method of the base material plate which concerns on this invention. It is a flow for demonstrating the cutting method which concerns on this invention. It is the figure which looked at the base material plate concerning the present invention from the upper surface. It is a figure for demonstrating the processing conditions of the pulse laser which concerns on this invention.

  Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples.

  First, the configuration of the cutting apparatus 1 according to the present invention will be described.

FIG. 1 is a perspective view showing a main configuration of a cutting apparatus 1 used in the present embodiment.
The cutting apparatus 1 according to the present embodiment scans a base plate 20 (radiation image conversion plate) provided with a stimulable phosphor layer 22 on a support 21 by scanning laser light from the base plate 20. It is the cutting device 1 of the base material plate 20 which cuts out the several radiographic image conversion panels 20a-20f of size.

  As shown in FIG. 1, in this embodiment, the cutting device 1 includes a purge chamber 2 formed in a box shape. The purge chamber 2 is a space in which the inside is almost sealed so that dust or the like floating in the outside space does not enter the inside. The purge chamber 2 is preferably in a low humidity environment. In addition, a transparent window 6 that transmits laser light is provided on the upper surface of the purge chamber 2.

A support base 3 on which the base plate 20 is placed is provided on the bottom surface inside the purge chamber 2.
The support base 3 is a flat plate-like member, and is formed larger than the maximum size of the base plate 20 cut by the cutting device 1 in the present embodiment. The support table 3 is provided with suction means (not shown) so that the base plate 20 installed on the support table 3 is sucked and held.
Further, the support table 3 is provided with a support table moving means 16 for moving the support table 3 in the horizontal direction (the XY direction in FIG. 1), and the base plate 20 installed on the support table 3 is It can move in the XY direction together with the support base 3.

Above the support 3, dust collecting means 7 is provided for collecting floating substances such as dust and soot generated in the purge chamber 2.
The dust collecting means 7 is formed substantially in an annular shape, and is arranged so that the hollow portion of the dust collecting means 7 is located at a position corresponding to the light transmitting window 6.
The dust collecting means 7 communicates with one end of a discharge pipe 8 that guides floating matter such as dust collected by the dust collecting means 7 to the outside of the purge chamber 2. The other end of the discharge pipe 8 penetrates through the upper surface of the purge chamber 2 and is exposed to the outside of the purge chamber 2, and suspended matter such as dust collected by the dust collecting means 7 passes through the discharge pipe 8. 2 is discharged outside.

  Further, above the purge chamber 2, a laser generator 4 that irradiates the base plate 20 placed on the support base 3 in the purge chamber 2 with laser light is provided.

FIG. 2 is a schematic view showing the laser generator 4 in the present embodiment.
The laser generator 4 includes a laser oscillation unit 9 that generates laser light, a beam expander 10 that adjusts the beam diameter of the laser light oscillated from the laser oscillation unit 9, and a laser beam on the base plate 20 by adjusting the optical path of the laser. It is comprised from the processing head 5 etc. which irradiate.

The laser oscillation unit 9 includes an optical resonator (not shown) including a laser optical medium such as YAG (Yttrium Aluminum Garnet) and a pair of reflecting mirrors opposed to each other. The laser beam having a predetermined frequency is oscillated by the repetition frequency setting means 11 attached to the optical resonator.
In the present embodiment, a solid-state laser including YAG or the like in the laser oscillation unit 9 will be described as an example. However, the laser oscillation unit is not limited to this, and a medium other than a solid such as a gas laser is used. May be.
The laser light oscillated from the laser oscillating unit 9 is adjusted to a predetermined beam diameter via the beam expander 10 and is emitted to the machining head 5.

The processing head 5 includes a folding mirror 12, a galvano mirror 13, and a condenser lens 14.
The folding mirror 12 is a total reflection mirror, and laser light oscillated from the laser oscillation unit 9 and irradiated through the beam expander 10 is incident on the folding mirror 12 and is redirected toward the base plate 20 by the folding mirror 12. Made.

  Further, the laser light whose direction has been changed by the folding mirror 12 enters the galvanometer mirror 13. The galvanometer mirror 13 includes, for example, a reflection mirror that totally reflects laser light and an angle adjustment unit that changes the angle of the reflection mirror (both not shown), and the laser incident on the galvanometer mirror 13. The light is incident on the condenser lens (fθ lens) 14 after adjusting the angle. Then, the laser light is condensed at one point on the base plate 20 that is a processing target by the condenser lens 14, and the irradiation angle is adjusted according to the movement of the galvanometer mirror 13. A predetermined scanning line S can be scanned. At this time, the galvanometer mirror 13 and the support base moving means 16 function as a scanning means 17 that operates relatively and scans the base plate 20 with laser light.

