JP3228521B2 - Radiation image conversion panel and radiation image recording and reading method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation image conversion panel, a process for recording a radiation image on a recording layer, and a method for recording and reading a radiation image on the recording layer.

[0002]

2. Description of the Related Art Conventionally, the following techniques have been proposed for a radiation image recording and reading method. (1) When a substance (gas, liquid, semiconductor) is irradiated with X-rays, it is ionized to form charges, and the behavior of the charges is determined by the characteristics of the charges and the characteristics of the medium, and can be predicted by the diffusion coefficient D. Based on the principle, a technique of recording an X-ray image using an X-ray fan beam and reading the recorded image information based on the presence or absence of charges (Kinestatic charge detection, Me
d. Phys. 12 (3), 339 (1985)). (2) The surface of the recording layer in which many bubbles or pores are dispersed is uniformly charged to cause a strong charge to act on the gas in the bubbles or pores, and the recording layer is irradiated with radiation carrying image information. In accordance with the radiation intensity, the electrostatic charge on the surface of the recording layer is erased imagewise to form an electrostatic latent image, and the electrostatic latent image is developed with toner and read (Japanese Patent Laid-Open No. 62-133).
No. 38). (3) a recording layer made of selenium on a transparent conductive support,
After applying a uniform charge to the surface of the radiation image conversion panel formed by laminating an insulating layer and a conductive layer in this order, the recording layer is irradiated with X-rays to erase the charge in an image form. Technology for forming an electrostatic latent image and optically scanning and reading the electrostatic latent image (Journal of Applied Photographic Engineering Vo
l.4, No. 4, 178 (1978)). (4) After applying a uniform charge to the recording layer made of selenium, the recording layer is irradiated with X-rays to eliminate the charge in an image-like manner to form an electrostatic latent image. Technology for reading images with an electrometer (Journal of Applied Photograp
hic Engineering Vol. 5, No. 4, 183 (1979)).

[0003]

However, in the technique (1), recording is performed using an X-ray fan beam.
There are disadvantages that the load on the radiation source is large and that exposure must be performed for a long time. Further, there is a problem that a latent image is easily blurred because ions generated by X-ray irradiation are diffused. In the technique (2), since the electrostatic latent image is developed with toner and the image is read, there is a problem that the gradation property and the resolving power are inferior and high-precision reading cannot be performed. In the technique (3), since selenium is used as the recording layer, there is a problem that a flexible recording layer cannot be obtained and that the SN ratio decreases in a high-pressure (high energy) region. Also,
Since the recording material serves both as a radiation conductor and a reading photoconductor, the radiation image forming characteristics and the optical reading characteristics cannot be independently adjusted. For example, if selenium is given sensitivity to a semiconductor laser (780 nm), it becomes unstable. On the other hand, an organic optical semiconductor (OPC) has a problem that the semiconductor laser has sensitivity but the X-ray sensitivity is low. The above (4)
According to the technique described above, since selenium is used as the recording layer, there is a problem that a flexible recording layer cannot be obtained and handling is inconvenient. In addition, there is a problem that the SN ratio decreases in a high pressure (high energy) region.

A first object of the present invention is to record a radiographic image with high sensitivity, to adjust the radiographic image forming characteristic and the optical reading characteristic separately and independently, and to control the latent image by ion diffusion. An object of the present invention is to provide a radiation image conversion panel (hereinafter, abbreviated as “panel” as appropriate) in which image blur does not occur. A second object of the present invention is to provide a radiation image recording and reading method capable of reading and digitizing a radiation image with high accuracy.

[0005]

According to the radiation image conversion panel of the present invention, a recording layer containing a large number of bubbles or pores separated by a photoconductor is formed on a first conductive layer. An insulating layer is formed on the insulating layer, a second conductive layer is formed on the insulating layer, and the first conductive layer and the second conductive layer are formed.
At least one of the electric layers is formed by bubbles or pores of the recording layer.
Penetrates radiation and reading light to ionize gas inside
And characterized in that. In the first radiation image recording / reading method of the present invention, the surface of the radiation image conversion panel is charged by applying a voltage, and the recording layer is irradiated with radiation in a pattern according to image information. By ionizing the gas in the bubbles or pores of the recording layer, the charge on the surface of the recording layer is erased imagewise according to the radiation intensity to form an electrostatic latent image. The electrostatic latent image is read by irradiating the reading light and detecting a change in charge. The second radiation image recording / reading method of the present invention uniformly charges the surface of a recording layer containing a large number of air bubbles or pores formed on a conductive layer and separated by a photoconductor. By irradiating radiation in a pattern according to image information to ionize the gas in the bubbles or pores of the recording layer, the charged charges on the surface of the recording layer are erased imagewise according to the radiation intensity. Forming an electrostatic latent image on the recording layer, irradiating the recording layer with reading light, and detecting a change in the electric charge of a conductor disposed on the recording layer to read the electrostatic latent image. .

