JP2002040197A - Reader for radiographic image data - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain images of high S/N ratio by improving the condensing efficiency even if stimulable luminescent light emitted from a section irradiated with excitation light has a prescribed broadness and the width of a photoelectric conversion element that receives light is narrower than that of the broad light in a reader that reads out radiation image data with a line sensor by linearly irradiating a storage phosphor sheet with excitation light. SOLUTION: A fiber optical element 18, made of numerous tapered fiber bundles whose and faces on the side of a Selfoc lens element 6 are larger than those on the side of the photoelectric conversion element 21, is located between the Selfoc lens element 6 and the photoelectric conversion element 21. An image is formed on a light-receiving surface of the photoelectric conversion element 21, by reducing an image in a luminescent section of the stimulable luminescent light M, based on a radiographic image on a phosphor sheet 50 with the fiber optical element 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation image information reading apparatus, and more particularly, to exciting radiation image information stored in a stimulable phosphor sheet by linear excitation light and stimulating emission light by a line sensor. The present invention relates to a radiation image information reading device to be read.

[0002]

2. Description of the Related Art When a stimulable phosphor is irradiated with radiation, a part of the radiation energy is accumulated, and then, when irradiated with excitation light such as visible light or laser light, the stimulable phosphor is stimulated according to the accumulated radiation energy. Emission light is emitted. Using this stimulable phosphor (stimulable phosphor), the stimulable phosphor is laminated on a support, and the sheet-like stimulable phosphor sheet is irradiated with radiation transmitted through a subject such as a human body. By temporarily storing and recording the radiation image information, and irradiating the stimulable phosphor sheet with excitation light such as laser light,
The photostimulated luminescence light is generated, and the photostimulated luminescence light is read by a reading unit including a photoelectric conversion element to obtain an image signal, and the stimulable phosphor sheet after reading the image signal is irradiated with erasing light. A radiation image recording / reproducing system that emits radiation energy remaining on the sheet and reuses the sheet is widely used as CR (Computed Radiography).

The image signal obtained by the above system is subjected to image processing such as gradation processing and frequency processing suitable for observation and interpretation, and the image signal after these processing is applied to a diagnostic visible image ( This is recorded on a film as a final image) or displayed on a high-definition CRT and provided for diagnosis by a doctor or the like. On the other hand, when the stimulable phosphor sheet is irradiated with erasing light to release residual energy, the sheet can again store and record radiation image information, and can be used repeatedly.

Further, in a radiation image information reading apparatus used in a radiation image recording / reproducing system, from the viewpoints of shortening the reading time of the stimulating light and reducing the size and cost of the apparatus, the sheet is used as an excitation light source. On the other hand, a line light source that irradiates the excitation light linearly is used, and as a photoelectric reading unit, the length direction of the linear portion of the sheet irradiated with the excitation light by the line light source (hereinafter, referred to as a main scanning direction)
Along with using a line sensor in which a large number of photoelectric conversion elements are arranged, one of the line light source and the line sensor and the phosphor sheet is relatively to the other, and the length of the linear portion is Japanese Patent Application Laid-Open Nos. 60-111568 and 60-23 propose a configuration having a scanning means that moves in a direction substantially perpendicular to the direction (hereinafter referred to as a sub-scanning direction).
6354, JP-A-1-101540). In addition, as a photoelectric conversion element of a line sensor, a CCD having a relatively high quantum efficiency and capable of reducing the size of an apparatus is used.

[0005]

However, in the radiation image information reading apparatus according to the above technique, when the phosphor sheet is irradiated with the linear excitation light, the stimulated emission light emitted from the irradiated portion is excited light. By the scattering in the phosphor sheet and the diffusion of the emitted stimulating light, the light becomes spread light having a predetermined spread. On the other hand, when a CCD is used as a photoelectric conversion element for receiving the photostimulated light,
The width of the CD is usually about 20 μm or less, and is smaller than the width of the spread light. Therefore, it is not possible to receive all of the stimulated emission light emitted from the irradiated portion, and to obtain a sufficient light collection efficiency. Can not. Also, since the phosphor layer of the phosphor sheet needs to have a certain thickness in order to have sufficient radiation absorption, even if the linear excitation light irradiation area is narrowed, the excitation light is scattered or stimulated. Diffusion of emitted light is inevitable, and it is difficult to make the width of the spread light narrower than the width of the CCD. Further, when the spread light is focused on a photoelectric conversion element by a reduction optical system including a lens, it is not preferable because light-collecting efficiency is significantly reduced.

