JP2000010217A - Radiographic image information reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a radiographic image information reader compacter than a conventional reader. SOLUTION: A hot mirror 14 being an excitation light guiding means guiding a laser light beam L being the excitation light to a sheet 50 and also being a stimulating light guiding means guiding stimulating light M to a line sensor 20 is arranged so that the optical path of the reflected laser light beam L and the optical path of the transmitting stimulating light M overlap. Since at least one part of the optical path of the excitation light and at least one part of the optical path of the stimulating light overlap, space occupied by the optical paths of both light is reduced. Thus, the device can be made compacter as a whole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a radiation image information reading apparatus, and more particularly to a radiation image information reading apparatus which reads stimulated emission light emitted from a stimulable phosphor sheet by a line sensor.

[0002]

2. Description of the Related Art When radiation is irradiated, a part of this radiation energy is accumulated, and thereafter, when irradiated with excitation light such as visible light or laser light, a stimulable phosphor that emits stimulated light in accordance with the accumulated radiation energy. (Photostimulable phosphor) is used to temporarily accumulate and record radiation image information of a subject such as a human body on a sheet-shaped stimulable phosphor sheet formed by laminating a stimulable phosphor on a support. Excitation light such as laser light is deflected and scanned for each pixel to generate stimulated emission light sequentially from each pixel, and the obtained stimulated emission light is photoelectrically sequentially read by photoelectric reading means to obtain an image signal. A radiation image recording / reproducing system that emits erasing light to the stimulable phosphor sheet after reading the image signal and emits radiation energy remaining on the sheet is widely used in practice.

An image signal obtained by this system is subjected to image processing such as gradation processing and frequency processing suitable for observation and interpretation, and the image signal after these processings is applied as a diagnostic visible image. Filmed or high-definition CR
It is displayed on T and used for diagnosis by a doctor or the like. on the other hand,
The stimulable phosphor sheet from which the residual radiant energy irradiated with the erasing light has been released can store and record radiation image information again, and can be used repeatedly.

Here, in the radiation image information reading apparatus used in the above-mentioned radiation image recording / reproducing system,
From the viewpoint of shortening the reading time of the stimulated emission light, downsizing of the device and cost reduction, a line light source that irradiates the sheet with the excitation light linearly as the excitation light source is used.
As the photoelectric reading means, a line sensor in which a large number of photoelectric conversion elements are arranged along the length direction of the linear portion of the sheet irradiated with the excitation light by the line light source, and the line light source and the line sensor are used. Japanese Patent Application Laid-Open Nos. 60-111568 and 60-236354 disclose a configuration having a scanning means which moves in a direction substantially perpendicular to the length direction of the linear portion relative to the sheet. JP-A-1-10
No. 1540).

[0005]

The radiation image information reading apparatus using the above-described line light source and line sensor is required to be further reduced in size.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a radiation image information reading and recording apparatus which can be made smaller in size than conventional ones.

[0007]

According to the present invention, there is provided a radiation image information reading apparatus which forms a part of an optical path of excitation light from a line light source to a sheet and a part of an optical path of stimulated emission light from a sheet to a line sensor. By overlapping, the space occupied by the optical path is reduced, and the device as a whole is downsized.

That is, a first radiation image information reading apparatus according to the present invention comprises a line light source for emitting linear excitation light, and a stimulable phosphor sheet on which radiation image information is stored by recording the linear excitation light. Excitation light guiding means for guiding light to a part of the sheet, and receiving the stimulated emission light emitted from the portion of the sheet irradiated with the excitation light linearly, and performing photoelectric conversion, the length direction of the portion A line sensor in which a plurality of photoelectric conversion elements are disposed, a stimulating luminescence light guiding unit that guides the stimulating luminescence light emitted from the sheet to the line sensor, the line light source and the line sensor. Relative to the sheet, a scanning means for moving in a direction different from the length direction, and a radiation image information reading apparatus comprising a reading means for sequentially reading the output of the line sensor according to the movement, Previous The optical path of the excitation light from the line light source to the sheet and the optical path of the stimulating light from the sheet to the line sensor are at least partially overlapped (the beam centers of both lights overlap). The same applies hereinafter.)

Here, by sharing at least a part of the optical element constituting the excitation light guiding means and at least a part of the optical element constituting the stimulated emission light guiding means, at least one of the optical paths of the two lights is provided. It is desirable that some of them overlap, but this is not a limitation.

As a line light source, a fluorescent lamp, a cold cathode fluorescent lamp, an LED array, or the like can be applied. Here, the line light source is not limited to a linear light source itself such as a fluorescent lamp as long as it irradiates one-dimensional excitation light to the sheet surface. A laser, an EL (Electroluminescence) element, or the like can be applied. More preferably, an LED array or a broad area laser is applied, and the excitation light emitted from these light sources becomes linear excitation light on the sheet surface. It is desirable to adopt a configuration further using a cylindrical lens or the like for suppressing the spread of the excitation light in a direction (short axis direction) orthogonal to the direction (short axis direction).