[0006]

When the surface of a recording layer containing a large number of bubbles or pores separated by a photoconductor is charged and then irradiated with patterned radiation, the radiation acts to convert the gas in the bubbles or pores into one unit. As a result, the charge corresponding to the bubbles or pores disappears and the radiation image is recorded with high sensitivity. Since these ions are confined in bubbles or pores, the latent image is not blurred due to diffusion.
A method of reading by irradiating the recording layer through at least one transparent conductive layer without using toner and detecting a change in charge by irradiating the recording layer, or irradiating the recording layer with reading light without using toner to perform the recording. According to the method of reading by detecting the change in the electric charge of the conductor arranged on the layer, the gradation and the resolving power are high, and the reading can be performed with high accuracy.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. 1 to 3, 1 is a radiation image conversion panel, 2 is a first conductive layer, 3 is a recording layer containing a number of bubbles or pores and containing a photoconductor, 4 is an insulating layer, and 5 is a second layer. 1 is a charging process, FIG. 2 shows a radiation irradiation process, and FIG. 3 shows a reading process.

In the charging process, as shown in FIG. 1, when a voltage is applied between a first conductive layer 2 and a second conductive layer 5 by a power supply 7, a photoconductor having many bubbles or pores is provided. Are charged on the surfaces of the recording layer 3 and the insulating layer 4 containing.
In the radiation irradiation process, as shown in FIG. 2, the recording layer 3 having a charged surface is irradiated with radiation in a pattern according to image information, and the surface of the recording layer 3 is irradiated with the radiation intensity. To form an electrostatic latent image. At this time, the charge on the surface of the insulating layer 4 changes as the charge on the surface of the recording layer 3 disappears. In the reading process, as shown in FIG. 3, the scanning light is irradiated to the recording layer 3 while scanning the light to erase the charge remaining on the surface of the recording layer 3.
The amount of charge on the surface of the insulating layer 4 changes according to the disappearance of the charge. The detection system 8 detects a current supplied from the power supply 7 in accordance with a change in the charge amount of the insulating layer 4 and detects a change in the charge of the recording layer 3 to electrically read the electrostatic latent image.

Although not necessary for the panel of the present invention, a support 6 may be provided as shown in FIG. 4 or FIG. Support 6
May be provided on the first conductive layer 2 side or on the second conductive layer 5 side. Further, the conductive layer may also serve as a support.

Next, a second embodiment of the present invention will be described with reference to FIGS. 6 to 8, 1 is a radiation image conversion panel, 3 is a recording layer, 6 is a support, 9 is a conductive layer,
0 is a corona charger, 11 is a conductor, 12 is an antireflection film,
Reference numeral 13 denotes a cylindrical lens, FIG. 6 shows a charging process, FIG. 7 shows a radiation irradiation process, and FIG. 8 shows a reading process.

In the charging process, as shown in FIG. 6, the surface of the recording layer 3 containing a large number of bubbles or pores separated by a photoconductor is uniformly charged by a corona charger 10. In the radiation irradiation process, as shown in FIG. 7, the surface of the recording layer 3 having a uniformly charged surface is irradiated with radiation in a pattern according to image information.
In accordance with the radiation intensity, the charge on the surface of the recording layer 3 is erased in an image according to the image information to form an electrostatic latent image. In the reading process, for example, as shown in FIG. 8, a conductor 11 that is substantially transparent to reading light is arranged on the recording layer 3, and the recording layer 3 is interposed via the conductor 11. It is preferable that the electrostatic latent image is electrically read by irradiating the electrostatic latent image with the reading light to detect a change in the charge of the conductor 11. In the configuration shown in FIG. 8, since the optical system for reading light and the electric conductor for charge detection can be formed integrally, there is an advantage that the size of the reading system can be reduced. However, the present invention is not limited to the configuration of FIG.
As shown in FIG. 9, a configuration may be employed in which the reading light is directly applied obliquely to the recording layer 3 from between the recording layer 3 and the conductor 11 without passing through the conductor 11. The object of the present invention can be sufficiently achieved by the configuration shown in FIG.

