JP2000013559A - Image read method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the damage of a sheet due to the slidable contact of a line sensor and the sheet at the time of reading radiation images recorded on a stimulable phosphor sheet by the line sensor. SOLUTION: A glass container 11 is filled with a liquid 13, such as silicon oil and tightly closed by the stimulable phosphor sheet 14, and the line sensor 31 is movably provided inside the glass container 11. Then, the line sensor 31 is brought into contact with the sheet 14, the line sensor 31 is moved in the direction of an arrow A and the radiation image recorded on the sheet 14 is read. At this time, since the liquid 13 is interposed between the line sensor 31 and the sheet 14, the liquid 13 acts as a lubricant, the slide resistance of the sheet 14 and the line sensor 31 is reduced and as a result, the damage to the sheet 14 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading method and apparatus for irradiating excitation light onto a stimulable phosphor sheet on which a radiation image is stored and obtaining an image signal representing the radiation image from the sheet, and to a stimulable phosphor. The present invention relates to a radiation image recording and reading apparatus that accumulates and records a radiation image on a body sheet and then irradiates the body sheet with excitation light to obtain an image signal representing the radiation image from the sheet.

[0002]

2. Description of the Related Art Conventionally, radiation (X-ray, α-ray, β-ray,
(γ-rays, electron beams, ultraviolet rays, etc.), a part of this radiation energy is accumulated, and then, when irradiated with excitation light such as visible light, it emits photostimulated luminescence of the amount corresponding to the accumulated energy. Using a phosphor (stimulable phosphor), a radiation image of a subject such as a human body is once photographed and recorded on a sheet-shaped stimulable phosphor, and the stimulable phosphor sheet is scanned with excitation light such as laser light. The photostimulated emission light is generated by a reading means such as a photomultiplier to obtain an image signal, and based on the image signal, a radiation image of the subject is converted into a photographic material. Recording material, CRT
Radiation recording / reproducing systems that output a visible image to the like have been proposed (JP-A-55-12429, JP-A-56-11395, and JP-A-56-11395).
55-0163472, 56-164645, 55-116340, etc.).

In this system, as a means for photoelectrically reading stimulated emission light emitted from a stimulable phosphor sheet, an image reading apparatus using a line sensor in which a plurality of solid-state photoelectric conversion elements are linearly arranged. (For example, JP-A-60-111568 and JP-A-60-236354). The image reading devices described in these publications use an array light source such as an LED or a semiconductor laser that is linearly connected and emits light simultaneously, or a non-directional light source such as a fluorescent lamp or a Xe lamp and a row of slits or small holes. By irradiating the stimulable phosphor sheet with linear excitation light by combining with an aperture etc.
The stimulated emission light emitted from the location where the excitation light is checked is photoelectrically read by a line sensor.

On the other hand, a circulating transport means for transporting the stimulable phosphor sheet along the circulating passage by the applicant, a photographing section for photographing a radiation image of a subject on the stimulable phosphor sheet on the circulating passage, A so-called built-in type radiation comprising a reading unit on the passage for reading the radiographic image taken, and an erasing unit on the circulation passage for releasing radiation energy remaining on the stimulable phosphor sheet after reading the radiation image. Image recording / reading apparatuses have been proposed (JP-A-59-192240, JP-A-3-238441, etc.) to realize efficient operation of the stimulable phosphor sheet.

Further, among such built-in type radiation image recording / reading apparatuses, there is also known an apparatus in which a stimulable phosphor sheet is circulated and transported by a liquid (Japanese Patent Application Laid-Open No. 64-90668). As described above, by using a liquid for transporting the stimulable phosphor sheet, the sheet can be prevented from being damaged due to friction between the sheet and the roller, as compared with a case where the sheet is transported using a roller or a belt. The service life can be extended.

[0006]

As described above, when a radiation image is read using a line sensor, the line sensor is required to be a stimulable phosphor in order to improve the light collection efficiency of the stimulated emission light. It must be close to, and preferably contact, the sheet. However, when the line sensor is brought into contact with the sheet, the surface of the sheet may be damaged due to the sliding contact between the line sensor and the sheet. Also, even if the line sensor and the sheet are brought close to each other,
The line sensor and the sheet come into contact with each other due to the distortion of the sheet or the vibration caused by the conveyance of the sheet, and as a result, the sheet is damaged.

The present invention has been made in view of the above circumstances, and provides an image reading method and apparatus and a radiation image recording / reading apparatus capable of reading a radiation image by a line sensor without damaging the stimulable phosphor sheet. It is intended to do so.

