JP2004258304A - Image reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reader low in cost, small in size and capable of obtaining an excellent image free from image irregularity. <P>SOLUTION: The image reader for reading image information from a stimulable phosphor sheet by photoelectrically converting stimulated luminescence generated by stimulating light radiated from a light source to a plate member 11 holding the stimulable phosphor sheet is equipped with a linear motor 15 for moving the plate member, a guide member 14 extended in the longitudinal direction of the linear motor so as to guide the movement of the plate member and a supporting member 12 extended in the longitudinal direction so as to support the linear motor and the guide member. The linear motor and the guide member are arranged nearly at right angle to the supporting member. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image reading apparatus excellent in scanning and transporting properties of a stimulable phosphor plate, and particularly to an image reading apparatus suitable for use in the medical field and the printing field.
[0002]
[Prior art]
Radiation images such as X-ray images are widely used for diagnosing diseases and the like. Conventionally, in order to obtain such a radiation image, X-rays passing through a subject are irradiated on a phosphor layer (fluorescent screen), This produces visible light, and so-called radiography, in which the visible light is applied to a silver halide film and developed in the same manner as in normal photography, has been used. However, in recent years, techniques have been devised for directly taking out an image from the phosphor layer without using a film coated with a silver salt.
[0003]
As an example of this method, radiation that has passed through a subject such as a patient is absorbed by a phosphor, and then the phosphor is excited by, for example, light or thermal energy, so that the phosphor is accumulated by the absorption. There is an apparatus that emits energy as fluorescent light, detects this fluorescent light, and forms an image. Specifically, for example, Patent Literature 1 and Patent Literature 2 below show a radiation image conversion method using a stimulable phosphor and using visible light or infrared light as stimulating excitation light. This method uses a stimulable phosphor plate having a stimulable phosphor layer formed on a support, and irradiates the stimulable phosphor layer of the stimulable phosphor plate with radiation transmitted through a subject. A latent image is formed by accumulating radiation energy corresponding to the radiation transmittance of each part of the subject, and thereafter, the accumulated radiation energy of each part is emitted by scanning this stimulable phosphor layer with stimulating excitation light. Then, this is converted into light, and the intensity of the light is converted into an image signal through a photoelectric conversion means such as a photomultiplier to obtain a radiation image as digital image data.
[0004]
Based on the digital image data, an image is formed on a silver halide film, or an image is output to a CRT or the like and visualized. The digital image data is stored in an image storage device such as a semiconductor storage device, a magnetic storage device, and an optical disk storage device. Thereafter, the digital image data is taken out from these image storage devices as necessary and visualized through a silver halide film, a CRT, or the like. Can be
[0005]
When the stimulable phosphor plate is scanned with the stimulable excitation light, the stimulable phosphor plate must be accurately moved relative to the stimulable excitation light source at a constant speed. For this reason, in the related art, a method has been proposed in which a conveyed object is smoothly moved by a linear motor and a guide member as disclosed in Patent Document 3 below.
[0006]
However, in the related art, two guide members are arranged so as to sandwich the linear motor in parallel with the linear motor, and the conveyed object is conveyed. Therefore, a difference in sliding resistance between the two guides is caused. , Depending on the parallel balance at the time of assembly, vibration may occur, and smooth conveyance may not be possible, so the speed unevenness of the conveyed object will be worsened and the stimulable phosphor plate will be excited by stimulating light. In the case of scanning with light, there is a case where an image becomes uneven and a formed diagnostic image is disturbed. In addition, the use of a plurality of guide members increases the size of the apparatus and increases the cost.
