JPH06217127A - Image processor - Google Patents

Abstract

PURPOSE:To accurately recognize a specified original by respectively detecting the change of visible image information, the non-change of information excepting for the visible information and completely opposite cases. CONSTITUTION:Respective added color components are outputted from adders 121 to subtracters 122, and difference from an attention picture element signal component is calculated. Each of difference is compared with a constant by a decision LUT 128 and when it is smaller, '1' is outputted. In the case of an infrared read signal, the difference and the ratio are similarly calculated by a decision LUT 129, when they are larger than constants, '1' is outputted and when the AND of them is '1' at an AND gate 130, data are latched in a latch 135 by judging the presence of the infrared signal change in a visible area. On the other hand, this difference and the infrared read signal are inputted to decision LUT 131 and 132 and compared with constants, and when '1' is outputted, they are ANDed and latched in a latch 133 by judging the presence of a visible signal in the infrared area. When both of outputs from latches 132 and 133 are '1', specified mark detection is recognized.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Conventionally, as image quality and color of copying machines have increased, there has been a fear of forgery of banknotes, stamps and securities. On the other hand, with respect to the recognition of banknotes, various methods have been devised, such as detecting the pattern of a stamp of a banknote.

Further, the present applicant has proposed a method of recognizing a banknote or the like from the color tone of the original document by utilizing the fact that the pattern of the original document is formed in a specific color tone.

There is also a bill in which a genuine mark and a counterfeit bill can be discriminated by printing a specific mark with fluorescent ink that reflects visible light by irradiating ultraviolet rays on the bill itself.

It has also been proposed by the applicant of the present invention to use an ink having a property 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 constructed and a common optical system is used. It is proposed in Japanese Patent Application No. 4-286350 that the miniaturization and easy optical adjustment can be realized.

Further, as a method for determining by reading infrared light and visible light, for example, a manuscript in which a transparent ink absorbing infrared light which cannot be visually recognized is overlapped in a uniform color area for human eyes is used. The applicant has also proposed a method of reading and detecting a change region of infrared light within a substantially uniform visible light region to make a determination.

[0008]

However, in the above-described conventional example, an ink that absorbs infrared light, which is invisible to the human eye, such as carb black, is used even in a normal general document. When there is an almost uniform color background on the front surface, if there are black characters etc. due to the ink on the back surface, show-through occurs, and it is detected that there is a change point of infrared light and erroneous judgment is made. There was a drawback.

Therefore, the present invention eliminates such misjudgment,
An object of the present invention is to provide an image processing device capable of accurately identifying a specific document.

[0010]

In order to solve the above-mentioned problems, an image processing apparatus of the present invention comprises means for inputting visible and non-visible image information, and the visible image information in a predetermined area. Detection means for detecting a change in the image information and a non-change of the image information other than the visible and visible, and a second detecting means for detecting the non-change of the visible image information and the change of the image information other than the visible in a predetermined area. And a discriminating means for discriminating the specific original according to the detection results of the first and second detecting means.

[0011]

[First Embodiment] The present invention will be described below based on a preferred embodiment.

In the following embodiments, a copying apparatus is shown as an application example of the present invention, but the present invention is not limited to this, and it is needless to say that it 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 section, which is a section for reading a document and performing digital signal processing. A printer unit 200 is a unit that prints out an image corresponding to the original image read by the image scanner 201 on paper in full color.

In the image scanner unit 201, 20
Reference numeral 2 denotes a document plate, which is a platen glass (hereinafter, platen) 2
It is used to fix the original document 204 on 03. The original 204 is illuminated with the light of the halogen lamp 205. Reflected light from the original 204 is guided to mirrors 206 and 207, and an image is formed by a lens 208 on a four-line sensor (hereinafter referred to as CCD) 210 including four CCD line sensors. The CCD 210 color-separates the light information from the original and sends it to the signal processing unit 209 as the red (R), green (G), and blue (B) components of the full-color information and the infrared information (IR) components. . Note that 205 and 20
6 is a speed v, and 207 is a 1/2 v, which mechanically moves in a direction (hereinafter, sub-scanning direction) perpendicular to the electrical scanning direction (hereinafter, main scanning direction) of the line sensor to scan the entire surface of the document. To do.