The excitation light emitted from the line light source may be emitted continuously, or may be pulsed light emitted in a pulse shape in which emission and stop are repeated. From the viewpoint of reduction, it is desirable that the light is a high-output pulsed light.

The length of the irradiation area in the major axis direction on the stimulable phosphor sheet by the linear excitation light emitted from the line light source is longer than or equal to one side of the stimulable phosphor sheet. It is preferable that the line light source is arranged so as to be inclined with respect to the side of the sheet.

As the excitation light guide means, the above-mentioned cylindrical lens, slit, selfoc lens (rod lens) array, fluorescent light guide sheet, optical fiber bundle, hot mirror, cold mirror, or a combination thereof are applied. can do.

When the optimum secondary excitation wavelength of the stimulable phosphor sheet is around 600 nm, the activator of the phosphor is Eu3 + (emission center) and the fluorescent light guide sheet is made of glass or a polymer medium. Some are desirable.

A hot mirror is a dichroic mirror set so as to reflect excitation light and transmit stimulated emission light, and a cold mirror is set so as to transmit excitation light and reflect stimulated emission light. Dichroic mirror.

It is appropriate that the light beam width of the excitation light emitted from the light source on the sheet is 10 to 4000 μm.

As the line sensor, an amorphous silicon sensor, a CCD sensor, a CCD with a back illuminator, a MOS image sensor, or the like can be applied.

The stimulated emission light guiding means may be a selfoc lens (registered trademark; hereinafter abbreviated) array or a rod lens array in which the object surface and the image surface are constituted by an imaging system corresponding to one to one. And the like, a gradient index lens array, a cylindrical lens, a slit, an optical fiber bundle, a hot mirror, a cold mirror, or a combination thereof can be applied.

Further, on the optical path of the stimulated emission light between the sheet and the line sensor and not overlapping with the optical path of the excitation light, an excitation light cut which transmits the stimulated emission light but does not transmit the excitation light is provided. It is preferable to provide a filter (sharp cut filter, band pass filter) to prevent excitation light from entering the line sensor.

The size of the light receiving surface of each of a large number of photoelectric conversion elements constituting the line sensor is suitably from 10 to 4000 μm, particularly preferably from 100 to 500 μm.
It is preferable that the number of photoelectric conversion elements arranged in the length direction of the line sensor is 1000 or more, and furthermore, the length of the line sensor is longer than or equal to one side of the sheet. In addition, these many photoelectric conversion elements are not limited to an array arranged in a straight line in the major axis direction, but may be arranged in a zigzag shape.

In a configuration in which the number of photoelectric conversion elements is increased so as to be affected by the transfer rate, a memory element corresponding to each photoelectric conversion element is provided, and the charge accumulated in each photoelectric conversion element is temporarily stored in each of the photoelectric conversion elements. A configuration may be employed in which the charge is stored in the memory element and the charge is read out from each memory element during the next charge accumulation period, so that the charge transfer time is not shortened due to an increase in the charge transfer time.

The direction in which the line light source and the line sensor are moved relative to the sheet by the scanning means (the direction different from the length direction) is a direction substantially orthogonal to the length direction. That is, it is desirable that the direction is the short axis direction. However, the direction is not limited to this direction. For example, as described above, in a configuration in which the line light source and the line sensor are longer than one side of the sheet, the line extends over substantially the entire surface of the sheet. Within a range in which the excitation light can be evenly irradiated, the light source and the line sensor may be moved in an oblique direction deviating from a direction substantially perpendicular to the length direction, or may be moved in a zigzag shape, for example. The movement may be performed by changing the direction.

The line light source and the line sensor are limited to those arranged on the same side of the sheet.

Each of the above descriptions can be applied to the following second radiographic image information reading apparatus of the present invention.

According to a second radiation image information reading apparatus of the present invention, instead of the line sensor in the first radiation image information reading apparatus of the present invention, a line sensor provided with a plurality of photoelectric conversion elements both vertically and horizontally is used. The line sensor detects the stimulated emission light emitted from the linear portion of the sheet by this line sensor, and calculates the output of each photoelectric conversion element for each scanning position by adding the output corresponding to the portion of the stimulable phosphor sheet. By performing the processing, the light collection efficiency is improved.

That is, a second radiation image information reading apparatus according to the present invention comprises a line light source for emitting linear excitation light, and a stimulable phosphor sheet on which radiation image information is accumulated and recorded. Excitation light guiding means for guiding light to a part of the sheet, and receiving the stimulated emission light emitted from the portion of the sheet irradiated with the excitation light linearly, and performing photoelectric conversion, the length direction of the portion A line sensor in which a plurality of photoelectric conversion elements are arranged in a (long axis direction) and a direction perpendicular to the long axis direction (short axis direction), and guides the stimulated emission light emitted from the sheet to the line sensor. Stimulating luminescence light guiding means, scanning means for moving the line light source and the line sensor relative to the sheet in a direction different from the length direction, and changing the output of the line sensor according to the movement. Read sequentially, before A radiation image information reading apparatus comprising: a reading unit having an operation unit that performs an operation process on an output of each of the photoelectric conversion elements at each position moved by a scanning unit in correspondence with a part of the sheet. An optical path of the excitation light from the sheet to the sheet and an optical path of the photostimulated light from the sheet to the line sensor are at least partially overlapped.