[0008]

According to an image reading method of the present invention, a stimulable phosphor sheet on which a radiation image is accumulated and recorded is linearly main-scanned by excitation light, and the stimulable phosphor sheet is scanned by the main beam. The radiation image is converted into photostimulated light by sub-scanning in a direction substantially perpendicular to the scanning direction, and photostimulated light obtained from the stimulable phosphor sheet is arranged at least in the length of the linear scanning portion. In an image reading method for reading by a line sensor including a large number of solid-state photoelectric conversion elements that receive the stimulated emission light and perform photoelectric conversion, a liquid is interposed between the line sensor and the stimulable phosphor sheet. And performing the sub-scanning.

An image reading apparatus according to the present invention comprises: an excitation light source that emits excitation light; a main scanning unit that linearly scans a stimulable phosphor sheet on which a radiation image is accumulated and recorded by the excitation light; Sub-scanning means for sub-scanning the phosphor sheet in a direction substantially perpendicular to the main scanning direction, and arranged at least in the length of the linear scanning portion, and emitted from the stimulable phosphor sheet by irradiation with the excitation light. A line sensor comprising a plurality of solid-state photoelectric conversion elements arranged at least along the length of the linear scanning portion, wherein the line sensor comprises: A means for interposing a liquid between the sensor and the stimulable phosphor sheet is provided.

[0010] The radiation image recording and reading apparatus according to the present invention comprises:
By irradiating radiation to a stimulable phosphor sheet capable of accumulating a radiation image through a subject, an image recording unit that accumulates and records a radiation image of the subject on the sheet, wherein the radiation image is accumulated and recorded in the image recording unit An excitation light source that emits excitation light that linearly scans the sheet linearly, and is arranged at least as long as the scanning portion of the sheet, and emits stimulated emission light emitted from the stimulable phosphor sheet by irradiation with the excitation light. Receiving light and performing photoelectric conversion, a line sensor composed of a large number of solid-state photoelectric conversion elements arranged at least in the length of the linear scanning portion, and applying a liquid between the line sensor and the stimulable phosphor sheet. An image reading unit having an intervening means, and a residual radiation on the sheet before an image is recorded on the sheet after the image is read in the image reading unit. Erasing section to release energy, and the stimulable phosphor sheet, said image recording section, is characterized in that a conveying means for relatively moving said image reading unit and the erasing unit.

Preferably, a high hardness film is provided on the surface of the stimulable phosphor sheet on the line sensor side.

[0012]

According to the present invention, the liquid is interposed between the line sensor and the stimulable phosphor sheet to perform the sub-scanning, so that the liquid acts as a lubricant and the line sensor and the stimulable phosphor sheet. The sliding resistance between the sheet and the body sheet can be reduced, thereby preventing the sheet from being damaged due to sliding contact between the sheet and the line sensor.

Further, by providing a high hardness film on the surface of the stimulable phosphor sheet on the line sensor side, it is possible to further reduce the occurrence of damage to the sheet due to sliding contact between the line sensor and the sheet. Can be improved in durability.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram showing a configuration of a radiation image recording and reading apparatus according to a first embodiment of the present invention. The first embodiment is a so-called built-in type radiographic image recording and reading apparatus, which includes a sheet assembly 1, an image recording unit 2, an image reading unit 3, and an erasing unit 4.

The sheet assembly 1 includes a box-shaped glass container 11 and a line sensor 31 which constitutes a part of the image reading section 3 as shown in FIG.
It is arranged so that it can reciprocate in the direction of arrow A,
The liquid container 13 is filled in the glass container 11, and the glass container 11 is sealed by the stimulable phosphor sheet 14. The line sensor 31 has a large number of solid-state photoelectric conversion elements arranged in a line extending in a direction perpendicular to the plane of FIG. 1, and the light receiving surface thereof faces the stimulable phosphor sheet 14. I have. Further, as the liquid 13, a liquid having a high insulating property such as silicon oil, liquid paraffin, higher alcohol, chlorofluorocarbon and trichloroethane is used. Furthermore, the line sensor 3 of the stimulable phosphor sheet 14
On one side, a high hardness film such as diamond-like carbon, amorphous carbon, SiC, or SiN is provided.

FIG. 2 shows a drive mechanism of the line sensor 31. As shown in FIG. 2, screw holes 15A and 15B are formed at both ends of the line sensor 31.
5A and 15B, screws 16A extending in the vertical direction of FIG.
16B is screwed. The screws 16A and 16B are rotatable in synchronization with motors 17A and 17B, respectively, and drive the motors 17A and 17B to rotate the screws 16A and 16B.
When 16B is rotated, the line sensor 31 reciprocates in the vertical direction in FIG. 2 (the direction of arrow A in FIG. 1) according to the rotation direction.

