JP3150220B2 - Image reading device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus for reading visible and non-visible optical information.

[0002]

2. Description of the Related Art Hitherto, with the high image quality and colorization of copiers, there has been a risk of counterfeiting bills, stamps and securities. On the other hand, various methods have been devised for recognizing bills and the like, for example, detecting a pattern of a seal of a bill.

Further, the present applicant has proposed a method of recognizing bills and the like from the color of the document by utilizing the fact that the picture of the document is formed in a specific color.

[0004] Further, there is also a paper money itself, in which a specific mark is printed with a fluorescent ink that reflects visible light by irradiating ultraviolet rays to distinguish the genuine paper from a counterfeit paper money.

It has also been proposed by the present applicant to use an ink having a characteristic of absorbing infrared rays as a method of forming a specific mark.

In such an apparatus for detecting infrared light, a reading sensor for forming a normal color image and a reading sensor for detecting infrared light are monolithically configured and a common optical system is used. It has been proposed in Japanese Patent Application No. 4-286350 that the size can be reduced and the optical adjustment can be easily performed.

[0007]

When a sensor that reads infrared information and visible information is used, it is necessary to clearly separate visible information and non-visible information.

In order to obtain a good resolution on a monolithic CCD sensor surface over a wide wavelength range from the visible region to the near infrared region or from the visible region to the near ultraviolet region, the number of lenses is greatly increased, resulting in an increase in cost. At the same time, the device becomes larger. Further, in an optical system using a short focus lens array, it is impossible to maintain a constant resolving power over a wide wavelength range because the lens array itself is a single lens.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image reading apparatus capable of reading visible and non-visible light satisfactorily.

[0010]

In order to solve the above-mentioned problems, an image reading apparatus according to the present invention uses visible information and information other than visible information.
Image reading device for reading an image of a document having
Exposure means for exposing the original,
The reflected light from the exposed document forms an image ,
First sensor to read and second to read non-visible information
And a sensor provided monolithically on the same substrate and provided between the first sensor and the document .
Is characterized by having a filter for blocking light other than the variable <br/> vision not provided between the second sensor and the document.

According to another aspect of the present invention, there is provided an image reading apparatus for reading an image of a document having visible information and non-visible information, comprising: an exposure unit for exposing the document; A first sensor for reading visible information and a second sensor for reading non-visible information are formed monolithically on the same substrate, and the solid-state image sensor is formed by reflecting light from a document. A lens for forming an image of reflected light from a document, fixedly provided between the lens and the solid-state imaging device, and an imaging position of visible information on the first sensor by the lens and the And an optical member for eliminating a difference in an imaging position of information other than visible information on the second sensor.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) The present invention will be described below based on preferred embodiments.

In the following embodiment, a copying apparatus is shown as an application example of the present invention. However, the present invention is not limited to this and can be applied to various other apparatuses such as an image scanner.

FIG. 2 is an external view of the apparatus according to the first embodiment of the present invention.

In FIG. 2, reference numeral 201 denotes an image scanner, which reads a document and performs digital signal processing. Reference numeral 202 denotes a printer unit which prints out an image corresponding to the document image read by the image scanner 201 on a sheet in full color.

In the image scanner unit 201, 20
0 is the pressure plate, the original on the platen glass 203 204
Is irradiated with the light of the halogen lamp 205 passing through the infrared cut filter 208 , and the reflected light from the original is reflected by the mirror 20.
6, 207, and forms an image on a 4-line sensor (hereinafter referred to as a CCD) 210 by a lens 209. The full-color information red (R), green (G), and blue (B) components
The signal is sent to the signal processing unit 211 as an infrared information (IR) component.

Reference numeral 5102 denotes a standard white plate.
Correction data of the read data of the R, G, B sensors of 0-2 to 210-4 is generated.

Reference numeral 5103 denotes a fluorescent reference plate on which a fluorescent ink exhibiting substantially the same fluorescent characteristics as the fluorescent information to be detected shown in FIG.
Used for correction of sensor output data.

The signal processor 211 electrically processes the read signal, decomposes the signals into magenta (M), cyan (C), yellow (Y), and black (BK) components, and sends them to the printer unit 202. . Also, the image scanner unit 201
For each original scan (scan) at, M, C,
One component of Y and BK is sent to the printer 202 in a frame-sequential manner, and one printout is completed by a total of four document scans.

