JPH06160311A - Radiation image reader - Google Patents

Abstract

PURPOSE:To provide a radiation image reader which achieves higher image reading sensitivity by expanding an angle of trapping of fluorescence excited on a recording surface of a radiation image recording body. CONSTITUTION:A fluorescence conduction means 11 made up of cylindrical body is provided to reflect fluorescence emitted from a radiation image recording body 1 at an internal part thereof and a tip opening part of the fluorescence conduction means 11 is arranged in proximity to a recording surface 1a of the radiation/image recording body 1. Then, the fluorescence brought inside at the tip opening part of the fluorescence conduction means 11 is reflected on an internal part surface to be introduced to a fluorescence detection means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation image reading apparatus for reading radiation image information recorded on a radiation image recording body (hereinafter also referred to as an imaging plate) used in an X-ray diffractometer or the like. .

[0002]

2. Description of the Related Art Some X-ray diffractometers utilize an imaging plate having a stimulable phosphor layer as a detector for diffracted X-rays emitted from a sample. This imaging plate absorbs and accumulates the diffracted X-rays from the sample, and emits fluorescence according to the intensity of the accumulated diffracted X-rays by irradiating with excitation light such as laser light.

Conventionally, as a radiation image processing apparatus for reading radiation image information recorded on the imaging plate, for example, one having a structure as shown in FIG. 9 is known. The radiographic image reading apparatus shown in the figure includes a scanning table 2 that can move in the XZ direction in parallel with the imaging plate 1, and an optical lens 3 is provided on the scanning table 2.
The recording surface of the imaging plate 1 is irradiated with the laser light (excitation light) emitted from the laser device 7 via the reflection mirrors 4 and 5 and the dichroic mirror 6.

When the recording surface of the imaging plate 1 is irradiated with laser light, fluorescence is output according to the intensity of the diffracted X-rays accumulated in the imaging plate 1. This fluorescence is converged by the optical lens 3 and guided to the photomultiplier tube 8 via the reflection mirror 4. Here, the photomultiplier tube 8 is installed on the back surface side of the dichroic mirror 6, and the dichroic mirror 6 uses a material that reflects laser light (633 mm) but transmits fluorescence (390 mm). There is.

[0005]

In the above-mentioned conventional radiation image reading apparatus, the fluorescence emitted from the imaging plate 1 is converged by using the optical lens 3 and guided to the photomultiplier tube 8. In such a configuration, since the lens barrel 9 for supporting the optical lens 3 and the adjusting holding barrel 10 for making the focus of the optical lens 3 coincide with the imaging plate surface are needed, the imaging plate 1 and the optical lens 3 are required. And must be separated from several mm to several tens of mm. However, since the fluorescent light is emitted radially from the recording surface of the imaging plate 1, if the distance between the imaging plate 1 and the optical lens 3 is long, the amount of fluorescent light that enters the optical lens 3 decreases, and the sensitivity of image reading is reduced. There was a problem that I could not give up.

The present invention has been made in view of the above-mentioned circumstances, and is directed to a radiation image reading apparatus for improving the image reading sensitivity by widening the capture angle of fluorescence excited on the recording surface of the radiation image recording body. For the purpose of provision.

[0007]

In order to achieve the above object, according to the invention of claim 1, a light source for outputting excitation light for exciting a recording surface of a radiation image recording body, and the radiation image recording body are provided. Fluorescent conducting means, which is formed by a cylindrical body that reflects emitted fluorescent light at its inner side, and whose tip opening is arranged close to the recording surface of the radiation image recording body, and the recording surface of the radiation image recording body. And an excitation light guide means for irradiating the excitation light from the light source, and a fluorescence detection means for inputting fluorescence from the radiation image recording medium via the fluorescence conduction means. According to the invention of claim 2, the fluorescence conducting means comprises a plurality of first flat plates formed by a mirror body that reflects fluorescence, and a semi-transparent second flat plate that reflects fluorescence and transmits excitation light. It is characterized in that it is configured by. According to a third aspect of the invention, the fluorescence conducting means is
It is characterized in that it is constituted by a parabolic cylindrical body that reflects fluorescence inside, and is arranged such that the recording surface of the radiation image recording body is located at the focal point of the parabolic surface. The invention according to claim 4 is characterized in that the end surface of the front end opening in the fluorescence conducting means is a curved surface concentric with the recording surface of the drum-shaped radiation image recording body.

