JPH0746358A - Image processing system and electronic equipment - Google Patents

Abstract

PURPOSE:To surely authenticate a printer by providing an image processing system with a means for authenticating whether or not the image forming device has a function for adding identification information by an electronic equipment. CONSTITUTION:In an ID signal adding circuit 410, and ID information such as the serial number of a printer is added onto a recorded material being a copied output with thin yellow, and if a full color copying mechanism is illegally used for the copying or a specific picture such as paper money, the kinds of the machine are specified. An authentication function is realized by confirming that only a printer 202 having the ID signal adding function has the imparted secret information by T an image scanner 201. Since that the printer 202 has the information T is confirmed by using a method so-called 'zero knowledge interaction certification' without sending the information T to a transmission line, safe authentication operation is realized and the addition of the identification information is guranted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing system and electronic equipment.

[0002]

2. Description of the Related Art In recent years, as the performance of color copiers and color printers has improved, crimes have been made in which paper money, securities, etc. are forged by illegally using them.

In order to prevent such crimes, a technique of adding information capable of specifying the equipment number of a copying machine to a printed image is being studied.

[0004]

However, conventionally, there has not been provided a means for accurately detecting whether or not the printer has the above-mentioned function of adding identification information.

Therefore, when image data is transferred from an electronic device such as an image scanner or a computer to a printer for printing, it is not always guaranteed that the above-mentioned identification information is added to the printed matter.

SUMMARY OF THE INVENTION In view of the above points, an object of the present invention is to provide an image processing system and an electronic device that can reliably authenticate a printer.

[0007]

In order to achieve such an object, an image processing system of a first invention of the present application is an image processing system for transferring image data from an electronic device to an image forming apparatus, wherein the image forming is performed. It is characterized in that means is provided for authenticating from the electronic device to the image forming apparatus whether or not the apparatus has a function of adding identification information.

The electronic device of the second invention of the present application is an electronic device for transferring image data to an image forming apparatus, and the image forming apparatus determines whether the image forming apparatus has specific identification information. It is characterized in that means for authenticating the device is provided.

[0009]

EXAMPLE 1 The present invention will be described in detail below based on a preferred example.

In the following embodiments, an example of a copying machine is shown as an application example of the present invention, but the present invention is not limited to this, and it goes without saying that it can be applied to various other apparatuses.

(Image Scanner) FIG. 1 is a block diagram showing the signal flow of the image scanner unit 201 and the printer 202.

In the figure, 210-1, 210-2,
Reference numeral 210-3 denotes a CCD (solid-state image sensor) sensor having a spectral sensitivity characteristic of red (R), green (G), and blue (B), respectively, and 8-bit outputs 0 to 255 after A / D conversion. Signal is output.

The sensor 210 used in this embodiment
Since -1, 210-2, and 210-3 are arranged with a constant distance, the spatial shifts of the delay elements 401 and 402 are corrected.

Reference numerals 403, 404, and 405 denote log converters, which are constituted by a look-up table ROM or RAM and convert a luminance signal into a density signal. Reference numeral 406 is a known masking and UCR (under color removal) circuit, and although detailed description is omitted, magenta (M), cyan (C), yellow (Y), and black for output are generated by the three input signals. Each signal of (Bk) is output in a frame-sequential manner with a predetermined bit length, for example, 8 bits, for each reading operation.

Here, the CNO signal is a 2-bit field sequential signal, which is a control signal indicating the order of four transfer operations as shown in Table 1, and switches the operating conditions of the masking / UCR circuit 406.

[0016]

[Table 1]

A known spatial filter circuit 407 corrects the spatial frequency of the output signal. A density conversion unit 408 corrects the density characteristics of the printer unit 202, and is composed of the same ROM or RAM as the log converters 403 to 405.

Reference numeral 410 is an identification signal adding circuit which will be described later with reference to FIG. With this circuit, identification information such as the printer serial number can be added to the recording material in light yellow on the recording material, and if the full-color copying machine is misused such as copying specific images such as banknotes, the equipment can be It becomes possible to specify.

Reference numeral 450 is a microprocessor for performing image signal processing of the image scanner 201 and authentication processing of the printer. By performing the control of the image signal processing circuit and the authentication processing for the printer 202 by the same microprocessor as in this configuration, an attempt was made to modify the authentication processing such as stopping the clock supply to the microprocessor 450. In this case, the control function of the image signal processing circuit also does not operate, and it becomes possible to increase the strength against the modification of the device.