Reference numeral 211 denotes a standard white plate, which is used for the sensors 210-1 to 210-4 at the time of shading correction.
It is used to generate data for correction of read data corresponding to the line sensors of R, G, B components.

As shown in FIG. 8, this standard white plate exhibits almost uniform reflection characteristics from visible light to infrared light, and has a white color in the visible.

Using this standard white plate, the IR sensor 210
It is used for correction of output data for infrared light of -1 and correction of output data of R, G, B visible sensors 210-2 to 210-4.

The signal processing unit 209 electrically processes the read signal, decomposes it into magenta (M), cyan (C), yellow (Y), and black (BK) components, and sends them to the printer unit 200. . In addition, the image scanner unit 201
M, C,
One component of Y and BK is sent to the printer 200 in a frame-sequential manner, and a total of four document scans completes one color image formation.

The image signals of M, C, Y and BK sent from the image scanner unit 201 are 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 a polygon mirror 214, an f-θ lens 215, and a mirror 21.
The photosensitive drum 217 is scanned by way of the scanning line 6.

Numerals 219 to 222 are developing units, which are a magenta developing unit 219, a cyan developing unit 220, and a yellow developing unit 2.
21 and a black developing device 222, four developing devices alternately contact the photosensitive drum, and develop the electrostatic latent images of M, C, Y, and BK formed on the photosensitive drum 217 with the corresponding toners.

223 is a transfer drum, which is a paper cassette 22.
4 or 225, the paper fed from this transfer drum 2
The toner image developed on the photosensitive drum 217 is transferred to a sheet by winding the sheet around the sheet 23.

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

The halogen lamp 205 is commonly used for reading visible information and infrared light information, and has both the illumination wavelength components necessary for reading the above two types of information. By making the illumination system common in this way, the illumination light beams of different wavelength components for reading visible and infrared information are both effectively applied to the document.

FIG. 7A shows the CCD 21 used in this embodiment.
The structure of 0 is shown.

Here, 210-1 is a light receiving element array for reading infrared light (IR), and 210-2, 210-
3, 210-4 are light receiving element arrays for reading R, G, B wavelength components in order.

IR, R, 210-1 to 210-4
G and B sensors are 10 μm in the main and sub scanning directions
With an opening of.

The four light-receiving element arrays having different optical characteristics are arranged 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 original. It is configured monolithically.

By using the CCD having such a structure, 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 optical adjustment and the like, and also facilitate the adjustment.

Reference numeral 210-5 is a glass plate having a characteristic of cutting infrared light in the shaded area, and its thickness is about 300 μm.

The infrared cut characteristic of the shaded portion can be obtained by the dichroic mirror 210-11 formed of a vapor deposition film. The characteristics of this infrared cut are shown in FIG.

Here, the glass plate is adhered to the chip surface such that the vapor deposition surface is on the sensor side.

FIG. 7B shows 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 4 in the lateral direction (297 mm) of an A3 document.
There are 5000 pixels in the main scanning direction so that the image can be read at a resolution of 0 dpi. The distance between the lines of the R, G, and B sensors is 80 μm, and 400 lpi (l
for each sub-scan resolution of 8 lines.

IR sensor 210-1 and R sensor 210-
The line spacing of 2 is 160 μm (16
Line). In this way, the IR sensor 210-
1 and the R sensor 210-2 by making the distance between them wider than the other sensors, the vapor deposition surface 210-1 of the glass plate 210-5.
1 corresponds to the sensors 210-2 to 210-4, and the non-evaporated portion corresponds to the sensor 210-1.
It is possible to make the mounting position accuracy low when -5 is bonded to the sensor chip surface.

FIG. 1 shows a cross-sectional view of the sensor used in this embodiment.

The line sensors 210-1 to 210-4 are monolithically formed on a common silicon chip 210-14, and the surface of each line sensor is IR, R, G, B.
Optical filter 210 for obtaining a predetermined spectral characteristic of
-6 to 210-10 are attached. 210-8, 2
Reference numerals 10-9 and 210-10 denote pigment filters that transmit the R, G, and B wavelength components, respectively, and thus the sensor 21
From 0-2, 210-3, 210-4, R, G, B respectively
Is obtained. The IR sensor 210-1 includes R filters 210-6 and 2 having the same optical characteristics as 210-8.
A B filter 210-7 having the same optical characteristic as that of 10-10 is attached in an overlapping manner, and only IR light having a wavelength of 750 nm or more is read by a combination of R and B filter characteristics described later.

