JP2005031113A - Color image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To determine as a counterfeit when anti-counterfeit images for banknotes or securities are printed, by eliminating the need for determination of an anti-counterfeit image and minimizing influence on normal copy prints or network prints. <P>SOLUTION: A specific image pattern in a color (e.g., yellow) which is difficult for humans to distinguish is stored. A copy restrictive mode and a normal mode can be selectively set. The copy restrictive mode has been set for use by general users. When a copy start key is operated (step ST1), determination whether the apparatus is in the copy restrictive mode or not is then made (step ST2). In the case of the copy restrictive mode, the pattern image stored in a scan image is added and printing is carried out (step ST3). In the specific case, when the normal mode has been set under conditions, only the scan image is faithfully printed as it is (step ST4. ). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a color image forming apparatus such as a color copying machine, a color facsimile machine, and a color complex machine.
[0002]
[Prior art]
In recent years, color image forming apparatuses can perform high-precision printing, and it is also possible to create counterfeits by copying banknotes and securities. In order to prevent such forgery, it is detected whether the scanned image is an anti-counterfeit image, and when it is an anti-counterfeit image, normal image output is blocked (for example, image output is stopped and forcedly changed) It is known to output an image with the same content.
[0003]
Further, as another anti-counterfeiting technique, the first anti-counterfeiting technique is designed so that a latent image for preventing forgery cannot be easily found when observed with the naked eye and a clear latent image pattern appears when copied. Only a common color component of the pattern and the second pattern is reproduced, and a color component that is not common is erased, whereby a copy prevention printed matter that discriminates copying is disclosed (for example, see Patent Document 1).
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 9-254519 [0005]
[Problems to be solved by the invention]
In the above-described method for preventing normal image output in the case of an anti-counterfeit image, it is necessary to determine whether or not the scanned image is an anti-counterfeit image. Further, the technique described in Patent Document 1 relates to a copy-prevented printed matter that has been subjected to anti-counterfeiting processing, and can protect banknotes, securities, etc. that have not been subjected to such processing from counterfeiting by copying. Can not.
[0006]
The present invention has been made paying attention to the above-mentioned problems, and it is not necessary to determine a forgery-preventing image, and minimizes the influence on a normal copy printed matter or network printed matter, while bills and securities. It is an object of the present invention to provide a color image forming apparatus capable of discriminating that a forgery prevention product such as a forgery is printed.
[0007]
[Means for Solving the Problems]
The color image forming apparatus of the present invention controls the mode switching means, the color image printing apparatus for printing an image, and the first mode (normal mode) so that the input image is faithfully printed by the color image printing apparatus. In the second mode (copy suppression mode), there is provided control means for controlling the input image to be printed by the color image printing apparatus in a form in which an additional image of a color that is difficult for a human to visually distinguish is added. ing. The first mode includes a case where the second mode is temporarily canceled at the time of calibration by a service person. The input image includes a stored test chart and the like.
[0008]
In the color image forming apparatus of the present invention, in the second mode, it is possible to add an additional image of a color that is difficult for a person to visually distinguish on the entire surface of the input image.
[0009]
In the color image forming apparatus of the present invention, the switching from the second mode to the first mode may be made on condition that a predetermined password is input.
[0010]
In the color image forming apparatus of the present invention, color space conversion means for converting image data in the input color space into image data in an output color space different from the input color space, and color space converted by the color space conversion means Binarization means for binarizing image data may be provided, and an additional image may be added to the image data binarized by the binarization means.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail with reference to embodiments. FIG. 1 shows a block diagram of a configuration example of a color image reading apparatus according to this embodiment.
[0012]
In FIG. 1, an MPU 1 (central processing unit) has a function of controlling the entire apparatus. Further, as will be described later, the MPU 1 adds a pattern image stored in the pattern image memory 21 to a document image read by the image reading unit 2 and controls to print with a printer in the copy suppression mode. Have
[0013]
An image reading unit 2, an operation unit 3, a display unit 4, a ROM 5, a RAM 6, a printer 7, and a LAN I / F 8 are connected to the MPU 1 via a system bus 9.
[0014]
The image reading unit 2 reads a document with a three-line sensor described later and acquires a scanned image. Specifically, the output of the 3-line sensor is analog-amplified and the digital data is output in multivalue. The operation unit 3 has a start key for instructing the start of copying and the like, and a numeric keypad for inputting the number of copies and the number of copies. The display unit 4 displays various information such as the number of copies and the number of copies input by the operation of the operation unit 3 and the toner remaining amount of the printer 7. For example, an LCD (Liquid Crystal Display) is used as the display unit 4.