[0008]

The excitation light emitted from the light source is applied to the recording surface of the radiation image recording body from the central axis of the fluorescent conducting means via the light guiding means. Fluorescence is radially emitted from this irradiated portion according to the intensity of the accumulated radiation.
This fluorescence enters the inside of the cylindrical body that forms the fluorescence conducting means through the front end opening, is guided to the rear end while repeating reflection inside, and is connected to the rear end. Input to the detector. Here, since the tip end opening of the cylindrical body forming the fluorescence conducting means is arranged close to the recording surface of the radiation image recording body, it is possible to capture the fluorescence emitted over a wide angle range.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 are views showing a first embodiment of the present invention, FIG. 1 is a plan sectional view of a radiation image reading apparatus according to this embodiment, FIG. 2 is a sectional view taken along line II-II in FIG. FIG. 3 is a perspective view of the fluorescence conducting means used in the device. As shown in these figures, the radiation image reading apparatus of this embodiment includes a light source 10, a fluorescence conducting means 11, an excitation light guiding means 12, and a photomultiplier tube 13 as a fluorescence detecting means.
Is equipped with.

The light source 10 outputs excitation light (laser light) for exciting the recording surface 1a of the imaging plate 1. That is, when the recording surface 1a of the imaging plate 1 made of a stimulable phosphor is irradiated with laser light, the recording surface 1
Fluorescence is radially emitted from the recording surface 1a according to the intensity of the radiation accumulated in the recording surface 1a.

The fluorescent conducting means 11 is composed of four flat plates 14 and 1.
It is formed in a tubular body composed of 4, 14, and 15. Three flat plates (first flat plates) 14, 14, 14 are formed by mirrors that reflect inside the fluorescent light, and the remaining one flat plate (second flat plate) 15 reflects the fluorescent light but is the light source 10. It is formed by a dichroic mirror that transmits the excitation light from. Generally, the wavelength of fluorescence is 390 mm and the wavelength of excitation light is around 633 mm. Therefore, the dichroic mirror reflects light with a wavelength near 390 mm,
A material having a property of transmitting light having a wavelength of about 33 mm is used. A reinforcing metal plate 16 is joined to the outer surfaces of the first flat plates 14, 14, 14. The fluorescent conduction means 11 is
X parallel to the recording surface 1a of the imaging plate 1
It is mounted on a scanning table 17 which can be moved in the −Z direction (the Z direction means a direction orthogonal to the paper surface in FIG. 1). The tip opening end surface 11a is arranged in proximity to the recording surface 1a of the imaging plate 1.

The excitation light guide means 12 is formed of a dichroic mirror which transmits fluorescence but reflects excitation light from the light source 10. That is, as the excitation light guiding means 12, a dichroic mirror having a property of transmitting light having a wavelength near 390 mm and reflecting light having a wavelength near 633 mm is used. The excitation light guiding means 12 is a fluorescence conducting means 11
It is installed in a hollow portion of the imaging plate 1 with a certain angle of inclination.

Further, the above-mentioned light source 10 is such that the excitation light a is located near the intersection of the central axis of the fluorescence conduction means 11 with the second flat plate (dichroic mirror) 15 and the excitation light guide means 12. Is positioned so that the laser beam can be emitted, and in synchronization with the movement of the scanning table 17 in the Z direction,
It is possible to move in the same direction. The inclination angle of the excitation light guide means 12 is adjusted to an angle that guides the excitation light emitted from the light source 10 to the imaging plate 1 along the central axis of the fluorescence conducting means 12.

The photomultiplier tube 13 is provided in contact with the end face of the rear end opening of the fluorescence conducting means 11 through a noise removing filter 18 that does not transmit light other than 390 nm.
This photomultiplier tube 13 is also mounted on the scanning table 17, and moves in the XY direction together with the fluorescence conducting means 11.

According to the radiation image reading apparatus having the above-mentioned structure, the excitation light a outputted from the light source 10 is excited by the excitation light guiding means 1.
Irradiate the imaging plate 1 via 2. From the irradiation point, an amount of fluorescence b is radially emitted according to the strength of the accumulated radiation. This fluorescence b is the fluorescence conduction means 1
It is taken into the hollow portion of No. 1 and proceeds to the rear end opening while repeating reflection inside the means 11. In the middle of this
Since the excitation light guide means (dichroic mirror) 12 installed in the hollow portion of the fluorescence conducting means 11 has a property of transmitting the fluorescence b, it does not hinder the progress of the fluorescence b. The noise is removed by the filter 18 from the fluorescence b that has traveled through the hollow portion of the fluorescence conducting means 11 and has reached the rear end opening.
Then, it is input to the photomultiplier tube 13. On the other hand, the excitation light a irradiated on the imaging plate 1 is
Is reflected by and enters the hollow portion of the fluorescence conducting means 11,
Since the excitation light guiding means 12 blocks the movement toward the rear end opening, it does not enter the photomultiplier tube 13. That is, the excitation light a is reflected by the dichroic mirror forming the excitation light guide means 12, passes through the second flat plate (dichroic mirror) 15 forming one side surface of the fluorescence conducting means 11, and is emitted to the outside.