Next, each component of the present invention will be described. In the recording layer 3, the size of bubbles or pores is
From the viewpoint of confining ions generated by radiation irradiation in a narrow range and preventing blurring of a latent image, the thickness is preferably 0.01 to 100 μm. From the viewpoint of forming a latent image with high sensitivity, it is preferable that the density of bubbles or pores is as high as possible as long as the holding strength of the recording layer 3 is not impaired. The thickness of the recording layer 3 is not particularly limited, but is usually about 0.5 μm to 1 mm. Further, in the second embodiment, the recording layer 3 is formed as shown in FIG.
It is provided in close contact with the conductive layer 9 of the support 6 as described above, or is provided by being laminated on the conductive layer 9.

As a constituent material of the recording layer 3, a photoconductor is used to separate a large number of bubbles or pores. As this photoconductor, an organic optical semiconductor having heat resistance up to 100 ° C. is preferably used. Specifically, carbazole derivatives such as polyvinylcarbazole, pyrene derivatives such as pyrene, tetraphenylpyrene, 1-methylpyrene, and azopyrene; higher condensed aromatic compounds such as anthracene and tetracene; chrysene, bicene, and 2,3-benzochrysene; Chrysenes, indole derivatives such as phenylindole, pyrazoline hydrochloride, pyrazoline derivatives such as pyrazoline picrate, fluorenone derivatives such as 2,4,7-trinitro-9-fluorenone, polyimidazopyrrolone derivatives, triphenylamine derivatives,
Oxadiazole derivative, triazole derivative, imidazole derivative, oxazole derivative, thiophene derivative, triazine derivative, hydrazone derivative, styryl compound, azomethine compound, acylhydrazine derivative, pyrazoline derivative, imidazolone derivative, imidazolethione derivative, benzimidazole derivative, benz Oxazole derivatives, benzothiazole derivatives, polyarylalkanes such as triarylmethane leuco dyes or squaric acid derivative dyes, and 2,4,8-trinitrothioxanthone.

Examples of the photoconductor include various photoconductive organic pigments such as phthalocyanine pigments, azo pigments, quinacridone pigments, bisbenzimidazole pigments, and the like.
Indigo pigments, quinone pigments, perylene pigments, quinoline pigments, cyanine pigments and the like are preferably used. As phthalocyanine pigments, Japanese Patent Publication Nos. 40-2780 and 45-8102,
No. 45-11021, No. 46-42511, No. 46-42512, No.
Nos. 48-163, 49-17535, 50-5059, JP-A-50
And photoconductive phthalocyanine pigments described in JP-B-38543. As the azo pigment,
Examples thereof include photoconductive azo pigments described in JP-A-51-90827 and JP-A-52-55643. Examples of the quinacridone pigment include a photoconductive quinacridone pigment described in JP-A-49-30332. Examples of the bisbenzimidazole pigment include a photoconductive bisbenzimidazole pigment described in JP-A-47-18543. Examples of the indigo pigment include a transindigo pigment and a cis indigo pigment described in JP-A-47-30331. As the quinone pigment, JP-A-47
And polycyclic quinone pigments described in JP-A-18544. Examples of the perylene pigment include perylene pigments described in JP-A-47-30330 and U.S. Pat. No. 3,871,882. Examples of the quinoline pigment include quinoline pigments described in JP-A-49-1231. Examples of the cyanine pigment include cyanine pigments described in JP-A-47-37544.

A plurality of the above photoconductive substances may be used in combination as appropriate. Further, the recording layer may be formed by dissolving or dispersing the photoconductive substance in an appropriate binder resin. Such binder resins include styrene-butadiene polymer, silicone resin, styrene-alkyd resin, polyvinyl chloride, polyacrylester, polymethylacrylester, polystyrene, isobutylene polymer, polyester, phenol-formaldehyde resin, polyvinylidene chloride,
Vinylidene chloride-acrylonitrile copolymer,
Polyvinyl acetal, vinyl acetate-vinyl chloride copolymer, polyvinyl formal acetate,
Ketone resins, polyamides, polycarbonates and the like can be mentioned. Still, the recording layer 3 may contain heavy metal fine powder such as Pb or Sn in order to increase absorption of radiation.