A radiation image information reading apparatus according to the present invention comprises:
In view of the above problems, the stimulated emission light emitted from the excitation light irradiation portion has a predetermined spread, and even when the width of the photoelectric conversion element that receives light is smaller than the width of the spread light, the light is collected. It is an object of the present invention to provide a radiation image information reading apparatus that obtains an image with a higher S / N by improving efficiency.

[0007]

A radiation image information reading apparatus according to the present invention comprises: an irradiating means for linearly irradiating a part of the surface of a stimulable phosphor sheet storing radiation image information with excitation light; A portion where the phosphor sheet is linearly irradiated with the excitation light by the means or a portion where the phosphor sheet is linearly irradiated to collect stimulated light emitted from the back surface portion of the phosphor sheet corresponding to the irradiated portion; A line in which a large number of condensing lenses arranged linearly in opposition to each other and a large number of photoelectric conversion elements that receive stimulated emission light condensed by the respective condensing lenses and photoelectrically convert the light are arranged in a straight line Detecting means having a sensor, scanning means for moving one of the irradiating means and the detecting means and the phosphor sheet relative to the other in a direction different from the length direction of the irradiated part, and moving the output of the detecting means Read sequentially according to In the radiation image information reading apparatus provided with reading means for obtaining data constituting a final image, a detecting means is provided between an end surface of the condensing lens and a converging lens disposed between each condensing lens and each photoelectric conversion element. A fiber optical system having a fiber optical element having a large number of tapered fiber bundles whose area is larger than the area of the end face on the photoelectric conversion element side is provided.

Here, the "fiber optical element comprising a tapered fiber bundle" means, for example, a fiber optical element 19 obtained by bundling a plurality of tapered single fibers 22 of several .mu.m as shown in FIG. . The image incident on the fiber optical element composed of the tapered fiber bundle is reduced and transmitted at the same vertical and horizontal ratio. Further, the fiber optical system may be constituted by arranging a large number of fiber optical elements 19 shown in FIG. 5 in a straight line, or by one fiber optical element having the same length and width as the line sensor. May be.

The linear excitation light emitted from the irradiating means may be a linear light source, which emits linear excitation light, or may be a linear excitation light emitted by an optical system. . Also, the emitted excitation light may be one that is continuously emitted, or may be pulsed light that is emitted in the form of a pulse that repeats emission and stop. It is desirable that the output light be pulsed light. As the line light source, one that forms an image of a fluorescent lamp, a cold cathode fluorescent lamp, or the like through a slit, or one that condenses an LED array, an LD array, a broad area laser, or the like with a cylindrical lens or the like can be used. it can.

Further, the irradiating means and the detecting means may be arranged on the same side of the sheet, or may be arranged separately on the opposite sides. However, in the case of adopting a configuration arranged separately, it is necessary to make the support of the phosphor sheet transparent to the stimulating light.

The condensing lens forms an image of the light-emitting portion of the stimulating light based on the radiation image on the phosphor sheet in a one-to-one size on the light receiving surface of the fiber optical element.

In the radiation image information reading apparatus according to the present invention, the detecting means includes a plurality of rows of condenser lenses, a fiber optical system, and a line sensor, and the stimulated emission light emitted from the linearly irradiated portion. May be detected by a plurality of rows of condenser lenses, fiber optics, and line sensors. In the case where the above-mentioned configuration is used and a fiber optical system in which a large number of fiber optical elements are linearly arranged is used, as shown in FIG. 10 (an upper cross-sectional view of the radiation image information reading apparatus having the above configuration). Adjacent to the fiber optic element 19 of at least one fiber optics and the fiber optic element 1 of another fiber optics
With respect to the excitation light irradiation portion 1 where the adjacent portion 9 ′ is linear,
The fiber optical element 1 is shifted by a predetermined distance in the main scanning direction.
It is desirable to arrange 9, 19 '. A detailed description of FIG. 10 will be described later.

Here, the plurality of rows of condenser lenses, fiber optics, and line sensors are arranged in parallel to the linearly irradiated portion of the excitation light.

A CCD can be used as the photoelectric conversion element.

