JP2001103290A - Image forming device and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device and an image forming method by which prescribed information can be attached to an image in order to execute criminal investigation or the like for falsification or the like of securities. SOLUTION: The image forming device to form an image relating to multi- value image data consists of a laser drive circuit 501 that receives a digital signal string (6) relating to the multi-value image data and drives a laser beam emitting element for forming an image and of a tracing pattern generating section 502 that generates a digital signal string on the basis of a prescribed attached data. The laser drive circuit 501 has input terminals (ON, OFF) of forcibly control light emission from the laser beam emitting element and the tracing pattern generating section 502 gives the digital signal string on the basis of the attached data to the input terminals to record the attached data onto the image.

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 and an image forming method, and more particularly to an image forming apparatus and an image forming method which can contribute to suppression of duplication of securities and the like.

[0002]

2. Description of the Related Art In recent years, the colorization of image forming apparatuses such as printers has been advanced, and they have been used as various expression means for users. In particular, color page printers are attracting attention because of their quietness, high quality printing, and high speed printing.

A multi-color light beam printer, which is one of the color page printers, is characterized in that a light beam is scanned on a photosensitive member in a main scanning direction to perform a first phenomenon, and then a recording on a transfer carrier is performed. The multi-color image is recorded by transferring the image onto a recording medium such as paper and performing a predetermined process.

A method of recording a multicolor image by a multicolor light beam printer will be described with reference to FIGS.

FIG. 16 is a schematic diagram of a conventional multicolor light beam printer, and FIG. 17 is a block diagram of signal processing.

In FIG. 16, a photosensitive drum 201 rotating at a predetermined constant speed in a direction indicated by an arrow in FIG.
4 is charged to a predetermined polarity and a predetermined voltage.

Next, the recording paper P is fed one by one from the paper feed cassette 215 by the paper feed roller 214 at a predetermined timing. When the leading end of the recording paper is detected by the detector 202, the laser beam L modulated by the image signal VDO is transmitted from the semiconductor laser device 205 to the polygon mirror 20.
7 is emitted.

The laser light L is scanned by the polygon mirror 207 and then guided onto the photosensitive drum 201 via the lens 208 and the mirror 209.

A signal (hereinafter referred to as TOPSNS) from the detector 202 disposed at one end of the optical scanning is output to the image processing unit 250 (FIG. 17) as a vertical synchronization signal.

The image signal VDO is sequentially sent to the semiconductor laser device 205 in synchronization with a BD signal described later, following the TOPSNS signal. When the laser light L is incident on the detector 217, a beam detection signal (hereinafter, referred to as a BD signal) serving as a horizontal synchronization signal is output.

The polygon mirror 207 is driven by a scanner motor 206.
7 is controlled by a motor control circuit 225 so as to rotate at a predetermined constant speed in accordance with a signal S2 from a frequency divider 221 for dividing the signal S1 from the reference transmitter 220.

The photosensitive drum 201 is scanned and exposed in synchronization with the BD signal, and then, after the first electrostatic latent image is developed by the developing device 203Y, a yellow first toner image is formed on the photosensitive drum 201. It is formed.

Immediately before the leading end of the recording paper P fed at a predetermined timing reaches the transfer start position, a predetermined transfer bias voltage having a polarity opposite to that of the toner is applied to the transfer drum 216, At the same time that one toner image is transferred to the recording paper P, the recording paper P is electrostatically attracted to the surface of the transfer drum 216.

Next, a laser beam L
The second electrostatic latent image is formed by the operation of
As a result, a second electrostatic latent image is formed, and a magenta second toner image is formed on the photosensitive drum 201. Then, the second toner image is adjusted to the position of the first toner image previously transferred to the recording paper P, and is transferred onto the recording paper P. Note that the leading end of each color image is defined by the TOPSNS signal.

Similarly, a third electrostatic latent image is formed, developed by the developing unit 203C, a cyan toner image is transferred to the recording paper P, and then a fourth electrostatic latent image is formed. Is formed, developed by the developing device 203K, and the black toner image is transferred to the recording paper P.

As described above, VD for one page is provided for each process.
O signals are sequentially output to the semiconductor laser 205. Further, the untransferred toner image is transferred to the cleaner 21 at each transfer step.
Scratched by 0.

Thereafter, when the leading end of the recording paper P on which the four color toner images have been transferred approaches the position of the separation claw 212, the separation claw 212 approaches and comes into contact with the surface of the transfer drum 216.
The recording paper P is separated from the transfer drum 216. The leading end of the separation claw 212 has a rear end of the recording paper P
The transfer drum 216 is kept in contact with the transfer drum 216 until the transfer drum 216 separates, and then returns to the original position. Then, the charge accumulated on the recording paper P is removed by the charger 211 and the separation claw 212 is removed.
At the same time, the air discharge at the time of separation is reduced.

FIG. 18 shows the above-mentioned TOPSNS signal and VD
6 is a timing chart illustrating a relationship between O signals. In the figure,
A1 is a printing operation of the first color, A2 is a printing operation of the second color, A
Reference numeral 3 denotes a printing operation of the third color, and A4 denotes a printing operation of the fourth color. The sections A1 to A4 correspond to a one-page color printing operation.

