JPH07111581A - Image recorder - Google Patents

Abstract

PURPOSE:To prevent picture quality from deteriorating by changing a tracking pattern for forgery prevention, etc., corresponding to the area of an inputted image, more surely tracking the output result of securities such as a note or stamp, etc., and hitting a pattern so as to prevent another image from being prominent. CONSTITUTION:A VDO signal 303 for Y, M, C, and BK inputted from a tracking pattern generating part and a color processing part 201, a color designation signal 210, a BD signal 212, a PCLK signal 213 and an area designation signal 308 from an area decision part 307 are provided as input. and after they are processed, the VDO signal 303 is inputted to a density correction part 202. The area decision part 307 discriminates whether or not an input image may be forged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording device,
For example, the present invention relates to a color image recording apparatus having a function of preventing forgery of bills or securities.

[0002]

2. Description of the Related Art In recent years, color image recording apparatuses such as printers and copying machines have made great progress in terms of performance improvement and popularization, and full-color image recording apparatuses also include silver salt system, thermal system and electrophotographic system. , Those using a large number of output systems such as an electrostatic recording system and an inkjet system have been developed, and have been widely spread while obtaining high-quality images. However, new problems arose. It is a problem that bills and securities can be easily forged using a full-color image recording device. Along with this, it has become necessary to equip a recording apparatus with a function of preventing forgery, and recent full-color image recording apparatuses have various anti-counterfeit functions. The most common method among them is to print a regular dot pattern that represents the machine number of the recording device on the paper at the time of recording, and when a forged banknote is found, the dot pattern that was printed on the banknote. This is a so-called tracking pattern method in which the machine number is calculated from the device and the recording device from which it is output is specified. Further, since this dot pattern is printed on all the output images, it is common to print with yellow, which has the lowest visibility.

[0003]

However, in the above-mentioned conventional method, since the dot pattern is uniformly printed in all the output images, the dots printed in the image can be visually recognized even if they are printed in yellow. That is, the image quality is deteriorated. Further, since the dot pattern represents the machine number by the positional relationship of a plurality of dots, if the dots are struck finely in accordance with an image having a relatively small area such as a stamp, the visibility of the dots becomes more remarkable.

Further, if a dot pattern is formed in accordance with a relatively large image such as a banknote, when an image with a relatively small area such as a stamp is forged, the dot spacing is too wide and the machine number becomes large. There was a problem that I could not recognize.

[0005]

The present invention has been made for the purpose of solving the above-mentioned problems, and has the following structure as one means for solving the above-mentioned problems. Recognition signal holding means for holding a specific recognition signal, area area determination means for determining the area of the image area to be recorded, and recognition signal for changing the recognition signal according to the area area determined by the area area determination means It has a changing means and a recording means for adding and recording the recognition signal.

For example, the recording means is of an electrophotographic type, and the recognition signal is composed of a plurality of dots. Further, a specific image area holding unit that holds a plurality of specific image areas, a region area determined by the region area determination unit, a plurality of specific image areas held by the specific image area holding unit Area recording means for comparing within a range of error, the recording means, as a result of the comparison by the area comparison means, if the area area is not equal to all of the plurality of specific image area, without adding the recognition signal On the other hand, if it is equal to one of the plurality of specific image areas, the recognition signal changing means changes the recognition signal according to the specific image areas determined to be equal, and the changed recognition signal is It is characterized by being added and recorded.

Further, even if the recording means determines that the area is equal to one of the plurality of specific image areas as a result of the comparison by the area comparing means, the recording area is recorded in the image area including only the white data or the image area including only the text image. On the other hand, the recognition signal is not added. For example, the specific image held by the specific image area holding means is a bill or securities.

[0008]

With the above configuration, by changing a specific recognition signal such as a tracking pattern for preventing forgery according to the area area of the input image, the output result of securities such as banknotes and stamps can be improved. Makes it possible to perform tracking more reliably, and it is possible to prevent image quality deterioration by striking a pattern in other images so that it is less noticeable.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described in detail below with reference to the drawings.

