JP3796637B2 - Image reading method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image reading method and apparatus for irradiating a stimulable phosphor sheet on which a radiation image is accumulated and recorded with excitation light and obtaining an image signal representing the radiation image from the sheet.
[0002]
[Prior art]
In various fields, a recorded radiation image is read to obtain an image signal, and an appropriate image process is performed on the image signal, and then the image is reproduced and recorded. For example, an X-ray image is recorded using a film having a low gamma value designed to be adapted for later image processing, and the X-ray image is read from the recorded film and converted into an electrical signal. A system capable of obtaining a reproduced image with good image quality performance such as contrast, sharpness, graininess, etc. by performing image processing on this electrical signal (image signal) and reproducing it as a visible image on a copy photograph or the like It has been developed (see Japanese Patent Publication No. 61-5193).
[0003]
In addition, when the applicant applies radiation (X-rays, α-rays, β-rays, γ-rays, electron beams, ultraviolet rays, etc.), a part of the radiation energy is accumulated, and when irradiated with excitation light such as visible light, it is accumulated. Using a stimulable phosphor (stimulable phosphor) that emits a quantity of stimulated emission light according to the energy that is emitted, a radiation image of a subject such as a human body is once photographed and recorded on a sheet-like stimulable phosphor The stimulable phosphor sheet is scanned with excitation light such as laser light to generate stimulated emission light, and the obtained stimulated emission light is photoelectrically read to obtain an image signal. Based on this image signal, A radiation recording / reproducing system for outputting a radiographic image of a subject as a visible image on a recording material such as a photographic photosensitive material or a CRT has already been proposed (Japanese Patent Laid-Open Nos. 55-12429, 56-11395, 55-55). 0163472, 56-164645, 55-116340, etc.). In such a radiographic image recording / reproducing system, the stimulated emission light is scattered and emitted from the stimulable phosphor sheet. Therefore, in order to efficiently collect the scattered stimulated emission light, irradiation with excitation light is performed. A condensing guide and a condensing mirror are provided in the vicinity of the position, and the scattered photostimulated light is reflected by the condensing mirror toward the condensing guide and condensed by the condensing guide.
[0004]
Further, in the radiation image information recording / reproducing system using such a stimulable phosphor sheet, as a method of photoelectrically reading the photostimulated luminescence light, photoelectric reading means are arranged on both sides of the stimulable phosphor sheet, A double-sided condensing reading method has been proposed in which excitation light is scanned only on both sides or one side of the stimulable phosphor sheet, and the photostimulated light emitted by this excitation light scanning is photoelectrically read from both sides of the stimulable phosphor sheet. (For example, see JP-A-55-87970). In such a double-sided condensing reading method, one radiation image is accumulated and recorded on the stimulable phosphor sheet, and the photostimulated emission light is condensed from both sides of the stimulable phosphor sheet. The light collection efficiency is improved and the S / N ratio is further improved.
[0005]
On the other hand, in the radiological image reproduction system as described above, a plurality of stimulable phosphor sheets obtained by photographing the same subject are respectively scanned to obtain a plurality of image signals, which are superposed to obtain an S / N ratio. When performing superimposition processing for obtaining an image with high contrast or subtraction processing for removing a part of the image from a certain image, it is necessary to perform scanning by accurately matching the starting ends at the time of each scanning. For this reason, for example, Japanese Patent Application Laid-Open No. 58-31662 proposes a method for detecting the front end of the stimulable phosphor sheet. In the method described in Japanese Patent Laid-Open No. 58-31662, when the front end of the stimulable phosphor sheet is scanned by the excitation light, the reflection of the excitation light by the front end is detected by a sensor or the like, and the stimulable fluorescence is detected. The tip of the body sheet is detected.
[0006]
[Problems to be solved by the invention]
The method described in the above Japanese Patent Application Laid-Open No. 58-31662 requires a sensor for detecting reflected light, but as described above, a condensing mirror or a collector for detecting scattered photostimulated luminescence. In the reading apparatus provided with the light guide, there is no degree of freedom in the mounting position of the sensor, and mounting restrictions are severe. For this reason, the mounting position of the sensor is limited, and stable tip detection cannot be performed at the limited position. In particular, in the apparatus that employs the above-described double-sided scanning method, the condensing guide is also provided on the back side of the stimulable phosphor sheet, so that the sensor mounting position is further limited.
[0007]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an image reading method and apparatus capable of stably detecting the leading end of a stimulable phosphor sheet.