At least a part of the optical path of the two lights overlaps at least a part of the optical element constituting the excitation light guiding means and at least a part of the optical element constituting the stimulated emission light guiding means. It is desirable to do this, but it is not limited to this.

Here, the size of the light receiving surface of each of a large number of photoelectric conversion elements constituting the line sensor is determined by the amount of the stimulated emission light emitted from the sheet irradiated with the above-mentioned beam width by the excitation light. And a plurality of photoelectric conversion elements are arranged in the length direction (long axis direction) and the light beam width direction (short axis direction) of the light beam, respectively. , Is set to be approximately equal to or longer than the light beam length, and is set to be approximately the same as the light beam width. Note that the plurality of photoelectric conversion elements are not limited to those having a matrix-like arrangement arranged linearly in any of the major axis direction and the minor axis direction, but are arranged linearly in the major axis direction. An arrangement in which the short axis direction is arranged in a zigzag shape, an arrangement in which the short axis direction is arranged in a straight line, but the long axis direction is arranged in a zigzag shape,
They may be arranged in a zigzag arrangement in both axial directions.

As described above, the line sensor has a plurality of photoelectric conversion elements arranged in both the major axis direction and the minor axis direction, and outputs the output of each photoelectric conversion element for each scanning position to the stimulable fluorescent light. By performing arithmetic processing such as addition in accordance with the part of the body sheet, even when the line width of the linear excitation light is larger than the width of the micro-chamber, the stimulus emitted from the micro-chambers adjacent in the line width direction is emitted. The emitted light can be collected by another photoelectric conversion element row, the light collection efficiency can be increased, and also when the width of the photoelectric conversion element is smaller than the width of the micro-chamber,
The stimulated emission light diffused in the line width direction in one micro-chamber can be condensed by a plurality of photoelectric conversion element rows, and the light-collecting efficiency can be increased while improving the resolution.

[0030]

According to the radiation image information reading apparatus of the present invention, at least a part of the optical path of the excitation light and at least a part of the optical path of the stimulated emission light are overlapped, so that the optical path of both lights is The occupied space can be reduced, and the whole device can be further downsized. In the configuration where the optical paths of the two lights are overlapped, at least a part of the optical element constituting the excitation light guiding means and at least a part of the optical element constituting the stimulated emission light guiding means are realized. In addition, since at least a part of the optical elements of these two light guides can be reduced, there is also an effect of cost reduction.

Further, the second aspect of the present invention in which the line sensor is constituted by arranging a plurality of photoelectric conversion elements in the length direction of the linear stimulating light emitted from the sheet and in the direction orthogonal thereto. According to the radiation image information reading apparatus described above, even if the light receiving width of each photoelectric conversion element is shorter than the line width of the stimulated emission light (the line width on the light receiving surface of the photoelectric conversion element), the stimulated emission light as a whole line sensor is Since the light can be received over substantially the entire width of the line, the light receiving efficiency can be improved. Then, the output of each photoelectric conversion element at each position where the sheet or the sensor is moved by the scanning means is subjected to arithmetic processing such as addition by using the arithmetic means so as to correspond to the part of the sheet, thereby obtaining each of the sheets. The light collection efficiency for each part can be increased. Moreover, since the light receiving width of each photoelectric conversion element is not increased to increase the light receiving size, the resolution does not decrease and a desired resolution can be secured.

It should be noted that the radiation image information reading apparatus of the present invention employs a configuration using a line sensor as a photoelectric reading means, in comparison with a conventional radiation image information reading apparatus using a photoelectric reading means other than a line sensor. Accordingly, it is also possible to reduce the time required for reading the stimulated emission light and to reduce the cost by reducing mechanical scanning optical components and the like.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the radiation image information reading apparatus of the present invention will be described with reference to the drawings.

FIG. 1A is a perspective view showing one embodiment of the radiation image information reading apparatus according to the present invention, and FIG. 1B is a sectional view taken along line II of the radiation image information reading apparatus shown in FIG. FIG. FIG. 2 is a diagram showing the line sensor 20 of the radiation image information reading apparatus shown in FIG.