[0007]
[Patent Document 1]
US Patent No. 3,859,527
[Patent Document 2]
JP-A-55-12144
[Patent Document 3]
JP-A-11-216921
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-described problems of the related art, and has as its object to provide an image reading apparatus which is a low-cost and miniaturized apparatus and can obtain a good image without image unevenness.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the image reading apparatus according to the present invention performs the photoelectric conversion by stimulating light emitted by excitation light emitted from a light source to a plate-like member holding a stimulable phosphor sheet. In an image reading device that reads image information from a stimulable phosphor sheet, a linear motor that moves the plate member for reading the image information, and a linear motor that guides the movement of the plate member. A guide member extending in the longitudinal direction, a support member extending in the longitudinal direction so as to support the linear motor and the guide member, and the linear motor and the guide member are substantially perpendicular to the support member. It is characterized by being arranged.
[0012]
According to this image reading apparatus, the linear motor and the guide member are arranged at substantially right angles to the support member, so that the arrangement structure of the linear motor and the guide member can be realized with a simple configuration, so that the cost is reduced and the size is reduced. In addition, since only one guide member is required, it is possible to suppress the occurrence of uneven speed of the plate member due to a difference in sliding resistance and parallel balance as compared with a case where the plate member is moved by a plurality of guide members. Therefore, good image reading can be performed on the stimulable phosphor sheet of the plate member, and a good image without image unevenness can be obtained.
[0013]
In the above image reading apparatus, the support member has at least two surfaces extending in the longitudinal direction and substantially orthogonal to each other, and the guide member is arranged on one of the two surfaces close to the plate-like member, and the other surface is provided. It is preferable that the linear motor be arranged at the right side.
[0014]
Another image reading apparatus according to the present invention is characterized in that the stimulable phosphor sheet is obtained by photoelectrically converting stimulable light emitted by excitation light emitted from a light source to a plate member holding the stimulable phosphor sheet. An image reading device that reads image information from a linear motor that moves the plate-shaped member for reading the image information, and a guide member that extends in a longitudinal direction of the linear motor so as to guide the movement of the plate-shaped member. And a support member extending in the longitudinal direction to support the linear motor and the guide member, wherein the linear motor is disposed on the back side of the guide member with the support member interposed therebetween. And
[0015]
According to this image reading device, the linear motor and the guide member can be arranged with a simple configuration by arranging the linear motor on the back side of the guide member with the support member interposed therebetween. In addition, since only one guide member is required, it is possible to suppress the occurrence of uneven speed of the plate member due to a difference in sliding resistance and parallel balance as compared with a case where the plate member is moved by a plurality of guide members. Therefore, good image reading can be performed on the stimulable phosphor sheet of the plate member, and a good image without image unevenness can be obtained.
[0016]
In the image reading apparatus, the support member has at least two surfaces extending in the longitudinal direction and facing each other, and the guide member is disposed on one surface of the two surfaces close to the plate-like member, and is opposed to the one surface. It is preferable that the linear motor be arranged on the other surface.
[0017]
In each of the image reading apparatuses, it is preferable that a linear encoder is disposed on the support member so as to extend in the longitudinal direction. Thus, the linear encoder for detecting the position of the linear motor can be arranged on the support member together with the linear motor and the guide member, and the arrangement structure can be easily configured.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, first and second embodiments of the present invention will be described with reference to the drawings.
[0019]
<First Embodiment>
[0020]
FIG. 1 is a perspective view of a main part of the radiation image reading apparatus according to the present embodiment as viewed from above. FIG. 2 is a side view of a main part of the radiation image reading apparatus of FIG. FIG. 3 is a top view of a main part of the radiation image reading apparatus of FIG.
[0021]
As shown in FIGS. 1 to 3, a radiation image reading apparatus (hereinafter, also simply referred to as an “image reading apparatus”) is provided with a carrier 17 on which a stimulable phosphor plate 11 is attached and transported in a vertical direction V in FIG. The optical fixed to the main body of the apparatus for scanning the stimulable phosphor plate 11 with the stimulating light L1 in the main scanning direction (perpendicular to the plane of FIG. 2) and detecting the generated stimulating light L2. And a unit 10. The stimulable phosphor plate 11 is attached and fixed to the carrier 17 with a rubber magnet or the like.