[0010]

First Embodiment In this embodiment, the construction of an image recording apparatus using a color electrophotographic technique is particularly shown. In this embodiment, the input density level is M (magenta) as an image signal,
It is assumed that the C (cyan), Y (yellow), and BK (black) colors are transmitted in an 8-bit sequential color plane.

FIG. 1 shows an example of the configuration of the color image recording apparatus of this embodiment. First, the photoconductor drum 100 is uniformly charged to a predetermined polarity by the charger 101, and a first latent image of magenta, for example, is formed on the photoconductor drum 100 by exposure with the laser beam light L. Then, in this case, the required developing bias voltage is applied only to the magenta developing unit Dm to develop the magenta latent image, and the magenta first toner image is formed on the photosensitive drum 100.

On the other hand, the transfer paper P is fed at a predetermined timing, and a transfer bias voltage (for example, +1.8 KV) having a polarity opposite to that of the toner (for example, a positive polarity) is transferred immediately before the leading edge of the transfer paper P reaches the transfer start position. The first toner image on the photosensitive drum 100 is transferred to the transfer paper P by being applied to the drum 102, and the transfer paper P is transferred to the transfer drum 102.
Is electrostatically adsorbed on the surface of. After that, the residual magenta toner is removed from the photoconductor drum 100 by the cleaner 103 to prepare for the latent image formation and development process of the next color.

Next, a second latent image of cyan is formed on the photosensitive drum 100 by the laser beam L, and then the second latent image on the photosensitive drum 100 is developed by the cyan developing device Dc. As a result, a cyan second toner image is formed. Then, this cyan second toner image is
The magenta first toner image transferred onto the transfer paper P is aligned with the position of the first toner image and transferred onto the transfer paper P. In transferring the toner image of the second color, a bias voltage (for example, + voltage) is applied to the transfer drum 102 immediately before the transfer paper P reaches the transfer portion.
2.1 KV) is applied.

Similarly, the third of yellow and black,
The fourth latent images are sequentially formed on the photosensitive drum 100,
Each of them is sequentially developed by the developing devices Dy and Db, aligned with the toner images previously transferred onto the transfer paper P, and the third and fourth toner images of yellow, black are transferred in sequence, and then transferred onto the transfer paper P. Thus, the four color toner images are formed in a superposed state.

Next, a block diagram of the multi-valued image processing unit for receiving the RGB image signals and transmitting the recording information to the laser drive unit is shown in FIG. 2 and will be described below. Note that FIG. 2 shows a basic configuration of the apparatus of this embodiment without a forgery prevention function. Below, yellow, magenta, cyan,
Black is represented as Y, M, C and BK.

A color processing unit 201 receives an RGB 24-bit image signal. Since the apparatus of this embodiment records one screen for each color of Y, M, C, and BK as described above, image data is frame sequential, that is, data for one screen of M, data for one screen of C, and one for Y. Data for one screen and data for one screen of BK are sent in this order. Therefore, the color processing unit 20
In 1, the image data for one screen of RGB is first converted pixel by pixel into an 8-bit VDO (video) signal of the M signal. Then, the C signal, the Y signal, and the BK signal are converted in this order.

In the color processing unit 201, the input RG
Which color of M, C, Y, and BK the data of B is to be converted is instructed by a color designation signal 210 sent from a formatter unit (not shown). That is, the color designation signal 210 first changes in the order of C, Y, BK every time M is designated and data for one screen is sent. Thereafter, each image data is input to the density correction unit 202, converted by the density correction unit described later, and then input to the PWM (pulse width modulation) unit 203. In the PWM unit 203, the 8-bit image signal is input to the image signal PCLK21 by the latch circuit 204.
In synchronization with the rising edge of 3, the D / A converter 205 converts the corresponding analog voltage, and the analog comparator 2
Enter in 06.

On the other hand, the triangular wave generator 207 generates a triangular wave by the image clock 213 and inputs it to the analog comparator 206. The analog comparator 206 compares the analog voltage and the two signals of the triangular wave and outputs the PW signal.
The M signal is output. And then the inverter 20
It is inverted at 8 and a PWM signal is obtained. The image forming apparatus of this embodiment has a recording capacity of 600 dpi (dots / inch) and a triangular wave frequency (number of lines) of 600 lines and 300 lines.
It has a means to switch to a line. Here, the wavelengths of 600 lines and 300 lines are 1 / wavelength at the time of comparison, respectively.
This means using 600-inch and / 300-inch triangle waves.