As means for forming the recording layer 3 containing many bubbles, (1) means for forming bubbles of gas molecules generated by photolysis of the recording layer material, and (2) thermal reaction by thermal decomposition of the recording layer material. (3) means for dissolving and bubbling the soluble substance contained in the recording layer material with water and a solvent, and sealing off the heated gas after elution; (4) microcapsules as the recording layer Means using an integrated layer, and the like.

Means for forming the recording layer 3 having a large number of pores include (1) an electric discharge machining method, a mechanical chemical method,
Means for providing a large number of pores in the recording layer material by an elution method or the like,
(2) means for binding the fine powder with a resin binder and applying or spraying; (3) means for hardening glass fibers or the like by an appropriate means to form a layer and laminating it with a film;
And the like.

As the first conductive layer 2 and the second conductive layer 5 in the first embodiment shown in FIGS. 1 to 3, aluminum, palladium, copper, iron, nickel, stainless steel,
Examples thereof include a deposited film or a laminated film of a metal made of gold, silver, tin, zinc, or the like, and a material in which a conductive material such as a metal or carbon black is dispersed and contained in a binder resin. First conductive layer 2 and second conductive layer 5
Is transparent to the wavelength of the reading light so that the reading light reaches the recording layer 3. The transmittance of the transparent conductive layer is preferably 80% or more. In order to obtain a transparent conductive layer, a thin film of aluminum, gold, silver, palladium, indium oxide, tin oxide, ITO, or the like is used. This thin film can be formed by an evaporation method, a sputtering method, a pressure bonding method, a lamination method, or the like. The first conductive layer 2 and / or the second conductive layer 5 may be formed continuously over the entire surface, or may be divided into stripes. If the conductive layer is formed in a stripe shape and reading is performed by scanning the reading light substantially perpendicularly to the stripe-shaped conductive layer,
The pixel position in the reading light scanning direction is the position of the stripe-shaped conductive layer, and the pixel position in the direction perpendicular to the reading light scanning direction can be independently detected with time.

The insulating layer 4 in the first embodiment shown in FIGS. 1 to 3 preferably has a specific resistance of 10 ¹⁴ Ω · cm or more. For example, a polyethylene terephthalate film (PE
T) and other resins. The thickness of the insulating layer 4 is not particularly limited, but is usually about 0.5 μm to 1 mm. When the reading light is irradiated from the second conductive layer 5 side, the insulating layer 4 also needs to transmit the reading light.

In the charging process shown in FIG. 1, a voltage is applied between the first conductive layer 2 and the second conductive layer 5 by the power supply 7 so that the potential difference between the two conductive layers is about 50 to 1500 V.
In the charging process shown in FIG. 4, in addition to the method using the corona charger 10, a triboelectric charging method, an electrode contact method, or the like used in electrophotography may be used. The charging potential is usually about 50 to 1500 V in absolute value of the surface potential.

In the reading process shown in FIG. 3 or FIG. 8, the reading light may be any light as long as the photoconductor constituting the recording layer 3 has sensitivity. Semiconductor laser light is preferred. The beam system of the reading light is 10 to 50 from the viewpoint of improving the reading accuracy.
0 μm is preferable, and further preferably 20 to 200 μm,
In particular, 50 to 200 μm is preferable.

As the constituent material of the conductor 11 in the second embodiment, when adopting the configuration of FIG. 8, a material that is substantially transparent to reading light and can induce electric charge is used.
In the case of adopting the configuration of FIG. 9, one that can induce a charge regardless of whether it is transparent or opaque is used. Specifically, the transparent material includes ITO and the like, and the opaque material includes metals or alloys such as gold, silver, copper, nickel, and aluminum. The length of the conductor 11 (in the direction perpendicular to the plane of the paper in FIGS. 8 and 9) is preferably about 10 mm larger than the recording layer 3, and the width of the conductor 11 (the horizontal direction in the plane of the paper in FIGS. 8 and 9) is It is preferably about 10 times the beam diameter of the reading light, specifically about 0.3 to 3 mm.

The reading system is preferably of an integrated type. The number of reading systems is not limited to one, and a plurality of reading systems may be provided. Further, the reading section has a configuration in which the reading optical system is fixed and the panel is conveyed (Japanese Patent Laid-Open Nos. 56-11395 and 57-76974).
No., No. 60-5665, No. 58-17767, No. 60-117212), or a configuration in which the reading optical system is moved while fixing the panel (see Japanese Patent Application Laid-Open No. 60-140215). However, the latter is more preferable in that the device can be downsized.

