JP3087530B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus having a function of preventing forgery of bills and the like.

[0002]

2. Description of the Related Art In recent years, high-quality digital color copying machines that provide a copy faithful to a document image have been put into practical use, and there is a risk that banknotes and securities are easily copied and forged. The counterfeiting prevention unit, which copes with this, determines whether or not the original set on the platen is copy-prohibited and stops the copying operation or disables normal copying. Function is conceivable. However, for manuscripts such as banknotes, securities, TCs, checks, and official documents all over the world that we want to prevent forgery, we memorize all these characteristics,
Prohibiting copying by performing pattern matching is virtually impossible due to storage capacity, processing time, new bill support, and the like.

Therefore, although copying itself cannot be prohibited, a special code (tracking information) that is normally invisible is inserted into the copied copy itself, and the manufacturer model name and serial No. of the machine used for copying are input. , Date and time of copy, and management card No. And a copying machine having a function of specifying a part thereof. For example, as shown in FIG. 1, the tracking information is converted into a small yellow (for example,
There is a technique in which dots are represented by an arrangement shape of one pixel (hereinafter, referred to as a tracking pattern) and are repeatedly written on a copy sheet (hereinafter, referred to as a hard copy) on which a document image is copied. Product name, serial No. Is performed by extracting the tracking pattern written in the block. As for the writing range of the yellow dot, it is not known where the illegal copy prohibited document (banknote, stamp, income stamp, securities, etc.) is placed on the platen. Into the entire image area obtained by the above. In addition, it is conceivable to cut out a part of the hard copy and use it.Also, make it possible to reduce the size of the block where the tracking pattern is written so that it can be analyzed when cutting and using small things such as stamps and stamps. It is desirable to make it smaller.

[0004]

As described above, data of tracking information represented by a tracking pattern as in the above-described conventional example is usually stored in a memory in a copying machine. When writing the tracking information in the hard copy, the data of the tracking information stored in the memory is read out, converted into the data of the tracking pattern, and repeatedly written in the hard copy. However, data of the tracking information stored in the memory may not be accurately read due to factors inside and outside the copying machine, for example, noise such as electrostatic noise. As a result, erroneous tracking information is written in the hard copy, and there is no point in writing the tracking information in the hard copy.

[0005] It is an object of the present invention to provide an image forming apparatus for writing accurate tracking information.

[0006]

According to the first aspect of the present invention, there is provided an image forming apparatus, comprising: a memory for storing tracking information data; a reading means for reading tracking information data from the memory;
Determining means for determining whether the data read by the reading means is the same as the data stored in the memory, and the data read from the reading means being stored in the memory by the determining means If it is determined that the data is the same as the data, the image forming means for forming an image based on the image data of the document image and the data of the tracking information output from the reading means, A control unit for prohibiting the operation of the image forming unit when it is determined that the output data is different from the data stored in the memory. According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the memory stores the data of the tracking information in a plurality of forms, and the reading unit stores the data of the tracking information in a plurality of forms. The reading unit reads the tracking information data stored in a plurality of forms, and the determining unit includes a conversion unit that unifies the plurality of forms of the tracking information data read by the reading unit into a specific form according to a predetermined rule. Comparing the data of each tracking information unified into a specific form by the conversion unit, and determining whether the read data is the same as the data stored in the memory by the reading means. It is characterized by.

According to a third aspect of the present invention, there is provided an image forming apparatus, comprising: an image forming means for forming an image based on image data; and a memory storing tracking information data having the same meaning at two locations having different addresses. Reading means for reading the data of the tracking information at two locations from the memory; determining means for determining whether the two data read by the reading means have the same meaning; If the two data have the same meaning, the tracking information is embedded in the image formed by the image forming means based on the data of the tracking information read from the memory, while if the two data do not have the same meaning, the image by the image forming means Control means for inhibiting the formation of According to a fourth aspect of the present invention, in the image forming apparatus according to the first aspect, the image forming means includes:
When the data read from the reading means is determined to be the same as the data stored in the memory, the data regarding the tracking information is checked again, and if the data is not the same, the image formation is stopped, On the other hand, if the data is correct, image formation is performed based on the image data of the document image and the data of the tracking information output from the reading means.