The stimulable phosphor sheet absorbs light in the ultraviolet to visible region, stores its energy, is excited by light in the visible to infrared region, and emits energy as photostimulated light. A phosphor containing a stimulable phosphor can also be used.

In this case, the radiation absorbing function and the energy storage function of the conventional stimulable phosphor are separated, and a phosphor excellent in radiation absorption and a phosphor excellent in responsiveness to stimulable emission are used separately. Using a phosphor having excellent absorption (phosphor for radiation absorption), it absorbs radiation and emits light in the ultraviolet to visible region, and this emitted light is used as a phosphor having excellent responsiveness to the stimulated emission (storage-only fluorescent light). ) To accumulate the energy, excite it with light in the visible to infrared region, and emit the energy as stimulated emission light.

[0017]

According to the radiation image information reading apparatus of the present invention, between each condenser lens and each photoelectric conversion element, the area of the end face on the condenser lens side is larger than the area of the end face on the photoelectric conversion element side. By arranging a fiber optical system having a fiber optical element composed of a tapered fiber bundle, the image of the light-emitting portion of the photostimulated light based on the radiation image on the phosphor sheet spreads due to diffusion of the photostimulated light. In the case where the width is larger than the width of the photoelectric conversion element, the image is reduced by the fiber optic element and formed on the light receiving surface of the photoelectric conversion element, so that the light collection efficiency can be improved. The S / N of the final image can be higher.

The detecting means may include a plurality of rows of condenser lenses,
Equipped with fiber optics and line sensors,
The stimulated emission light emitted from the portion where the excitation light is linearly irradiated can be detected by a plurality of rows of condenser lenses, fiber optics, and line sensors, further improving the light collection efficiency. be able to. In this case, the linear excitation light is made to enter the phosphor sheet almost perpendicularly, and a plurality of rows of condenser lenses, fiber optics, and line sensors are arranged on both sides of the linearly irradiated portion. Then, the stimulated emission light can be collected from a direction more perpendicular to the phosphor sheet, so that the light collection efficiency can be further improved. Further, in the above-described configuration, when a fiber optical system in which a large number of fiber optical elements are linearly arranged is used, at least one fiber optical system adjacent to the fiber optical element and another fiber optical system are used. By arranging each fiber optic element so as to be shifted by a predetermined distance in the main scanning direction with respect to a part of the fiber optic system that is linearly irradiated with an adjacent part of the fiber optic element, at least one fiber optic system is adjacent Since stimulated emission light emitted from the excitation light irradiation part corresponding to the part can be received by another fiber optical system, an image in which artifacts (false images) due to joints of fiber optical elements are suppressed can be obtained. Can be.

Further, since a CCD can be used as the photoelectric conversion element, the size of the device can be reduced.

The stimulable phosphor sheet absorbs light in the ultraviolet to visible region, stores its energy, is excited by light in the visible to infrared region, and emits energy as photostimulated light. A phosphor containing a stimulable phosphor can also be used.

In this case, the radiation absorbing function and the energy storage function of the conventional stimulable phosphor are separated, and a phosphor excellent in radiation absorption and a phosphor excellent in response to stimulable luminescence are used separately. Using a phosphor having excellent absorption (phosphor for radiation absorption), it absorbs radiation and emits light in the ultraviolet to visible region, and this emitted light is used as a phosphor having excellent responsiveness to the stimulated emission (storage-only fluorescent light). ) To accumulate the energy, excite it with light in the visible to infrared region, and emit the energy as stimulated emission light.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an embodiment of the radiation image information reading apparatus according to the present invention, and FIG. 2 is a sectional view showing a cross section taken along line II of the radiation image information reading apparatus shown in FIG.