In FIG. 2, the triangular wave generation unit 207 generates triangular waves of 600 lines and 300 lines, and which one is to be input to the analog comparator is determined by a line number switching signal 211 input from a formatter unit (not shown). Selection is made by switching the changeover switch 209. Also,
Reference numeral 212 denotes a horizontal scanning (main scanning) synchronizing signal of the laser, which is called a BD signal.

Next, regarding the forgery prevention function of this embodiment,
explain. FIG. 3 is an example in which the forgery prevention function of the apparatus of this embodiment is added to the block diagram of FIG. The same components as those in FIG. 2 are denoted by the same reference numerals as those in FIG. 2 and their description is omitted. Reference numeral 301 denotes a tracking pattern generation unit, which is a Y, M, C, and BK VDO signal 303 and a color designation signal 210, and a BD signal 212 and a PCLK signal 21 input from the color processing unit 302.
3, the area designation signal 308 from the area determination unit 307 is input, and after processing, the VDO signal 303 is input to the density correction unit 202.

Next, the processing of the area determination unit 307 will be described below with reference to the flowcharts of FIGS. 4 and 5.
FIG. 4 is a flowchart of edge determination processing for one plane. First, in step S401, pixel data for five lines, for example, is stored in a buffer (not shown).

Next, in step S402, each pixel data is binarized by an appropriate threshold value (a value such that the frame portion of the banknote or stamp area is 1 is ideal). Then, in step S403, patterns that match the registered edge pattern are extracted by pattern matching, and several types of patterns are registered in advance in a ROM (not shown). FIG. 6 shows an example of the right-angled edge partial pattern. In the present embodiment, pattern extraction is performed for an area of 7 × 5 pixels, for example.

Subsequently, in step S404, the coordinates of the edge extracted by the pattern matching are stored in a memory (not shown). Next, in step S405, the buffer is shifted by one pixel in the main scanning direction, and step S406.
Check to see if all the pixels in the buffer have been processed. If there is an unprocessed pixel in step S406, the process proceeds to step S403.

If all the pixels in the buffer have been processed in step S406, the flow advances to step S407 to check whether the processing has been completed for all lines in one plane. If the processing for all the lines is completed in step S407, the edge determination processing for, for example, the R image is completed. If there is an unfinished line in step S407, the process proceeds to step S401.

Although the edge determination processing for one plane is completed by the above processing, this processing is performed for each RGB plane. Then, the process proceeds to the region determination process. Figure 5
3 is a flowchart of a region determination process. First, in step S501, the coordinate information of each edge obtained for each RGB plane is compared, and then in step S502,
The coordinates extracted in common for the three planes are stored in a memory (not shown) as the edges of the image area.

FIG. 7 shows an example of the edges stored in the memory in step S502. Each coordinate of the edge is indicated by a cross. Next, in step S503, a rectangular shape (for example, the dotted line in FIG. 7) is searched for among these edges. At this time, if there is no rectangle, step S51.
In step 4, the processing area is determined to be neither the banknote area nor the stamp area, and other areas.

On the other hand, if there is an edge forming a rectangle in step S503, the flow advances to step S504 to obtain the area of the rectangle. Next, the process proceeds to step S505, and the calculated area of the rectangle and the ROM (not shown) in advance.
Compare the areas of the banknotes registered in. Step S505
In, if the area of the rectangle and the area of the registered banknotes match within a predetermined error range, the process proceeds to step S507, and it is determined whether the rectangular area is an area including only a text image or white data. To do.

If the rectangular area is not an area consisting of only a text image or white data, step S5.
At 09, it is determined that the rectangular area is a banknote area. If the area is composed of only a text image or white data, it is determined as another area in step S510. If the area of the rectangle and the area of the registered banknote do not match in step S505, the process proceeds to step S506, and the area of the rectangle is compared with the area of a stamp registered in advance in a ROM (not shown).