The glass plate 210-5 is attached in the vicinity of the sensor surface, and the vapor deposition film 21 for blocking infrared light is further provided.
0-11 are directed to the sensor side. This is because the light to the sensor is condensed by the lens 209 as shown in FIG. 13, and the light fluxes to the sensors are overlapped at a position apart from the sensor surface. That is, the sensor 2
If the infrared cut filter 210-11 is made to act only on the light to 10-2 to 210-4, the infrared cut filter 210-1 is provided in the vicinity of the sensor where IR light and R light do not overlap.
This is because it is necessary to attach 1.

Therefore, the infrared cut filter 210-1
By placing 1 near the sensor surface, the IR filter
It is possible to widen the mounting allowable width a for setting between the luminous flux of R and the luminous flux of R, and it is possible to reduce the mounting accuracy of the glass plate 210-13 to the sensor chip.

When an infrared cut filter is attached to the surface of the glass 210-5 on the side opposite to the sensor, the IR light flux and the R light flux overlap, so that a sufficient margin is provided for the R light flux and the red light flux is red. If you try to place an outer cut filter I
This is because most of the IR luminous flux imaged on the R sensor 210-1 is blocked and the IR signal level is lowered.

As shown in FIG. 14, the glass plate 210-5 is used.
Instead of mounting the infrared cut filter 210-11 on the sensor side of the cover glass 210-13. In this case, the ceramic package 210-12 of the CCD sensor is configured such that the distance d between the sensor surface and the inner surface of the cover glass is sufficiently short, and the infrared cut filter 210-11 formed on the inner surface of the cover glass is an IR light flux. So that it does not cross over.

Referring to FIG. 10, IR of CCD 210,
The spectral characteristics of the filters of the R, G, and B line sensors will be described.

The characteristic indicated by R is the output characteristic of the sensor by the filter 210-8 and the filter 210-6, and is sensitive to light in the red wavelength range and the infrared wavelength range. The characteristic indicated by G is the output characteristic of the sensor by the filter 210-9, and is sensitive to light in the green wavelength band and the infrared wavelength band. Characteristic filter 210-10 and filter 2 indicated by B
The output characteristics of the sensor according to 10-7 are sensitive to light in the blue wavelength range and the infrared wavelength range.

The IR sensor 210-1 includes a filter 210
Since -6 and 210-7 are mounted in an overlapping manner,
It has sensitivity only to light in the infrared region shown by the shaded area.

As can be seen from this figure, the R, G and B filters 210-8 to 210-10 are sensitive to infrared light of 700 nm or more. Therefore, the infrared cut filter 210-11 has the characteristics shown in FIG.

FIG. 9 shows the spectral absorptance of the infrared absorbing material SIR-159 manufactured by Mitsui Toatsu Chemical Co., Inc., which is used as the detection mark of a specific original in this embodiment. In this embodiment, since the presence or absence of the infrared absorbing material is read by the IR sensor,
Only infrared light from m to 850 nm is detected.

Therefore, the lens 209 is provided with a far infrared cut filter by a dichroic mirror shown in FIG. This filter is provided not only for the IR sensor 210-1 but also for the R, G, B sensors 210-2 to 210-4 without causing any actual damage. As a result, the filter attached to the lens 209 can be designed in consideration of only the far-infrared cut characteristic, and good far-infrared cut characteristic can be realized with a simple interference film structure.

FIG. 15 is a block diagram showing the flow of image signals in the image scanner unit 201. CCD 210
The image signal output from the analog signal processing unit 300
After input to 1 and gain adjustment and offset adjustment,
8 for each color signal with A / D converters 3002 to 3005
It is converted into a digital image signal of bit. After that, it is input to the shading correction units 3006 to 3009, and known shading correction using the read signal of the standard white plate 211 is performed for each color.