In FIG. 1, the optical axis of the laser beam irradiated from the processing head 5 is indicated by a two-dot chain line.
As shown in FIG. 1, the processing head 5 of the laser generator 4 is directed to a position corresponding to the light transmission window 6 and the hollow portion of the dust collecting means 7, and the laser light is directed from the processing head 5 in the direction of the arrow. The substrate plate 20 on the support 3 is irradiated through the hollow portion of the light transmission window 6 and the dust collecting means 7.
The base plate 20 installed on the support table 3 is moved in the XY direction together with the support table 3 so that the laser beam is irradiated onto a predetermined scanning line and cut.

In addition, the cutting device 1 includes a control device 15. FIG. 3 is a block diagram illustrating a control mechanism of the cutting apparatus 1.
The control device 15 includes a CPU (Central Processing Unit) that performs arithmetic processing according to a control program, a ROM (Read Only Memory) that stores a control program and the like, and a RAM (Random Access Memory) that temporarily stores data and the like (none of which are shown). The control program recorded in the ROM is developed in the work area of the RAM and executed by the CPU.

  In addition, the cutting apparatus 1 cuts out the radiation image conversion panels 20a to 20f of any size from the base plate 20, or how many of the radio image conversion panels 20a to 20f from the single base plate 20. An input unit 18 for inputting a cutting condition, a cutting start instruction, and the like is provided, and information input from the input unit 18 is sent to the control device 15. The input unit 18 is, for example, a keyboard or an operation panel, and the user can set the size and number of the radiation image conversion panels 20a to 20f to desired numerical values by operating the input unit 18. Note that the input unit 18 is not an essential component of the cutting apparatus 1 and may be configured to input cutting conditions, a cutting start instruction, and the like from an external PC (Personal Computer), for example.

Further, the control device 15 controls the repetition frequency setting means 11 to emit laser light having a predetermined frequency from the laser oscillation unit 9 at a predetermined repetition frequency.
Further, the control device 15 operates the support table moving means 16 based on the cutting conditions and the like input from the input unit 18 to move the support table 3 horizontally in the XY direction of FIG. At least one of the galvano mirror 13 and the support table moving means 16 is operated so that a desired position of the base plate 20 placed on the support table 3 is irradiated with a laser beam with a desired beam diameter. It is like that.
In the present embodiment, the cutting apparatus 1 is configured to cut out six radiation image conversion panels 20a to 20f from one base plate 20, and along the outer periphery of each of the radiation image conversion panels 20a to 20f. The radiation image conversion panels 20a to 20f are cut one by one from the base plate 20 by scanning the laser beam a plurality of times. For this reason, the control device 15 includes the galvano mirror 13 and the support base so that the laser light is scanned a plurality of times along the outer periphery (scanning line S on the base plate 20) of each of the radiation image conversion panels 20a to 20f. At least one of the moving means 16 is operated.

  Here, the base material plate 20 (radiation image conversion plate) cut by the cutting device 1 according to the present embodiment will be described with reference to FIG.

  In the present embodiment, the base plate 20 (radiation image conversion plate) has a multilayer structure including a support 21 and a photostimulable phosphor layer 22 formed on the support 21. The radiation image conversion panels 20a to 20f cut out by cutting the plate 20 cause the stimulable phosphor layer 22 to absorb the radiation transmitted through the subject and accumulate radiation energy corresponding to the radiation transmission density of each part of the subject. Can do. Then, by stimulating the stimulable phosphor in time series with electromagnetic waves (excitation light) such as visible light and infrared light, the radiation energy accumulated in the stimulable phosphor is released as stimulated emission. Let For example, an electric signal can be obtained by photoelectric conversion of the light intensity signal and reproduced as a visible image on a recording material such as a silver halide photographic material or a display device such as a CRT.

  As the support 21, various polymer materials (polymers), for example, a plastic film such as a cellulose acetate film, a polyester film, a polyethylene terephthalate film, a polyamide film, a polyimide film, a triacetate film, and a polycarbonate film can be applied. In addition, the material which forms the support body 21 is not limited to what was illustrated here.

  Although the thickness dimension of the support 21 varies depending on the material used, etc., it is generally 80 μm to 5000 μm, and more preferably 100 μm to 4000 μm from the viewpoint of handling.