As described above, in the apparatus of this embodiment, the fluorescence b emitted from the imaging plate 1 is taken in from the tip end opening end surface 11a of the fluorescence conducting means 11, so that the end surface 11a is the recording surface 1a of the imaging plate 1. The fluorescent light emitted radially can be taken in over a wide angular range by arranging the fluorescent light in close proximity to. Further, since the photomultiplier tube 13 is arranged immediately behind the end face of the rear end opening of the fluorescence conducting means 11, the optical path of the fluorescence b is shorter than that of the conventional device shown in FIG. Little fluorescence decay.

Next, FIGS. 4 to 6 are views showing modified examples of the above-mentioned radiation image reading apparatus. The radiation image reading apparatus shown in FIG. 4 is configured to read the radiation image recorded on the drum type imaging plate 1. That is, the fluorescence conducting means 1 that takes in fluorescence
1 and the imaging plate 1
The recording surface 1a is formed on a curved surface concentric with the recording surface 1a.
It is possible to dispose it close to a.

Also, the radiation image reading apparatus shown in FIG.
Similarly, the radiation image recorded on the drum type imaging plate 1 is read. That is, the first flat plate 14 and the second flat plate 15 (not shown in FIG. 5) forming the side wall of the fluorescence conducting means 11 are shaved inward by a predetermined length at the tip opening edge of the imaging plate 1.
In the configuration, the portion irradiated with the excitation light in (1) is inserted into the hollow portion of the fluorescence conducting means 11. With these configurations, the fluorescence that is radially generated on the recording surface 1a of the imaging plate 1 is the fluorescence conducting means 1 over a wide angle range.
1 can be taken into the hollow portion, and as a result, the amount of light incident on the photomultiplier tube 13 is increased, and the detection sensitivity can be improved.

FIG. 6 is a plan sectional view showing another modification of the radiation image reading apparatus shown in FIG. In the radiation image reading apparatus shown in the figure, a total reflection mirror 20 is arranged on the central axis in the fluorescence conducting means 11 as the excitation light guiding means, and the fluorescence conducting means 11 is entirely formed of the first flat plate 14. . The total reflection mirror 20 has a minimum required size for reflecting the excitation light a in the direction of the imaging plate 1, and it is an obstacle to the fluorescence b traveling from the imaging plate 1 to the photomultiplier tube 13. It is preferable to reduce it as much as possible. In addition, the excitation light a output from the light source 10 is provided on a part of the first flat plate 14 as a total reflection mirror 20.
A minute through hole 21 that allows the light to pass through is provided. In this device, the excitation light a reflected by the imaging plate 1 also travels toward the photomultiplier tube 13. Therefore, a filter 22 that removes not only noise but also the excitation light a between the rear end opening end face of the fluorescence conducting means 11 and the photomultiplier tube 13.
Is provided.

FIG. 7 is a plan sectional view showing a second embodiment of the present invention. In the radiation image reading apparatus shown in the figure, the fluorescence conducting means 11 is formed of a parabolic cylindrical body, and the inner portion of this cylindrical body is a mirror surface that reflects at least the fluorescence b. Here, the front end opening end surface 11a of the fluorescence conducting means 11
Is cut and formed so that the focal point p of the parabolic surface is slightly exposed to the outside. Then, the recording surface 1a of the imaging plate 1 is placed on the focal point p of the paraboloid. The configurations of the light source 10, the total reflection mirror 20 as the excitation light guiding means, the through hole 21, and the filter 22 are the same as those of the device shown in FIG. In the apparatus of this embodiment, the excitation light a output from the light source 10 is applied to the recording surface 1a of the imaging plate 1 via the total reflection mirror 20. This irradiation point is the focus p of the parabolic surface of the fluorescence conducting means 11 as described above.
Then, the fluorescence b is radially emitted from this focus position and is taken into the hollow portion of the fluorescence conducting means 11. The fluorescence b taken into the fluorescence conducting means 11 is reflected on the inner side and travels toward the photomultiplier tube 13. Here, as a characteristic of the paraboloid, the fluorescence emitted from the focal point p is reflected by the inner side of the paraboloid and then travels as parallel light. Therefore, since the reflection is not repeated in the fluorescence conducting means 11, the optical path until the light enters the photomultiplier tube 13 is further shortened, and the attenuation of the fluorescence is small.