The illustrated radiation image information reading apparatus has a stimulable phosphor sheet (hereinafter, referred to as a phosphor sheet) on which radiation image information is stored.
A scanning belt 40 on which a sheet 50 is placed and conveyed in the direction of the arrow Y, and a broad area semiconductor that emits a linear laser beam L having a line width of about 100 μm and an oscillation wavelength of 600 to 700 nm substantially parallel to the surface of the sheet 50. Laser (hereinafter referred to as BLD) 11, B
An optical system 12 comprising a combination of a collimator lens for condensing the linear laser light L emitted from the LD 11 and a toric lens for expanding the beam only in one direction, which is disposed at an angle of 45 degrees with respect to the surface of the sheet 50. A hot mirror 14, which is set so as to reflect the laser light L so as to be incident on the sheet 50 almost perpendicularly and transmit a stimulating light M described later;
The linear laser light L reflected by the hot mirror 14 is
A line extending along the arrow X direction on the sheet 50 (line width approximately 1
And a linear laser beam L is condensed and emitted from the sheet 50, and is a gradient index lens that emits a stimulating luminescence light M according to accumulated and recorded radiation image information as a parallel light flux. An array (a lens formed by arranging a large number of gradient index lenses, hereinafter referred to as a first Selfoc lens array) 15 and a parallel light flux formed by the first Selfoc lens array 15 and a hot mirror 14
A second selfoc lens array 16, which condenses the photostimulated light M transmitted through the light receiving surface of each photoelectric conversion element 21 constituting the line sensor 20, which will be described later, has passed through the second selfoc lens array 16. Slightly mixed with the stimulating light M,
An excitation light cut filter 17 that cuts the laser light L reflected by the surface of the sheet 50 and transmits the stimulating light M, and a large number of photoelectric converters that receive the stimulating light M transmitted through the excitation light cut filter 17 and perform photoelectric conversion. The configuration includes a line sensor 20 in which the conversion elements 21 are arranged, and an image information reading unit 30 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 device or the like.

The first selfoc lens array 15 irradiates the photostimulated light M on the sheet 50 on the hot mirror 14.
The second selfoc lens array 16 functions as an image plane for forming an image with a one-to-one size on the light emitting area of the hot mirror 14 on the light receiving surface of the photoelectric conversion element 21. This has an effect of setting the image of M as an image plane for forming a one-to-one image. As shown in FIG. 10, instead of the first and second Selfoc lens arrays 15 and 16,
It is also possible to adopt a configuration in which one selfoc lens array 16 'is provided which functions to form an image of the photostimulated light M on the sheet 50 in a one-to-one size on the light receiving surface of the photoelectric conversion element 21. it can.

The optical system 12 composed of a collimator lens and a toric lens expands the laser light L from the BLD 11 onto a hot mirror 14 to a desired irradiation area. The optical system 12 is not limited to a combination of a collimator lens and a toric lens, but may be a cylindrical lens or any other combination as long as it expands the laser beam L to a desired irradiation area on the hot mirror 14. You may.

Here, the hot mirror 14 is an excitation light guiding means for guiding the laser light L, which is an excitation light, to the sheet 50, and a stimulating emission light guiding means for guiding the stimulating light M to the line sensor 20. However, the optical path of the reflected laser light L and the optical path of the stimulated emission light M are arranged to overlap.

More specifically, as shown in FIG. 2, a large number of line sensors 20 (for example,
(1000 or more) photoelectric conversion elements 21 are arranged. Each of the photoelectric conversion elements 21 constituting the line sensor 20 has a light receiving surface having a size of approximately 100 μm × 100 μm in width, and the size is 100 μm × width in the surface of the sheet 50. It is a size that receives the stimulated emission light M emitted from a portion having a size of about 100 μm. In addition, as the photoelectric conversion element 21, specifically, an amorphous silicon sensor, a CCD sensor, a MOS image sensor, or the like can be applied.

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

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

On the other hand, the BLD 11 emits a linear laser beam L having a line width of approximately 100 μm substantially parallel to the surface of the sheet 50, and the laser beam L is transmitted through a collimator lens and a toric provided on the optical path. The beam is converted into a parallel beam by the optical system 12 composed of a lens, is reflected by the hot mirror 14, and proceeds in a direction perpendicular to the surface of the sheet 50,
The first SELFOC lens 15, is focused on the sheet 50 on the arrow X directions extending along the linear (line width d _L shown 100 [mu] m).

The laser beam L excites the stimulable phosphor in the linear condensing area (line width d _{L of about} 100 μm) on the sheet 50, whereby the stimulable phosphor in the condensing area is stored and recorded. The stimulated emission light M having an emission intensity corresponding to the radiation image information is emitted.

The stimulated emission light M emitted from the sheet 50 is converted into a parallel light beam by the first selfoc lens 15 and travels in the same optical path as the laser light L in the opposite direction.
Incident on. Here, the stimulated emission light M passes through the hot mirror 14, and is condensed by the second Selfoc lens array 16 on the light receiving surface of each photoelectric conversion element 21 constituting the line sensor 20. At this time, the second SELFOC lens array 16
The laser light L reflected on the surface of the sheet 50 slightly mixed with the stimulated emission light M transmitted through the filter 50 is cut by the excitation light cut filter 17.