The M, C, Y, and BK image signals sent from the image scanner unit 201 are transmitted to the laser driver 21.
Sent to 2. The laser driver 212 modulates and drives the semiconductor laser 213 according to the image signal. The laser light is reflected by the polygon mirror 214, the f-θ lens 215, the mirror 21
6 and scans over the photosensitive drum 217.

Reference numerals 219 to 222 denote developing units, which are a magenta developing unit 219, a cyan developing unit 220, and a yellow developing unit 2
21; a black developing device 222; four developing devices are sequentially formed on the photosensitive drum 217;
The electrostatic latent images of Y and BK are developed with the corresponding toner.

Reference numeral 223 denotes a transfer drum.
4 or 225 to the transfer drum 2
23, and transfers the toner image developed on the photosensitive drum 217 to a sheet.

After the four colors M, C, Y, and BK are sequentially transferred in this manner, the sheet passes through the fixing unit 226 and is discharged.

FIG. 3 shows the spectral characteristics of the infrared cut filter 208 disposed between the document illumination halogen lamp 205 and the document table glass 203. Thereby, infrared light of about 700 nm or more is cut out of the spectral characteristics of the halogen lamp 205 shown in FIG.

FIG. 5A shows the configuration of a sensor 210 (in this embodiment, a CCD line sensor is used) used in the present embodiment.

Here, reference numeral 210-1 denotes a light receiving element array for reading infrared light (IR).
Reference numerals 3 and 210-4 denote light receiving element arrays for sequentially reading R, G, and B wavelength components.

The four light receiving element rows having different optical characteristics are mounted on the same silicon chip so that the IR, R, G, and B sensors are arranged in parallel with each other to read the same line of the document. It is monolithic.

By using the sensor having such a configuration, an optical system such as a lens is commonly used for reading visible light and reading infrared light. This makes it possible to improve the accuracy of the optical adjustment and the like, and also facilitates the adjustment.

FIG. 5B is an enlarged view of the light receiving element. Each sensor has a length of 10 μm per pixel in the main scanning direction. Each sensor measures the short side (297 mm)
There are 5000 pixels in the main scanning direction so that the image can be read at a resolution of 00 dpi (dot per inch). The distance between the lines of the R, G, and B sensors is 8
0 μm, and are separated by 8 lines for each 400 lpi sub-scanning resolution.

IR sensor 210-1 and R sensor 210-
The line spacing of 2 is 160 μm (1
6 lines). FIG. 7 shows the spectral sensitivity characteristics of this CCD. 261 is a visible CCD, 262 is an IR,
It is a spectral characteristic of a CCD.

R, G, B of 210-2 to 210-4
Each of the sensors has an aperture of 10 μm in the sub-scanning direction.
The aperture of the IR sensor 10-1 is twice as large as that of the IR sensor. This is because the IR sensor 210-1 reads infrared fluorescent light.

Generally, the intensity of the fluorescent light is less than half that of the excitation light, and may be about 10% or less. In this embodiment, the dynamic range of the infrared reading signal is secured by increasing the light receiving area per pixel at the expense of the sub-scanning reading resolution of the IR sensor.

In this embodiment, the dynamic range of the signal is secured by increasing the length of the sub-scanning pixels of the IR sensor. However, the pixel length in the main scanning direction may be increased by lowering the resolution in the main scanning direction.

The above difference in aperture need not be implemented if the output of the IR sensor can sufficiently secure a dynamic range.

Each line sensor is composed of IR, R, G, B
An optical filter is formed on the sensor surface in order to obtain a predetermined spectral characteristic.

Referring to FIGS. 8 and 9, R,
The spectral characteristics of the G and B line sensors will be described.

FIG. 8 shows R, G, B conventionally used.
Of the filter of FIG. As you can see from this figure,
Conventional R, G, and B filters have sensitivity to infrared light of 700 nm or more. Conventionally, the lens 209 is provided with the infrared cut filter shown in FIG. In this embodiment, the infrared component of the light passing through the lens 209 is set to 210-1.
The lens 209 cannot be provided with an infrared cut filter for reading by the IR sensor.