A metal thin film 23 is disposed between the support 21 and the photostimulable phosphor layer 22. The metal thin film 23 is for uniformly depositing the photostimulable phosphor layer 22 on the support 21 to ensure the flatness of the base plate 20 as a whole. For example, aluminum, iron, copper, chromium Etc. are formed.
In addition, if the stimulable phosphor layer 22 is brought into direct contact with the metal thin film 23 made of aluminum or the like, the metal thin film 23 is corroded, so the surface of the metal thin film 23 (the side on which the stimulable phosphor layer is formed). Is covered with a coating layer 24.

The photostimulable phosphor layer 22 is composed of at least one layer and varies depending on the type of phosphor, but the layer thickness is 50 μm or more, and more preferably in the range of 50 to 1000 μm from the viewpoint of obtaining the effects of the present invention. is there. Further, as shown in FIG. 5, the stimulable phosphor layer 22 has a columnar structure in which a large number of columnar crystals 22a, 22a,.
In FIG. 5, the metal thin film 23 and the coating layer 24 are omitted.

As shown in FIG. 6, the substrate plate 20 is prepared by first preparing a predetermined support 21 and brightening it on the support 21 (the lower surface in FIG. 6) by a well-known vapor deposition method. The stimulable phosphor layer 22 can be formed.
Here, the case where the photostimulable phosphor layer 22 is formed by, for example, a vapor deposition method among a plurality of known vapor deposition methods will be described. The support 21 is fixed and installed on the support holder 25 in the vapor deposition apparatus, and the inside of the vapor deposition apparatus is evacuated to a certain degree of vacuum. Thereafter, the phosphor is heated and evaporated by a resistance heating method, an electron beam method, or the like, using the phosphor as an evaporation source, and the phosphor is grown on the surface of the support 21 to a desired thickness. The phosphor layer 22 is formed on the support 21.

  As shown in FIG. 5, on the surface of the photostimulable phosphor layer 22, a phosphor having a structure in which columnar crystals 22a having a length of several tens to several hundreds μm and an average diameter of several μm are regularly arranged can be formed.

  Next, a cutting method of the cutting apparatus 1 according to the present invention will be described.

  First, the base plate 20 is placed on the support base 3 of the cutting apparatus 1 with the support 21 side as the bottom surface, and the base plate 20 is sucked and held on the support base 3. Accordingly, the base plate 20 is held with the stimulable phosphor layer 22 facing upward.

The base plate 20 placed on the support 3 is positioned immediately below the processing head 5 of the laser generator 4 by the support moving means 16 (FIG. 7; START). When the base plate 20 is positioned immediately below the processing head 5, the control device 15 executes an alignment operation for detecting a processing region (X1 in FIG. 8) of the base plate 20 to be laser processed.
That is, the control device 15 performs alignment between a predetermined scanning line S set in advance on the base plate 20 and the condenser lens 14 of the processing head 5 that irradiates laser light along the scanning line S. Then, processing such as pattern matching is performed to align the laser irradiation position (step S1).

  Thus, after the scanning line S of the base plate 20 held on the support 3 is detected and the laser irradiation position is aligned, a predetermined start point X1 is positioned immediately below the processing head 5 ( Step S2). At this time, the base plate 20 is positioned so that one place (X1 in FIG. 8) of the scanning line S is located immediately below the processing head 4.

Next, a laser beam having a predetermined frequency in accordance with a preset condition is emitted from the laser generator 4, and the laser beam is emitted from the processing head 5 to the base plate 20.
Next, at least one of the support base 3 (that is, the base plate 20) and the galvanometer mirror 13 is moved by an arrow X or -X in FIG. 8 so that the laser beam scans the scanning line S at a predetermined speed. It moves to one or both of the direction shown and the direction shown by arrow Y or -Y. In this way, the laser beam scans on the preset scanning line S (step S3).
Then, when the processing head 5 scans the scanning line S and reaches the start point X1, this is regarded as one scanning, and the processing head 5 scans the same scanning line S again at a predetermined scanning speed. To start. At this time, it is determined whether or not the predetermined number of scans has been reached for each scan (step S4). Repeat step S4 from step S3.
When the same scanning line S is scanned a preset number of times (step S4; YES), the laser beam irradiation is stopped (FIG. 7; END). As a result, the base plate 20 is molded with a radiation image conversion panel 20a that is uniformly cut out along a predetermined scanning line S as shown in FIG.