In the image recording section 2, radiation is emitted from a radiation source (not shown), passes through the subject, and
Irradiates the stimulable phosphor sheet 14 via the hologram, and a radiation image of the subject is recorded on the stimulable phosphor sheet 14. At this time, the line sensor 31 in the sheet assembly 1 has been moved to the uppermost position or the lowermost position in FIG. 1 so as not to hinder the recording of the radiation image on the sheet 14.

The image reading section 3 includes an excitation light source 32 having a light guide 33. The excitation light source 32 emits excitation light in a fan shape in a direction perpendicular to the plane of FIG. Is irradiated. Here, the excitation light source 32 can reciprocate in the direction of arrow A in FIG. 1 by the same mechanism as the line sensor 31 and in synchronization with the line sensor 31. Then, the excitation light emitted from the excitation light source 32 is scanned on the stimulable phosphor sheet 14, and the stimulated emission light emitted from the sheet 14 by this scanning is photoelectrically detected by the line sensor 31 and recorded on the sheet 14. An image signal representing the radiation image obtained is obtained. At the time of this reading, the line sensor 31 is provided close to or in contact with the sheet 14. However, since the liquid is sealed in the glass container 11, the liquid 13 is placed between the line sensor 31 and the sheet 14. Will be interposed.

An image signal representing a radiation image obtained by the line sensor 31 is input to an image processing unit (not shown), and after being subjected to predetermined image processing, is subjected to reproduction.

The erasing section 4 is provided with a large number of erasing light sources 41 such as fluorescent lamps, and a reflector 42 for reflecting the erasing light emitted from the erasing light source 41 toward the sheet 14.
Then, the sheet 14 that has been read is the light source 41 for erasing.
, The residual radiation energy on the sheet 14 is released. After the erasing, the sheet 14 is again subjected to photographing in the image recording unit 2, and the radiation image is read and erased by the image reading unit 3 and the erasing unit 4 in the same manner as described above.

As described above, in the present embodiment, the liquid 13 is sealed in the glass container 11 and the line sensor 31 is provided. Since the exhaust light is received, the liquid 13 always intervenes between the line sensor 31 and the sheet 14 during reading of the radiation image. As a result, the liquid 13 acts as a lubricant, and the sliding resistance between the line sensor 31 and the sheet 14 can be reduced. As a result, it is possible to prevent the sheet 14 from being damaged.

Further, by providing a high-hardness film on the surface of the stimulable phosphor sheet 14 on the line sensor 31 side, the occurrence of scratches on the sheet 14 due to the sliding contact between the line sensor 31 and the sheet 14 is further reduced. And the durability of the sheet 14 can be improved.

The refractive index of the liquid 13 is larger than that of air (refractive index: about 1), and is close to the refractive index of the surface of the sheet 14 or the solid-state photoelectric conversion element of the line sensor 31 (refractive index: about 1.4). ~ 1.7), and optical coupling is formed. That is, the total reflection of the photostimulated light on the surface of the sheet 14 or the surface of the solid-state photoelectric conversion element is reduced, and the light collection efficiency of the photostimulated light can be improved.

Next, a second embodiment of the present invention will be described.

FIG. 3 is a diagram showing a configuration of a radiation image recording and reading apparatus according to a second embodiment of the present invention. In the first embodiment, the line sensor 31 is disposed on one side of the stimulable phosphor sheet 14 so as to read a radiation image from one side of the sheet 14. However, in the second embodiment, As shown in FIG. 3, line sensors 35 and 36 are provided on both sides of the sheet 14 to read a radiation image from both sides of the sheet 14. Here, as shown in FIG. 4, the line sensors 35 and 36 include element rows 35B, 35C, 36B and 36 each including a large number of solid-state photoelectric conversion elements.
C, and one of the line sensors 35 and 36 is provided with an LED array that emits excitation light. In the present embodiment, it is assumed that the line array 36 is provided with the LED array 36A. The line sensors 35 and 36 are moved by the arrow A in FIG.
It will be reciprocated in the direction. In the second embodiment, it is preferable to provide a high hardness film on both surfaces of the sheet 14. When reading the radiation image, the excitation light emitted from the LED array 36A of the line sensor 36 is irradiated on one side of the sheet 14, and the stimulated emission light emitted from both sides of the sheet 14 by the irradiation of the excitation light is emitted to the element. Row 35
B, 35C, 36B, and 36C are used to obtain an image signal representing a radiation image recorded on the sheet 14 by being photoelectrically detected. In the present embodiment, the excitation is performed from the surface of the sheet 14 far from the radiation source. Alternatively, the excitation may be performed from the surface near the radiation source. In this case, contrary to FIG. 3, the line sensor 35 having no LED array is disposed on the side farther from the radiation source with respect to the sheet 14, and the line sensor 36 having the LED array 36A is disposed on the side closer to the radiation source. The Rukoto.