The specific configuration of the detection system 8 shown in FIGS. 1 to 3 is not particularly limited. For example, a current-voltage conversion amplifier is connected between the power supply 7 and the conductive layer 2 or 5, and the output from the amplifier is A / A. A system for converting into a digital signal by a D converter is used. When a stripe-shaped conductive layer is used, a current-voltage conversion amplifier is connected to each of the stripe-shaped electrodes, and an output from each amplifier is connected to an A / D converter via an analog multiplexer.
A system for converting to a digital signal may be used. In this case, the frequency band required for each amplifier may be narrower than when a single amplifier is used, which is preferable in terms of speeding up reading and reducing noise.

X-rays, γ-rays, α-rays, β-rays
A material such as a line that can ionize bubbles in the recording layer or gas in the pores is used.

After reading the electrostatic latent image, in order to erase the electrostatic latent image, the first conductive layer 2 and the second conductive layer 5 are short-circuited in the embodiments shown in FIGS. Then, the entire surface may be irradiated with light using a halogen lamp or the like. 6 to 8
In the embodiment, the next radiation image forming process may be performed by performing recharging in a state where the residual charge is present, or may be erased by applying an electric field having a polarity opposite to that of the residual charge or an attenuated AC electric field. You may. Alternatively, a photoconductor such as a halogen lamp may be irradiated with sensitive light for erasing.

In the reading process, in order to increase the reading accuracy by adjusting the reading gain, a preliminary reading may be performed with low-energy light before actually reading (Japanese Patent Laid-Open No. 58-67240). , Pp. 58-6724).

In the reading process, in order to enhance the diagnostic performance by enhancing the contrast by enhancing the response in the frequency region important for the diagnosis of the radiographic image, for example, the frequency response from the very low frequency region is enhanced. Frequency processing may be performed (see JP-A-55-163472).

Further, tone processing for processing signals may be performed so that a final reproduced image of an appropriate density can be obtained even for radiation images of different subjects and different imaging conditions (Japanese Patent Application Laid-Open No. 55-1979).
No. 116340). Specifically, the maximum level of the signal,
Processing includes detecting the minimum level, and determining the maximum and minimum optical densities of the output image based on the detected level.

In the medical X-ray image, the patient's
In some cases, the irradiation field is squeezed for the purpose of reducing exposure dose, and the signal level outside the irradiation field is significantly lower than that inside the irradiation field. There is. Therefore, for proper processing, it is important to recognize the irradiation field in advance and perform image processing within the irradiation field (see Japanese Patent Application Laid-Open No. 60-120349). Furthermore, in order to enable appropriate image processing without failure, the part, body position (front, side, etc.) of the subject,
It is important to perform processing after recognizing the position in the image in advance.

A plurality of radiation images of the same subject from the same direction are recorded simultaneously or sequentially on another radiation image conversion panel, and the densities of these radiation images are averaged from the plurality of radiation images. A superposition process for obtaining an image may be performed (see Japanese Patent Application Laid-Open No. Sho 56-11034).

Further, an energy subtraction process for reproducing a radiation image from which only a specific structure is extracted may be performed (see Japanese Patent Application Laid-Open No. Sho 60-225541). This energy subtraction process irradiates the same subject with radiation having different energy distributions, and takes advantage of the fact that a specific structure has a specific radiation energy absorption characteristic to generate two images with different specific structures. This is a process of extracting an image of a specific structure by causing the image to exist between the radiation images and then performing an appropriate subtraction (subtract) between the image signals of the two radiation images as necessary.

In carrying out the method of the present invention, a device in which a charging unit, a photographing unit, and a reading unit are integrated is preferably used. This integrated device is disclosed in, for example,
It can be constructed using the technology of each of the publications 6931 and 58-66934. In a specific example, the charging unit,
There is an apparatus in which a radiographing unit and a reading unit are provided integrally, and these units are circulated by a radiation image conversion panel.