Next, the control device 15 executes again an alignment operation for detecting a processing region (X2 in FIG. 8) of the base plate 20 to be laser processed.
That is, when cutting the plurality of radiation image conversion panels 20a to 20f from the base plate 20, the control device 15 repeats Steps S1 to Step 4 for each of the radiation image conversion panels 20a to 20f.

In the cutting process described above, the laser light emitted from the processing head 5 of the laser generator 4 is preferably a pulse laser.
By using a pulse laser, since there is less overlap of the processing region between adjacent pulses compared to a continuous wave laser, there is less thermal interaction between adjacent pulses and thermal melting around the processing portion is suppressed.

Furthermore, when the scanning speed of the pulse laser is V (mm / s) and the repetition frequency of the pulse laser is f (Hz), the scanning speed V (mm / s) of the pulse laser satisfies the general formula (1). In addition, it is preferable to set so that the irradiation position (phase) of the pulse laser on the same scanning line S is shifted for each scanning.
V [mm / s] ≧ f [Hz] × w [mm] (1)

FIG. 9 is a conceptual diagram showing how the pulse laser processes the base plate 20. Here, the processing region (irradiation position) at the time of one pulse irradiation of the pulse laser is represented by O1, O2,..., And the diameter (processing diameter) is represented by w1, w2,. Further, the processing area at the first scanning is indicated by a solid line, and the processing area at the second scanning is indicated by a two-dot chain line.
In addition, w (processed diameter (diameter)) in the general formula (1) is one processed hole formed when the same location of the radiation image conversion plate is irradiated with a pulse laser at the number of times that the radiation image conversion plate can be completely cut. The diameter of the part which becomes the smallest diameter among the diameters of.

  When such a setting is satisfied, the adjacent processing regions O1 and O2 do not overlap, so that the thermal melting portion around the processing portion processed by one scan can be minimized, and pulse laser irradiation for each scan Since the positions are different, different positions on the same scanning line can be used as processing regions, and cutting can be performed reliably while preventing the fusion regions T around the processing regions O1, O2,.

  This scanning speed V (mm / s) is implemented by controlling the galvanometer mirror 13 which is the scanning means 17 and the support base moving means 16 by the control device 15. That is, the control device 15 controls the repetition frequency setting unit 11 of the laser generator 4, the support table moving unit 16 that moves the base plate 20, and the galvano mirror 13, and is oscillated by the laser generator 4. The repetition frequency f (Hz) of the pulse laser beam and the scanning speed V (mm / s) of the laser beam that scans the base plate 20 are set as appropriate, and V (mm / s) ≧ w (mm) × f ( Hz) is established.

The laser beam used at this time is preferably an ultraviolet laser beam having a wavelength of about 266 nm.
With an ultraviolet laser beam having a wavelength of about 266 nm, it is possible to dissociate molecular bonds such as C—H bonds and C—C bonds with an organic material at the same time as a workpiece is processed by thermal action. That is, in the present embodiment, the stimulable phosphor layer 22 is cut by thermal action by scanning the ultraviolet laser light a plurality of times, and the support 21 is cut because molecular bonds are dissociated. . For this reason, the photostimulable phosphor layer 22 is thermally actuated and the support 21 is cut by dissociation of molecular bonds, so that it is possible to prevent crystal breakage at the cut portion.

As described above, according to the cutting device and the cutting method according to the present invention, the laser light is used to cut the base plate 20 to cut the photostimulable phosphor layer 22 that does not contain the binder resin. However, productivity can be improved to prevent crystal cracking.
In addition, by scanning the same scanning line a plurality of times, processing can be performed with low output, so that thermal melting around the processing region is suppressed, the melting width of the cut portion can be reduced, and the effective image region can be widened.
Further, by using a pulse laser, thermal melting around the processing area is suppressed, so that the melting width of the cut portion can be reduced and the effective image area can be widened.
Further, by using laser light in the ultraviolet region, the photostimulable phosphor layer 22 is cut by heat and the support 21 is cut by dissociation of molecular bonds, so that crystal breakage at the cut portion is prevented and productivity is improved. It is possible to make it.

The frequency and scanning speed of the laser light can be set and changed for each scanning.
Further, the moving direction of the laser light may be any one that scans the same scanning line a plurality of times as a result, and may be cut by scanning the entire circumference of the radiation image conversion panel 20a a plurality of times, or cutting one side at a time. You may make it scan so. Also, the position of the start point can be set as appropriate.

  In the present embodiment, the case where a stimulable phosphor is used as the phosphor layer has been described. However, in the present invention, a phosphor other than the stimulable phosphor can be used, for example, FPD. You may use the instantaneous light emission fluorescent substance used as a scintillator.