In order to eliminate the influence of the infrared light, R,
By providing an infrared cut filter only between each of the G and B sensors and the lens, good visible reading can be performed.

FIG. 6 shows the characteristics of the visible cut filter attached to the IR sensor 210-1. This filter removes visible light components incident on an IR sensor that reads infrared fluorescent components.

In the present embodiment, as an example of a copy-inhibited original, a mark is printed at the position (Xc, Yc) in FIG. 1 with ink having the above-described fluorescence characteristics with respect to near-infrared light. It is assumed that there is a manuscript.

When the mark is detected in the infrared signal read from the document placed on the document table, the normal image forming operation is blocked.

The size and mark of the copy-inhibited document are not limited to those shown in FIG.

FIG. 10 shows the reflection spectral characteristics of a copy-inhibited document recognition mark (hereinafter, a recognition mark) included in the copy-inhibited document targeted in the present embodiment.

In FIG. 12, reference numeral 12201 denotes a spectral characteristic obtained by synthesizing the infrared cut filter 208 disposed between the halogen lamp 205 and the platen glass 203. Of the spectral characteristics, in this embodiment, the infrared component 12 near about 700 nm is used.
A copy-inhibited document is identified by detecting infrared fluorescence having a peak at about 800 nm from a recognition mark indicated by reference numeral 12203 in the drawing and using excitation light 202.

In this embodiment, a halogen lamp is used as a document illumination lamp that simultaneously generates at least excitation light components for visible light and infrared fluorescent light. The components are prevented from reaching the document surface.

In this embodiment, the recognition mark is formed by using a material which is excited by infrared light and generates fluorescence by infrared light. Therefore, the characteristics of this recognition mark with respect to visible light can be set arbitrarily. In the present embodiment, infrared fluorescent ink is used, which uses infrared fluorescent ink exhibiting characteristics that are substantially transparent to visible light, without making a general user aware of the presence of a recognition mark in a copy-protected document.

Hereinafter, the principle of reading IR fluorescence will be briefly described. The document 204 on the platen glass 203 is irradiated with light from a halogen lamp 205 passing through an infrared cut filter 208. As described above, generally, the intensity of the fluorescent light of, for example, 800 nm emitted from the recognition mark is a weak object less than half of the excitation light, for example, on the order of 10%.

Therefore, the long-wavelength component including the wavelength component of the 800 nm infrared fluorescent light, which is directly reflected from the original, is cut by the infrared cut filter 208, and the 800 nm wavelength component incident on the CCD is It is almost a fluorescent component.

As described above, the light emitted from the light source to the document cuts the spectral component of the fluorescent light emitted from the recognition mark, and the 700 nm fluorescence excitation light sufficiently irradiates the document, thereby obtaining the recognition mark. S of the fluorescence signal from
/ N is better.

The reflected light from the original is reflected by mirrors 206 and 207.
Through the lens 209, an image is formed on each line sensor for reading full-color information red (R), green (G), blue (B) components and infrared information (IR) components on each sensor of the CCD 210 by the lens 209.

As described above, the R, G, and B line sensors 210-2 to 210-4 are provided with an infrared cut filter between the lens and the sensor so as to sufficiently attenuate the 700 nm excitation light. Therefore, full-color reading can be performed without being affected by the infrared fluorescence excitation wavelength of 700 nm and the infrared fluorescent light.

Also, since the IR sensor 210-1 is provided with a filter for cutting 700 nm or less as shown in FIG. 6, only the infrared fluorescent component 12203 shown in FIG. 10 can be read.

With these filters, original reading,
Infrared fluorescence can be extracted at the same time as the image is recorded, and an extra original scanning operation for detecting a recognition mark by infrared fluorescence such as pre-scan is not required.

With the above configuration, the normal color region of the document and the infrared region of the recognition mark are well separated.

(Second Embodiment) The filter of the present invention may be placed at any position where the visible light beam and the infrared light beam can be separated between the lens and the CCD. For example, as shown in FIG. 11, if it can be fabricated as a part of a CCD element by being bonded to a cover glass on the entire surface of the CCD, the positional accuracy can be improved, and the correction glass of the present invention can be used when adjusting the lens and the CCD unit. No position adjustment is required, and the assembling time is shortened.