FIG. 8 shows an example in which the radiation image reading apparatus shown in FIG. 7 is applied to read a drum type imaging plate. That is, the front end opening end surface 11a of the fluorescence conducting means 11 that takes in the fluorescence b is formed into a curved surface concentric with the recording surface 1a of the imaging plate 1, and the fluorescence b emitted radially from the recording surface 1a is wide angle. It is possible to import within a range. The recording surface 1a of the imaging plate 1 is arranged on the focal point p of the parabolic surface formed by the fluorescence conducting means 11, as in the above-described embodiment (FIG. 7).

As an example of manufacturing the fluorescence conducting means 11 composed of the above-mentioned parabolic cylindrical body, the outer peripheral surface of the quartz rod is polished into a parabolic shape, and only the fluorescence is reflected on the outer surface of the quartz rod for excitation. There is a method of applying a coating material having a property of transmitting light. Further, there is a method in which an optical glass is hot-pressed with a press die to form a tubular body having a parabolic outer surface, and a coating material having a property of reflecting only fluorescence and transmitting excitation light is applied to the outer surface. . When a fluorescent reflection mirror surface is formed with such a coating material, the excitation light is emitted to the outside through the coating layer, and thus the filter 22 only needs to have a function of removing noise. It should be noted that the present invention is not limited to the above-described embodiments, and various modifications and applications are possible without changing the gist.

[0023]

As described above, according to the radiographic image reading apparatus of the present invention, the fluorescence emitted from the recording surface of the radiographic image recording body is taken into the cylindrical fluorescence conducting means to the fluorescence detecting means. By arranging the tip end opening of the fluorescence conducting means close to the recording surface of the radiation image recording body, it is possible to capture the fluorescence excited on the recording surface in a wide range of angles and improve the image reading sensitivity. effective.

[Brief description of drawings]

FIG. 1 is a plan sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a perspective view showing a fluorescence conducting means in the embodiment.

FIG. 4 is a front sectional view showing a modified example of the first embodiment.

FIG. 5 is a front sectional view showing another modification of the first embodiment.

FIG. 6 is a front sectional view showing another modification of the first embodiment.

FIG. 7 is a plan sectional view showing a second embodiment of the present invention.

FIG. 8 is a front sectional view showing a modified example of the second embodiment.

FIG. 9 is a diagram showing a conventional example.

[Explanation of Codes] 1 Imaging Plate 10 Light Source 11 Fluorescence Conducting Means 12 Excitation Light Guide Means 13 Photomultiplier Tube 18 Filter 20 Excitation Light Guide Means 21 Through Hole 22 Filter

Claims (4)

[Claims] 1. A light source that outputs excitation light for exciting a recording surface of a radiation image recording body, and a cylindrical body that reflects fluorescence emitted from the radiation image recording body at an inner portion, Fluorescent conduction means having a tip opening disposed in proximity to the recording surface of the radiation image recording body, excitation light guiding means for irradiating the recording surface of the radiation image recording body with excitation light from the light source, and the fluorescence conduction. And a fluorescence detecting unit for inputting fluorescence from the radiation image recording medium via the means. 2. The radiation image reading apparatus according to claim 1, wherein the fluorescence conducting means includes a plurality of first flat plates formed of a mirror body that reflects fluorescence, and a half that reflects the fluorescence and transmits the excitation light. A radiation image reading device comprising a transparent second flat plate. 3. The radiation image reading apparatus according to claim 1, wherein the fluorescence conducting means is formed of a parabolic cylindrical body that internally reflects fluorescence, and is located on the focus of the parabola. A radiation image reading device, characterized in that it is arranged such that the recording surface of the radiation image recording body is positioned. 4. The radiation image reading apparatus according to claim 1, wherein the radiation image recording body is formed in a drum shape, wherein the front end opening end face of the fluorescence conducting unit is the drum. Image reading device, characterized in that it has a curved surface that is concentric with the recording surface of a radiation image recording body having a circular shape.