JP2000131238A - Acquiring method for shading correction information and image information reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To acquire shading correction information without making a carrier carry uniform image information by reading scattered light of exciting light as shading information. SOLUTION: Of light emitted from an accumulative phosphor sheet 50 caused by irradiation of a laser beam L to the sheet 50, scattered light L' of the laser beam L but not stimulated phosphorescent light M' is read as shading information, while a correction value for shading is acquired on the basis of the read shading information. Thereby, such trouble as exposure of (image) information having a uniform energy distribution to the sheet 50 is not required for the purpose of acquiring the shading information. Accordingly, the correction value for the shading is easily acquired.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method for obtaining shading correction information in an image information reading apparatus and an image information reading apparatus for implementing the method for obtaining shading correction information.

[0002]

2. Description of the Related Art A carrier such as a stimulable phosphor sheet carrying image information is irradiated with excitation light such as a laser beam, and emitted light such as photostimulated light emitted at an intensity corresponding to the image information carried by the carrier. 2. Description of the Related Art An image information reading apparatus that reads image information by reading light with a photoelectric reading unit is conventionally known.

This image information reading apparatus will be described with reference to FIG. 3 by taking an image information reading apparatus for reading image information from a stimulable phosphor sheet carrying image information such as a radiation image.

[0004] The image information reading apparatus shown in FIG.
The laser beam L emitted from the light source 10 and reflected by the light deflector 12 is main-scanned in the direction of the arrow X on the stimulable phosphor sheet 50 mounted thereon and conveyed (sub-scanning) in the direction of the arrow Y, Sheet
The photostimulable light M emitted at an intensity corresponding to the image information recorded in the photomultiplier 50 is passed through a condensing guide 14 to a photomultiplier tube (P
MT: Photomultiplier (16) performs photoelectric detection. Note that, in addition to the stimulated emission light M, scattered light (other than specular reflection light) of the laser light L as excitation light is also incident on the condensing guide 14. This scattered light becomes a noise component with respect to the stimulating light M carrying image information, and is generally about ten orders of magnitude stronger than the stimulating light M, so that the light guide 14 and the PMT 16
And the excitation light cut filter 15B disposed between
It does not enter the MT16.

The image information thus detected is amplified by a logarithmic amplifier 21 and converted into a digital signal by an A / D converter 22.

In the above-described image information reading apparatus, the intensity unevenness of the scanning light beam L due to the uneven reflectance of the reflecting surface of the optical deflector 12 and the unevenness of the scanning speed of the light beam L due to the variation of the deflection speed of the optical deflector 12. Alternatively, the obtained image information may fluctuate due to uneven light collection in the main scanning direction (X direction) of the light guide 14 or the like. Further, in addition to those shown in the drawings, the detection surface extends in a line shape in the main scanning direction, and the photoelectric detection can be performed simultaneously over the entire area of the sheet 50 in the main scanning direction. In the information reading apparatus, the obtained image information may fluctuate due to light detection unevenness in the direction in which the photomultiplier extends (main scanning direction). The phenomenon that the light detection efficiency is partially reduced due to such various unevenness is called shading.

Here, the shading caused by the shape of the condensing guide 14 in the image information reading apparatus shown in FIG. 3 will be described. When uniform light is incident over the entire area in the main scanning direction of the incident end face of the illustrated condensing guide 14, the intensity distribution of the light detected at the outgoing end face is as shown in FIG. It can be seen that shading in which the intensity of the emitted light is reduced by 10 to 20% occurs at a portion corresponding to the cutting position where the light is cut into four strip-shaped portions on the emission end side.

As described above, when shading occurs,
Naturally, it becomes impossible to correctly detect the image information recorded on the surface to be scanned.

In order to read image information with high accuracy, various methods for correcting the shading have been proposed (JP-A-61-189763, JP-A-64-86759 and JP-A-86-75959).
2-58973).

According to these shading correction methods, first, uniform image information such that uniform intensity light can be emitted from the entire surface of the carrier (such as the stimulable phosphor sheet) is previously carried on the carrier. Is irradiated with excitation light by the same operation as that for reading image information, and the light emitted from the carrier is read by a photoelectric reading means via a light condensing system to obtain shading information. Originally, the read information should be uniform over the entire surface of the carrier, but when shading occurs due to the various factors described above, the shading is not uniform due to the influence of the shading, and FIG. As shown, the information indicates shading characteristics (shading information).