In step S506, if the area of the rectangle and the area of the registered stamp coincide with each other within a predetermined error range, the process proceeds to step S508, and the rectangular area is a text image or an area including only white data. Determine if there is. If the rectangular area is not an area consisting of only a text image or white data, it is determined in step S513 that the rectangular area is a stamp area. If the area is composed of only a text image or white data, it is determined as another area in step S512.

If the area of the rectangle does not match the area of the registered stamp in step S506, it is determined as another area in step S511. As described above, it is determined whether the processing area is a special area such as a bill or a stamp, or another area, and the area determination process ends. Then, in synchronization with each pixel in the area being sent to the tracking pattern generation unit 301,
The area designation signal 308 is designated and sent as "banknote", "stamp" or "other".

The other areas, particularly in the case of only white data and in the case of a text image, are that it is certain that the white area and the text area are not images of banknotes or stamps, and that dots are printed on the white background. This is because when you hit, the dots are easily visible. Next, a method of recording the tracking pattern will be described below. Recording examples of tracking patterns are shown in FIGS. 8 and 9.

FIG. 8 shows an example of a recording pattern in the bill area. These dots are printed only on the yellow plane, which has low visibility. 12 × 12 shown in the shaded area 701
For pixels, the density is set to 25 with respect to the original image data.
"30" is added in 6 gradations, and the density is subtracted "30" for the portions 702 and 703 of 6 × 12 pixels on both sides thereof. This keeps the overall average density. In addition, as a result of the processing, when the density is "255" or more, "255" is set,
When it is less than "0", it is set to "0".

An area of 24 × 12 pixels formed by this 701 and the portions 702 and 703 on both sides is one dot. Such dots are printed at 16-dot intervals in the main scanning direction. The 12 lines on which these dots are printed will be referred to as the first dot line, the second dot line, ... Next 24 from the first dot line
Strike a second dot line with a line interval. Here, the phase difference in the horizontal direction (main scanning direction) between the dot position of the second dot line and the dot position of the first dot line represents the first digit of the machine number. In the example of FIG. 8, the first digit number is written on the second dot line. As shown in the figure, since the phase difference can take from "0" to "F" in hexadecimal, 16 values from "0" to "F" can be taken per digit. After that, similarly, 24 lines are opened to hit the third dot line, and the phase difference from the second dot line (9 in the example of FIG. 8) represents the second digit of the machine number.

In this way, for example, when dots are printed up to the 16th dot line, the machine number of hexadecimal 16 digits is displayed. When the 16th dot line is hit, the first dot line is hit again and the same operation is repeated. As described above, since the image recording apparatus of this embodiment has a resolution of 600 dpi, the size of one pixel is about 0.042 mm × 0.042 mm. Therefore, for example, in order to recognize a 16-digit machine number, at least 24 pixels x 17 dots x 0.042 mm = about 17.1 mm in the main scanning direction, and (12 + 24) pixels x 17 dots x 0 in the sub scanning direction. An area of 0.042 mm = about 25.7 mm is required. Further, in order for this area to be always included in the image, an image area twice as large as that in the main scanning direction and the sub-scanning direction is required, so that an area of 34.2 mm × 51.4 mm is required.

Of course, since this exceeds the area of a standard stamp, the machine number stamped on the stamp cannot be recognized with this recording pattern. Therefore, a separate recording pattern for stamps is prepared. FIG. 9 shows an example of a recording pattern in the stamp area. Basically, it is the same as the example of the recording pattern of the banknote area shown in FIG. 8, but the size of 1 dot is 6 × 6 pixels in the shaded area 703 for increasing the density, and the areas 704 on both sides for decreasing the density. , 705 each have 3 × 6 pixels. Therefore, the size of one dot is 12 × 6 pixels.

The interval between the first dot line and the second dot line is also 12 lines. When printing is performed according to this example, the image area necessary for recognizing the machine number is 1/2 of the banknote recording pattern shown in FIG.
1 mm × 25.7 mm is enough. It can be seen that this is within the standard stamp size range, and thus the recorded pattern can identify the stamp body number.