The radiation image information reading apparatus according to the present invention comprises:
A scanning belt 40 on which a stimulable phosphor sheet (hereinafter, referred to as a phosphor sheet) 50 on which radiation image information is stored and conveyed in the direction of arrow Y, a linear secondary excitation light (hereinafter, simply excitation light) ) That emits L substantially parallel to the surface of the phosphor sheet 50 (hereinafter referred to as BLD) 11, and linear excitation light L emitted from the BLD 11.
Optical system 1 consisting of a combination of a collimator lens that focuses light and a toric lens that expands the beam in only one direction
2. It is disposed so as to be inclined at an angle of 45 degrees with respect to the surface of the phosphor sheet 50, and is installed so as to reflect the excitation light L in a substantially vertical direction toward the phosphor sheet 50 and transmit the stimulating light M described later. The dichroic mirror 14 and the linear excitation light L reflected by the dichroic mirror 14 are condensed on the phosphor sheet 50 into a linear shape extending in the X direction, and the phosphor sheet 50 is irradiated with the excitation light. Refractive index distribution type lens array 15 that makes stimulated emission light M according to the stored and recorded radiation image information emitted from the light source a parallel light flux
(Hereinafter, referred to as a first Selfoc lens array), the stimulated emission light M which has been converted into a parallel light beam by the first Selfoc lens array 15 and transmitted through the dichroic mirror 14 is transmitted to a light receiving surface of a fiber optical element 18 described later. The second selfoc lens array 16 which forms an image of a radiation image, and the excitation light L reflected on the surface of the phosphor sheet 50 slightly mixed with the stimulating light M transmitted through the second selfoc lens array 16 An optical filter 19 for reducing the image formed by the excitation light cut filter 17 and the second selfoc lens array 16 and forming an image on a light receiving surface of a photoelectric conversion element 21 of a line sensor 20 described later.
, A line sensor 20 that photoelectrically converts an image formed by the fiber optical element 19 of the fiber optical system 18 with the photoelectric conversion element 21, and a signal output from the line sensor 20. Image information reading means 30 for reading the image.

Here, the line sensor 20 has a structure in which a large number (for example, 1000 or more) of photoelectric conversion elements 21 are arranged along the X direction, as shown in FIG. In the line sensor shown in FIG. 3, the arranged photoelectric conversion elements are arranged at predetermined intervals. However, the line sensor may be arranged so as to receive all the stimulated emission light M collected from the fiber optical system 18. Any arrangement may be used. Also,
Specifically, as the photoelectric conversion element 21, an amorphous silicon sensor, a CCD sensor, a MOS image sensor, or the like can be used.

Further, the fiber optical system 18 is described in detail in FIG.
As shown in (partial upper cross-sectional view of the radiation image information reading apparatus in the present embodiment), fiber optical elements 19 are linearly arranged in the X direction.
9 has a multi-fiber structure in which single fibers 22 of several μm are bundled, as shown in FIG.
In addition, since each single fiber 22 is formed in a tapered shape, the incident image is transmitted at the same ratio in both the X direction and the Y direction while being reduced. The area of the end surface of the fiber optical element 19 on the side of the second Selfoc lens is large enough to collect the stimulated emission light M transmitted through the second Selfoc lens.

The distance between the line sensor 20 and the fiber optical system 18 is preferably as short as possible, and it is desirable to arrange them so as to be close to each other. Therefore, the excitation light cut filter is preferably disposed between the second selfoc lens array 16 and the fiber optical system 18 as shown in FIG. 4, but a thin film interference filter or the like is used as the excitation light cut filter. In this case, it may be arranged between the line sensor 20 and the fiber optical system 18.

Further, the first and second selfoc lens arrays 15 and 16 are, as shown in detail in FIG. 6, in which a number of selfoc lens elements 5 and 6 are linearly arranged. An image of the light-emitting portion of the photostimulated light M based on the radiation image on the phosphor sheet 50 is formed on the light receiving surface of the fiber optical element 19 in a one-to-one size. FIG.
It is not necessary to arrange them in one row as shown in
A configuration in which a plurality of rows are arranged may be used, and in essence, any configuration may be used as long as it operates as described above.

The optical system 12 composed of a collimator lens and a toric lens expands the excitation light L from the BLD 11 onto a desired irradiation area on the phosphor sheet 50.

Next, the operation of the radiation image information apparatus according to this embodiment will be described.

First, by moving the scanning belt 40 in the direction of arrow Y, the scanning belt 40 is placed on the scanning belt 40.
The phosphor sheet 50 on which the radiation image information is stored is conveyed in the direction of arrow Y. At this time, the conveying speed of the phosphor sheet is equal to the moving speed of the belt 40, and the moving speed of the belt 40 is input to the image reading means 30.