As described above, even when a radiation image is read from both sides of the sheet 14, the liquid 13 is interposed between the sheet 14 and the line sensors 35 and 36. The sliding resistance with the sheet 36 can be reduced to prevent the sheet 14 from being damaged.

Next, a third embodiment of the present invention will be described.

FIG. 5 is a diagram showing the configuration of only the image reading section in another embodiment of the radiation image recording and reading apparatus of the present invention. In the first embodiment, the glass container 11
The liquid 13 is interposed between the line sensor 31 and the sheet 14 by sealing the liquid 13 therein.
In the embodiment, the liquid reservoir 3 is
7, and the liquid 13 is stored in the liquid storage 37,
When reading a radiation image, the liquid 13
Is moved while the line sensor 31 is flowing. A liquid pool 38 for storing the liquid 13 is provided at a lower end of the sheet 14, and the liquid 13 stored in the liquid pool 38 is returned to the liquid pool 37 by a pump or the like.

As described above, by providing the liquid reservoir 37 in the line sensor 31 and reading the radiation image while allowing the liquid 13 to flow out of the liquid reservoir 37, the liquid 13 is also placed between the line sensor 31 and the sheet 14. Always intervene, thereby the line sensor 31 and the sheet 1
4 can be reduced to prevent the sheet 14 from being damaged.

Note that the image reading unit 3 in the above embodiment is
May be used alone as an image reading device.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of a radiation image recording and reading apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a detailed configuration of an image reading unit.

FIG. 3 is a schematic diagram showing a configuration of a radiation image recording and reading apparatus according to a second embodiment of the present invention.

FIG. 4 is a diagram illustrating a configuration of a line sensor according to a second embodiment.

FIG. 5 is a schematic diagram showing a configuration of an image reading unit in a radiation image recording and reading apparatus according to a third embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 sheet assembly 2 image recording unit 3 image reading unit 4 erasing unit 11 glass container 13 liquid 14 stimulable phosphor sheet 21 top plate 31, 35, 36 line sensor 41 erasing light source 42 reflector

Claims (5)

[Claims] 1. A stimulable phosphor sheet on which a radiation image is stored and recorded is linearly main-scanned by excitation light, and the stimulable phosphor sheet is sub-scanned in a direction substantially perpendicular to the main scanning direction. The radiation image is converted into photostimulated light, and photostimulated light obtained from the stimulable phosphor sheet is arranged at least in the length of the linear scanning portion. An image reading method for reading by a line sensor including a plurality of solid-state photoelectric conversion elements for performing conversion, wherein the sub-scanning is performed by interposing a liquid between the line sensor and the stimulable phosphor sheet. Reading method. 2. An excitation light source for emitting excitation light; main scanning means for linearly scanning a stimulable phosphor sheet on which a radiation image is accumulated and recorded by the excitation light in a linear manner; Sub-scanning means for sub-scanning in a direction substantially perpendicular to the main scanning direction; stimulable luminescence light emitted from the stimulable phosphor sheet by irradiation with the excitation light, being arranged at least in the length of the linear scanning portion. An image reading apparatus comprising: a plurality of solid-state photoelectric conversion elements arranged at least as long as the length of the linear scanning portion; An image reading apparatus, comprising: means for interposing a liquid between the body sheet and the body sheet. 3. The image reading device according to claim 2, wherein a hard film is provided on a surface of the stimulable phosphor sheet on the side of the line sensor. 4. An image recording unit for irradiating a stimulable phosphor sheet capable of accumulating a radiographic image with radiation through a subject to accumulate and record a radiographic image of the subject on the sheet. An excitation light source that emits excitation light that linearly scans the accumulated and recorded sheet linearly, and is arranged at least as long as the scanning portion of the sheet, and is emitted from the stimulable phosphor sheet by irradiation with the excitation light. Performs photoelectric conversion by receiving stimulated emission light, a line sensor consisting of a large number of solid-state photoelectric conversion elements arranged at least in the length of the linear scanning portion, and the line sensor and the stimulable phosphor sheet An image reading unit having means for interposing a liquid between the image reading unit and the image reading unit. An erasing section for emitting the above-mentioned residual radiation energy, and transport means for moving the stimulable phosphor sheet relative to the image recording section, the image reading section and the erasing section. Radiation image recording and reading device. 5. The radiation image recording and reading apparatus according to claim 4, wherein a high hardness film is provided on a surface of the stimulable phosphor sheet on the side of the line sensor.