The structure of the tracking pattern generator 301 for producing such a recording pattern will be described with reference to the block diagram of FIG. Reference numeral 809 denotes a tracking pattern control unit, which is 8
01 is the input Y, M, C, BK 8-bit VDO
Signal, 802 is BD signal, 803 is PCLK signal, 80
Reference numeral 4 is a color designation signal, and 805 is a region designation signal sent from the area determination unit 307.

The VDO signal 801 to be input is first of all a plus modulator 80 which carries out plus modulation processing to increase the density by 30.
6, a negative modulation unit 807 that performs a negative modulation process that lowers the density by 30 and a through 808 that does not perform the process. In the tracking pattern control unit 809, first, the phase difference in the main scanning direction between dots is determined by the machine number signal 815 input from a memory (not shown). Next, based on the information on the phase difference in the main scanning direction, the counter 810 in the main scanning direction and the sub-scanning direction is rotated by the PCLK signal 803 and the BD signal 802.

The contents of the counter 810 are input to the bill pattern generating unit 811 and the stamp pattern generating unit 812, and the contents of the counter 810 and the machine number signal 815.
According to the information of the phase difference obtained by the above, as shown in FIG. 8 in the banknote pattern generation unit 811, as shown in FIG. 9 in the stamp pattern generation unit 812, the dot processing is performed for each pixel, and the selector B813 is processed. input.

Next, in the selector B 813, the color designation signal 8
When a color other than Y is designated by 04, B3 is unconditionally selected. When B3 is selected, the selector signal 814 instructs the selector A 815 to select A1. Therefore, for the M, C, and BK data, the input data is output as it is. When Y is specified by the color specifying signal 804, the area specifying signal 805 inputs whether the pixel is a banknote area, a stamp area, or another area.

When the banknote area is specified by the area specifying signal 805, B1 of the selector B813 is selected,
A select signal 814 is sent to the selector A 815 so that the dots shown in FIG. 8 are printed, and the selector A 815 selects one of the corresponding A1, A2, and A3. When the stamp area is designated by the area designation signal 805, B2 of the selector B813 is selected, the select signal 814 is sent to the selector A815 so that the dots shown in FIG. 9 are printed, and the selector A815 responds to the corresponding A1, A2. , A3 is selected.

When another area is selected by the area designation signal 805, B3 of the selector B813 is selected. As described above, in this case, A of the selector A815
1 is selected and the input data is output as it is.
By performing the above processing, the dot pattern for the banknote is printed in the banknote area, the dot pattern for the stamp is printed in the stamp area, and the dot pattern is not printed in the other areas. An example of this recording is shown in FIG.

The forgery prevention tracking pattern of this embodiment is realized as described above. In the above description, the case where the area registered in the ROM is a banknote and a stamp has been described as an example.
The present invention is not limited to the above examples, and can be applied to any securities such as checks and stock certificates. Further, the target to be discriminated may be arbitrarily registered for each device. This also applies to the second embodiment.

As described above, according to the present embodiment, by changing a specific recognition signal such as a tracking pattern for preventing forgery according to the area area of the input image, valuables such as bills and stamps can be obtained. By making it possible to more reliably track the output results of securities, and by making patterns less noticeable for other images,
It is possible to obtain the effect of preventing deterioration of image quality.

[0045]

Second Embodiment Next, a second embodiment according to the present invention will be described below. The edge determination by the area determination unit 307 is performed according to the first
In this embodiment, pattern matching is used, but in this embodiment, the density difference between adjacent pixels is used.

The method of edge determination by the area determination unit 307 in this embodiment will be described below with reference to the flowchart of FIG. FIG. 12 is a flowchart of edge determination processing for one plane in this embodiment. First, in step S111, pixel data for one line is stored in a buffer (not shown).

Then, in step S112, it is confirmed whether adjacent pixels have a density difference of 30 or more.
Subsequently, in step S113, the coordinates confirmed to be the edge portion are stored in a memory (not shown). Then step S
At 114, the buffer is shifted by one pixel in the main scanning direction, and at step S115, it is confirmed whether or not all the pixels in the buffer have been processed.