On the other hand, the BLD 11 converts the linear excitation light L into
The excitation light L is emitted substantially parallel to the surface of the phosphor sheet 50, and the excitation light L is converted into a parallel beam by an optical system 12 including a collimator lens and a toric lens provided on the optical path. The light is reflected in a direction perpendicular to the light 50, and the reflected light is radiated by the first selfoc lens 15 onto the phosphor sheet 50 in a linear shape extending along the X direction. In the portion irradiated with the excitation light L, the excitation light excites the stimulable phosphor in the light-collecting area and the fluorescent sheet 5
The light is incident on the inside of the lens and diffuses into a portion near the light-collecting region, and the stimulable phosphor near the light-collecting region is also excited. As a result, stimulated emission light M having an intensity corresponding to the stored and recorded radiation image information is emitted from the light-collecting region of the phosphor sheet 50 and its vicinity. The stimulated emission light M is converted into a parallel light beam by the first selfoc lens 15, passes through the dichroic mirror 14, and is received by the second selfoc lens array 16 on the light receiving surface of the fiber optical element 19 of the fiber optical system 18. Is formed as a radiation image. At this time, the second
Even if the stimulated emission light M transmitted through the SELFOC lens array 16 slightly contains the excitation light L reflected on the surface of the phosphor sheet 50, the excitation light L is cut by the excitation light cut filter 17, so that the fiber optical element The light does not enter the light receiving surface 19. The image formed on the light receiving surface of the fiber optical element 19 is reduced by the fiber optical element 19 and formed on the light receiving surface of the photoelectric conversion element 21 of the line sensor 20. The image formed on the line sensor 20 is photoelectrically converted by a photoelectric conversion element 21, and the image signal is output to an image reading unit 30. The image reading unit converts the image signal into a digital signal, and then converts the image signal into a digital signal. Output to the processing unit.

According to the radiation image information reading apparatus according to the present invention, the area of the end face on the Selfoc lens element 6 side is larger than the area of the end face on the photoelectric conversion element side between the Selfoc lens element 6 and the photoelectric conversion element 21. By arranging the fiber optical element 18 composed of a large number of tapered fiber bundles, the image of the light-emitting portion of the photostimulated light based on the radiation image on the phosphor sheet has a spread due to the diffusion of the photostimulated light, Even when the width is larger than the width of the photoelectric conversion element 21, the image is reduced by the fiber optic element 18 and formed on the light receiving surface of the photoelectric conversion element 21, so that the light collection efficiency can be improved. The S / N of the image can be made higher.

Further, the radiation image information reading apparatus in the above embodiment employs a configuration in which the optical path of the excitation light L and the optical path of the stimulating light M are partially overlapped, thereby further reducing the size of the apparatus. However, the present invention is not limited to such a configuration. For example, as shown in FIGS. 7 and 8, a configuration in which the optical path of the excitation light L and the optical path of the stimulated emission light M do not overlap at all is applied. You can also.

The radiation image information reading apparatus shown in FIG. 7 includes a scanning belt 40, BLDs 11 and BLDs 1 which emit linear excitation light L at an angle of approximately 45 degrees with respect to the surface of a phosphor sheet 50.
An optical system 12 for irradiating the surface of the phosphor sheet 50 with the linear excitation light L, comprising a combination of a collimator lens for condensing the linear excitation light L emitted from 1 and a toric lens for expanding the beam only in one direction. A luminous axis which is inclined by approximately 45 degrees with respect to the surface of the phosphor sheet 50 and has an optical axis which is substantially perpendicular to the direction in which the excitation light L travels, Selfoc lens array 16 that forms stimulated emission light M on the light receiving surface of fiber optical element 19 as a radiation image, excitation light that cuts excitation light L mixed with stimulated emission light M incident on fiber optical element 19 An image formed by reducing the image formed by the cut filter 17 and the SELFOC lens array 16 and forming a fiber optical element for forming an image on the photoelectric conversion element 21 of the line sensor 20 is linearly arranged. Optical system 18, the fiber optics 19
Sensor 20 that photoelectrically converts the image formed by the photoelectric conversion element 21 with the photoelectric conversion element 21, and an image information reading unit that reads a signal output from each photoelectric conversion element 21 included in the line sensor 20 and outputs the signal to an image processing apparatus 30.