[0022]
The image reading apparatus shown in FIGS. 1 to 3 further includes a column-shaped support member 12 fixed to the apparatus main body and having a rectangular cross section and elongated in the vertical direction V, and a support member 12 proximate to the carriage 17. A linear motion guide member 14 attached to and supported by the elongated flat surface 12a; a linear motor 15 attached to and supported by the elongated flat surface 12b of the support member 12 and serving as a driving source of the carrier 17; And a linear encoder 13 that is attached to and supported by 12c and detects the position of the linear motor 15 for controlling the sub-scanning position and the transport speed of the stimulable phosphor plate 11 in the vertical direction V. The entire device is covered with a light blocking member (not shown) for blocking external light.
[0023]
The stimulable phosphor plate 11 is composed of a stimulable phosphor sheet and a plate-like member such as a metal plate or a resin plate that supports the stimulable phosphor sheet by bonding or the like, and is attached to the carrier 17; The sub-scanning is performed by moving in the vertical direction V in FIG. 2 while being guided by the linear motion guide member 14 by the linear motor 15.
[0024]
The stimulable phosphor plate 11 absorbs radiation transmitted through the subject when another subject is irradiated with radiation by another radiation imaging apparatus, and a part of the energy is absorbed in the stimulable phosphor layer on the surface by the radiation image. Is stored as information.
[0025]
Since the stimulable phosphor sheet is not rigid in itself and difficult to handle in the apparatus, it is hardly used alone, and a back plate (cassette of a cassette) which is detachable from a cassette used for radiography. It is handled in such a state that it is held by being adhered to the inner surface (on the side opposite to the photographing surface side) or the like. Therefore, as described above, the inner surface of the support member or the back plate of the cassette is used as the stimulable phosphor plate 11 as described above. Used to be used.
[0026]
As shown in FIG. 2, the optical unit 10 shapes the laser light with a shaping optical system, deflects the laser light with a deflecting mirror such as a polygon mirror, and forms an image with an image forming lens to thereby generate stimulable fluorescent light as stimulating excitation light L1. A stimulating excitation light source and an optical system for irradiating the plate 11 to perform main scanning are mounted inside, and further, the stimulating light L2 generated from the stimulable phosphor plate 11 by the stimulating excitation light L1 is collected and guided. Light-guiding member 23, a stimulable light-emitting condensing tube 21 for condensing stimulable light emitted from the light-guiding member 23, and a photomultiplier that converts light from the stimulable light-emitting tube 21 into an electric signal. And a photoelectric converter 22 such as a plier.
[0027]
The electric signal from the photoelectric converter 22 passes through an analog / digital conversion circuit (not shown) to be visualized and displayed on a display device, or is exposed to a silver halide film (not shown) to be visualized.
[0028]
As shown in FIGS. 2 and 3, the linear motor 15 extends along the elongated plane 12 b of the support member 12, is supported by the elongated plane 12 b, a movable coil section 15 b attached to the carrier 17, The energization control to the movable coil portion 15b is performed based on the position detection of the linear encoder 13 by a linear motor controller (not shown).
[0029]
The linear motor 15 conveys the carrier 17 in the vertical direction V. At this time, the linear motion guide member 14 moves in the vertical direction V while the linear motion guide movable portion 16 attached to the carrier 17 guides the carrier 17. And move.
[0030]
The elongated flat surface 12a of the support member 12 to which the linear motion guide member 14 is attached is substantially orthogonal to the other two elongated flat surfaces 12b and 12c. Therefore, the magnet portion 15a of the linear motor 15 attached to the elongated flat surface 12b is The linear encoder 13 is located at a position substantially orthogonal to the linear motion guide member 14, and the linear encoder 13 attached to the elongated flat surface 12c is also at a position substantially orthogonal to the linear motion guide member 14.