[0015]
The ROM 5 stores in advance a program for controlling the operation of the entire apparatus. The RAM 6 stores data necessary for control by the MPU 1 and data that needs to be temporarily stored during the control operation. The printer 7 prints the scan image data acquired by the image reading unit 2 or the image data received from the external processing device (PC) on paper in color or monochrome. The LAN I / F 8 is a port for connecting to a LAN and is thereby connected to an external processing device (PC) or the like.
[0016]
As shown in FIG. 2, the image reading unit 2 includes an R signal processing unit 11R, a G signal processing unit 11, a B signal processing unit 11B, a first color conversion unit 17, an image processing unit 18, 2 color conversion unit 19, binarization circuit 20, pattern image memory 21, and color synthesis unit 22.
[0017]
The R signal processing unit 11R includes a line image sensor 12R, an analog front end (AFE) circuit 13R, an A / D conversion unit 14R, a shading correction circuit 15R, and a line correction memory 16R. The G signal processing unit 1G includes a line image sensor 2G, an analog front end circuit 13G, an A / D conversion unit 14G, a shading correction circuit 15G, and a line correction memory 16G. The B signal processing unit 11B includes a line image sensor 12B, an analog front end circuit 13B, an A / D conversion unit 14B, and a shading correction circuit 15B. Here, the reason why the B signal processing unit 11B is not provided with a line correction memory is to delay other R signals and G signals based on the B signal. Each shading correction circuit 15R, 15G, 15B includes a shading RAM.
[0018]
The line image sensor 12R is composed of a CCD having a large number of image sensors arranged side by side, and each time a timing signal is applied, the R signal of the image of one scan line of the document is separated and read, and the image of the read one scan line is read. Output data. By moving relative to the original, the R signal of the image of the next one scanning line is sequentially read at a predetermined interval. The analog front end circuit 13R receives the output of the line image sensor 12R and amplifies the analog signal. The A / D converter 14R receives the analog output of the analog front end circuit 13R and converts it into a digital signal. Here, the shading correction circuit 15R includes a shading RAM, and the shading RAM stores the output of the A / D conversion unit 14R when reading the reference plate (white reference plate) as shading correction data. The shading correction circuit 15R corrects and outputs the output of the A / D conversion unit 14R at the time of document reading with the shading correction data. The line correction memory 16R receives the output of the shading correction circuit 15R, delays it by a predetermined line, and outputs it. The same applies to the circuits constituting the other G signal processing unit 11G and B signal processing unit 11B.
[0019]
If the interval between the line image sensors 12R, 12G, and 12B is equivalent to four scanning lines, the shading correction circuit is delayed by four lines after the R signal of one scanning line is output from the shading correction circuit 15R. The G signal for one scanning line is output from 15G, and the B signal for one scanning line is output from the shading correction circuit 15B with a delay of four lines. Therefore, the R signal is delayed by 8 lines in the line correction memory 16R, and the G signal is delayed by 4 lines in the line correction memory 17G and is input to the first color conversion unit 17, respectively. Therefore, the R, G, and B signals input to the first color conversion unit 17 are on the same scanning line.
[0020]
In the first color conversion unit 17, color signals in the R, G, and B spaces are converted into color signals in the L ^* , a ^* , and b ^* spaces that are uniform color spaces. The data converted into the L ^* , a ^* , b ^* space by the first color conversion unit 17 is input to the second color conversion unit 19 via the image processing unit 19. The second color conversion unit 19 converts the color signals L, a, and b into color signals in a CMYK space that is a multi-value printing color space. The multivalued CMYK signal is binarized by the binarization circuit 20 to be a binary CMYK signal, which is input to the color synthesis unit 21.
[0021]
The pattern image memory 21 stores a pattern image of a color (for example, yellow) that is difficult for humans to visually distinguish as binary data. The scan color image binarized by the binarization circuit 20 is combined with the pattern image stored in the pattern image memory 21 by the color synthesis circuit 22 and input to the printer 7. In the normal mode instead of the copy suppression mode, the scanned image data from the binarization circuit 20 passes through the color synthesis circuit 22 and is input to the printer 7 as it is.
[0022]
In this embodiment, at the time of copying, a normal mode (first mode) in which a scan color image is faithfully printed and a predetermined pattern image unrelated to the original image are combined (added) to the scan color image and printed. Copy suppression mode (second mode). In this embodiment, rather, it always operates in the copy suppression mode, and in a specific case it operates in the normal mode. That is, as shown in FIG. 3, when entering this processing routine, in step ST1, it is determined whether or not the copy is made. When the copy start key of the operation unit 3 is pressed, the process proceeds to step ST2. In step ST2, it is determined whether or not the current mode is a copy suppression mode. If this apparatus is used for use by an unspecified number of people, and is operating in the copy suppression mode in the normal use state, the determination is YES, and the process proceeds to step ST3. In step ST3, the yellow pattern image in the pattern image memory 21 is combined with the original image, which is a scanned image output from the binarization circuit 20, by the color combining unit 22, input to the printer 7, and printed. As a result, an image in which a predetermined yellow pattern is added to the entire scanned image data is printed. Thus, in the copy suppression mode, an image that is not faithful to the original image is printed. In step ST2, when the apparatus is set to the normal mode by inputting a password or other specific operation, the determination is NO, and the process proceeds to step ST4. In step ST4, the scan image data is printed with the content faithful to the original image, as in a well-known general apparatus.