The BLD 11 emits the linear excitation light L in a direction inclined at an angle of approximately 45 degrees with respect to the surface of the phosphor sheet 50, and the excitation light L is provided on a collimator lens provided on the optical path. The light is converted into a parallel beam by the optical system 12 composed of a toric lens, and is incident on the surface of the phosphor sheet 50 at an angle of approximately 45 degrees. Then, from the irradiated area of the phosphor sheet 50 and the vicinity thereof, the stimulated emission light M having an intensity corresponding to the accumulated and recorded radiation image information is obtained.
Is emitted. The stimulated emission light M is condensed by the selfoc lens 16, the excitation light mixed therewith is cut by the excitation light cut filter 17, and then imaged on the light receiving surface of the fiber optical element 19. Fiber optic element 19
Reduces this image and forms an image on the photoelectric conversion element 21 of the line sensor 20. Other operations are the same as in the above embodiment.

The radiation image reading apparatus shown in FIG. 8 uses a stimulable phosphor sheet whose support is formed of a stimulable luminescent light transmissive material. Arranged on different sides of the body sheet 50,
This employs a configuration of a transmitted light condensing type configured to receive stimulated emission light emitted from a surface opposite to a side on which excitation light is incident.

The radiation image information reading apparatus shown in FIG. 8 uses a front end portion and a rear end portion of the stimulable phosphor sheet 50 (no radiographic image is recorded on the front end portion and the rear end portion, Transport belt 40 ′ that supports the sheet in the Y direction while supporting it, and a BLD 11 that emits linear excitation light L in a direction substantially perpendicular to the surface of the phosphor sheet 50. An optical system for irradiating the linear excitation light L onto the surface of the phosphor sheet 50, comprising a combination of a collimator lens for condensing the linear excitation light L emitted from the BLD 11 and a toric lens for expanding the beam only in one direction. 12. The back surface of the phosphor sheet 50 having an optical axis substantially orthogonal to the surface of the phosphor sheet 50 and being irradiated with the excitation light L (the surface opposite to the incident surface of the excitation light L)
A self-occurring lens array 16 which forms a radiation image on the light receiving surface of the fiber optical element 19 with the photostimulated light M ′ emitted from the phosphor sheet 50 and transmitted through the phosphor sheet 50, and the photostimulated light emitted to the fiber optical element 19 An excitation light cut filter 17 for cutting the excitation light L mixed in M ′, a fiber optical element 19 for reducing an image formed by the SELFOC lens array 16 and forming an image on the photoelectric conversion element 21 of the line sensor 20; A line sensor 20 for photoelectrically converting the image formed by the optical element 19 by the photoelectric conversion element 21, and a signal output from each photoelectric conversion element 21 included in the line sensor 20, and an image output to the image processing apparatus This is a configuration including information reading means 30.

First, as the transport belt 40 'moves in the Y direction, the phosphor sheet 50 supported by the transport belt 40' and storing radiation image information is transported in the Y direction. At this time, the transport speed of the phosphor sheet 50 is equal to the moving speed of the belt 40 ', and the moving speed of the belt 40' is input to the image information reading means 30.

On the other hand, the BLD 11 converts the linear excitation light L into
The excitation light L is emitted in a direction substantially orthogonal to the surface of the phosphor sheet 50, and the excitation light L is converted into a parallel beam by an optical system 12 including a collimator lens and a toric lens provided on the optical path. Incident substantially perpendicularly. At this time, the excitation light L irradiates a linear region extending along the X direction on the surface of the phosphor sheet 50. By irradiation with the excitation light L, stimulated emission light M having an intensity corresponding to the accumulated and recorded radiation image information is emitted from the irradiation area of the phosphor sheet 50 and the vicinity thereof. At the same time, the stimulated emission light M ′ that has passed through the transparent support of the phosphor sheet 50 is also emitted from the rear surface side portion of the phosphor sheet 50. The stimulated emission light M ′ emitted from the portion on the back side of the phosphor sheet 50 is condensed by the selfoc lens array 16 and is formed as a radiation image on the light receiving surface of the fiber optical element 19. For other actions,
This is the same as the above embodiments.

As shown in FIG. 9, the radiation image information reading apparatus according to the present invention further includes a line sensor 20 ', a fiber optical system 18', a selfoc lens 16 ' Optical cut filter 17 '
And irradiates the stimulated emission light emitted from the linear excitation light irradiation portion with two lines of line sensors 20 and 20 ′, fiber optical systems 18 and 18 ′, and selfoc lenses 16 and 1.
6 'and the excitation light cut filters 17, 17'.