[0008]
[Means for Solving the Problems]
In the first image reading method according to the present invention, the stimulable phosphor sheet on which radiation images are accumulated and recorded is subjected to main scanning with excitation light, and the stimulable phosphor sheet is sub-scanned in a direction substantially perpendicular to the main scanning direction. Then, the radiation image is converted into stimulated emission light, and the stimulated emission light obtained from the stimulable phosphor sheet is disposed in the vicinity of the location of the stimulable phosphor sheet irradiated with the excitation light. In an image reading method in which the light is reflected and collected by a collecting mirror and read photoelectrically,
The condensing mirror has a characteristic of transmitting reflected excitation light reflected by the stimulable phosphor sheet,
When the leading edge of the stimulable phosphor sheet is main-scanned by the excitation light, the stimulable phosphor sheet is detected by detecting reflected excitation light transmitted through the condenser mirror from the reflected excitation light by the leading edge of the stimulable phosphor sheet. The tip of the phosphor sheet is detected.
[0009]
Further, the second image reading method according to the present invention has a characteristic that the condensing mirror transmits reflected excitation light reflected by the stimulable phosphor sheet in the above-described double-sided reading type image reading method,
When the leading edge of the stimulable phosphor sheet is main-scanned by the excitation light, the stimulable phosphor sheet is detected by detecting reflected excitation light transmitted through the condenser mirror from the reflected excitation light by the leading edge of the stimulable phosphor sheet. The tip of the phosphor sheet is detected.
[0010]
Moreover, it is preferable that the said condensing mirror has a characteristic which reflects the said photostimulated luminescence light.
[0011]
Furthermore, in the first and second image reading methods, the stimulable phosphor sheet is sub-scanned with a lower surface supported by a guide plate,
It is preferable that an opening is provided at the position of the guide plate corresponding to the location where the excitation light of the stimulable phosphor sheet is irradiated, and at least the stimulable fluorescence is substituted for the opening. You may color the position of the said guide plate corresponding to the location where the said excitation light of a body sheet is irradiated to black.
[0012]
According to the present invention, there is provided a first image reading apparatus for carrying out the first image reading method according to the present invention, wherein main scanning of excitation light is performed on a stimulable phosphor sheet on which radiation images are accumulated and recorded. Main scanning means, sub-scanning means for sub-scanning the stimulable phosphor sheet in a direction substantially perpendicular to the main scanning direction, and stimulated emission light obtained from the stimulable phosphor sheet by the main scanning of the excitation light A condensing mirror disposed in the vicinity of the location of the stimulable phosphor sheet that is irradiated with the excitation light, a stimulating light obtained from the stimulable phosphor sheet, and the condensing mirror In an image reading apparatus provided with reading means for photoelectrically reading reflected photostimulated luminescence light,
The condensing mirror has a characteristic of transmitting reflected excitation light reflected by the stimulable phosphor sheet,
The supporting means for supporting the condenser mirror is provided with a detecting means for detecting reflected excitation light transmitted through the condenser mirror,
When the front end of the stimulable phosphor sheet is main-scanned by the excitation light, the reflected excitation light transmitted through the condenser mirror is detected by the detection means from among the reflected excitation light by the front end of the stimulable phosphor sheet. Then, the tip of the stimulable phosphor sheet is detected.
[0013]
Furthermore, the second image reading apparatus according to the present invention has a characteristic that the condensing mirror transmits reflected excitation light reflected by the stimulable phosphor sheet in the above-described double-sided image reading apparatus,
The supporting means for supporting the condenser mirror is provided with a detecting means for detecting reflected excitation light transmitted through the condenser mirror,
When the front end of the stimulable phosphor sheet is main-scanned by the excitation light, the reflected excitation light transmitted through the condenser mirror is detected by the detection means from among the reflected excitation light by the front end of the stimulable phosphor sheet. Then, the tip of the stimulable phosphor sheet is detected.
[0014]
Moreover, it is preferable that the said condensing mirror has a characteristic which reflects the said photostimulated luminescence light.
[0015]
Further, the first and second image reading devices further include a guide plate for guiding the lower surface of the stimulable phosphor sheet,
The guide plate is preferably provided with an opening at a position corresponding to the location of the stimulable phosphor sheet irradiated with the excitation light, and instead of the opening, at least the You may color the position corresponding to the location where the excitation light of a stimulable phosphor sheet is irradiated with black.