Reference numeral 3019 denotes a clock generator which generates a clock for each pixel. A line counter 3020 counts clocks and generates a pixel address output of one line. Reference numeral 3021 denotes a decoder, which decodes the main scanning address from the main scanning address counter 3020 to generate a C for each line such as a shift pulse or a reset pulse.
CD drive signal, VE signal that represents the effective area in the one-line read signal from CCD, and line synchronization signal HSYN
Generate C. The counter 3020 is cleared by the HSYNC signal and starts counting the main scanning address of the next line.

As shown in FIG. 1, since the light receiving portions 210-1, 210-2, 210-3, 210-4 of the CCD 210 are arranged with a predetermined distance, the line delay elements 3010, 3011, 3012. At, the spatial deviation in the sub-scanning direction is corrected. Specifically, the IR, R, and G signals for reading the original document information in the sub-scanning direction with respect to the B signal are line-delayed in the sub-scanning direction to match the B signal.

Reference numerals 3013, 3014, and 3015 denote light quantity / density converters which are constituted by a look-up table ROM and convert the R, G, and B luminance signals into C, M, and Y density signals. Reference numeral 3016 is a known masking and UCR circuit, and detailed description thereof will be omitted, but the input Y, M,
With the C3 primary color signal, Y, M, C, and Bk signals for output are sequentially output with a predetermined bit length, for example, 8 bits, for each reading operation.

An identification unit 3 detects a specific pattern in a document, which is a feature of the present invention.

Reference numeral 3018 denotes a CPU section, which controls the original reading optical system, sequence control such as ON / OFF control of the original illumination lamp 205, and the pixel section signal V in the sub-scanning direction.
Generate SYNC. In addition, the selector 3017 is controlled according to the determination result from the recognition unit 3 to output the port output to the printer instead of the read signal to prevent the copy operation of the specific document.

FIG. 16 shows the timing of each control signal.

The VSYNC signal is an image effective section signal in the sub-scanning direction, and in the section "1", image reading (scanning) is sequentially performed (C), (M), (Y), (B).
k) form the output signal. VE is an image effective section signal in the main scanning direction, which takes the timing of the main scanning start position in the section of "1". The CLOCK signal is a pixel synchronization signal and transfers image data at the rising timing of 0 → 1.

Next, the image pattern (recognition mark) to be detected in the present invention will be outlined with reference to FIG.

FIG. 3 is an explanatory diagram of a specific original in which a specific pattern is added on the original. Area a is a substantially uniform color area recorded with an ink that does not absorb infrared light of a specific wavelength, and b and c are transparent inks of the characteristics shown in FIG. 9 that absorb infrared light of a specific wavelength. It is piled up, and in the eyes of people,
Only the color of a can be identified.

Further, the area d is printed with ink having a density such that the visible signal changes in a minute area while preserving the density with the surrounding area.

Timing charts A and B show the output signal of the CCD sensor 210 at the position on the dotted line, and the area c has a low IR output due to the infrared absorbing ink. Area d is RG of timing chart A.
As in the case of the output B, the density of the color a is changed by ± α, and printing is performed so that the eyes of the human eye look almost the same.

This means that the infrared signal in a certain area is flat and the visible signal changes in that area.

The timing chart B shows the signal on the dotted line B, and shows that the infrared light signal changes in the region where the visible signal is flat.

The method for forming the pattern is not limited to this example.

The details of the identification unit shown in FIG. 15 will be described with reference to FIG. Reference numerals 10-1 to 10-4 in FIG. 4 denote image data line delay units configured by a FIFO, in which the address pointer is initialized by a line synchronization signal HSYNC (not shown), and data is written in pixel units by a CLOCK signal.
Read data. Each is 32BIT R,
G, B, and IR data are delayed by one line.

First, the input signal is input to the flip-flop 11-
A pixel data of A is generated by delaying and holding two pixels at 1 and 11-2. Furthermore, the line memories 10-1, 10-2
Then, the pixel data of C is generated with a delay of 2 lines. The pixel data of C is delayed by 2 pixels and 4 pixels respectively to generate pixel data of the target pixel data X and B. Similarly,
The pixel data of D are input to the determination unit 12, respectively.

Here, the positional relationship of the four pixels A, B, C and D in the vicinity of the target pixel position X is as shown in FIG.