The stimulated emission light M that has passed through the filter 17
Represents a number of photoelectric conversion elements 21 constituting the line sensor 20.
And is converted into each image signal Q by photoelectric conversion. These image signals Q obtained by the photoelectric conversion are input to the image information reading means 30, and are output to an image processing device or the like in association with the position of the sheet 50 corresponding to the amount of displacement of the scanning belt 40.

As described above, according to the radiation image information reading apparatus of the present embodiment, a part of the optical path of the laser beam L and a part of the optical path of the stimulating light M are transferred to the hot mirror 14 and the first self- Since the optical path of the laser light L and the optical path of the photostimulated light M are separated by the lens array 15, the space occupied by the two lights L and M is smaller than that of the conventional radiation image information reading apparatus. The size of the device can be reduced by the reduced space.

FIG. 3 is a view showing an embodiment of the second radiation image information reading apparatus of the present invention, and FIG. 4 is a view showing a detailed configuration of the line sensor 20 of the reading apparatus shown in FIG.

The radiation image information reading apparatus shown in FIG.
A scanning belt 40 on which the sheet 50 is placed and conveyed in the direction of the arrow Y, a linear laser light L having a line width of about 100 μm is emitted substantially parallel to the surface of the sheet 50, and a linear laser light L emitted from the BLD 11 is emitted. An optical system 12 composed of a combination of a collimating lens for focusing and a toric lens for expanding the beam only in one direction, arranged at an angle of 45 degrees with respect to the surface of the sheet 50 so that the light is incident on the sheet 50 almost perpendicularly. Laser light L
And a linear laser beam L reflected by the hot mirror 14 are set on the sheet 50 to extend along the X direction. (A width of about 100 μm), and a linear laser beam L is condensed and emitted from the sheet 50, and the stimulated emission light M according to the accumulated and recorded radiation image information is converted into a first parallel light beam. The stimulated emission light M that has been converted into a parallel light flux by the selfoc lens array 15 and the first selfoc lens array 15 and has passed through the hot mirror 14 is received by each photoelectric conversion element 21 constituting a line sensor 20 described later. The second selfoc lens array 16 for focusing light on the surface, the second
Photostimulated light M that has passed through the SELFOC lens array 16
Light L reflected on the surface of the sheet 50 slightly mixed
An excitation light cut filter 17 that cuts through and emits the stimulating light M, and a line sensor in which a large number of photoelectric conversion elements 21 that receive the stimulating light M transmitted through the excitation light cut filter 17 and perform photoelectric conversion are arranged. 20 and the signals output from the photoelectric conversion elements 21 constituting the line sensor 20 are
It has an adding means 31 for performing addition processing in correspondence with 50 parts,
The configuration is provided with image information reading means 30 for outputting the image signal subjected to the addition processing.

The first selfoc lens array 15 has the function of forming, on the hot mirror 14, the light emission area of the stimulating light M on the sheet 50 as an image plane for forming an image with a one-to-one size. The second selfoc lens array 16 has an effect of setting the image of the photostimulated light M on the hot mirror 14 on the light receiving surface of the photoelectric conversion element 21 as an image surface on which the image is formed in a one-to-one size.

The optical system 12 composed of a collimator lens and a toric lens expands the laser light L from the BLD 11 onto a hot mirror 14 to a desired irradiation area.

The hot mirror 14 is an exciting light guiding means for guiding the laser light L, which is an exciting light, to the sheet 50, and is also a stimulating light emitting light guiding means for guiding the stimulating light M to the line sensor 20. The optical path of the reflected laser light L and the optical path of the stimulated emission light M are arranged to overlap.

More specifically, as shown in FIG. 4, a large number (for example, 1000 or more) of the line sensors 20 are arranged along the arrow X direction.
And the rows of photoelectric conversion elements 21 extending in the direction of the arrow X are arranged in three rows in the conveying direction of the sheet 50 (the direction of the arrow Y). Each of the photoelectric conversion elements 21 constituting the line sensor 20 has a light receiving surface having a size of approximately 100 μm × 100 μm in width, and the size is 100 μm × width in the surface of the sheet 50. It is a size that receives the stimulated emission light M emitted from a portion having a size of about 100 μm. In addition, as the photoelectric conversion element 21, specifically, an amorphous silicon sensor, a CCD sensor, a MOS image sensor, or the like can be applied.

As the addition processing by the addition means 31, simple addition, weighted addition, or the like can be applied. Instead of the addition means 31, an arithmetic processing means for performing other arithmetic processing may be applied.

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

First, as the scanning belt 40 moves in the direction of the arrow Y, the sheet 50 on which the radiation image information is stored and conveyed is conveyed in the direction of the arrow Y. At this time, the conveying speed of the sheet 50 is equal to the moving speed of the belt 40, and the moving speed of the belt 40 is input to the adding means 31.