(Third Embodiment) As a filter of the present invention, it is not necessary to use a filter of a pigment or a dye, and as shown in FIG. 12, a dichroic filter is provided only at a part of a cover glass, that is, at a position where a visible light beam passes. A configuration in which a filter is deposited may be used.

(Fourth Embodiment) The above description relates to a four-line sensor which is all monolithically constructed.

However, this method may be used for an equal-magnification optical system using the short focus lens array 12801 shown in FIG. In this case, the sensor may use a two-line sensor 12802 including an RGB inline sensor 12802-2 for reading visible light and an IR sensor 12802-1 for reading infrared light shown in FIG.

(Fifth Embodiment) FIG. 15 shows the deviation of the imaging position (axial chromatic aberration) due to the wavelength of the optical system used in the reading system having the above-described spectral characteristics.

As can be seen from the figure, good resolution is normally obtained in the visible region. Therefore, in an infrared fluorescent region or an ultraviolet fluorescent region, an image is formed with a shifted imaging position, and the resolution is reduced. Normally, if it is attempted to correct this deterioration by the performance of the lens, the number of lenses is greatly increased and the cost performance is very poor. Therefore, a glass flat plate 12101 for correcting the imaging position , that is, for eliminating the difference in the imaging position, is inserted between the lens for correcting the deterioration of the resolving power and the visible sensor. From FIG. 15, since the deviation of the imaging position between the visible region and the infrared fluorescent region is about 0.4 mm, a thickness of 1 to 1.5 mm for the glass for correction is sufficient. This makes it possible to obtain a desired resolution over the entire visible to infrared range.

(Sixth Embodiment) The compensating glass of the present invention comprises:
As shown in FIG. 16, if it can be integrally formed with the cover glass by molding of plastic, the accuracy of positioning is improved,
In addition, since a separate component is not used as the correction glass, the cost can be reduced.

(Seventh Embodiment) FIG. 17 shows an element configuration of an optical path separating means and an optical path length correcting means in this embodiment.
1-1 is a half mirror for separating an optical path. 1-2 is a normal mirror in which the characteristics of the reflection film are changed so as to obtain a high reflectance in the infrared region.

FIG. 19 shows the spectral reflection characteristics of the mirrors 1-1 and 1-2. 1-1 is the spectral characteristic of the half mirror, 1
-2 is the spectral characteristic of the reflection mirror.

FIG. 18 is a view showing the configuration of a reading optical system using the element of this embodiment after the lens is emitted. The light emitted from the lens is split into two by a half mirror 1-1, which is the first surface of the element, and the reflected light is reflected by a visible sensor, and the transmitted light is reflected by a mirror 1-2 on the second surface. Then, the light is guided on the IR sensor to form an image.

In this configuration, the half mirror 1
Assuming that the distance between -1 and the reflecting mirror 1-2 is d, the refractive index of the material between the half mirror and the reflecting mirror is n, and the incident angle of the light beam on the reflecting mirror is θ, the optical path length of visible light and infrared light The difference L is L = 2d (2n−1−n ² sin ² θ) / n cos θ. The separation interval y between the visible light beam and the infrared light beam is y = 2dtan ² θ cos θ ′ (sin θ ′ = nsin
θ). In this embodiment, the desired L is 0.3 mm to 0.3 mm.
It is about 4 mm. Here, when L = 0.35 mm and the refractive index n = 1.51633, the incident angle, the interval d, and the separation distance y are uniformly determined for a specific incident angle.

FIG. 21 shows the relationship between the interval d and the separation distance y with respect to the incident angle. As can be seen from this figure, when the incident angle is designed in the vicinity of 50 to 60 degrees, the separation distance y is 0.11.
8 to 0.119 mm, and the variation in the separation distance between the visible light beam and the infrared light beam due to the variation in the incident angle can be suppressed to about 1 μm. If the pixel size is 10 μm, the deviation from an integral multiple of 120 μm (12 times here) of the pixel size is 2 μm.
It is about μm, and the line interpolation between the visible light beam and the infrared light beam can be performed well.