The ROM 451 is a microprocessor 450.
This is a read-only memory that stores the program.

The RAM 452 is a microprocessor 452.
Is a random access memory used as a work area.

The microprocessor 460 is the printer 2
02 is a microprocessor for performing image signal processing and authentication processing. Similar to the microprocessor 450, by performing the control of the image signal processing circuit and the authentication processing by the same microprocessor, the strength against the modification of the device can be increased.

(Outline of Apparatus) FIG. 2 shows an outline view of the apparatus according to the first embodiment of the present invention. In FIG. 2, an image scanner unit 201 is a unit that reads a document and performs digital signal processing. A printer unit 202 is a unit that prints an image corresponding to the original image read by the image scanner 201 on paper in full color.

In the image scanner 201, 200
Is a mirror pressure plate, and is a platen glass (hereinafter referred to as a platen) 20.
The original 204 on the image No. 3 is illuminated by a lamp 205, guided to mirrors 206, 207, and 208, forms an image on a three-line sensor (hereinafter, CCD) 210 by a lens 209, and full-color information red (R) and green ( G) and blue (B) components are sent to the signal processing unit 211. Note that 205 and 206 are speed v, and 207 and 208 are speed 1/2 v, and mechanically move in the direction perpendicular to the electrical scanning (main scanning) direction of the line sensor to scan the entire surface of the document (sub scanning). ) And sent to the signal processing unit 211.

In the signal processing unit 211, the read image signal is once stored in the image memory and then electrically processed to be magenta (M), cyan (C), yellow (Y), black (Bk). ) Is decomposed into each component and sent to the printer unit 202. In addition, the image scanner 201
The image data read by one time of the original scanning in 4 is read out four times, and one component of M, C, Y, and Bk is generated by the image processing, respectively, and is sent to the printer unit 202. One printout is completed by reading and processing four times.

The M, C, Y, and Bk image signals sent from the image scanner unit 201 are sent to the laser driver 212. The laser driver 212 modulates and drives the semiconductor laser 213 according to the sent image signal. The laser light is polygon mirror 214, f
Through the -θ lens 215 and the mirror 216, the photosensitive drum 2
Scan over 17.

Reference numeral 218 denotes a rotary developing device, which includes a magenta developing portion 219, a cyan developing portion 220, a yellow developing portion 221,
The black developing unit 222 is composed of four developing units alternately contacting the photosensitive drum 217 to develop the electrostatic development formed on the photosensitive drum with toner.

Reference numeral 223 denotes a transfer drum, which winds the paper supplied from the paper cassette 224 or 225 around the transfer drum 223 and transfers the image developed on the photosensitive drum onto the paper.

In this way, after the four colors M, C, Y, and Bk are sequentially transferred, the paper passes through the fixing unit 226, the toner is fixed on the paper, and then the paper is ejected.

FIG. 3 is a flow chart for explaining a process in which the image scanner 201 authenticates that the printer 202 has the identification signal adding function.

In this process, the authentication function is realized by confirming from the image scanner that the printer holds the secret information T to be added only to the printer having the identification signal adding function.

At this time, it is possible to confirm that the printer 202 side holds the secret information T without placing the secret information T on the transmission path by using a method called so-called "zero knowledge dialogue proof". A safe authentication operation can be realized.

In FIG. 3, reference numerals 301 to 310 are flowcharts relating to the operation of the microprocessor 450 of the image scanner 201.

Reference numerals 320 to 329 are flow charts regarding the operation of the microprocessor 460 of the printer 202.

At 301, the microprocessor 45
0 sends an authentication start code (eg code) to the microprocessor 460.

Upon receiving the authentication start code, the microprocessor 460 generates a random number Rm in 321 and calculates X = R _m ² modn in 322, and sends it to the microprocessor 450. Here, n is a predetermined large composite number (product of large prime numbers). Microprocessor 450 stores the received X data in internal RAM at 303.

At 304, a random number B _m is generated.
Here, B _m is a value of 0 or 1. At 305, B _m data is sent to the printer side.