Based on the shading information obtained in advance, shading correction information for canceling the shading characteristics is prepared for each position of the carrier in advance. The shading correction information corresponds to a value for addition, a coefficient value for multiplication, and the like.

[0012]

In the above-described conventional shading correction method, the emission light having uniform intensity from the entire surface of the carrier or another carrier for shading correction is read before the desired image information is read. It is necessary to carry in advance uniform image information such that light can be emitted. For example, in the reading apparatus shown in FIG. 3 described above, it is necessary to irradiate the stimulable phosphor sheet 50 with radiation having a uniform energy distribution over the entire surface of the sheet 50.

[0013] However, performing such uniform exposure is troublesome, and thus there is a problem in that it is troublesome to periodically generate shading correction information. On the other hand, a dedicated irradiation device for easily performing uniform irradiation is expensive.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a method of acquiring shading correction information that enables acquisition of shading correction information without carrying uniform image information on a carrier. It is an object of the present invention to provide an image information reading device capable of acquiring such shading correction information.

[0015]

According to the present invention, there is provided a method for obtaining shading correction information, comprising the step of irradiating a carrier for obtaining shading correction information with excitation light to emit light which is excited to emit light. Instead of light (fluorescence, stimulated emission light, etc.), scattered light of excitation light is read as shading information.

That is, according to the method of the present invention for obtaining shading correction information in an image information reading apparatus, a carrier carrying image information is irradiated with excitation light, and the carrier is excited by the excitation light and has an intensity corresponding to the image information. In a method for obtaining shading correction information for correcting shading characteristics of an image information reading device for reading the image information by reading the emitted light emitted by the photoelectric reading means by a photoelectric reading means, a position on the optical path from the carrier to the photoelectric reading means The excitation light cut filter for preventing the excitation light from being incident on the photoelectric reading means, which is provided on the optical path, is retracted from a position on the optical path, and the carrier for shading correction information acquisition is irradiated with the excitation light to emit the excitation light. The scattered light of the excitation light emitted from the carrier is read by the photoelectric reading means, and the read scattered light is Zui and obtains the shading information representing the shading properties, and is characterized in that to obtain the shading correction information based on the shading information.

Here, as the carrier carrying the image information, a stimulable phosphor sheet on which the image information to be read is recorded, and a biochemical substance labeled with a fluorescent dye is electrophoresed. Various types of gels or gels can be applied, such as gels that are electrophoresed and then labeled with a predetermined fluorescent substance or the like, or microtiter plates in which a sample is placed in each well.

The excitation light includes laser light, ultraviolet light, visible light,
Various things such as an electron beam can be applied, and the irradiation may be performed by alternately or in parallel performing main scanning and sub-scanning of a light beam having a point-like cross section, The light beam having a linear cross section may be made to coincide with the main scanning direction and be simultaneously irradiated over the whole of the main scanning direction, and the light beam may be sub-scanned.

The emission light that is excited by the excitation light and emits light at an intensity corresponding to the image information means, for example, stimulated emission light or fluorescence, and does not include specular reflection light or scattered light of the excitation light. .

As the photoelectric reading means, various means such as PMT, CCD, and phototransistor can be applied. However, the light emitted when excited by the excitation light is very weak like stimulated emission or fluorescence. If so, PMT is preferred.

The excitation light cut filter can be appropriately selected according to the type of excitation light to be irradiated.

The carrier for obtaining shading correction information may be the carrier before the image information to be read is recorded, or may be another carrier different from the carrier. The carrier for shading correction information acquisition may or may not carry any information, but the carrier itself before the image information to be read is recorded is used. However, it is cheaper and more preferable than using a dedicated one. However, when a carrier that carries some information is used, the carried information must be information that does not need to be read because it may be erased by excitation when shading information is acquired. It is. For example, a device in which reading of image information has already been completed and which is waiting for deletion can be applied.

The scattered light of the excitation light means light excluding specular reflection light of the excitation light and light emitted by the excitation light. The intensity of the scattered light of the excitation light may be higher than that of the emission light excited by the excitation light by 10 digits or more. May be damaged. Therefore, in such a case, it is desirable to arrange an ND filter having an appropriate OD value between the carrier and the photoelectric reading means. However, the means for reducing the intensity level is not limited to the ND filter.