[0008]

In the image forming apparatus according to the first aspect, the reading means reads the data of the tracking information stored in the memory. The determining means determines whether the data read by the reading means is the same as the data stored in the memory. When the determining unit determines that the data of the tracking information read from the memory by the reading unit is the same as the data of the tracking information stored in the memory, the image forming unit determines whether the image data of the document image and the tracking information are the same. An image is formed based on the data. When the determining unit determines that the data of the tracking information read from the memory by the reading unit is different from the data of the tracking information stored in the memory, the control unit prohibits the operation of the image forming unit.
Note that, in an embodiment described later, the reading unit, the determining unit, and the control unit are provided in the printer control unit 201 (FIG. 3). The tracking information adding unit receives the image data of the document image and the data output from the tracking information adding unit, and adds the data of the input tracking information to the image data of the document image and outputs the result. The output unit forms a toner image based on the data output from the tracking information adding unit, and prints the toner image on copy paper.

[0009] In the image forming apparatus according to the second aspect,
2. The image forming apparatus according to claim 1, wherein the memory stores tracking information data in a plurality of forms. Here, the form corresponds to a format (array rule) representing the data of the tracking information. For example, "0010011
When the tracking information data represented by "0" is stored in two forms, one is stored as it is, and the other is stored as it is.
The data is logically inverted, converted into data represented by "11011001", and stored. The reading means reads all data of a plurality of forms of tracking information stored in the memory. That is, in the case of the above example, two types of data of the tracking information are read. The determining means is
A conversion unit is provided, and the conversion unit unifies the data of the plurality of forms of tracking information read by the reading unit into a specific form according to a predetermined rule. In the above example, the stored data is read out as is,
The other data stored in the logically inverted form is again logically inverted and converted to the original form. The determining means compares the data of each piece of tracking information unified into a specific form, and determines whether the data read from the memory is the same as the data stored in the memory. In the image forming apparatus according to the third aspect,
Tracking information data having the same meaning is stored at two different addresses in the memory. When the determining unit determines that the two pieces of tracking information data read from the two locations in the memory do not have the same meaning, the control unit prohibits the image forming unit from forming an image. Further, in the image forming apparatus according to the fourth aspect, in the image forming apparatus according to the first aspect, when it is determined that the read data is the same as the data stored in the memory Then, the data regarding the tracking information is checked again, and if the data is not the same, the image formation is stopped.

[0010]

In this embodiment, a digital color copying machine is used as an image forming apparatus. Hereinafter, the image forming apparatus of this embodiment will be described in the following order with reference to the accompanying drawings. (1) Copier configuration (2) Tracking information write processing (3) Tracking information storage state confirmation processing

(1) Configuration of Copying Machine FIG. 2 is a sectional view showing the overall configuration of a digital color copying machine according to the present embodiment. The digital color copying machine is roughly divided into an image reader unit 100 for reading a document image and a copying unit 200 for reproducing an image read by the image reader unit 100 on copy paper.

In the image reader unit 100, a scanner 10 includes an exposure lamp 12 for irradiating a document, a rod lens array 13 for condensing light reflected from the document, and a contact type for converting the condensed light into an electric signal. The CCD color image sensor 14 of FIG. The scanner 10 is driven by the motor 11 when reading a document, moves in the direction of the arrow (sub-scanning direction), and scans a document placed on the document table 15. The image of the document surface irradiated by the exposure lamp 12 is photoelectrically converted by the image sensor 14. Image sensor 1
The multi-valued electrical signals of the three colors R, G, and B obtained by step 4 are
The read signal processing unit 20 converts the data into 8-bit gradation data of any of yellow (Y), magenta (M), cyan (C), and black (BK), and stores the 8-bit gradation data in the synchronization buffer memory 30.

Next, in the copying unit 200, the print head unit 31 performs gradation correction (γ correction) on the inputted gradation data according to the gradation characteristics of the photosensitive member, and then performs the corrected image. The data is D / A converted to generate a laser diode drive signal, and the semiconductor laser 264 (FIG. 3) provided in the head section 31 is caused to emit light by the drive signal.
The print head unit 31 will be described in detail with reference to FIG. The laser beam generated from the print head unit 31 in accordance with the gradation data exposes the rotatably driven photosensitive drum 41 via the reflecting mirror 37. The photoreceptor drum 41 is irradiated by an eraser lamp 42 before receiving exposure for each copy, and is uniformly charged by a charger 43. When exposure is performed in this state, an electrostatic latent image of the document is formed on the photosensitive drum 41. Only one of the cyan (C), magenta (M), yellow (Y), and black (BK) toner developing units 45a to 45d is selected to develop the electrostatic latent image on the photosensitive drum 41. . The developed toner image is transferred to a transfer charger 46.
Is transferred onto the copy paper wound around the transfer drum 51.