On the other hand, the BLD 11 emits a linear laser beam L having a line width of approximately 100 μm substantially in parallel to the surface of the sheet 50, and the laser beam L is transmitted through a collimator lens and a toric provided on the optical path. The beam is converted into a parallel beam by the optical system 12 composed of a lens, is reflected by the hot mirror 14, and proceeds in a direction perpendicular to the surface of the sheet 50. The first selfoc lens 15 moves the beam onto the sheet 50 in the direction of arrow X. Line extending along (line width d _L approximately 100 μm)
(See FIG. 5A).

The linear laser light L incident on the sheet 50 is
Excitation of the stimulable phosphor in the condensing area (line width d _{L of about} 100 μm) is performed, and the light enters the inside of the sheet 50 from the condensing area and diffuses into the vicinity of the condensing area. Width d _M )
Stimulable phosphor is also excited. As a result, stimulated emission light M having an intensity corresponding to the accumulated and recorded radiation image information is emitted from the light condensing area of the sheet 50 and its vicinity (line width d _M ) (see FIG. 2B). The intensity distribution in the line width direction is as shown in FIG.

The stimulated emission light M emitted from the portion of the sheet 50 having the line width d _M is converted into a parallel light flux by the first Selfoc lens 15 and travels in the same optical path as the laser light L in the opposite direction. It is incident on 14. Here, the stimulated emission light M
Are transmitted through the hot mirror 14 and condensed by the second selfoc lens array 16 on the light receiving surfaces of the photoelectric conversion elements 21 constituting the line sensor 20. At this time, the laser light L reflected on the surface of the sheet 50 slightly mixed with the stimulated emission light M transmitted through the second selfoc lens array 16 is cut by the excitation light cut filter 17.

[0059] Here, on the light receiving surface of the line sensor 20, the relationship between the distribution of the size and emitted light M of the photoelectric conversion element 21, as shown in FIG. 4, beam width d _M of the surface of the sheet 50 is , Photoelectric conversion elements 21 for three rows in the arrow Y direction
(Approximately 300 μm in width).

The line sensor 20 photoelectrically converts the stimulated emission light M received by each photoelectric conversion element 21, and each signal Q obtained by the photoelectric conversion is input to the adding means 31.

The addition means 31 accumulates and stores the signals Q from the corresponding photoelectric conversion elements 21 in a memory area provided for each part of the sheet 50 based on the moving speed of the scanning belt 40. Let it.

This operation will be described below in detail with reference to FIGS. In order to simplify the explanation in this embodiment, the line width d _M of the emitted light M on the light receiving surface of the line width of the emitted light M of the sheet 50 on the surface d _M and the line sensor 20 The optical system arranged between the sheet 50 and the line sensor 20 is set so that
Line width d _M of photostimulated light M on the surface and line sensor
Not have a line width d _M of the emitted light M to be limited to necessarily match on the light receiving surface of 20, the photoelectric conversion elements constituting the line sensor 20 according to the corresponding relationship between the two 21 And the number of columns in the line width direction may be set.

First, as shown in FIG.
In a state where the fluorescent light L is condensed on the leading end S1 in the conveying direction (the direction of the arrow Y), the spread of the laser light L
The stimulated emission light M as shown in the emission distribution curve of the figure is emitted not only from the front end portion S1 of the 50 but also from the neighboring region S2 as described above. The amount of the stimulating light M generated from the portion S1 of the sheet 50 is Q2, and the amount of the stimulating light M of the light amount Q2 is equal to the photoelectric conversion element array 20 corresponding to the portion S1 of the sheet 50.
B (see FIG. 4) is received by the photoelectric conversion element 21 and the amount of photostimulated light M generated from the portion S2 of the sheet 50 is Q3. Light is received by the photoelectric conversion element 21 of the photoelectric conversion element row 20C corresponding to S2.

The photoelectric conversion element 21 (20B column) photoelectrically converts the received stimulating light M of the light quantity Q2 into a charge Q'2, and transfers this to the adding means 31. The adding means 31 is a photoelectric conversion element 21
The charge Q′2 transferred from the (20B column) is
Is stored in the memory corresponding to the portion S1 of the sheet 50 based on the scanning speed (see FIG. 7). Similarly, the photoelectric conversion element 21 (20C column) photoelectrically converts the stimulating light M of the received light quantity Q3 into a charge Q'3, and transfers this to the adding means 31.
The adding means 31 stores the transferred charge Q'3 in a memory corresponding to the portion S2 of the sheet 50.

Next, the sheet 50 is conveyed, and FIG.
As shown in the figure, in a state where the fluorescent light L is condensed on the portion S2 of the sheet 50, the sheet 50 is operated by the same operation as described above.
Stimulated luminescent light M is also generated from the neighboring portions S1 and S3 around the portion S2, and the stimulated luminescent light M is generated from the portion S1 as the light amount Q4, the portion S2 as the light amount Q5, and the portion S3 as the light amount Q6. The stimulated emission light M is received by the corresponding photoelectric conversion elements 21 (20A column), 21 (20B column), and 21 (20C column).