As can be seen from FIG. 15, good resolution can be obtained in the normal visible region. Therefore, in an infrared fluorescent region or an ultraviolet fluorescent region, an image is formed with a shifted imaging position, and the resolution is reduced. Normally, if it is attempted to correct this deterioration by the performance of the lens, the number of lenses is greatly increased and the cost performance is very poor. Therefore, in order to correct the deterioration of the resolving power, an element 1 for splitting the optical path and correcting the optical path length as shown in FIG. 18 is provided between the lens and the sensor. This makes it possible to obtain a desired resolution over the entire visible to infrared range.

At this time, the separation interval between the visible light beam and the infrared light beam is set to be an integral multiple of the pixel size of the four-line sensor. Furthermore, the separation interval is set so that the reading position is the same as that of the sensor that does not perform line delay, in which the three line sensor for visible light is corrected for spatial displacement in the sub-scanning direction by the line delay element. Then, the line delay element becomes unnecessary as the infrared sensor.

FIG. 20 shows a configuration example of a copying apparatus according to this embodiment. The difference from the configuration of FIG. 2 is that an element 1 for optical path length correction is provided.

(Eighth Embodiment) In the above embodiment, a mirror having a high reflectance in the infrared region is used as an infrared reflection mirror, but a dichroic having a visible cut characteristic shown in 210-1. If a mirror is used, there is no need to provide a visible cut filter in the IR CCD, and the manufacture of the CCD is simplified. Further, unlike the pigment or dye filter provided in the CCD, the visible cut region can be set arbitrarily, so that the accuracy of separating visible light and infrared light is improved.

(Ninth Embodiment) In the above embodiment, a half mirror is used to separate visible light and infrared light. However, if a dichroic filter having the characteristics shown in FIG. 22 is used, only light in a desired visible region is reflected and guided to the visible light reading CCD. As a result, it is not necessary for the CCD filter to have the characteristics of the infrared cut filter shown in FIG.
Can be used, and the fabrication of the CCD is simplified.

(Tenth Embodiment) The description of the seventh embodiment has been made with reference to a four-line sensor which is all monolithically constructed. However, this method may be used for an equal-magnification optical system using a short focus lens array 12801 as shown in FIG. In this case, the sensor is an RGB inline sensor 12802 for reading visible light shown in FIG.
2 and a two-liner sensor 12802 composed of an IR sensor 12802-1 for infrared reading. In the case of the above-mentioned lens, the correction of the shift of the imaging position due to the wavelength has to be improved because the composition of the glass is a single lens, and it is almost impossible to cope by increasing the number of lenses as in a reduction optical system. It is almost impossible, and the present invention is effective.

As described above, according to the above-described embodiment of the present invention, detection from an original using infrared fluorescent ink, which is substantially transparent to visible light, makes it possible to change the actual use state to visible light. It is possible to detect a copy-inhibited document without affecting it.

Further, by providing a light-shielding filter so that light in other wavelength ranges is not detected in the signal for detecting the infrared fluorescent information and the signal for reading the visible information, it is possible to obtain a good signal in which the information is not mixed in the visible and the infrared. Reading can be performed.

Further, by recording information that cannot be identified by visible light as visible information, it is possible to prevent a normal copy operation of a copy-inhibited document.

Further, by providing a means for correcting the imaging position of the signal for detecting the infrared fluorescent information and the signal for reading the visible information, it is possible to perform reading with good resolution over a wide range from visible to infrared. Will be possible.

Further, by providing a means for separating a signal for detecting infrared fluorescent information and a signal for reading visible information satisfactorily and providing a means for correcting an image forming position, the resolution in a wide range from visible to infrared can be improved. Good reading can be performed.

As the solid-state imaging device, in addition to the above-described charge-coupled device (CCD) type, a MOS type or a device described in US Pat. No. 4,791,469 assigned to Tadahiro Omi and Nobuyoshi Tanaka is described. An amplification type device in which a capacitive load is connected to the emitter of the optical transistor may be used.

[0079]

As described above, according to the present invention, visible and non-visible light can be read well.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a detection state of an identification mark of a copy-inhibited document in a first embodiment.

FIG. 2 is a configuration diagram of a color copying apparatus using the present invention.

FIG. 3 is a spectral characteristic diagram of a filter immediately after a document illumination lamp in the embodiment.

FIG. 4 is a spectral characteristic diagram of a document illumination lamp according to the embodiment.

FIG. 5 is a configuration diagram of a CCD sensor in the present embodiment.