The above printing process is repeated for four colors of yellow (Y), magenta (M), cyan (C) and black (BK). At this time, the photosensitive drum 4
The scanner 10 repeats the scanning operation in synchronization with the operation of the transfer drum 51 and the transfer drum 51. After that, the copy paper is separated
Is operated, is separated from the transfer drum 51, is fixed through the fixing device 48, and is discharged to the discharge tray 49. The copy paper is fed from a paper cassette 50, and the leading end thereof is chucked by a chucking mechanism 52 on the transfer drum 51, so that no positional deviation occurs during transfer.

FIG. 3 is a block diagram of processing of image data in the print head unit 31. Printer control unit 2
Reference numeral 01 denotes a control ROM 202 including a CPU, in which a control program is stored, and various data (gamma correction data and the like).
ROM 203 storing the ID code of the copying machine main body, which is the tracking information,
210 is connected. The printer control unit 201 controls a printing operation based on the data in the ROM.
The printer control unit 201 controls the control ROM 2 based on data from the operation panel 221 and the data ROM 203.
02 according to the contents of the display panel 23 and the display panel 23
2 is controlled. The image data (8 bits) from the image signal processing unit 20 is transmitted through the interface unit 251.
First-in / first-out memory (FIF)
O memory 252). The FIFO memory 252 is a line buffer memory capable of storing gradation data of a predetermined number of rows of images in the main scanning direction, and absorbs a difference in operation clock frequency between the image reader unit 100 and the copying unit 200. It is provided in order to. F
The data in the IFO memory 252 is input to the tracking pattern generation and addition unit 255.

The image data from the image signal processing unit 20 is
If the image data is for forming a yellow (Y) toner image on the photosensitive drum 41, the printer control unit 20
1 reads out the data of the ID code of the copying machine from the tracking information storage ROM 210. The tracking information storage ROM 210
The ID code data is stored in a plurality of forms. For example, as shown in FIG. 4, the data of the ID code is stored in two places of address 1 and address 2. “001001110” is stored in the address 1. Further, the address 2 is obtained by logically inverting the data stored in the address 1 “1101100”.
1 "is stored. The printer control unit 201 checks whether the ID code data read out in the procedure described later is correct or incorrect. If it is determined that the ID code is correctly read out, The control section 201
The data of the D code is transferred to the tracking pattern generation adding section 255. The tracking pattern generation and addition unit 255 temporarily stores the data of the transmitted ID code. The printer control unit 201 checks whether the ID code data is correctly stored in the tracking pattern generation and addition unit 255 in a procedure described later. If it is determined that the ID code data is correctly stored, the printer control unit 201 causes the tracking pattern generation and addition unit 255 to generate tracking pattern data corresponding to the ID code, and sends the data from the FIFO memory 252. The data added to the incoming image data is output to the next gamma correction unit 253. Here, the tracking pattern data is, as shown in FIG. 1, image data in which tracking information is represented by an arrangement of small yellow (for example, one pixel) dots in a predetermined block.

The image data from the image signal processing unit 20 is
If the image data is for forming a toner image other than yellow (Y) on the photosensitive drum 41, the printer control unit 201 sends the data sent from the FIFO memory 252 to the tracking pattern generation addition unit 255 as it is. Is output to the γ correction unit 253. The γ correction unit 253 corrects the input data using the γ correction data sent from the data ROM 203, and sends the corrected data to the next D / A conversion unit 254. The analog voltage converted from the output level (digital value) by the D / A conversion unit 254 is sent to the semiconductor laser driver 263, and causes the semiconductor laser 264 to emit light at the intensity of the value.

(2) Tracking Information Writing Process In the copying machine of this embodiment, the printer control unit 201 reads out the ID code data of the copying machine from the tracking information storage ROM 210 in order to write the tracking pattern data in the hard copy. At this time, it is checked whether or not correct data has been read. Further, the printer control unit 201
When the data of the read tracking information is output to the tracking pattern generation and addition unit 255, it is checked whether the data is correctly sent to the tracking pattern generation and addition unit 255. And if the data exchange was performed correctly,
Write the tracking pattern. If the data exchange has not been performed correctly, the copying operation is stopped and the fact is displayed on the display panel 232.