[0016]
【The invention's effect】
According to the image reading method and apparatus of the present invention, the reflected excitation light reflected by the tip of the stimulable phosphor sheet that has passed through the collector mirror for reflecting and condensing the scattered stimulated emission light is detected. Therefore, it is not necessary to consider the mounting position of the detection means for detecting the reflected excitation light, and the apparatus can be configured simply. In particular, in the image reading method and apparatus for performing double-sided condensing, since the reading means is disposed also on the back surface of the stimulable phosphor sheet, it is very difficult to attach the detection means, but as in the present invention. By detecting the reflected excitation light transmitted through the collector mirror, the detector can be attached to the support means of the collector mirror as in the apparatus according to the present invention, and the apparatus can be configured without any trouble. Can do. Moreover, since the attachment position of the detection means can be fixed to the support means of the condensing mirror, the tip of the stimulable phosphor sheet can always be detected stably.
[0017]
In addition, when the lower surface of the stimulable phosphor sheet is guided by the guide plate, an opening is provided at the position of the guide plate corresponding to the location where the excitation light of the stimulable phosphor sheet is irradiated. The excitation light is not reflected by the guide plate until the tip of the phosphor sheet is sub-scanned at the position where the excitation light is irradiated, and therefore the reflected excitation light is not detected by the detection means. As a result, the reflected excitation light is detected by the detecting means only when the excitation light is irradiated on the front end of the stimulable phosphor sheet, so that the front end of the stimulable phosphor sheet can be detected more accurately. it can.
[0018]
Further, in this case, the guide plate is irradiated with the excitation light by coloring the position corresponding to the portion of the stimulable phosphor sheet irradiated with the excitation light in black without providing an opening in the guide plate. However, the excitation light is less likely to be reflected. Therefore, the excitation light is not reflected by the guide plate until the tip of the stimulable phosphor sheet is sub-scanned at the position where the excitation light is irradiated, so the reflected excitation light is detected by the detection means. As a result, the reflected excitation light is detected by the detection means only when the tip of the stimulable phosphor sheet is irradiated with the excitation light, and the tip of the stimulable phosphor sheet can be detected more accurately. .
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0020]
FIG. 1 is a diagram illustrating a radiographic image capturing apparatus. As shown in FIG. 1, the stimulable phosphor sheet 4 is disposed, the radiation source 3 is driven, and the radiation 2 is emitted, whereby the radiation 2 transmitted through the subject 1 is irradiated onto the stimulable phosphor sheet 4. The radiation image information of the subject 1 is accumulated and recorded on the stimulable phosphor sheet 4.
[0021]
Next, a radiation image is read from the stimulable phosphor sheet 4 by an image reading apparatus according to the present invention as shown in FIG. 2 to obtain an image signal representing the radiation image.
[0022]
The stimulable phosphor sheet 4 is disposed on endless belts 9a and 9b that are rotated by a motor (not shown). The endless belts 9 a and 9 b support both side portions of the stimulable phosphor sheet 4, and the center portion of the stimulable phosphor sheet 4 is supported by the center guide 8. Above the sheet 4 are a laser light source 10 that emits laser light 11 that is excitation light, and a rotating polygon mirror 12 that reflects and deflects the laser light 11 and is rotated by a motor (not shown) that scans the sheet 4. It is arranged. Note that an opening 8A is formed at a position of the center guide 8 where the laser beam 11 is irradiated. Further, above the position where the laser beam 11 is scanned, a condensing guide 14a for condensing the stimulated emission light emitted by the scanning of the laser beam 11 from above is disposed close to the position below the position. In this case, a light collecting guide 14b for condensing the stimulated emission light from below is arranged perpendicular to the sheet 4. In the vicinity of the light collecting guide 14a, there is disposed a light collecting mirror 7 for reflecting the photostimulated light emitted from the stimulable phosphor sheet 4 toward the light collecting guide 14a. . The condensing mirror 7 is supported by the mirror mount 6. The light collecting guides 14a and 14b are connected to photomultipliers (photomultiplier tubes) 15a and 15b for photoelectrically detecting the stimulated emission light, respectively. The photomultipliers 15a and 15b are connected to logarithmic amplifiers 16a and 16b. The logarithmic amplifiers 16a and 16b are further connected to A / D converters 17a and 17b. The A / D converters 17a and 17b are storage means. Connected to 18.