An image information reading apparatus according to the present invention is an apparatus for performing the method for obtaining shading correction information according to the present invention, wherein the light source for emitting excitation light and the carrier for carrying image information are provided with the excitation light. An irradiating optical system, a scanning unit that relatively moves the excitation light and the carrier so that the excitation light scans the carrier, and emits light at an intensity corresponding to the image information when excited by the excitation light. Photoelectric reading means for reading emitted light to be emitted, an excitation light cut filter disposed on an optical path from the carrier to the photoelectric reading means for preventing the excitation light from entering the photoelectric reading means, and shading correction. Based on shading information that is obtained by reading light emitted from the information acquisition carrier by the photoelectric reading unit and that represents shading characteristics, the shading characteristics An image information reading apparatus comprising: a shading correction information calculating unit for obtaining shading correction information for correction; and a shading correction unit for performing shading correction processing on the image information using the obtained shading correction information. A filter is provided so as to be movable between a position on the optical path and a position retracted from the optical path, and the shading correction information calculating means is configured such that, in a state where the excitation light cut filter is at the retracted position, The shading correction information is obtained based on shading information obtained by reading scattered light of the excitation light emitted from a carrier for obtaining shading correction information.

Here, the optical system for irradiating the carrier with the excitation light means an optical system for irradiating the excitation light emitted from the light source in a zero-dimensional or one-dimensional manner. The optical system for illuminating in zero dimensions is a condensing lens or a concave mirror, and the optical system for illuminating in one dimension is a condensing lens or a concave mirror with a rotating polygon mirror or the like. In some cases, a cylindrical lens or the like may be used.

The carrier for obtaining shading correction information is:
The carrier may be the carrier before the image information to be read is recorded, or may be another carrier different from the carrier, and the carrier for obtaining the shading correction information carries some information. It may or may not be, but it is preferable to use the carrier itself before the image information to be read is recorded, because it is cheaper than using a dedicated one. . However, when a carrier that carries some information is used, the carried information must be information that does not need to be read because it may be erased by excitation when shading information is acquired. It is.
For example, a device in which reading of image information has already been completed and which is waiting for deletion can be applied.

Further, the optical path further includes an ND filter for reducing the intensity of the scattered light of the excitation light so as to be movable between a position retracted on the optical path and a position on the optical path. In the retracted position, N
It is more preferable to adopt a configuration in which the D filter moves to a position on the optical path. This is because the intensity level of the scattered light of the excitation light may be higher than that of the emission light excited by the excitation light by 10 digits or more. However, the means for reducing the intensity level is not limited to the ND filter.

[0028]

According to the shading correction method in the image information reading apparatus and the image information reading apparatus for implementing the shading correction method according to the present invention, the carrier for obtaining the shading correction information is irradiated with the excitation light to radiate the excitation light from the carrier. Among the emitted light, the scattered light of the excitation light is read as shading information, not the emission light (fluorescence, stimulated emission light, etc.) that emits light when excited, and shading correction information is obtained based on the read shading information. However, since the scattered light of the excitation light does not depend on (image) information carried by the carrier, the carrier carries (image) information having a uniform energy distribution before reading the shading information. No need.

Therefore, according to the shading correction method and the image information reading apparatus of the present invention, it is not necessary to perform the operation of carrying (image) information having a uniform energy distribution on the carrier, and such an operation is dedicated. There is no need to prepare equipment to perform.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an image information reading apparatus that implements a shading information acquisition method according to the present invention will be described.

FIG. 1 is a diagram showing the configuration of an embodiment of an image information reading apparatus for implementing the shading information acquisition method of the present invention.

The image information reading apparatus shown in the figure is a transport belt which places a stimulable phosphor sheet 50 on which image information is recorded and transports (sub-scans) the sheet 50 at a constant speed in the direction of arrow Y.
30 and a laser light source 10 for emitting a laser light L as an excitation light.
And a motor 11 for reflecting and deflecting the emitted laser light L.
A rotating polygonal mirror 12 rotated by, a fθ lens 13 for scanning the reflected laser beam L on the sheet 50 on the transport belt 30 at a constant speed in the arrow X direction (direction substantially orthogonal to the arrow Y direction). A photomultiplier (hereinafter referred to as PMT) 16 is provided from the incident end face of the scattered light L 'of the laser light L and the photostimulated light M excited by the irradiation of the laser light L. The light-collecting guide 14 for guiding the light to the output end face, and reflects at least a part of the stimulated emission light M and the scattered light L 'emitted and diffused from the sheet 50 toward the incident end face of the light-collecting guide 14. A converging mirror 17, a PMT 16 for outputting an electric signal corresponding to the intensity of the incident light,
16 and a laser light cut filter (for example, B390) having a characteristic of cutting scattered light L '
15B and an ND filter 15A, and a PMT
Log amp 21 that logarithmically amplifies the electrical signal output from 16
And an A / D converter 22 for performing analog / digital conversion of the logarithmically amplified signal, and a correction value (shading correction information) obtained by calculating a correction value (shading correction information) for correcting shading based on the input shading information. The correction value calculation unit 24 stored in the memory 25 and, when the input signal is based on the scattered light L ', output to the correction value calculation unit 24 as shading information. If the image information is based on the image information, the image information is subjected to shading correction by calculating the correction value stored in the memory 25 and each pixel as desired image information, and the corrected image information is used as an external image processing device. And the like, and a digital operation unit 23 that outputs the result.