FIG. 6 is a filter characteristic diagram for an infrared reading sensor in the present embodiment.

FIG. 7 is a spectral sensitivity characteristic diagram of a CCD in the present embodiment.

FIG. 8 is a spectral sensitivity characteristic diagram of the visible line sensor in the present embodiment.

FIG. 9 is a spectral sensitivity characteristic diagram of the infrared cut filter in the present embodiment.

FIG. 10 is a fluorescence characteristic diagram in this example.

FIG. 11 is an external view of a CCD according to a second embodiment.

FIG. 12 is an external view of a CCD according to a third embodiment.

FIG. 13 illustrates an equal-magnification optical system according to a fourth embodiment.

FIG. 14 is a configuration diagram of a CCD sensor used in a fourth embodiment.

FIG. 15 is an axial chromatic aberration diagram of a reading lens.

FIG. 16 shows the shape of a CCD cover glass in the sixth embodiment.

FIG. 17 is an external view of an optical path separation / optical path length correction element of the present invention.

FIG. 18 is an enlarged view of a reading unit.

FIG. 19 is a spectral characteristic diagram of an element.

FIG. 20 is a configuration diagram of a color copying apparatus.

FIG. 21 is a diagram showing the relationship between the distance between the optical path correcting mirror and the Hahoo mirror, the separation distance of the visible infrared light beam, and the incident angle of the light beam.

FIG. 22 is a spectral characteristic diagram of a dichroic filter.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor ▲ Yoshi ▼ Kazuo Naga 3-2-30 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Nobunatsu Sasanuma 3-30-2 Shimomaruko, Ota-ku, Tokyo (72) Inventor Toshio Hayashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Hiroshi Tanioka 3- 30-2 Shimomaruko, Ota-ku, Tokyo Canon stock In-house (72) Inventor Tsutomu Utagawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Within Canon Inc. (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 1/028-1/031 H04N 1/04-1/207

Claims (14)

(57) [Claims] 1. An image reading apparatus for reading an image of a document having visible information and information other than visible, comprising: an exposure unit for exposing the document; and a reflected light from the document exposed by the exposure unit forming an image. A first sensor that reads visible information and a second sensor that reads information other than visible are monolithically fabricated on the same substrate, and a solid-state imaging device is provided between the first sensor and the document. An image reading device, comprising: a filter that is not provided between the second sensor and the document and that blocks light other than visible light. 2. The non-visible information generates fluorescence .
2. The image reading apparatus according to claim 1, wherein the information is information using a material . 3. The filter according to claim 1, wherein the filter includes: a first sensor;
2. The image reading device according to claim 1, wherein the image reading device is inserted between lenses provided in front of the solid-state imaging device. 4. The image reading apparatus according to claim 3, wherein the filter is a glass filter and is made by bonding the filter to a cover glass on a solid-state imaging device. 5. The image reading device according to claim 3, wherein the filter is a dichroic filter deposited on a cover glass on the solid-state imaging device. 6. An image reading apparatus for reading an image of a document having visible information and information other than visible, comprising: an exposure unit for exposing the document; and a reflected light from the document exposed by the exposure unit forming an image. A first sensor for reading visible information and a second sensor for reading non-visible information are monolithically fabricated on the same substrate; A lens for causing the lens to be fixedly provided between the lens and the solid-state imaging device; And an optical member for eliminating a difference in information imaging position. 7. The non-visible information generates fluorescence .
7. The image reading apparatus according to claim 6, wherein the information is information using a material . 8. The image reading apparatus according to claim 6, wherein said optical member is a glass flat plate inserted between said first sensor and said lens. 9. The image reading apparatus according to claim 8, wherein the optical member is formed by attaching a cover glass on a solid-state imaging device. 10. The optical member according to claim 6, further comprising means for separating visible information and non-visible information.
The image reading device according to claim 1. 11. The image reading apparatus according to claim 10, wherein said separation means uses a half mirror. 12. The image reading apparatus according to claim 10, wherein said separating means uses a dichroic mirror. 13. The image reading apparatus according to claim 12, wherein the dichroic mirror reflects visible information and transmits non-visible information. 14. The image reading apparatus according to claim 6, wherein the optical member is a member that changes an optical path length of visible information and information other than visible information.