If there is an unprocessed pixel in step S115, the process proceeds to step S112. In addition, when the processing of all the pixels in the buffer is completed in step S115, the process proceeds to step S116, and it is confirmed whether the processing is completed for all the lines of one plane.

If the processing for all the lines is completed in step S116, for example, the edge determination processing for the R image is completed, but if there is an unfinished line in step S116, the process proceeds to step S117. . In step S117, for example, 100 lines are skipped in the sub-scanning direction on the plane, and the process proceeds to step S111.

With the above processing, the edge determination processing for one plane in this embodiment is completed. This process is RGB
Although the process is performed for each plane and then the region determination process is performed, the subsequent process is the same as that of the first embodiment, and thus the description thereof is omitted. FIG. 13 shows an example of the coordinate information of each edge obtained by performing the above-described edge determination processing on each of the RGB planes and matching.

The dotted line in FIG. 13 is a line for viewing the density for every 100 lines, and the X mark is each detected edge portion. For example, there are 901, 902, etc. that form a rectangle in a region formed by these edges. It should be noted that the edge determination is performed every 100 lines for the purpose of improving the processing speed, and therefore it is not particularly limited to 100 lines. Of course, the optimum number of lines may be set depending on the device.

In the case of the edge determination method in this embodiment, the edge detection is not always performed accurately, so the determination of the banknote area, the stamp area, and other areas must be interpreted as suspicious areas. I won't. Therefore, a dot pattern with a slightly weaker modulation amount is printed in the other regions, and a dot pattern with a stronger modulation amount is printed in the banknote and stamp regions.

When the tracking pattern generator 301 is constructed so as to print the above dot pattern, the block diagram shown in FIG. 14 is obtained. The basic configuration is the same as that of FIG. 10 shown in the first embodiment, but the density modulation unit is ± 40 modulation 1
There are two types, 115 and 1116, ± 20 modulations 1117 and 1118, and there is no modulation processing.
There is 4.

In the tracking pattern control section 1101, first, the phase difference in the main scanning direction between dots is determined by the machine number signal 1108 input from a memory (not shown). Next, based on the information on the phase difference in the main scanning direction, the PCLK signal 1102 and B
The counter 1104 in the main scanning direction and the sub scanning direction is rotated by the D signal 1103. The contents of the counter 1104 are input to the bill pattern generating unit 1105, the stamp pattern generating unit 1106, and the other pattern generating unit 1107, and the contents of the counter 1104 and the phase difference information obtained by the machine number signal 1108. As shown in FIG. 8 in the banknote pattern generation unit 1105 with a modulation of ± 40, and in the stamp pattern generation unit 1106 with a modulation of ± 40 as shown in FIG. 9, the other pattern generation unit 110.
In No. 7, dot processing is performed on each pixel by modulation of ± 20, and the dot processing is input to the selector B1113.

Next, the selector B1113 unconditionally selects B4 when a color other than Y is designated by the color designation signal 1111. When B4 is selected, the select signal 1109 instructs the selector A1110 to select A1. Therefore, for the M, C, and BK data, the input data is output as it is. Color designation signal 1
Area designation signal 11 when Y is designated by 111
12, the pixel is input as to whether the pixel is a bill area, a stamp area, or another area.

When the banknote region is designated by the region designation signal 1112, B1 of the selector B1113 is selected, and the select signal 1109 is sent to the selector A1110 so that the dots shown in FIG. The selector A1110 selects any of the corresponding A1, A2 and A3. When the stamp area is designated by the area designation signal 1112, B2 of the selector B1113 is selected and the select signal 1109 is sent to the selector A1110 so that the dots shown in FIG.
The selector A1110 selects any of the corresponding A1, A2 and A3.

When another area is selected by the area designation signal 1112, B3 of the selector B1113 is selected and the select signal 1109 is sent to the selector A1110 so that the dots shown in FIG. , The selector A1110 selects one of the corresponding A1, A4, and A5. By performing the above processing, a dot pattern modulated to ± 40 for banknotes is printed in the banknote area, a dot pattern modulated to ± 40 for stamps is stamped in the stamp area, and ± is stamped in other areas. A dot pattern modulated into 20 is printed. An example of this recording is shown in FIG.