[0023]
The condensing mirror 7 is composed of a dichroic mirror, transmits light in the wavelength region of 600 to 700 nm that is the wavelength region of the laser beam 11, and light in the wavelength region of 400 to 500 nm that is the wavelength region of the excitation light. Is reflected. A sensor 5 for detecting light transmitted through the condenser mirror 7 is embedded in the center of the mirror mount 6 that supports the condenser mirror 7 as shown in FIG. As shown in FIG. 2, a path 6 </ b> A that guides the light that has passed through the condenser mirror 7 is formed in a substantially central portion of the mirror mount 6, and the light that has passed through the path 6 </ b> A is detected by the sensor 5. The detection output of the sensor 5 is input as a start point signal B to the sequence controller 20 of the present apparatus. Here, the sequence controller 20 starts the detection of the photostimulated light by the photomultipliers 15a and 15b in response to the start point signal B input from the sensor 5.
[0024]
The stimulable phosphor sheet 4 on which the radiographic image of the subject is accumulated and recorded is set on the endless belts 9a and 9b and the center guide 8. The stimulable phosphor sheet 4 set at the predetermined position is conveyed (sub-scanned) in the arrow Y direction by the endless belts 9a and 9b. On the other hand, the laser light 11 emitted from the laser light source 10 is reflected and deflected by a rotating polygon mirror 12 driven by a motor (not shown) and rotated at high speed, enters the sheet 4 and is substantially perpendicular to the sub-scanning direction (arrow Y direction). Main scanning is performed in the direction (direction perpendicular to the paper surface).
[0025]
Here, until the sheet 4 is conveyed to the irradiation position of the laser beam 11, the laser beam 11 is irradiated to the center guide 8, but there is an opening at a position corresponding to the irradiation position of the laser beam 11 in the center guide 8. Since 8A is formed, the laser beam 11 is not reflected by the center guide 8. When the sheet 4 is transported to the irradiation position of the laser beam 11, the stimulated emission light 13a, 13b having a light amount corresponding to the radiation image information stored and recorded from the portion of the sheet 4 irradiated with the laser beam 11. (Here, the photostimulated emission lights 13a and 13b are those emitted from above and below the sheet 4, respectively) and the laser beam 11 is reflected by the tip of the sheet 4. Although the stimulated emission light 13a emitted from the surface of the sheet 4 is scattered, it is reflected by the condensing mirror 7 and collected on the condensing guide 14a. On the other hand, the laser beam 11 reflected on the sheet 4 passes through the condenser mirror 7 and is detected by the sensor 5 provided on the mirror mount 6. When the sensor 5 detects the laser beam 11 transmitted through the condenser mirror 7, it outputs a start point signal B to the sequence controller 20. The sequence controller 20 starts detection by the photomultipliers 15a and 15b based on the start point signal B input from the sensor 5.
[0026]
The photostimulated emitted light 13a that has entered the condensing guide 14a from the incident end face repeatedly undergoes total internal reflection inside the condensing guide 14a, exits from the exit end face, is received by the photomultiplier 15a, and represents a radiation image. The amount of the stimulated emission light 13a is converted into an electric signal by the photomultiplier 15a. Similarly, the stimulated emission light 13b is guided by the condensing guide 14b and is detected photoelectrically by the photomultiplier 15b.
[0027]
The analog image signal S _A output from the photomultiplier 15a is logarithmically amplified by the logarithmic amplifier 16a and input to the A / D converter 17a, where it is converted into the digital image signal S ₁ and input to the storage means 18. Is done. Similarly, photomultiplier 15b analog image signals output from the S _B is inputted is logarithmically amplified by a logarithmic amplifier 16b to the A / D converter 17b, a storage where it is converted into a digital image signal S ₂ Input to means 18. The digital image signals S ₁ and S ₂ stored in the storage means 18 are input to the image processing means 19 and added together. The added image signal Sadd obtained in this way is subjected to predetermined image processing, and is used for reproduction of a radiation image by a reproduction means (not shown).
[0028]
This reproducing means may be a display means such as a CRT, or a recording apparatus that performs optical scanning recording on a photosensitive film.
[0029]
Thus, in the present embodiment, the sensor 5 for detecting the tip of the stimulable phosphor sheet 4 is provided on the mirror mount 6 that supports the condenser mirror 7, and therefore the sensor 5 for detecting the tip of the sheet 4. Therefore, it is not necessary to consider the mounting position of the apparatus, and the apparatus can be configured simply. In particular, in the image reading apparatus that performs both-side light condensing as in the present embodiment, it is very difficult to attach the sensor 5 because the light condensing guide 14b is also disposed on the back surface of the stimulable phosphor sheet 4. However, by attaching the sensor 5 to the mirror mount 6 of the condenser mirror 7 as in this embodiment, the apparatus can be configured without any trouble. Moreover, since the mounting position of the sensor 5 is fixed to the mirror mount 6, the front end of the stimulable phosphor sheet 4 can be detected stably.