Here, the light-collecting guide 14 is formed in a shape in which the exit end face side is formed into four strip-shaped portions, stacked in the thickness direction thereof, and bundled. This is PMT
This is for adapting to the shape of the 16 photoelectric detection surfaces.

The filter composed of the laser beam cut filter 15B and the ND filter 15A is composed of both filters 15A, 15A.
One of B is selectively disposed on the optical path between the emission end face of the light guide 14 and the PMT 16, and the other is movably provided so as to be retracted from a position on the optical path.

Next, the operation of the present embodiment will be described with reference to FIG. 2 showing a schematic algorithm.

First, since a shading correction value is obtained, an appropriate stimulable phosphor sheet 50 is disposed at a predetermined position on the transport belt 30. The stimulable phosphor sheet 50 to be arranged may be a sheet for recording image information later, or may be a sheet different from the sheet for reading image information, and even after the previous recording information is read. It may still remain.

Subsequently, the ND filter 15A is connected to the light guide 14
The laser light cut filter 15B is disposed on the optical path between the light emitting end face of the PMT 16 and the PMT 16, and the laser light cut filter 15B is retracted from the position on the optical path (Step 1 (denoted as # 1 in FIG. 2)).

The transport belt 30 on which the sheet 50 is placed moves at a constant speed in the direction of the arrow Y, and the sheet 50 placed on the belt 30 is moved integrally with the belt 30 in the direction of the arrow Y. .

On the other hand, a laser beam L is emitted from the laser light source 10, is reflected and deflected by each reflecting surface of the rotary polygon mirror 12, and is condensed on the sheet 50 on the transport belt 30 by the fθ lens 13, and the sheet 50 is Is repeatedly main-scanned in the X direction. At this time, since the sheet is sub-scanned in the direction of arrow Y by the transport belt 30, the laser beam L irradiates substantially the entire surface of the sheet 50 by a combination of the main scanning and the sub-scanning (#
2).

From the sheet 50 irradiated with the laser beam L,
The stimulated emission light M 'which emits at an intensity corresponding to the radiation energy stored in the sheet 50 emits light, a part of which is directly incident on the incident end face of the condensing guide 14, and another part is collected. The light is reflected by the optical mirror 17 and is incident on the incident end face of the light collecting guide 14. On the other hand, the laser light L is reflected on the surface of the sheet 50, and the specularly reflected light does not enter the light-collecting guide 14 or the light-collecting mirror 17, but the scattered light L 'scattered on the sheet 50 or inside the sheet 50. A part of the light is incident on the incident end face of the light collecting guide 14 directly or reflected by the light collecting mirror 17. Here, the scattered light L ′ incident on the condensing guide 14 is
Shading on the optical path of the laser light L from 10 to the irradiation of the sheet 50 (reflectance for each reflecting surface of the rotary polygon mirror 12,
It carries information on the angle with respect to the rotation axis (so-called tilting), the distance from the rotation axis, or the fluctuation of the rotation speed, such as shading due to the dimming around the fθ lens 13.

The stimulated emission light M 'and the scattered light L' of the laser light are incident on the condensing guide 14, and are guided to the emission end face and emitted from the emission end face. Here, the scattered light L ′ emitted from the emission end face also carries shading information of the light collection guide 14.

The stimulated emission light M 'and the scattered light L' emitted from the emission end face of the condensing guide 14 are incident on the ND filter 15A, and the intensity thereof is reduced, and both are emitted from the ND filter 15A. Here, the stimulated emission light M 'is very weak light whose intensity is lower than that of the scattered light L' by about 10 orders of magnitude, so that the OD value of the ND filter 15A is
The scattered light L 'emitted from the ND filter 15A is set to a value such that the scattered light L' that has passed through 15A is detected by the PMT 16 but the stimulating light M 'that has passed is not detected. Scattered light L 'of
Only PMT16 is detected (# 3).