The microprocessor 460 includes 324 and 32.
When the value of B _m received in 5 is 0, the value is 326, and the value of B _m is 1
In case of, the processing of 327 is performed.

At 326, the data of Y = R _m is sent to the image scanner side. At 327, Y = TR _m
The value of modn is sent to the image scanner.

Here, T is secret information given only to the printer having the identification signal adding function.

At 306, the microprocessor 450, which has received the Y data, checks at 307 the validity of the value of Y by the following equation. X = Y ² modn if B _m = 0 ... (1) ZX = Y ² modn if B _m = 0 ... (2) where X is the number stored in the RAM at 303, and Z is Z = T ² modn ... (3).

If the received Y data is valid, the processes of 301 to 309 and 320 to 328 are performed again. When the above processing is repeated 1 times and all ends normally, image data is transferred at 310 and 329.

If the Y data is incorrect at 307, then at 308 the microprocessor 450 is stopped after displaying the error message shown in FIG.

By performing this process, when the Y data received by the microprocessor 450 is inappropriate, the power of the image scanner 201 must be turned off / on in order to restore the operation of the microprocessor 450. Will not happen.

(Pattern Addition Circuit) FIG. 5 is a block diagram showing the configuration of the identification signal addition circuit 410 according to the first embodiment. In the figure, 901 is a sub-scanning counter, 90
2 is a main scanning counter, 903 is a lookup table R
OM (hereinafter referred to as “LUT”), 905 is a flip-flop, 913 is an AND gate, 906 is a register, 91
0 is a 4 tol selector, 911 is an AND gate, 91
2 indicates adders, respectively.

Here, the sub-scanning counter 901 repeatedly counts the main scanning synchronizing signal HSYNC and the main scanning counter 902 repeatedly counts the pixel synchronizing signal CLK with a 9-bit width, that is, 512 cycles. Further, the LUT 903 is a read-only memory (hereinafter referred to as ROM) in which the pattern to be added is held, and the lower 6 bits of the count value of each of the sub-scanning counter 901 and the main scanning counter 902 are input. Only one bit of the output of the LUT 903 is referred to, the AND gate 904 performs a logical product with each of the upper 3 bits of the main scanning counter 901 and the sub-scanning counter 902, and the flip-flop 905 outputs CL.
It is synchronized with the K signal, and in the AND gate 913,
A logical operation is executed with both of the 2-bit field sequential signals CNO “0” and CNO “1”, and the result is sent to the AND gate 911. This is a signal that is valid only when CNO = 2, that is, currently printed in yellow (Y) (see Table 1).

On the other hand, the register 906 holds the value P1 in advance. The data from the AND gate 913 is logically ANDed with P1 by the AND gate 911, and then added to the input signal V by the adder 912 as a pattern. From the adder 912, the addition result V ′ is output. Therefore, when CNO = 2, that is, when printing is currently performed in yellow, the pattern held in the LUT 903 is repeatedly read and added to the signal V to be output.

Here, the pattern to be added is added only by the yellow toner so that it is difficult for the human eye to identify it. This is because the human eye is identified with respect to the pattern drawn by the yellow toner. It takes advantage of the weak ability.

(Copy Result) FIG. 6 is a diagram showing an example of the copy result according to the first embodiment. In the figure, 1001
Is the added pattern, and the LUT
This is a pattern to which the contents held in 903 are added. In the example shown in FIG. 6, a pattern in which “ABCD” and “1234” are arranged in the sub-scanning direction is added in a pattern of 64 pixels × 64 pixels so that it is difficult for the human eye to identify. This is repeated every 512 pixels for scanning and 512 lines for sub-scanning. Therefore, by setting the pattern as a machine-specific serial number or by encoding the serial number, the copy apparatus can be limited by identifying the copy to which the pattern is added.

Furthermore, when there is a high possibility that a specific original document that should not be copied exists in the read image,
It is also possible to add a pattern with a strength according to the possibility such as adding a clear pattern.

Further, in the present embodiment, the pitch for adding the pattern is set to every 512 pixels (or lines) in the main scanning, but in the present embodiment, it is 400 dpi (dot / i).
Since the resolution is nch), a pattern is added about every 32.5 mm. On the other hand, the width of the banknotes (Bank of Japan notes) in the lateral direction is about 76 mm, and the width of the banknotes of the major countries in the lateral direction is also about 60 mm to 120 mm.
Since it is between mm, when a bill is copied,
This pattern is always added to the inside of the copied banknote. Therefore, even if only a banknote portion is cut and misused, the copy machine used for copying can be limited by identifying the copy and reading the added pattern.