[0023]
FIG. 4 is a flowchart for explaining another embodiment of the present invention. In this embodiment, the state of the apparatus can be set in advance to either a copy suppression mode or a normal mode similar to a general apparatus.
[0024]
After operating the copy key, it is determined in step ST12 whether or not the copy suppression mode is set. If the copy suppression mode is set, a pattern image is added to the scanned image and printed in step ST13. In step ST12, in the normal mode, the process proceeds to step ST14 to accept a password input. Next, the process proceeds to step ST15. In step ST15, if the input password does not match the password set in advance for mode conversion, or if the password is not input within a predetermined time, the process proceeds to step ST13, where the scanned image and the password image are combined. I do. If the passwords match in step ST15, the process proceeds to step ST16, and printing faithful to the scanned image (printing an image without adding a pattern image) is executed.
[0025]
As described above, the color image reading apparatus according to this embodiment has not only a copy function for printing a document image read by the image reading unit with a printer but also an external processing apparatus via a network (LAN I / F 8). It has a network print function and a network scanner function for executing network print or network scan upon request. The copy suppression mode can be set for all these functions at once. Further, a copy suppression mode may be set for each function. Also, password setting for canceling the copy suppression mode may be possible for all functions at once, or a different password may be used for each function.
[0026]
【The invention's effect】
According to the first aspect of the invention, by setting the second mode (copy suppression mode), it is possible to easily prevent faithful copying / printing of banknotes and the like without providing an anti-spoofing image determination unit. . When faithful copying / printing or accurate calibration is desired, the mode may be switched to the first mode.
[0027]
According to the second aspect of the invention, since the additional image is added to the entire surface, the additional image is surely superimposed on the original image regardless of the position of the original on the image reading unit. be able to.
[0028]
According to the invention of claim 3, since a password is required to cancel the second mode, the user can easily switch to the first mode and faithfully copy a bill or the like. Can be prevented.
[0029]
According to the fourth aspect of the invention, since the additional image is added to the binary data in the output color space, the amount of data handled for adding the additional image may be small. In addition, when added before binarization (multi-value state), the pattern of the additional image may be destroyed by binarization processing, but by adding after binarization as in the present application, Therefore, it is possible to reliably prevent the pattern of the additional image from being broken, and it is possible to reliably add the pattern in the intended form.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a color image reading apparatus according to an embodiment of the present invention.
FIG. 2 is a block diagram illustrating a configuration of a color image reading unit of the color image reading apparatus according to the embodiment.
FIG. 3 is a flowchart illustrating a copy processing operation of the color image reading apparatus according to the embodiment;
FIG. 4 is a flowchart illustrating a copy processing operation of a color image reading apparatus according to another embodiment.
[Explanation of symbols]
1 MPU
2 Image reading unit 3 Operation unit 4 Display unit 5 ROM
6 RAM
7 Printer 8 LAN I / F
9 System bus 11R, 11G, 11B Signal processor 12R, 12G, 12B Line image sensor 13R, 13G, 13B AFE circuit 14R, 14G, 14B A / D converter 15R, 15G, 15B Shading correction circuit 16R, 16G Line correction memory 17 First color converter 18 Image processor 19 Second color converter 20 Binary circuit 21 Pattern image memory 22 Color composition circuit

Claims (4)

A mode switching means, a color image printing apparatus for printing an image, and control to faithfully print an input image with the color image printing apparatus in the first mode, and a person visually discriminates in the second mode. A color image forming apparatus comprising: a control unit configured to control an input image to be printed by the color image printing apparatus in a form in which an additional image of a difficult color is added. 2. The color image forming apparatus according to claim 1, wherein in the second mode, an additional image having a color that is difficult for a person to visually distinguish is added to the entire surface of the input image. 3. The color image forming apparatus according to claim 1, wherein the switching from the second mode to the first mode is based on an input of a predetermined password. Color space conversion means for converting image data in the input color space into image data in an output color space different from the input color space, and binarization means for binarizing the image data after color space conversion by the color space conversion means 4. The color image forming apparatus according to claim 1, wherein the additional image is added to the image data binarized by the binarizing means.

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