Each of the photoelectric conversion elements 21 (20A column), 21 (20B
Columns 21 and 21 (column 20C) convert the received photostimulated light M into charges Q'4, Q'5, Q'6 and transfer them to the adding means 31, respectively.

The adding means 31 includes each photoelectric conversion element (20A column),
The charges Q'4, Q'5, and Q'6 transferred from 21 (column 20B) and 21 (column 20C) are respectively transferred to portions S1, S2, and S3 of the sheet 50 based on the scanning speed of the scanning belt 40. It is added to the corresponding memory and stored.

Hereinafter, when the sheet 50 is conveyed and the fluorescent light L is condensed on the portion S3 of the sheet 50 as shown in FIG. 6 (3), each of the photoelectric conversion elements 21 (20A row) and 21 (20B
) And 21 (20C column), respectively,
7, Q'8 and Q'9 are added and stored in the memories corresponding to the portions S2, S3 and S4 of the sheet 50 by the same operation.

The same operation as described above is repeated for each transport position of the sheet 50, and the memory corresponding to each part of the sheet 50 in the adding means 31 stores the transport position of the sheet 50 as shown in FIG. The total sum of the stimulated emission light M received for each is stored.

Then, the signal stored in the memory is output from the image information reading means 30 to an external image processing device or the like to be used for reproducing a diagnostic image.

As described above, according to the radiation image information reading apparatus of the present embodiment, a part of the optical path of the laser light L and a part of the optical path of the stimulating light M are combined with the hot mirror 14 and the first self- Since the optical path of the laser light L and the optical path of the photostimulated light M are separated by the lens array 15, the space occupied by the two lights L and M is smaller than that of the conventional radiation image information reading apparatus. The size of the device can be reduced by the reduced space. Further, by using a photoelectric conversion element having a light receiving width d _P (<d _M ) shorter than the line width d _M of the stimulated emission light (the line width on the light receiving surface of the photoelectric conversion element), it is possible to secure a desired resolution while using the photoelectric conversion element. Since the entire line sensor can receive light over substantially the entire width of the stimulated emission light, the light receiving efficiency can be improved. Then, the addition means increases the light-collecting efficiency of each part of the sheet by adding the output of each photoelectric conversion element at each position where the sheet is moved by the scanning belt in correspondence with the part of the sheet. Can be.

The radiation image information reading apparatus according to the present invention is not limited to the above-described embodiment, but includes a broad area laser, a condensing optical system between the broad area laser and the sheet, and a light beam between the sheet and the line sensor. Various known configurations can be adopted as the optical system, the line sensor, or the calculation means. In addition, the image processing apparatus further includes an image processing device that performs various signal processing on signals output from the image information reading unit, and an erasing unit that appropriately emits radiation energy still remaining on the sheet whose excitation has been completed. An equipped configuration can also be adopted.

Further, as shown in FIG. 4, the line sensor 20 in the present embodiment
In both the length direction (long axis direction) and the direction orthogonal to the long axis direction (short axis direction), the arrangement is arranged in a matrix in a straight line. The line sensor used in the image information reading apparatus is not limited to the one in such an embodiment. As shown in FIG. 8A, the line sensor is arranged in a straight line in the long axis direction (the direction of arrow X), but is short in the short axis. The direction (arrow Y direction) is arranged in an arrangement arranged in a zigzag pattern, or as shown in FIG. 2B, arranged in a straight line in the short axis direction but arranged in a zigzag form in the long axis direction. There may be.

Further, each of the radiation image information reading apparatuses of the above-described embodiments uses a hot mirror,
Although a part of the optical path of the laser light L and a part of the optical path of the stimulating light M are overlapped with each other, for example, as shown in FIG. A configuration in which a part of the optical path of the laser light L and a part of the optical path of the stimulated emission light M overlap using the cold mirror 14 ′ that reflects light may be adopted.

That is, the illustrated radiation image information reading apparatus is a scanning belt 40, a BLD 11 that emits a linear laser beam L at an angle substantially orthogonal to the surface of the sheet 50, and condenses a linear laser beam L emitted from the BLD 11. An optical system 12 for irradiating a linear laser beam L to the surface of the sheet 50, and a laser beam inclined by approximately 45 degrees with respect to the surface of the sheet 50, A cold mirror 14 ′ set to transmit the light L as it is and reflect the stimulating light M, and a linear laser light L transmitted through the cold mirror 14 ′ are placed on the sheet 50 along the arrow X direction. The laser beam L is condensed into an extended linear shape (line width of about 100 μm), and the stimulated emission light M according to the accumulated and recorded radiation image information, which is emitted from the sheet 50 by condensing the linear laser light L, is a parallel light beam. The first selfoc lens array 15 and the first selfoc lens array 15 convert the light beam into a parallel light beam, and the cold mirror 14 '
The second selfoc lens array 16 for condensing the stimulated emission light M reflected by the light on the light receiving surface of each photoelectric conversion element 21 constituting the line sensor 20, and the brightness passing through the second selfoc lens array 16 A sheet that is slightly mixed with the emitted light M
Excitation light cut filter 17 that cuts laser light L reflected by 50 surface and transmits stimulating light M, and a large number of photoelectric conversions that receive stimulating light M that has passed through excitation light cut filter 17 and perform photoelectric conversion A line sensor 20 in which elements 21 are arranged,
And an image information reading means 30 for reading a signal output from each photoelectric conversion element 21 constituting the line sensor 20 and outputting the signal to an image processing device or the like.