The PMT 16 photoelectrically detects the scattered light L ', converts the scattered light L' into an electric signal, and outputs the electric signal to the log amplifier 21. The log amplifier 21 logarithmically amplifies the input signal and performs an A / D converter
The A / D converter 22 digitizes the input signal and outputs it to the digital operation unit 23.

The signal based on the scattered light L ′ input to the digital operation unit 23 is a signal that carries shading information from the light source 10 to the condensing guide 14 as described above. The signal is output to the correction value calculation unit 24 as shading information.

The correction value calculator 24 calculates a correction value for correcting shading based on the input shading information (# 4), and stores the obtained correction value in the memory 25.

Next, the stimulable phosphor sheet 50 on which the image information desired to be read is recorded is placed at a predetermined position on the conveyor belt 30.

Subsequently, the output end face of the light guide 14 and the PMT 16
Then, the ND filter 15A disposed on the optical path between them is retracted from the position on the optical path, and the laser light cut filter 15B is disposed on the optical path (# 5).

The transport belt 30 on which the sheet 50 is placed moves at a constant speed in the direction of the arrow Y, and the sheet 50 placed on the belt 30 is moved integrally with the belt 30 in the direction of the arrow Y. On the other hand, the laser light L is emitted from the laser light source 10,
The reflected light is deflected by each reflecting surface of the rotating polygon mirror 12, and the fθ lens 13
Thereby, the sheet 50 is condensed on the sheet 50 on the transport belt 30, and the sheet 50 is repeatedly main-scanned in the direction of arrow X, and the laser light L irradiates substantially the entire surface of the sheet 50 by a combination of the main scanning and the sub-scanning (# 6).

From the sheet 50 irradiated with the laser beam L,
The stimulated emission light M that emits light at an intensity corresponding to the radiation energy of the image information stored in the sheet 50 emits light, and a part of the light is reflected directly on the incident end face of the condensing guide 14 or by the condensing mirror 17. Incident. On the other hand, the scattered light L 'of the laser light L also enters the light collecting guide 14.

Here, the stimulated emission light M incident on the condensing guide 14 is influenced by shading on the optical path of the laser light L from when the light source 10 irradiates the sheet 50.

The stimulated emission light M and the scattered light L 'of the laser light are incident on the condensing guide 14, and are guided to the emission end face and emitted from the emission end face. Here, the stimulated emission light M (and the scattered light L ′) emitted from the emission end face is further affected by the shading of the condensing guide 14.

The stimulated emission light M and the scattered light L 'emitted from the emission end face of the condensing guide 14 enter a laser light cut filter (B390) 15B, and the scattered light L'
It is cut at 15B and only the stimulated emission light M passes. Therefore, only the stimulated emission light M is detected by the PMT 16 (#
7).

The PMT 16 photoelectrically detects the stimulated emission light M, converts it into an electric signal, and outputs the electric signal to the log amplifier 21. The log amplifier 21 logarithmically amplifies the input signal and outputs it to the A / D converter 22, and the A / D converter 22 digitizes the input signal and outputs it to the digital operation unit 23.

The image signal based on the stimulated emission light M input to the digital operation unit 23 is a signal which is affected by shading from the light source 10 to the condensing guide 14 as described above. The unit 23 reads the correction value from the memory 25 and performs a correction process for eliminating the influence of the shading of the image signal based on the stimulating light M using the correction value (# 8).

The image signal subjected to the shading correction in this manner is output to an external image processing device, subjected to predetermined image processing, and then visualized by a reproducing device such as an image display device or an output device such as a printer. It is reproduced as an image.

As described above, according to the image information reading apparatus of the present embodiment, of the stimulated emission light that is excited and emits light, of the emission light emitted from the stimulable phosphor sheet by irradiating the sheet with laser light, In addition, the scattered light of the laser beam can be read as shading information, and a correction value of shading can be obtained based on the read shading information. Does not need to be exposed to the sheet, and therefore, it is possible to easily obtain the shading correction value.

The image information reading apparatus according to the present embodiment is an example in which a laser beam L having a point-like cross section is irradiated onto the sheet 50 by combining the main scanning and the sub-scanning. The method for acquiring shading correction information and the image information reading apparatus are not limited to this embodiment, and a light beam having a linear cross section is made to coincide with the main scanning direction and is simultaneously irradiated over the whole of the main scanning direction. A configuration having a so-called long photomultiplier, which irradiates the sheet by sub-scanning and can simultaneously perform photoelectric detection over the entire area in the main scanning direction, may be employed. In the configuration having such a long photomultiplier, shading in the direction in which the photomultiplier extends can also occur.However, the method of acquiring shading correction information and the image information reading apparatus of the present invention are not limited to this. Correction information including shading of a long photomultiplier can be obtained.