Examples of the stimulable phosphor that can be used in the present invention include the following phosphors (see paragraphs [0060] to [0061] of JP-A-11-249243).
General formula aBaX ₂ · (1-a) BaY ₂ : bEu ²⁺ (wherein X and Y represent at least one of F, Cl, Br and I, respectively, X ≠ Y, a, b Represents a number satisfying 0 <a <1, 10 ⁻⁵ <b <10 ⁻¹ ).
General formula M _I X · aM _II X ′ ₂ · bM _III X ″ ₃ : cA (where M _I represents at least one alkali metal of Li, Na, K, Rb, Cs, and M _II represents Be , Mg, Ca, Sr, Ba, Zn, Cd, Cu, Ni represents at least one divalent metal, M _III is Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Al, Ga, In represents at least one trivalent metal, and X, X ′, X ″ are F, Cl, Br, I Represents at least one halogen, A is at least Eu, Tb, Ce, Tm, Dy, Pr, Ho, Nd, Yb, Er, Gd, Lu, Sm, Y, Tl, Na, Ag, Cu, Mg A, b, c represents a number satisfying 0 ≦ a <0.5, 0 ≦ b <0.5, and 0 ≦ c <0.2)) .
General formula (Ba _1-x (M _I ) _x ) FX: yA (where M _I represents at least one of Mg, Ca, Sr, Zn, Cd, and X represents at least one of Cl, Br, I) A represents a species, A represents at least one of Eu, Tb, Ce, Tm, Dy, Pr, Ho, Nd, Yb, Er, x, y represents 0 ≦ x <0.6, 0 ≦ y <0.2 The stimulable phosphor is represented by the following formula:
General formula M _I FX · xA: yLn (where M _I represents at least one of Mg, Ca, Ba, Sr, Zn, Cd, and A represents BeO, MgO, CaO, SrO, BaO, ZnO, Al ₂ At least one of O ₃ , Y ₂ O ₃ , La ₂ O ₃ , In ₂ O ₃ , SiO ₂ , TiO ₂ , ZrO ₂ , GeO ₂ , SnO ₂ , Nb ₂ O ₅ , Ta ₂ O ₅ , ThO ₂ Ln represents at least one of Eu, Tb, Ce, Tm, Dy, Pr, Ho, Nd, Yb, Er, Sm, Gd, X represents at least one of Cl, Br, I, x , y represents a number satisfying 5 × 10 ⁻⁵ ≦ x ≦ 0.5 and 0 <y ≦ 0.2.)

In addition, as the instantaneous light emitting phosphor that can be used in the present invention, for example, a phosphor in which a crystal is formed based on Cs, and CsI is preferable.
Examples of the activator include indium (In), thallium (Tl), lithium (Li), potassium (K), rubidium (Rb), sodium (Na), europium (Eu), copper (Cu), and cerium (Ce). ), Zinc (Zn), titanium (Ti), gadolinium (Gd), terbium (Tb), and the like, and at least one of them can be selected. Any known activator can be used as long as it is based on CsI, and can be arbitrarily selected according to required characteristics such as emission wavelength and moisture resistance. The types are not limited to those exemplified here.
Moreover, it is good also as a structure which uses CsBr, CsCl, etc. instead of CsI which is fluorescent substance used as a base. In addition, the phosphor layer may be formed of crystals based on a mixed crystal in which two or more kinds of phosphors are formed at an arbitrary mixing ratio among CsI, CsBr, and CsCl (Japanese Patent Application Laid-Open No. 2005-260260). (See paragraph numbers [0063] to [0064] of 2007-139604).

  In the present invention, when an instantaneous light emitting phosphor is used, CsI (activator is Tl) is preferably used. In the present invention, it is preferable to use a stimulable phosphor among the phosphors, and it is particularly preferable to use CsBr (the activator is Eu).

  Hereinafter, the present invention will be described with reference to examples. In addition, this invention is not limited by these Examples.

(Production of vapor deposition type radiation image conversion plate)
A support (crystallized glass with a thickness of 1 mm and an area of 410 mm × 410 mm (manufactured by Nippon Electric Glass Co., Ltd.)) is placed in a vapor deposition apparatus, and then a phosphor material (CsBr: 0.0001Eu) is press-molded and filled into a crucible. And after cooling with water, it put in the vapor deposition apparatus and made it a vapor deposition source. The distance between the support and the evaporation source was 60 cm. An aluminum slit was disposed between the support and the vapor deposition source.