The radiation image information reading apparatus of the present invention is not limited to the apparatus using the above-described hot mirror or cold mirror, but includes a part of the optical path of the excitation light and one of the optical paths of the photostimulated light. Various modes can be applied as long as the light guide means is arranged such that the portions overlap.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of a first radiation image information reading apparatus of the present invention.

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

FIG. 3 is a configuration diagram showing an embodiment of a second radiation image information reading apparatus of the present invention.

FIG. 4 is a diagram showing details of a line sensor of the radiation image information reading apparatus shown in FIG. 3;

FIG. 5 is a diagram showing the relationship between the beam width of laser light and the beam width of stimulated emission light.

FIG. 6 is a view for explaining the operation of the radiation image information reading apparatus of the embodiment shown in FIG. 3;

FIG. 7 is a conceptual diagram showing a memory of an adding unit corresponding to each part of a sheet.

FIG. 8 is a diagram showing another arrangement state of the photoelectric conversion elements constituting the line sensor.

FIG. 9 is a configuration diagram showing another embodiment of the radiation image information reading apparatus of the present invention (part 1).

FIG. 10 is a configuration diagram showing another embodiment of the radiation image information reading apparatus of the present invention (part 2).

[Explanation of symbols]

11 Broad-area semiconductor laser (BLD) 12 Optical system consisting of collimator lens and toric lens 14 Hot mirror 14 'Cold mirror 15, 16 Selfoc lens array 17 Excitation light cut filter 20 Line sensor 21 Photoelectric conversion element 30 Image information reading means 31 Addition means (calculation means) 40 scanning belt 50 stimulable phosphor sheet L laser light M photostimulated light

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Sumihiro Nishihata Fuji Photo Film Co., Ltd. 798, Kaidai-cho, Kaigara-gun, Ashigarashimo-gun, Kanagawa Prefecture F term in reference (reference) 2H013 AC03 5C072 AA01 BA01 CA05 CA06 DA02 DA06 DA21 EA05 EA06 NA01 NA08 VA01

Claims (4)

[Claims] A line light source for emitting linear excitation light;
Excitation light guide means for guiding the linear excitation light to a part of the stimulable phosphor sheet on which the radiation image information is stored and emitted, and light is emitted from the part of the sheet irradiated with the excitation light linearly. A line sensor in which a plurality of photoelectric conversion elements are disposed in a length direction of the portion, which receives the stimulated emission light that has been subjected to photoelectric conversion, and the line includes the stimulated emission light emitted from the sheet. Stimulating luminescence light guiding means for guiding light to a sensor; scanning means for moving the line light source and the line sensor relative to the sheet in a direction different from the length direction; and an output of the line sensor. A reading means for sequentially reading the light according to the movement, wherein the light path of the excitation light from the line light source to the sheet and the luminous emission from the sheet to the line sensor. A radiation image information reading apparatus, wherein an optical path of light is at least partially overlapped. 2. The optical system according to claim 1, wherein at least a part of the optical element constituting the excitation light guiding means is shared with at least a part of the optical element constituting the stimulated emission light guiding means. The radiation image information reading device according to the above. 3. A line light source for emitting linear excitation light;
An excitation light guiding means for guiding the linear excitation light to a part of the stimulable phosphor sheet on which the radiation image information is accumulated and recorded, and light emission from a part of the sheet irradiated with the excitation light linearly. A line sensor in which a plurality of photoelectric conversion elements are disposed in a length direction of the portion and a direction orthogonal thereto, and the photoelectric conversion device receives the stimulated emission light and emits light. Stimulating luminescence light guiding means for guiding stimulating light to the line sensor, and scanning means for moving the line light source and the line sensor relative to the sheet in a direction different from the length direction; Calculating means for sequentially reading the output of the line sensor in accordance with the movement and calculating the output of each of the photoelectric conversion elements at each position moved by the scanning means in correspondence with the portion of the sheet In the radiation image information reading apparatus provided with a reading unit having, the optical path of the excitation light from the line light source to the sheet and the optical path of the stimulating light from the sheet to the line sensor, at least in part A radiation image information reading device, wherein the radiation image information reading device is overlapped. 4. The optical system according to claim 3, wherein at least a part of the optical element constituting the excitation light guiding means is shared with at least a part of the optical element constituting the stimulated emission light guiding means. The radiation image information reading device according to the above.