The radiation image information reading apparatus shown in FIG. 9 uses a scanning belt 40 on which a phosphor sheet 50 is placed and conveyed in the Y direction, and a linear secondary excitation light (hereinafter simply referred to as excitation light) L. A broad area laser (hereinafter, referred to as BLD) 11 emitted in a direction substantially orthogonal to the surface of the phosphor sheet 50, a collimator lens for condensing linear excitation light L emitted from the BLD 11, and a beam spread only in one direction. An optical system 12, which is composed of a combination of toric lenses and irradiates a linear excitation light L onto the phosphor sheet 50, a stimulus according to accumulated and recorded radiation image information emitted from the phosphor sheet 50 by the irradiation of the excitation light. The excitation light cut filters 17, 17 'and the excitation light cut filters 17, 17' for cutting the excitation light L reflected from the phosphor sheet 50 slightly mixed with the emission light M are provided. The emitted light M having passed into a parallel light beam, a SELFOC lens array 16, 16 which formed on the light receiving surface of the 'fiber optics 19 and 19' the fiber optics 18, 18 ', SELFOC lens array 16,
A fiber optical system 18, comprising fiber optical elements 19, 19 'for reducing the image formed on the light receiving surface by 16' and forming an image on the light receiving surface of the photoelectric conversion elements 21, 21 'of the line sensors 20, 20', 18 ′, line sensors 20, 2 for photoelectrically converting the image formed by the fiber optics 18, 18 ′
0 'and an image information reading means 30 for reading signals output from the line sensors 20 and 20'. Further, the image information reading means 30 includes the line sensors 20, 2
An image data adding means (not shown) for adding signals output from 0 'may be provided.

In the above configuration, the selfoc lens arrays 16, 16 'and the excitation light filter are so arranged that the stimulated emission light M due to the linearly irradiated excitation light is received by the line sensor 20 and the line sensor 20'. 17, 17 'and fiber optics 18, 18' are arranged.

As shown in FIG. 10, the portion of the fiber optical system 18 adjacent to the fiber optical element 19 and the portion of another fiber optical system 18 'adjacent to the fiber optical element 19' are linearly irradiated. It is desirable to arrange the fiber optic elements 19 and 19 ′ in the shifted portion in the X direction.

In the radiation image information reading apparatus configured as described above, the BLD 11 emits the linear excitation light L substantially perpendicularly to the surface of the phosphor sheet 50, and this excitation light L
Is converted into a parallel beam by an optical system 12 including a collimator lens and a toric lens provided on the optical path, and is incident on the phosphor sheet 50 almost perpendicularly in a linear shape extending along the arrow X direction. The linear excitation light L incident on the phosphor sheet 50 emits stimulating light M having an intensity corresponding to the radiation image information stored and recorded. The stimulated emission light M is converted into a parallel light beam by the selfoc lenses 16, 16 ', and is imaged on the light receiving surfaces of fiber optical systems 18, 18' composed of fiber optical elements 19, 19 '.
At this time, the excitation light L reflected on the surface of the phosphor sheet 50 slightly mixed with the stimulated emission light M incident on the fiber optical elements 19, 19 'is supplied to the excitation light cut filters 17, 17'.
Is cut by The images formed on the light receiving surfaces of the fiber optical elements 19 and 19 ′ are reduced and
An image is formed on the light receiving surfaces of the photoelectric conversion elements 21 and 21 'of 0 and 20'. The line sensors 20, 20 '
The image of the photostimulated luminescence light M formed on the elements 1, 21 'is photoelectrically converted and output to the image reading means 30.

According to the radiation image information reading apparatus configured as described above, the two-line Selfoc lens array 1
6, 16 ′, tapered fiber optical elements 18 and 18 ′ and line sensors 20 and 20 ′, and two rows of selfoc lens arrays 16 each of which emits stimulated light emitted from a linearly irradiated portion. , 16 ′, the tapered fiber optical elements 18, 18 ′, and the line sensors 20, 20 ′, so that the light collection efficiency can be further improved.

The radiation image information reading apparatus of the present invention is not limited to the above-described embodiment, but includes a light source, a condensing optical system between the light source and the sheet, an optical system between the sheet and the line sensor, A line sensor and various known configurations can be employed. Further, the image processing apparatus further includes an image processing device that performs various signal processing on the signal output from the image information reading unit, and an erasing unit that appropriately emits radiation energy still remaining on the sheet after the excitation is completed. An equipped configuration can also be adopted.