(Other Embodiments) In the first embodiment, 1
By controlling the authentication processing and the image signal processing circuit with one microprocessor, it is intended to have strength against modification of the device. In the second embodiment, as shown in FIG.
By constructing the portion 701 or 702 shown in (1) with a one-chip LSI, a remodeling countermeasure function that is more resistant to remodeling of the device than the first embodiment is realized.

By arranging the arithmetic unit and the ROM storing the authentication function control program in the same chip,
It becomes impossible to trace the arithmetic processing related to the authentication processing from the outside. Further, by having at least a part of the image signal processing circuit control program coexist in 701 or 702, the image signal processing circuit operates normally when the microprocessor incorporating the modified ROM is connected to operate. Disappear.

(Third Embodiment) FIG. 8 is a view for explaining the third embodiment of the present invention.

In the above-mentioned first and second embodiments, the image is transmitted from the image scanner to the printer.

In the third embodiment, an image is transmitted from the computer to the printer.

In FIG. 8, reference numeral 800 is a device for receiving image data from a computer and transferring it to a printer.

Reference numeral 801 is a microprocessor for executing an authentication operation between the image memory control circuit 803 and the printer 202.

The microprocessor 801 executes the same processing as the authentication operation of the microprocessor 450 of FIG.

The embodiment of the present invention described above has a function of detecting whether or not the printer has the function of adding the identification information when the image data is transferred from the electronic device for processing the image data to the printer. By providing it, it is intended to ensure that the identification information is added to the print.

More specifically, the password (secret) given only when the printer has a function of adding identification information is referred to as a so-called zero-knowledge dialogue proof (reference document: Journal of Information Processing Society, June 1991). By using the method, the image data is transferred to the printer only when the external device determines that the external device authenticates and the printer has a function of adding the identification information.

By using this method (zero-knowledge interactive proof), the password can be authenticated without passing through the data transfer path, and a safe and reliable authentication function can be realized.

In the above embodiment, the embodiment of the authentication is described by using the zero-knowledge interactive proof method. However, the printer has the specific secret information by using another encryption method (for example, RSA method). Of course, it is possible to authenticate that

In this embodiment, the printer has been described as an example of the image forming apparatus, but the image forming apparatus of the present invention is not limited to the printer and may be a display.

As described above, according to this embodiment,
By providing means for authenticating whether or not the printer has the identification information addition function from an external device, it is possible to better ensure that the identification information is added to the print.

Further, by making the microprocessor for executing the authentication operation the same as the microprocessor for controlling the image signal processing circuit, it is possible to make the system stronger against malicious alteration.

Further, the ROM for storing the program for executing the authentication operation and the microprocessor are LS of one chip.
By configuring as I, it becomes possible to configure a system that is strong against modification.

[0068]

According to the present invention, the identification information can be surely added to the image-formed product.

[Brief description of drawings]

FIG. 1 is an image scanner unit 201 and a printer 202.
Block diagram showing the flow of signals in FIG.

FIG. 2 is a schematic view of the apparatus according to the first embodiment of the present invention.

FIG. 3 is a flowchart of the first embodiment.

FIG. 4 is a diagram showing an error message display of the image scanner 201 of the first embodiment.

5 is a block diagram showing a configuration of a pattern adding circuit 410 of FIG.

FIG. 6 is a diagram showing an example of a copy result.

FIG. 7 is a block diagram showing a signal flow of an image scanner unit 201 and a printer 202 according to a second embodiment.

FIG. 8 is a block diagram illustrating a third embodiment.

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Claims (2)

[Claims] 1. An image processing system for transferring image data from an electronic device to an image forming apparatus, wherein the electronic device determines whether or not the image forming apparatus has a function of adding identification information. An image processing system, characterized in that means for authenticating the forming apparatus is provided. 2. An electronic device for transferring image data to an image forming apparatus, comprising means for authenticating to the image forming apparatus whether or not the image forming apparatus has specific identification information. Characteristic electronic equipment.