Hereinafter, more specific examples will be described, but the present invention is not limited to these examples. In the following, “parts” means “parts by weight”. Example 1 Chromophtal Blue 4GN (β-type copper phthalocyanine) 1
Parts, 1.5 parts of m-cresol formaldehyde resin,
Liquid A was prepared by dispersing 1 part of polymethyl methacrylate resin, 0.5 part of vinylidene chloride-acrylonitrile copolymer, and 15 parts of methyl ethyl ketone for 10 minutes using glass beads. Liquid B was prepared by mixing 1 part of zinc chloride double salt of p-diazo-N, N-dimethylaniline chloride, 1 part of methyl alcohol, and 6 parts of methyl ethyl ketone. The solution B was added to the solution A with stirring to prepare a coating solution, and a 100 μm-thick polyethylene terephthalate film (PET) was provided with a vapor deposition film of aluminum on one surface. After the coating solution is applied, the coating solution is uniformly exposed to ultraviolet light, and is heated for a short time to form uniform bubbles in the layer. The thickness of the support, the first conductive layer, and the layer is 250 μm. Was obtained. On the surface of the recording layer opposite to the first conductive layer, PET having an ITO deposited film is laminated so that the deposited film becomes an exposed surface to provide an insulating layer and a second conductive layer. A radiation image conversion panel was produced. The ITO vapor deposition film was formed in advance in the form of stripes at intervals of 150 μm by etching. This radiation image conversion panel is fixed to a reading unit of a reading optical system movable type, and the first conductive layer and the second
And a surface potential of the second conductive layer was set to -900 V. In this state, the tube voltage is 120k
The recording layer was uniformly irradiated with X-rays under the conditions of V, a tube current of 200 mA, an irradiation time of 0.1 second, and a distance from the radiation source of 150 cm. Next, irradiation is performed while scanning at a scanning speed of 25 m / s using semiconductor laser light having a wavelength of 780 nm as reading light. At this time, a current flowing between the first conductive layer and the second conductive layer is detected. This was converted to a digital voltage signal, and an electrostatic latent image was read. Note that the light amount of the semiconductor laser was sufficient to eliminate the charged charges on the recording layer 3. As a result, a signal having a good SN ratio was obtained. Next, the residual charge in the recording layer was erased, and X-rays were recorded using a slit formed by bonding the end faces of two lead plates having a thickness of 2 mm to each other via a PET having a thickness of 10 μm as a subject. After irradiating the layer, reading was performed in the same manner as above, and an image signal was obtained. From this image signal, the modulation transfer function (MTF)
Was found to be a high-resolution image.

Example 2 Chromophtal Blue 4GN (β-type copper phthalocyanine) 1
Parts, 2 parts of m-cresol formaldehyde resin, 1 part of polymethyl methacrylate resin, and 15 parts of methyl ethyl ketone were dispersed with glass beads for 10 minutes to prepare a dispersion. This dispersion is poured into a 100 μm thick P
ET is coated on the vapor-deposited film of a film made by Toray, which is provided with a vapor-deposited film of aluminum on one side, and dried so as to cause a brushing phenomenon. A first conductive layer and a recording layer having a thickness of 250 μm were obtained. A radiation image conversion panel was produced in the same manner as in Example 1 except that this support, the first conductive layer and the recording layer were used. When reading was performed using this radiation image conversion panel in the same manner as in Example 1, a signal having a good SN ratio was obtained. When the modulation transfer function (MTF) was determined in the same manner as in Example 1, it was confirmed that the image was a high-resolution image.

Example 3 A liquid A and a B liquid were prepared in the same manner as in Example 1. The solution B was added to the solution A while stirring to prepare a coating solution,
100 μm thick polyethylene terephthalate film
(PET) After coating the coating liquid on the vapor-deposited film of a film made by Toray having an aluminum vapor-deposited film provided on one surface of the film, the film is uniformly exposed to ultraviolet light, heated for a short time, and recorded. Uniform air bubbles were formed in the layer to produce a radiation image conversion panel. The thickness of the recording layer was 500 μm. The conductive layer of the radiation image conversion panel is grounded, and the surface of the recording layer is uniformly charged to -600 V by a corona charger. Thereafter, the tube voltage is 120 kV, the tube current is 200 mA, the irradiation time is 0.1 second, and the radiation source is connected. Under a condition of a distance of 150 cm, X-rays were irradiated in a pattern using a Funk chart. Next, as shown in FIG. 8, the center of the cylindrical lens is 1 mm wide.
A cylindrical lens system having a photoconductor made of ITO and an anti-reflection film for 780 nm light provided on the surface of the ITO has a gap with the recording layer of 200 μm.
m, and a pulsed semiconductor laser light with a wavelength of 780 nm from the center of the cylindrical lens (duty:
50%, emission time 1 μs) while scanning at a scanning speed of 25 m / s.
The electrostatic latent image was read by detecting a change in the induced charge of O using an external preamplifier. The light amount of the semiconductor laser was set to a value sufficient to eliminate the charged charges. As a result, the pattern SN corresponding to the chart
Good ratio signals were obtained.