That is, if the pixel of interest X is reading the ink b in FIG. 3, all of the above A, B, C, and D are reading the pixels of the pattern located around it.

The determination algorithm of the determination unit 12 used in this embodiment is shown below.

Now, the R component, G component, B component, and IR component of the read signal forming the pixel signal of A are AR and A, respectively.
If G, AB, and AIR are defined and pixel signals of B, C, and D are similarly defined, R, G, B, and IR in each pixel signal are defined.
Average values YR, YG, YB of the read signals of the respective color components of
YIR is calculated by the following formula.

[0069]

[Outer 1]

The determination of the target pattern follows the difference between the average value Y obtained by the above equation and the target pixel X.

That is, R component of X, G component, B component,
Each XR an IR component, XG, XB, if the _{XIR, ΔR = | Y R -X} R | ΔG = | Y G -X G | ΔB = | Y B -X B | ΔIR = | Y IR -X _IR | Here, it is judged that there is a pattern when the following equation is satisfied.

ΔR <K and ΔG <K and ΔB <K and (ΔIR> L1 or Y _IR / X _IR > L2) (K, L1 and L2 are constants), that is, the target pixel X and its surroundings A, B and C , D when the difference in tint is small in the visible region (smaller than K) and there is a difference of a constant L1 or more in the infrared region, or when the level of the pixel of interest X in the infrared region is the peripheral level ratio. If it is equal to or larger than the constant L2, it is determined that there is a specific pattern.

In the determination of the infrared region, not only the difference but also the ratio is considered in consideration of the decrease in the level of the infrared signal due to the stain on the original. In this embodiment, it is assumed that the infrared reading signal is attenuated as a whole due to the influence of dirt, and the influence of dirt is eliminated by detecting the ratio.

FIG. 6 shows the configuration of the determination unit 12 that implements the above algorithm.

The adder 121 simply adds each color component for four pixels and outputs the upper 8 bits to obtain YR, YG, YB, and YIR, respectively. The subtractor 122 finds the difference between each component of the pixel signal of interest and calculates its ΔR, Δ.
The upper 5 bits of each of the G and ΔB components are input to the determination LUT 128 formed of a ROM, and when each is smaller than the constant K, 1 is output from the LUT 128.

Similarly, in the case of an infrared read signal, 8-bit YIR and XIR are used as a judgment L constructed by a ROM.
Input to the address terminal of UT129, and the above ΔIR = Y
ΔIR> L1 or YIR calculated by IR-XIR
When the determination result of / XIR> L2 is established, LUT1
1 is output from 29.

The output of each LUT is logically ANDed by the AND gate 130, and when the output terminal is 1, the pattern is detected, and the information is latched in the latch 135.

This is a case where the signal in the visible region is flat as shown by the dotted line B in FIG. 3 and there is a change in the infrared signal in the flat region.

On the other hand, the judgment ROM 3 (LUT 13 of 131)
ΔR, ΔG, and ΔB are input to 1), and when each of them is larger than the constant M, 1 is output from the LUT 131.

Similarly, the YIR and XIR are input to the determination ROM 4 (LUT 132) of 132, and ΔIR = Y
When ΔIR calculated by IR-XIR is smaller than the constant N1 and in the range of N2 <XIR <N3, LUT132
Becomes 1 and is ANDed with the output from the LUT 131, and is latched by the latch 133.

This is indicated by the dotted line A in FIG. The case where the signal in the infrared region is flat and there is a change in the visible signal in the flat region is shown.

In this way, when the conditions such as the dotted lines A and B are both satisfied on the original, the outputs of the latch 132 and the latch 133 are both 1, and the output of the AND gate 134 is 1. These latch outputs are the CPU 3018
This resets the port (not shown) for the next recognition operation.

The determination result is input to the latch 3022 shown in FIG. Latch output is input port P1 of CPU 3018
0 is input, and the CPU recognizes that the specific mark is detected. Before the start of the copy sequence, the CPU
The latch 3022 is cleared by the output port P9 signal to prepare for the next pattern detection.

The control operation of the CPU 3018 for the recognition mark determination operation which accompanies the normal copy operation will be described below with reference to FIG.
Will be described.