Thereafter, the vapor deposition apparatus is evacuated by connecting a pump to the exhaust port, and nitrogen is further introduced from the gas inlet (flow rate 1000 sccm (sccm: standard cc / min (1 × 10 ⁻⁶ m ³ / min)). )), And the degree of vacuum in the apparatus was maintained at 6.65 × 10 ⁻³ Pa. In this state, the vapor deposition source was heated to 650 ° C., and a photostimulable phosphor made of CsBr: 0.0001Eu was vapor deposited on one surface of the support.

  The vapor of the photostimulable phosphor passes through the aluminum slit and is incident at an incident angle of 0 ° with respect to the normal direction of the support, and is deposited while transporting the support in a direction parallel to the support. Went. Vapor deposition was terminated when the thickness of the photostimulable phosphor layer reached 400 μm, and a radiation image conversion plate (base material plate) was produced.

  A radiation image conversion panel was prepared by irradiating a pulsed laser beam having a wavelength of 266 nm, a repetition frequency of 5000 Hz, and a beam diameter of 20 μm with an output of 300 mW onto the radiation image conversion plate prepared as described above, and cutting it by scanning 24 times.

<Comparative Example 1>
Using a continuous wave (CW) laser beam having a wavelength of 365 nm and a beam diameter of 20 μm, the radiation image conversion plate produced as described above is irradiated at an output of 50 mW and cut by scanning 150 times to form a radiation image conversion panel. Produced.

<Comparative example 2>
A radiation image conversion panel was manufactured by irradiating the radiation image conversion plate produced as described above with a laser beam having a wavelength of 1064 nm, a repetition frequency of 20000 Hz, and a beam diameter of 20 μm at an output of 8600 mW, and by scanning three times.

<< Evaluation of base plate >>
Using the radiation image conversion panel produced as described above, the cut portion was visually observed and the state thereof was evaluated as shown below and shown in Table 1. The pulse energy [mJ] and energy density [J / cm ² ] under each condition were measured and shown in Table 1.
◯: Crystal melting exceeding 0.1 mm width or burnt traces are not observed at the cut part ×: Crystal melting exceeding 0.1 mm width or burnt traces are observed at the cutting part Note that the cutting part is 0.1 mm wide As long as no crystal melting or burnt marks exceeding the above value occur, it can be used without any problem.

  As shown in Table 1, when the radiation image conversion plate is cut by scanning a plurality of times using UV pulsed laser light, a good radiation image conversion panel is observed without any crystal cracks or burnt marks at the cut portion. Can be produced.

DESCRIPTION OF SYMBOLS 1 Cutting apparatus 2 Purge chamber 3 Support stand 4 Laser generator 5 Processing head 6 Light transmission window 7 Dust collection means 8 Drain pipe 9 Laser oscillation part 10 Beam expander 11 Repeat frequency setting means 12 Folding mirror 13 Galvano mirror 14 Condensing lens 15 Control device 16 Support table moving means 17 Scanning means 18 Input unit 20 Base plate 20a-20f Radiation image conversion panel 21 Support 22 Stimulable phosphor layer 22a Columnar crystal 23 Metal thin film 24 Cover layer 25 Support holder S Scanning line
X1, X2 Start point O1, O2 Processing region T Melting region

Claims (7)

  A radiation image conversion plate having a multilayer structure having a support formed of a polymer material and a phosphor layer formed on the support by a vapor deposition method. A method for cutting a radiation image conversion plate, comprising cutting into a panel.   The method of cutting a radiation image conversion plate according to claim 1, wherein the cutting is performed by laser light.   The method for cutting a radiation image conversion plate according to claim 2, wherein the radiation image conversion plate is cut by the laser beam scanning the same scanning line a plurality of times.   The radiographic image according to any one of claims 1 to 3, wherein the phosphor layer is either an instantaneous light-emitting phosphor or a photostimulable phosphor containing Cs in the composition. Cutting method of conversion plate.   The method for cutting a radiation image conversion plate according to claim 4, wherein the phosphor layer is a mixed crystal in which at least two kinds of CsI, CsBr, and CsCl are formed at an arbitrary mixing ratio. .   5. The method for cutting a radiation image conversion plate according to claim 4, wherein the instantaneous light emitting phosphor is CsI made of at least one kind of activator.   The method for cutting a radiation image conversion plate according to claim 4, wherein the photostimulable phosphor is CsBr containing Eu as an activator.

Images