[0031]
As described above, in the image reading apparatus shown in FIGS. 1 to 3, the linear motion guide member 14 and the linear motor 15 are disposed substantially at right angles to the support member 12, and the linear motion guide member 14 and the linear encoder 13 are further connected. By arranging at a substantially right angle with respect to the support member 12, only one linear motion guide member 14 is required, the number of components is reduced, and the arrangement structure of the linear motor 15, the linear motion guide member 14, and the linear encoder 13 is compact and easy. Therefore, the size of the apparatus can be reduced at low cost.
[0032]
Next, the operation of the image reading apparatus of FIGS. 1 to 3 will be described. After fixing the stimulable phosphor plate 11 to the carriage 17 with a rubber magnet or the like, the stimulable phosphor plate 11 is irradiated with the stimulable excitation light L1 from the optical unit 10. At this time, a luminous phenomenon occurs according to the latent image from the stimulable phosphor layer on the surface of the stimulable phosphor plate 11, and the stimulable luminescence light L 2 is guided by the light guide member 23 to the stimulable luminescence condensing tube 21. The information of the radiation image stored in the stimulable phosphor plate 11 is read by being illuminated and converted into an electric signal by the photoelectric converter 22.
[0033]
The carriage 17 is conveyed in the sub-scanning direction V while being guided by the linear motor 15 by the linear motion guide member 14 in synchronization with the irradiation of the stimulating light L1 and the reading of the stimulating light L2 at a predetermined timing. Sub-scanning is performed.
[0034]
According to the image reading apparatus of the present embodiment, since the stimulable phosphor plate is moved while being guided by the plurality of guide members as in the related art, a delay occurs in one of the guide members due to a difference in sliding resistance between the plurality of guide members. In addition, vibration occurred due to parallel balance at the time of assembly, and smooth conveyance was not possible, which caused unevenness in the speed of the stimulable phosphor plate and caused image unevenness. When the transport table 17 to which the fluorescent plate 11 is fixed is transported by the linear motor 15 in the sub-scanning direction V, the transport table 17 is guided by the single linear guide member 14, so that there is a delay in one side due to the difference in sliding resistance of the guide members. Occurrence of unevenness in the speed of the transport table 17 can be suppressed without causing vibrations due to the occurrence of the collapse or the collapse of the parallel ball, so that a good image can be read from the stimulable phosphor sheet 11. Better diagnostic image with no image unevenness can be obtained. In addition, a single linear motion guide member 14 is sufficient, and the arrangement of the linear motion guide member 14, the linear motor 15, and the linear encoder 13 can be made compact, so that the cost and size of the device can be reduced.
[0035]
<Second embodiment>
[0036]
FIG. 4 is a side view of a main part of the radiation image reading apparatus according to the present embodiment. FIG. 5 is a top view of a main part of the radiation image reading apparatus of FIG. The image reading apparatus of FIGS. 4 and 5 has basically the same structure as that of FIGS. 1 to 3, but differs in the mounting position of the linear motor.
[0037]
That is, as shown in FIGS. 4 and 5, the linear motor 25 is bent in an L-shape by the magnet portion 25 a extending along the elongated flat surface 12 d of the support member 12 and supported by the elongated flat surface 12 d and the carrier 17. And a movable coil unit 25b attached thereto, and energization control of the movable coil unit 25b is performed based on the position detection of the linear encoder 13 as described above.
[0038]
In the support member 12, the elongated flat surface 12d on which the magnet portion 25a of the linear motor 25 is disposed is a surface opposed to the elongated flat surface 12a on which the linear motion guide member 14 is disposed. Is located on the back side with the support member 12 interposed therebetween.
[0039]
As described above, according to the image reading apparatus of the present embodiment, the linear motor 25 is disposed on the back side of the support member 12 so as to face the linear guide member 14, and the linear guide member 14 and the linear encoder 13 is disposed substantially at right angles to the support member 12, a single linear guide member 14 is required, the number of components is reduced, and the arrangement structure of the linear motor 25, the linear guide member 14, and the linear encoder 13 is compact. Therefore, the size of the apparatus can be reduced at low cost.