FIG. 5 is a flowchart of the copying process of the copying machine according to the present embodiment. When the copying process starts,
Copy paper is fed from the paper cassette 50 to the transfer drum 51 (step S10). If it is the development of the yellow (Y) toner image (YES in step S20), a tracking information writing process is executed (step S100). After the end of the tracking information writing process (step S100), an image forming process is executed (step S30). Further, in step S20, in the case of developing a toner image of a color other than yellow (Y) (NO in step S20), the tracking information writing process (step S100) is skipped and an image forming process is performed (step S100). Step S30). When the development of the toner images of all the colors of yellow (Y), magenta (M), cyan (C), and black (BK) is completed (Y in step S40)
ES), and terminates the copying process.

FIG. 6 shows a tracking information writing process (step S1).
It is a process flowchart of (00). First, the printer control unit 201 reads the ID code data stored in the tracking information storage ROM 210. Tracking information storage ROM
As shown in FIG. 4, the ID code data stored in 210 is stored in two different locations, address 1 and address 2, in different forms. The address 1 stores the ID code data “00100110” as it is. At address 2, “11011001” which is the logically inverted version of the ID code data “00100110” is stored. When reading the ID code data, the printer control unit 2
No. 01 reads the data stored at the address 1 and the address 2 from the tracking information storage ROM 210 (steps S101 and S102). The printer control unit 201 inverts the data read from address 2 (step S103) and compares the data with the data at address 1 (step S104). Here, tracking information storage RO
When the data exchange between the M210 and the printer control unit 201 is performed normally, the data obtained by inverting the data at address 2 read by the printer control unit 201 and the data at address 1 are completely the same (step S105). And Y
ES). In the case where the data exchange is abnormal due to the incorporation of electrostatic noise, or when the ROM 210 is damaged, the data obtained by inverting the data at address 2 and the data at address 1 are different from each other. (NO in step S105). As in this embodiment, the ID
If the code data is stored in a plurality of addresses in different forms, it is possible to perform a check when the data cannot be read accurately. Further, the data stored in the address 2 is not limited to the data obtained by logically inverting the ID code data as in the present embodiment, and any rules may be used as long as the ID code data can be reliably restored. May be done.

When the data obtained by inverting the data at address 2 matches the data at address 1 (step S1).
05 (YES), the printer control unit 201 writes the ID code data into the tracking pattern generation and addition unit 255 (step S106). Next, the printer control unit 201
The ID code data stored in the tracking pattern generation and addition unit 255 is read (step S107), and the read data and the ID transmitted to the tracking pattern generation and addition unit 255 are read.
The data is compared with the code data (step S108). Here, the read data and the tracking pattern generation and addition unit 2
If the data of the ID code sent to the server 55 matches (YES in step S109), the printer control unit 201
The tracking pattern control unit 255 generates tracking pattern data (see FIG. 1) represented by the arrangement of yellow dots in a predetermined block from the ID code data, and stores the tracking pattern data in a FIFO memory 252 (FIG. 3) is added to the data sent from (step S11)
0). If the data obtained by inverting the data at address 2 in step S105 does not match the data obtained by inverting the data at address 1, and if the data stored in tracking pattern generation adding section 255 in step S109 is
If the code data does not match, the process is stopped (step S111), and a message is displayed on the display panel 232 indicating that accurate tracking information write processing cannot be executed (step S112), and then the copy processing itself is performed. (Step S
113).

(3) Confirmation process of tracking information storage state In the copying machine of this embodiment, when the copying process is stopped because it is impossible to write the accurate tracking information during the copying operation, , The user operates the operation panel,
Address 1 and address 2 of the tracking information storage ROM 210
Has a function of reading data stored in the display panel 232 and confirming the read data on the display panel 232. Hereinafter, the operation panel processing for confirming the storage state of the tracking information will be described.

FIG. 7 is a front view of the operation panel section 221. The ten keys 1 are used to input copy information such as the number of copies. The clear key 2 initializes the setting of the number of copies. The print key 3 starts a copying operation. The stop key 4 starts a copying operation. The panel reset key 5 switches the display screen of the display panel 232 to the initial screen. The auto same-size key 6 detects the size of the copy sheet placed on the document table 15 and is used to set an auto same-size mode for automatically selecting and setting an appropriate copy sheet. The auto scaling key 7 is used to set an auto scaling mode for automatically setting an appropriate copy magnification based on the size of the original paper placed on the original table 15 and the size of the selected copy paper. Used. The manual key 8 is used to set a manual mode for arbitrarily setting a copy paper size and a copy magnification. The up / down key 9 is used to increase / decrease the copy magnification in the manual mode. The six function keys 10 are used to set items of copy conditions on the basic screen.