Further, the radiation image reading apparatus according to the present invention, as a stimulable phosphor sheet, can absorb light in the ultraviolet to visible region and store its energy, and can be excited by light in the visible to infrared region. It is also possible to use a phosphor containing a stimulable phosphor capable of emitting energy as stimulating light.

[Brief description of the drawings]

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

FIG. 2 is a sectional view of the radiation image information reading apparatus shown in FIG.
Sectional view showing a line section

FIG. 3 is a diagram showing details of a line sensor of the radiation image information reading apparatus shown in FIGS. 1 and 2;

FIG. 4 is a diagram showing details of a fiber optical system of the radiation image information reading apparatus shown in FIGS. 1 and 2;

FIG. 5 is a diagram showing details of a fiber optical element of the radiation image information reading apparatus shown in FIG. 4;

FIG. 6 is a view showing details of first and second selfoc lens arrays of the radiation image information reading apparatus shown in FIGS. 1 and 2;

FIG. 7 is a schematic configuration diagram of another embodiment of the radiation image information reading apparatus according to the present invention.

FIG. 8 is a schematic configuration diagram of another embodiment of the radiation image information reading apparatus according to the present invention.

FIG. 9 is a schematic configuration diagram of another embodiment of the radiation image information reading apparatus according to the present invention.

10 is a partial upper cross-sectional view of the radiation image information reading apparatus shown in FIG.

[Explanation of symbols]

Reference Signs List 1 excitation light irradiation part 5, 6, 6 'selfoc lens element 11 broad area laser (BLD) 12 optical system including collimator lens and toric lens 15 first selfoc lens array 16 second selfox lens array 16' Selfoc lens array 17, 17 'Excitation light cut filter 18, 18' Fiber optical system 19, 19 'Fiber optical element 20, 20' Line sensor 21, 21 'Photoelectric conversion element 22, 22' Single fiber 30 Image information reading means 40 scanning belt 50 stimulable phosphor sheet L excitation light M, M 'stimulated emission light

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G083 AA03 BB04 CC10 DD11 DD13 DD16 DD18 EE01 EE02 EE03 2H013 AC01 AC05 5B047 AA17 AB02 BA01 BB02 BC08 5C024 AX16 CX00 CX37 EX01 EX42 EX51 EX54 GY01 5C076 AA01 BA0101

Claims (4)

[Claims] 1. An irradiating means for irradiating a part of the surface of a stimulable phosphor sheet storing radiation image information with excitation light in a linear manner, and said irradiating means applies a linear excitation light to said phosphor sheet. Are arranged linearly in opposition to the linearly irradiated portion that collects the stimulated emission light emitted from the back portion of the phosphor sheet corresponding to the irradiated portion or the irradiated portion. Detecting means having a line sensor in which a large number of condensing lenses and a large number of photoelectric conversion elements that receive and stimulate photoelectric conversion of the stimulated emission light condensed by each of the condensing lenses are linearly arranged; Irradiating means and scanning means for moving one of the detecting means and the phosphor sheet relative to the other in a direction different from the length direction of the irradiated portion; and outputting the output of the detecting means in accordance with the movement. Read sequentially A radiation image information reading apparatus comprising: reading means for obtaining data forming an image; wherein the detecting means is disposed between each of the condensing lenses and each of the photoelectric conversion elements, and an end surface on the condensing lens side. A radiation image information reading apparatus comprising a fiber optical system having a fiber optical element having a large number of tapered fiber bundles whose area is larger than the area of the end face on the photoelectric conversion element side. 2. The method according to claim 1, wherein the detecting unit includes a plurality of rows of the condenser lens, the fiber optical system, and the line sensor, and the plurality of rows emit the stimulated emission light emitted from the linearly irradiated portion. 2. A radiation image information reading apparatus according to claim 1, wherein the radiation image information is detected by a condensing lens, a fiber optical system, and a line sensor. 3. The radiation image information reading apparatus according to claim 1, wherein the photoelectric conversion element is a CCD. 4. The stimulable phosphor sheet absorbs light in the ultraviolet to visible region, stores its energy, and is excited by light in the visible to infrared region to convert the energy into photostimulated light. 4. The radiation image information reading apparatus according to claim 1, further comprising a stimulable phosphor to be emitted.