In the above embodiment, the ND filter 15A is used to obtain shading information. However, the shading information obtaining method and the image information reading device of the present invention are not necessarily limited to those using the ND filter. Instead, any means for sufficiently reducing the intensity level of the scattered light L 'can be applied instead of the ND filter.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of an embodiment of an image information reading apparatus that performs a shading information acquisition method of the present invention.

FIG. 2 is a diagram showing a schematic algorithm of the image information reading apparatus shown in FIG. 1;

FIG. 3 is a diagram illustrating an example of a conventional image information reading apparatus.

FIG. 4 is a diagram illustrating an example of shading of a light-collecting guide.

[Explanation of symbols]

 10 Light source 11 Motor 12 Rotating polygon mirror 13 fθ lens 14 Focusing guide 15A ND filter 15B Laser beam cut filter 16 Photomultiplier 17 Focusing mirror 21 Log amplifier 22 A / D converter 23 Digital operation unit 24 Correction value operation unit 25 Memory 30 Conveying belt 50 Storage phosphor sheet L Laser light L 'Scattered light of laser light M, M' Stimulated light

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G043 AA03 BA16 CA03 DA05 EA01 EA19 FA01 GA02 GA04 GB03 GB18 GB19 HA01 JA03 KA09 LA01 LA02 MA01 MA11 NA01 NA06 2G059 AA05 BB04 BB12 CC16 DD01 DD12 EE07 FF01 GG01 KK01 MM01 KK01 MM01 NN01 NN05 5C072 AA01 BA08 CA02 DA09 DA12 FB12 LA15 RA16 UA02 VA01

Claims (6)

[Claims] 1. A carrier carrying image information is irradiated with excitation light, and emission light excited by the excitation light and emitted at an intensity corresponding to the image information is read by photoelectric reading means to read the image information. In a method for acquiring shading correction information for correcting shading characteristics of an image information reading device to be read, the excitation light, which is provided at a position on an optical path from the carrier to the photoelectric reading unit, enters the photoelectric reading unit. The excitation light cut filter for preventing the light is retracted from the position on the optical path, and the carrier for shading correction information acquisition is irradiated with the excitation light, and the scattered light of the excitation light emitted from the carrier is photoelectrically read. Means for obtaining shading information representing the shading characteristics based on the scattered light read; And obtains the shading correction information based on the ring information acquisition method of shading correction information in the image information reading apparatus. 2. The method according to claim 1, wherein the carrier for acquiring the shading correction information is the carrier before carrying the image information. 3. An image information reading apparatus according to claim 1, wherein an ND filter for reducing the intensity of scattered light of said excitation light is provided on an optical path from said carrier to said photoelectric reading means. A method for acquiring shading correction information in a device. 4. A light source for emitting excitation light, an optical system for irradiating the carrier carrying image information with the excitation light, and the excitation light and the carrier so that the excitation light scans the carrier. Scanning means for relatively moving light, photoelectric reading means for reading emission light excited by the excitation light and emitting light at an intensity corresponding to the image information, and disposed on an optical path from the carrier to the photoelectric reading means. The excitation light cut filter for preventing the excitation light from being incident on the photoelectric reading means, and the light emitted from the carrier for obtaining shading correction information was obtained by reading the light by the photoelectric reading means.
Shading correction information calculation means for obtaining shading correction information for correcting the shading characteristics based on shading information representing shading characteristics, and shading correction means for performing shading correction processing on the image information using the obtained shading correction information Wherein the excitation light cut filter is provided so as to be movable between a position on the optical path and a position retracted from the optical path, and wherein the shading correction information calculation unit includes the excitation light cut filter. In a state where the light cut filter is at the retracted position,
An image information reading apparatus, wherein the shading correction information is obtained based on shading information obtained by reading the scattered light of the excitation light emitted from the carrier for obtaining the shading correction information. 5. The image information reading apparatus according to claim 4, wherein the carrier for obtaining the shading correction information is the carrier before carrying the image information. 6. An ND filter on the optical path, the ND filter configured to reduce the intensity of scattered light of the excitation light so as to be movable between a position retracted on the optical path and a position on the optical path. 6. The image information reading apparatus according to claim 4, wherein the ND filter is arranged to move to a position on the optical path when the light cut filter is at the retracted position.