The operator sets the original 204 on the platen 203.
When a copy operation is started by an operating unit (not shown), the CPU 3018 controls a motor (not shown) to move the reflection mirror 206 to below the standard white plate 211.

Next, the halogen lamp 205 is turned on, the standard white plate 211 is illuminated, and the shading correction unit 300 is illuminated.
In 6 to 3009, shading data for IR, R, G and B signals are sampled (step 1).

Next, the port output P9 is set to 0 and the latch 30
The output of 22 is cleared to 0, the output of P8 is cleared to 0, the A input of the selector 3017 is selected, and the masked and UCR image signal is supplied to the printer. Then P
9 output is set to 1 and the clearing operation of the latch 3022 is completed (step 2).

Next, the document reading operation is performed four times in accordance with the four-color image recording operation of M, C, Y, and BK in the printer unit to perform image recording, the recognition mark is detected, and the detection result is obtained. The recording operation is controlled accordingly.

First, for magenta recording, the CPU masks, identifies the processing conditions for magenta in the UCR processing part, scans the optical system, gives a magenta signal to the printer, and returns the optical system to the scanning start position after scanning ( Step 3).

During the reading of the original, the CPU periodically reads the port 10 and determines whether the input is 1. Where P
If 10 is 1, it is determined that a specific document that should not be prohibited from being reproduced normally is being copied, and in step 7, the outputs of P0 to P7 are set to FFH and the output of P8 is set to 1 to the printer. A solid signal of FFH is output to prevent a normal copy operation thereafter.

Similarly, in steps 4 to 6, cyan,
The recording control of yellow and black is performed, and the CPU is in the meantime.
Periodically checks the state of P10, and if it is 1, outputs solid FFH data to the printer in step 7.

If P10 = 1 is detected during cyan recording, magenta will perform a normal copying operation.
The cyan, yellow, and black recordings are all recorded in solid FFH.

<Second Embodiment> FIG. 18 shows a second configuration example of the image reading apparatus using the present invention.

This CCD, as shown in FIG.
A two-line line sensor is monolithically formed on a common silicon chip.

The line sensor 3301-1 is an infrared light reading sensor (IR sensor).
Is a full color line sensor in which R, G and B sensors are alternately arranged in pixel units.

A glass plate 33 having an infrared cut dichroic filter 3301-11 vapor-deposited on this sensor.
01-5 is attached similarly to FIG. 7.

The dichroic filter 3301-11 has the infrared cut characteristic shown in FIG. 11 like the 210-11.

As in the case of FIG. 7, the glass plate is attached to the CCD chip so that the vapor deposition surface side faces the chip surface, and the end of the vapor deposition portion is line sensor 3301-1.
And 3301-2.

FIG. 18B shows the line sensor 3301-1.
And a pixel enlarged view of 3301-2.

The IR sensor 3301-1 has a length of 18 μm and a width of 18 μm.
The pixel size of m is m, and the R and B filters having the characteristics shown in FIG.
It has the same infrared transmission characteristics as the IR sensor of.

By combining with a far infrared cut filter having the characteristic shown in FIG. 12 which is provided in the same imaging optical system as that of the first embodiment (not shown), the infrared reading characteristics similar to those of the first embodiment are obtained. Have.

3301-2 is an IR sensor and 180 μm
The R, G, and B sensor rows are separated by (10 lines), and the R, G, and B pixels of 6 μm each are formed corresponding to 18 μm of one pixel of the IR sensor in the main scanning direction. Each R,
The G and B pixels are provided with a color separation filter having the characteristics shown in FIG.

This sensor has 5000 pixels in the main scanning direction in order to read an A3 original at 400 dpi,
There are also 5000 combinations of R, G, and B pixels.

63.5 μm (400 dp
The scale of the optical system is 18.5 / 63.5 so that 1 pixel of i) is projected on 18.5 μm.

<Third Embodiment> FIG. 19 shows a third configuration example of the image reading apparatus using the present invention.

As shown in FIG. 18A, this CCD 3401 is composed of a sensor 3402 in which R, G, B and IR pixels are arranged on a line, and IR, R, G and B pixels are arranged.
Image data of one pixel is color-separated (wavelength-separated) and read.

The pixel size of each pixel of IR, R, G, B in the main scanning direction is 63.5 / 4 μm, and IR, R, G,
The set B reads one pixel of 63.5 μm.