[0030]
In the present embodiment, since the opening 8A is provided at a position corresponding to the position irradiated with the laser light 11 in the center guide 8 that guides the lower surface of the stimulable phosphor sheet 4, the stimulable phosphor sheet 4 Since the laser beam 11 is not reflected by the center guide 8 even if the tip is not located at the position where the laser beam 11 is irradiated, the reflected laser beam 11 is not detected by the sensor 5. Thereby, since the reflected laser beam 11 is detected by the sensor 5 only when the tip of the stimulable phosphor sheet 4 is irradiated with the laser beam 11, the tip of the stimulable phosphor sheet 4 can be detected more accurately. Can do.
[0031]
In the above-described embodiment, the image reading apparatus that performs double-sided reading has been described. However, as illustrated in FIG. 4, the radiation image reading apparatus that reads a radiation image from only one side of the stimulable phosphor sheet 4 may also be used. The present invention can be applied in the same manner as the radiation image reading apparatus shown in FIG. In FIG. 4, the same components as those in FIG. 2 are denoted by the numbers obtained by removing “a” from the reference numbers in FIG. 2, and detailed description thereof is omitted.
[0032]
In the above-described embodiment, the opening 8A is provided at a position where the laser light 11 of the center guide 8 is irradiated. However, the surface of the center guide 8 is colored black without providing the opening 8A. May be. Thereby, even if the center guide 8 is irradiated with the laser beam 11, the laser beam 11 is not easily reflected. Therefore, until the tip of the stimulable phosphor sheet 4 is conveyed to the position where the laser beam 11 is irradiated, The laser beam 11 is not reflected by the guide 8. As a result, the reflected laser beam 11 is detected by the sensor 5 only when the tip of the stimulable phosphor sheet 4 is irradiated with the laser beam 11, so that the tip of the stimulable phosphor sheet 4 can be detected more accurately. Can be done. Note that the portion colored black may be the entire surface of the center guide 8 or only the portion irradiated with the laser beam 11.
[0033]
Further, in the above embodiment, the sensor 5 is provided at the substantially central portion of the mirror mount 6 as shown in FIG. 3, but if the reflected laser light 11 transmitted through the condenser mirror 7 can be detected, It may be provided at any position. Further, although the sensor 5 is embedded in the mirror mount 6, the present invention is not limited to this, and it may be attached to the surface of the mirror mount 6.
[Brief description of the drawings]
FIG. 1 is a view showing a radiographic image capturing apparatus. FIG. 2 is a view showing an image reading apparatus according to an embodiment of the present invention. FIG. 3 is a view showing a configuration of a mirror mount. Diagram showing image reader [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Subject 2 Radiation 3 Radiation source 4 Storage phosphor sheet 5 Sensor 6 Mirror mount 7 Condensing mirror 8 Center guide 8A Opening
10 Laser light source
11 Laser light
12 rotating polygon mirror
13a, 13b Photoluminescent light
14a, 14b Condensing guide
15a, 15b Photomultiplier
16a, 16b logarithmic amplifier
17a, 17b A / D converter
18 Storage means
19 Image processing means
20 Sequence controller

Claims (10)

The stimulable phosphor sheet on which the radiographic image is accumulated and recorded is subjected to main scanning with excitation light, and the stimulable phosphor sheet is sub-scanned in a direction substantially perpendicular to the main scanning direction to convert the radiographic image into stimulated emission light. The stimulated emission light obtained from the stimulable phosphor sheet after conversion is reflected and collected by a condensing mirror disposed in the vicinity of the location of the stimulable phosphor sheet irradiated with the excitation light. In an image reading method for automatically reading,
The condensing mirror has a characteristic of transmitting reflected excitation light reflected by the stimulable phosphor sheet,
When the leading edge of the stimulable phosphor sheet is main-scanned by the excitation light, the stimulable phosphor sheet is detected by detecting reflected excitation light transmitted through the condenser mirror from the reflected excitation light by the leading edge of the stimulable phosphor sheet. An image reading method comprising detecting a leading end of a phosphor sheet. The stimulable phosphor sheet on which the radiographic image is accumulated and recorded is subjected to main scanning with excitation light, and the stimulable phosphor sheet is sub-scanned in a direction substantially perpendicular to the main scanning direction to convert the radiographic image into stimulated emission light. The stimulated emission light obtained from the surface of the stimulable phosphor sheet is converted by a condensing mirror disposed in the vicinity of the portion irradiated with the excitation light on the surface side of the stimulable phosphor sheet. In the image reading method of photoelectrically reading the stimulated emission light obtained from the back surface of the stimulable phosphor sheet while photoelectrically reflecting and condensing,