Example 4 A dispersion was prepared in the same manner as in Example 2. This dispersion is applied to a film of Toray made by depositing an aluminum film on one side of a PET film having a thickness of 100 μm, and then dried so as to cause a brushing phenomenon. Air bubbles were formed to produce a radiation image conversion panel. The thickness of the recording layer was 500 μm. Using this radiation image conversion panel, as in Example 3,
After performing the charging process, radiation irradiation process, and reading process, the pattern SN corresponding to the chart
Good ratio signals were obtained.

[0038]

As described above in detail, according to the present invention, a radiation image can be recorded with high sensitivity, and the radiation image forming characteristic and the optical reading characteristic can be adjusted independently. Thus, a radiation image conversion panel free from blurring of a latent image due to ion diffusion can be provided. Further, it is possible to provide a radiation image recording / reading method capable of reading a radiation image with high precision using the panel and digitizing the radiation image.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a charging process according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a radiation irradiation process according to the first embodiment of the present invention.

FIG. 3 is an explanatory diagram of a reading process according to the first embodiment of the present invention.

FIG. 4 is an explanatory diagram showing another configuration example of the radiation image conversion panel.

FIG. 5 is an explanatory diagram showing still another configuration example of the radiation image conversion panel.

FIG. 6 is an explanatory diagram of a charging process according to a second embodiment of the present invention.

FIG. 7 is an explanatory diagram of a radiation irradiation process according to the second embodiment of the present invention.

FIG. 8 is a diagram illustrating an example of a reading process according to the second embodiment of the present invention.

FIG. 9 is an explanatory diagram of another example of the reading process according to the second aspect of the present invention.

[Explanation of symbols]

 Reference Signs List 1 radiation image conversion panel 2 first conductive layer 3 recording layer 4 insulating layer 5 second conductive layer 6 support 7 power supply 8 detection system 9 conductive layer 10 corona charger 11 conductor 12 antireflection film 13 cylindrical lens

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-58-199351 (JP, A) JP-A-58-1884878 (JP, A) JP-A-58-199351 (JP, A) 25486 (JP, A) JP-A-63-249100 (JP, A) JP-A-1-131500 (JP, A) JP-A-3-123899 (JP, A) JP-A-61-142497 (JP, A) JP-A-47-10526 (JP, A) JP-A-60-211448 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G21K 4/00 G03B 42/02

Claims (3)

(57) [Claims] 1. A recording layer containing a large number of bubbles or pores separated by a photoconductor is formed on a first conductive layer, an insulating layer is formed on the recording layer, and an insulating layer is formed on the recording layer. A second conductive layer is formed, and at least one of the first conductive layer and the second conductive layer is
A discharge for ionizing gas in bubbles or pores of the recording layer.
A radiation image conversion panel that transmits radiation and reading light . 2. The radiation image conversion panel according to claim 1, wherein the surface is charged by applying a voltage to the radiation image conversion panel, and the recording layer has image information.
By irradiating radiation in a pattern according to the above to ionize the gas in the bubbles or pores of the recording layer, the charged charges on the surface of the recording layer are erased in an image-like manner in accordance with the intensity of the radiation, and the electrostatic charge is removed. A radiographic image recording and reading method, comprising: forming a latent image, irradiating the recording layer with reading light, and detecting a change in charge to read the electrostatic latent image. 3. A surface of a recording layer formed on a conductive layer and containing a large number of bubbles or pores separated by a photoconductor is uniformly charged, and a pattern according to image information is formed on the recording layer. By irradiating radiation in the form of ions to ionize the gas in the air bubbles or pores of the recording layer, the charged charges on the surface of the recording layer are erased in an image-like manner in accordance with the intensity of the radiation, thereby forming an electrostatic image. Forming a latent image on the recording layer, irradiating the recording layer with reading light, and detecting a change in electric charge of a conductor disposed on the recording layer to read the electrostatic latent image; Reading method.