Since this sensor reads a document at 400 dpi, the scale factor of the optical system is 1 × so that 63.5 μm (one pixel at 400 dpi) of the document table is projected onto the above 63.5 μm.

In the IR reading pixel, R and B filters having the characteristics shown in FIG. 10 are superposed on the sensor, and have the same infrared passing characteristics as the IR sensor 210-1.

By combining with a far infrared cut filter having the characteristic shown in FIG. 12 provided in an image forming optical system (not shown), the infrared reading characteristic similar to that of the first embodiment is obtained. The R, G, B read pixels are provided with color separation filters having the characteristics shown in FIG.

On this sensor, a glass plate 3403 on which an infrared cut dichroic filter 3404-11 is vapor-deposited with a pitch of 63.5 μm and a width of 63.5 / 4 μm is attached as shown in FIG. 19 (A). .

The dichroic filter 3404 has 210
Similar to -11, it has the infrared cut characteristic shown in FIG.

The glass plate is attached to the CCD chip in the same manner as in FIG. 7 so that the vapor deposition surface side faces the chip surface, and the non-evaporated portion corresponds to the IR pixel as shown in FIG. Attached to.

<Other Embodiments> In the third embodiment, four pixels of IR, R, G and B for reading one pixel are arranged in the main scanning direction, but the four pixels are arranged two-dimensionally. ,
An infrared cut dichroic filter may be formed only in the portion corresponding to the R, G, and B pixels of the glass plate.

In the above-mentioned embodiment, the infrared cut filter is formed of a transparent member and attached to the sensor. However, the characteristics of this filter are not limited to infrared, and it is also possible to cut ultraviolet rays unnecessary for reading visible information. good.

As described above, the first detecting means including the means for detecting the flatness of the visible signal in a certain read area and the means for detecting the non-flatness of the invisible signal in the area. A second detection means including a means for detecting the flatness of the non-visible signal in the read certain area and a means for detecting the non-flatness of the visible signal in the area; Second detecting means composed of a simple circuit
There is an effect that it is possible to accurately recognize the specific document, which is to be determined by adding the detection means of.

[0117]

As described above, according to the present invention, it is possible to accurately identify a specific original.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a CCD according to a first embodiment.

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

FIG. 3 is a configuration diagram of a specific document identification pattern in the first embodiment.

FIG. 4 is a diagram for detecting a specific pattern in the first embodiment.
Dimensional area signal generator.

FIG. 5 is a specific pattern detection reference pixel in the first embodiment.

FIG. 6 is a configuration diagram of a specific pattern determination unit according to the first embodiment.

FIG. 7 is a configuration diagram of a CCD according to the first embodiment.

FIG. 8: Spectral reflectance of a standard white plate.

FIG. 9: Spectral transmittance of a specific pattern.

FIG. 10 is a spectral sensitivity characteristic of a visible line sensor and a filter characteristic diagram for an infrared reading sensor in the present embodiment.

FIG. 11 is a characteristic diagram of an infrared cut dichroic filter.

FIG. 12 is a characteristic diagram of a far infrared cut filter.

FIG. 13 is a mounting view of an infrared cut glass on a CCD sensor.

FIG. 14 is an attachment diagram of a cover glass when an infrared cut filter is formed on the CCD cover glass.

FIG. 15 is an image signal control unit.

FIG. 16 is a timing diagram of image control signals.

FIG. 17 is a control flow chart of the CPU.

FIG. 18 is a configuration diagram of an image reading apparatus according to a second embodiment.

FIG. 19 is a configuration diagram of an image reading apparatus according to a third embodiment.

[Explanation of symbols]

 210-5 glass plate 210-1 line sensor for IR 210-2 line sensor for R 210-3 line sensor for G 210-4 line sensor for B

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location G07D 7/00 E 9340-3E

Claims (1)

[Claims] 1. Input means for inputting visible and non-visible image information, and first detecting means for detecting a change of the visible image information and a non-change of the non-visible image information within a predetermined area. A second detection unit that detects a non-change of the visible image information and a change of the image information other than the visible image within a predetermined region; An image processing apparatus comprising: an identification unit for identifying a document.