The condensing mirror has a characteristic of transmitting reflected excitation light reflected by the stimulable phosphor sheet,
When the leading edge of the stimulable phosphor sheet is main-scanned by the excitation light, the stimulable phosphor sheet is detected by detecting reflected excitation light transmitted through the condenser mirror from the reflected excitation light by the leading edge of the stimulable phosphor sheet. An image reading method comprising detecting a leading end of a phosphor sheet. The image reading method according to claim 1, wherein the condensing mirror further has a characteristic of reflecting the stimulated emission light. The stimulable phosphor sheet is sub-scanned with its lower surface supported by a guide plate,
The image according to any one of claims 1 to 3, wherein an opening is provided at a position of the guide plate corresponding to a portion of the stimulable phosphor sheet irradiated with the excitation light. Reading method. The stimulable phosphor sheet is sub-scanned with its lower surface supported by a guide plate,
4. The image reading according to claim 1, wherein at least the position of the guide plate corresponding to a portion of the stimulable phosphor sheet irradiated with the excitation light is colored black. 5. Method. Main scanning means for main-scanning excitation light on a stimulable phosphor sheet on which radiation images are accumulated and recorded; sub-scanning means for sub-scanning the stimulable phosphor sheet in a direction substantially perpendicular to the main scanning direction; and the excitation A condensing mirror disposed in the vicinity of the location of the stimulable phosphor sheet irradiated with the excitation light, which reflects the stimulated emission light obtained from the stimulable phosphor sheet by main scanning of light; In an image reading apparatus comprising a reading unit that photoelectrically reads the photostimulated luminescence obtained from the stimulable phosphor sheet and the photostimulated luminescence reflected by the collector mirror,
The condensing mirror has a characteristic of transmitting reflected excitation light reflected by the stimulable phosphor sheet,
The supporting means for supporting the condenser mirror is provided with a detecting means for detecting reflected excitation light transmitted through the condenser mirror,
When the front end of the stimulable phosphor sheet is main-scanned by the excitation light, the reflected excitation light transmitted through the condenser mirror is detected by the detection means from among the reflected excitation light by the front end of the stimulable phosphor sheet. An image reading apparatus that detects the leading end of the stimulable phosphor sheet. Main scanning means for main-scanning the stimulable phosphor sheet on which radiation images are accumulated and recorded; sub-scanning means for sub-scanning the stimulable phosphor sheet in a direction substantially perpendicular to the main scanning direction; and excitation light A condensing mirror disposed in the vicinity of the location of the stimulable phosphor sheet irradiated with the excitation light, which reflects the stimulated emission light obtained from the surface of the stimulable phosphor sheet by the main scanning of Obtained from the first reading means for photoelectrically reading the photostimulated luminescence obtained from the surface of the stimulable phosphor sheet and the photostimulated luminescence reflected by the collector mirror, and from the back surface of the stimulable phosphor sheet In an image reading apparatus comprising a second reading unit that photoelectrically reads the photostimulated luminescence light,
The condensing mirror has a characteristic of transmitting reflected excitation light reflected by the stimulable phosphor sheet,
The supporting means for supporting the condenser mirror is provided with a detecting means for detecting reflected excitation light transmitted through the condenser mirror,
When the front end of the stimulable phosphor sheet is main-scanned by the excitation light, the reflected excitation light transmitted through the condenser mirror is detected by the detection means from among the reflected excitation light by the front end of the stimulable phosphor sheet. An image reading apparatus that detects the leading end of the stimulable phosphor sheet. The image reading apparatus according to claim 6, wherein the condenser mirror further has a characteristic of reflecting the stimulated emission light. A guide plate for guiding the lower surface of the stimulable phosphor sheet;
9. The guide plate according to claim 6, wherein an opening is provided at a position corresponding to a portion of the stimulable phosphor sheet irradiated with the excitation light. Image reading device. A guide plate for guiding the lower surface of the stimulable phosphor sheet;
The image according to any one of claims 6 to 8, wherein the guide plate is colored black at least at a position corresponding to a portion of the stimulable phosphor sheet irradiated with the excitation light. Reader.

Images