FIG. 8 is a flowchart showing the operation panel process. The confirmation of the tracking information is executed by a special operation method other than a normal operation. First, the auto equal-size key 6, the auto-variable-size key 7, and the manual key 8 are simultaneously pressed (YES in step S200). Next, the panel reset key 5 is pressed (step S210). The confirmation process is executed by executing the above process. First, the data stored at the address 1 and the address 2 is read from the tracking information storage ROM 210 (step S22).
0). The data of the read address 2 is inverted (step S230). The read data of address 1 and the inverted data of address 2 are displayed on display panel 23.
2 (step S240). FIG. 9A shows the display panel 232 when the step S240 is performed. FIG. 9A shows data stored at address 1 as data 1, and data obtained by inverting data stored at address 2 as data 2. In the case of FIG.
Data 1 and data 2 are both “2A” and have ID
Indicates that the reading of the code data is performed normally. In response to the depression of the panel reset key 5 (YES in step S250), the normal screen shown in FIG. 9B is displayed (step S260), and the confirmation processing ends.

[0025]

According to the image forming apparatus of the present invention, it is confirmed whether or not the tracking information is correctly read from the memory storing the tracking information. Only when the tracking information is correctly read, the data of the tracking information is added to the image data of the document image and output. This allows
It is possible to always write accurate tracking information on a document image.

[Brief description of the drawings]

FIG. 1 is a diagram showing a conventional example in which tracking information is written in a hard copy.

FIG. 2 is a configuration sectional view of a digital color copying machine.

FIG. 3 is a diagram showing processing blocks in a print head unit 31.

FIG. 4 is a diagram showing tracking information stored in a tracking information storage ROM 210.

FIG. 5 is a diagram illustrating a flowchart of a copying process performed by the copying machine according to the present embodiment.

6 is a diagram showing a flowchart of a tracking information writing process (step S100) shown in FIG.

FIG. 7 is a front view of an operation panel 221.

FIG. 8 is a diagram showing a flowchart of operation panel processing.

FIGS. 9A and 9B are diagrams showing screens displayed on the display panel 232 during operation panel processing.

[Explanation of symbols]

 41 photoconductor drums 45a to 45d toner developing device 48 fixing device 51 transfer drum 100 image reader unit 210 tracking information storage ROM 201 printer control unit 255 tracking pattern generation adding unit 264 semiconductor laser

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-14682 (JP, A) JP-A-5-22568 (JP, A) JP-A-61-52758 (JP, A) JP-A-55-1982 90000 (JP, A) JP-A-6-334484 (JP, A) JP-A-5-219353 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 21/00 550- 562 H04N 1/00 G06F 12/16 310

Claims (4)

(57) [Claims] 1. A memory for storing tracking information data, reading means for reading the tracking information data from the memory, and whether the data read by the reading means is the same as the data stored in the memory. Determining means for determining whether or not the data read from the reading means is the same as the data stored in the memory, the image data of the document image and the output from the reading means; An image forming unit that forms an image based on the data of the tracking information to be obtained, and an image forming unit that determines that the data read from the reading unit is different from the data stored in the memory by the determining unit. An image forming apparatus comprising: a control unit that prohibits the operation of the forming unit. 2. The image forming apparatus according to claim 1, wherein the memory stores tracking information data in a plurality of forms, and the reading unit stores the tracking information in a plurality of forms in the memory. The data of information is read, and the judging means includes a conversion unit that unifies the data of the plurality of forms of tracking information read by the reading means into a specific form according to a predetermined rule, and the conversion unit converts the data into a specific form. An image forming apparatus, wherein data of each unified tracking information is compared with each other, and a reading unit determines whether or not the read data is the same as data stored in a memory. 3. An image forming means for forming an image on the basis of image data, and tracking information data having the same meaning having different addresses.
A memory stored at a location, reading means for reading the tracking information data at two locations from the memory, a determining means for determining whether the two data read by the reading means have the same meaning, a determining means If the two data have the same meaning, the tracking information is embedded in the image formed by the image forming unit based on the data of the tracking information read from the memory, while the two data do not have the same meaning. ,
An image forming apparatus including a control unit that prohibits an image forming unit from forming an image. 4. The image forming apparatus according to claim 1, wherein the image forming unit determines, by the determining unit, that the data read from the reading unit is the same as the data stored in the memory. In this case, the data on the tracking information is checked again. If the data is not the same, the image formation is stopped. On the other hand, if the data is correct, the image data of the original image and the tracking output from the reading means are output. An image forming apparatus for forming an image based on information data.