[0040]
Also, as in FIGS. 1 to 3, when the transport table 17 to which the stimulable phosphor plate 11 is fixed is transported in the sub-scanning direction V by the linear motor 25, the guide is guided by the single linear guide member 14. There is no delay in one side due to the difference in the sliding resistance of the members, and no vibration occurs due to the collapse of the parallel ball, and it is possible to suppress the occurrence of speed unevenness of the carrier 17. Good image reading can be performed, and a good diagnostic image without image unevenness can be obtained.
[0041]
As described above, the present invention has been described with the embodiments, but the present invention is not limited to these, and various modifications can be made within the technical idea of the present invention. For example, in FIGS. 1 to 5, the transport table, which is the transported object, is sub-scanned and conveyed in the vertical direction V, but may be sub-scanned and conveyed in the opposite direction V ′. Further, the sub-scanning direction is not limited to the vertical direction (or the opposite direction), and the image reading device may be configured to be a horizontal direction or an inclined direction inclined from the vertical direction.
[0042]
【The invention's effect】
According to the present invention, it is possible to provide an image reading device which is a low-cost and miniaturized device and can obtain a good image without image unevenness.
[Brief description of the drawings]
FIG. 1 is a perspective view of a main part of a radiation image reading apparatus according to a first embodiment as viewed from above.
FIG. 2 is a side view of a main part of the radiation image reading apparatus of FIG. 1;
FIG. 3 is a top view of a main part of the radiation image reading apparatus of FIG. 1;
FIG. 4 is a side view of a main part of a radiation image reading apparatus according to a second embodiment.
FIG. 5 is a top view of a main part of the radiation image reading apparatus of FIG. 4;
[Explanation of symbols]
10 optical unit 11 stimulable phosphor plate (plate-like member)
12 Support members 12a to 12d Slender flat surface 13 of support member 12 Linear encoder 14 Linear guide members 15 and 25 Linear motor 17 Carrier L1 Stimulated excitation light L2: Stimulated emission light V: Vertical direction, sub-scanning direction

Claims (5)

In an image reading device that reads image information from the stimulable phosphor sheet by photoelectrically converting stimulable luminescence light emitted by excitation light emitted from a light source to a plate member holding the stimulable phosphor sheet,
A linear motor that moves the plate member for reading the image information, and a guide member that extends in the longitudinal direction of the linear motor to guide the movement of the plate member,
A support member extending in the longitudinal direction to support the linear motor and the guide member,
An image reading apparatus, wherein the linear motor and the guide member are disposed substantially at right angles to the support member. The support member has at least two surfaces that extend in the longitudinal direction and are substantially orthogonal to each other. The guide member is arranged on one surface of the two surfaces close to the plate member, and the linear motor is arranged on the other surface. The image reading device according to claim 1, wherein: In an image reading device that reads image information from the stimulable phosphor sheet by photoelectrically converting stimulable luminescence light emitted by excitation light emitted from a light source to a plate member holding the stimulable phosphor sheet,
A linear motor that moves the plate member for reading the image information, and a guide member that extends in the longitudinal direction of the linear motor to guide the movement of the plate member,
A support member extending in the longitudinal direction to support the linear motor and the guide member,
An image reading apparatus, wherein the linear motor is disposed on the back side of the guide member with the support member interposed therebetween. The support member has at least two surfaces extending in the longitudinal direction and facing each other, the guide member is arranged on one surface of the two surfaces close to the plate-like member, and the guide member is arranged on the other surface facing the one surface. The image reading device according to claim 3, wherein a linear motor is arranged. The image reading device according to any one of claims 1 to 4, wherein a linear encoder is arranged on the support member so as to extend in the longitudinal direction.

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