As described above, the forgery prevention tracking pattern of this embodiment is realized. As described above, according to this embodiment, the same effect as that of the first embodiment can be obtained. The present invention may be applied to a system including a plurality of devices or an apparatus including one device. Further, it goes without saying that the present invention can be applied to the case where it is achieved by supplying a program to a system or an apparatus.

[0059]

As described above, according to the present invention, by changing a specific recognition signal such as a tracking pattern for preventing forgery according to the area area of the input image, a bill, a stamp, etc. By making it possible to more reliably trace the output results of securities, and by making patterns less noticeable for other images,
Image quality deterioration can be prevented.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a recording unit of a color image recording apparatus according to a first embodiment of the invention.

FIG. 2 is a block diagram of a basic configuration of a multi-valued image processing unit in this embodiment.

FIG. 3 is a block diagram in which a forgery prevention function of a multi-valued image processing unit according to the present embodiment is added.

FIG. 4 is a flowchart showing edge determination processing for one plane according to the present embodiment.

FIG. 5 is a flowchart showing a region determination process of this embodiment.

FIG. 6 is a diagram illustrating an example of an edge portion that performs pattern matching according to the present exemplary embodiment.

FIG. 7 is a diagram showing edges detected by pattern matching according to the present embodiment.

FIG. 8 is a diagram showing a recording pattern of a banknote portion of the present embodiment.

FIG. 9 is a diagram showing a recording pattern of a stamp portion of the present embodiment.

FIG. 10 is a block diagram of a tracking pattern generation unit in this embodiment.

FIG. 11 is a diagram showing an example of a recording result of the present embodiment.

FIG. 12 is a flowchart showing edge determination processing for one plane according to the second embodiment of the present invention.

FIG. 13 is a diagram showing an edge detected by the density difference determination of this embodiment.

FIG. 14 is a block diagram of a tracking pattern generation unit in this embodiment.

FIG. 15 is a diagram showing an example of a recording result of the present embodiment.

[Explanation of symbols]

 100 Photoreceptor Drum 101 Charging Device 102 Transfer Drum 103 Cleaner Dm Magenta Developer Dc Cyan Developer Dy Yellow Developer Db Black Developer

Claims (8)

[Claims] 1. A recognition signal holding means for holding a specific recognition signal, an area area determination means for determining the area of an image area to be recorded, and the recognition signal according to the area area determined by the area area determination means. An image recording apparatus comprising: a recognition signal changing means for changing the recognition signal; and a recording means for adding and recording the recognition signal. 2. The image recording apparatus according to claim 1, wherein the recording unit prints out by an electrophotographic method. 3. The image recording apparatus according to claim 1, wherein the recognition signal is composed of a plurality of dots. 4. A specific image area holding means for holding a plurality of specific image areas, and a plurality of specific image areas held by the specific image area holding means for the area area determined by the area area determination means. Area comparing means for comparing within a predetermined error range, and the recording means outputs the recognition signal when the area area is not equal to all of the plurality of specific image areas as a result of the comparison by the area comparing means. The image recording apparatus according to claim 1, wherein the image is recorded without being added. 5. The recognition signal changing means recognizes according to the specific image area determined to be equal when the area area is equal to one of the plurality of specific image areas as a result of the comparison by the area comparing means. The image recording apparatus according to claim 4, wherein a signal is changed, and the recording unit adds and records the changed recognition signal. 6. The recording means does not add the recognition signal to an image area consisting of only white data even if the recording means determines that the area is equal to one of the plurality of specific image areas as a result of the comparison by the area comparing means. The image recording apparatus according to claim 4 or 5, wherein 7. The recording means does not add the recognition signal to an image area formed of only a text image even if the recording means determines that the area is equal to one of the plurality of specific image areas as a result of the comparison by the area comparison means. The image recording device according to claim 4 or 5, wherein 8. The image recording apparatus according to claim 4, wherein the specific image held by the specific image area holding means is a bill or securities.