FIG. 19 is a block diagram showing a system configuration of a conventional printer.

In FIG. 19, a printer 302 receives a control signal and an image signal 307 from an external device, for example, a host computer 301, and
In 3, the control signal is sent to the printer control unit 304, and the image signal is sent to the semiconductor laser 306 via the image processing unit 305 in the printer controller 303 and the laser driver 310 on the printer engine side.

FIG. 20 is a block diagram showing the internal configuration of the image processing unit 305 in FIG. The image processing unit shown in FIG. 8 receives an image signal of 8 bits for each of RGB and 24 bits of image data from a printer controller (not shown), and a Y signal, an M signal,
The 8-bit V for the C signal or K signal
Conversion to a DO signal is performed (FIG. 21 is a time chart at that time).

The Y, M, C, and K VDO signals are converted to a γ-corrected 8-bit signal by a γ correction section 325, and then converted to a next-stage pulse width modulation section 353 (hereinafter, referred to as “pulse width modulation section”).
PWM unit). In the PWM unit 353,
An 8-bit image signal is latched by an image clock iV at a latch 345.
The D / A converter 35
The signal is converted into an analog voltage at 5 and then input to an analog comparator 356.

On the other hand, the image clock IVCLK is converted into a triangular wave by the triangular wave generator 358 and input to the analog comparator 356. This analog comparator 35
6 compares the above two signals, and as a result, outputs a PWM-processed image signal 309. Then, this output signal is inverted by the inverter 357, and a desired PWM signal is obtained.

FIG. 22 is a time chart when the PWM unit 353 generates a PWM signal. As shown in the figure, when the 8-bit image data input to the PWM unit 353 is FF [H] (H indicates hexadecimal), the widest PWM signal is output. Data is 00
[H], the narrowest PWM signal is output.

[0025]

However, in such a conventional image forming apparatus, high-quality printing can be performed by improving the printing performance, and as a result, crimes caused by forgery of securities such as banknotes frequently occur. There is a problem that is going on.

In the future, it is expected that image quality will be further improved due to the improvement of image forming technology, and that crimes of this kind will increase.

Accordingly, it is an object of the present invention to provide an image forming apparatus and an image forming method capable of adding certain information to an image for tracking such crimes.

[0028]

According to the present invention, there is provided an image forming apparatus for forming an image relating to multi-valued image data, wherein a digital signal sequence relating to the multi-valued image data is inputted, and image forming is performed. A driving unit for driving an image forming element for generating an additional data generating unit for generating a digital signal sequence based on predetermined additional data, wherein the driving unit includes:
An image forming apparatus having an input terminal for forcibly controlling light emission of the image forming element, wherein the additional data generating means inputs a digital signal sequence based on the additional data to the input terminal. Is provided. In this device, the input terminal may be for forcibly turning on or off light emission of the image forming element.

Further, according to the present invention, there is provided an image forming apparatus for forming an image relating to multi-valued image data, wherein the image forming apparatus comprises two or more image forming means, Means for driving an image forming element for image formation, additional data generating means for generating a digital signal sequence based on predetermined additional data, a digital signal sequence related to the multi-valued image data, and the additional data And an input unit for inputting the digital signal sequence superimposed on the digital signal sequence to the driving unit. In this device, the input means may execute an exclusive OR operation of a digital signal sequence related to the multi-valued image data and a digital signal sequence based on the additional data.

In the apparatus according to the present invention, the additional data may be data based on information for specifying each of the image forming apparatuses.

In the apparatus of the present invention, there is provided means for generating horizontal scanning position information and vertical scanning position information in the recording scan by the image element, and the additional data generating means comprises the horizontal scanning position information and the vertical scanning position information. A digital signal sequence based on the additional data may be generated based on the scanning position information.

In the apparatus of the present invention, the additional data generating means may include a means for inputting positional information on the image to which the additional data is to be added.

In the apparatus of the present invention, the multi-valued image data comprises at least data of yellow, cyan, and magenta colors, and the additional data generating means includes a digital signal of the multi-valued image data for yellow. A digital signal sequence based on the additional data can be generated for only the sequence.

In the apparatus according to the present invention, the image forming element may be a light emitting element.

Further, according to the present invention, there is provided an image forming method for forming an image related to multi-valued image data by using an image forming element for forming an image and a driving means for driving the image forming element. The driving unit has an input terminal for forcibly controlling light emission of the image forming element, and a step of inputting a digital signal sequence related to the multi-valued image data to the driving unit; Generating a digital signal sequence based on data and inputting the digital signal sequence to the input terminal. In this method, the input terminal may be for forcibly turning on or off light emission of the image forming element.

Further, according to the present invention, there is provided an image forming method for forming an image relating to multi-valued image data by using two or more image forming elements for forming an image and driving means for driving the image forming elements. Generating a digital signal sequence based on predetermined additional data for each of the driving units, and for each of the driving units, based on the digital signal sequence related to the multi-valued image data and the additional data. Superimposing a digital signal sequence and inputting the superimposed digital signal sequence. In this method, a digital signal sequence related to the multi-valued image data and a digital signal sequence based on the additional data can be superimposed by executing an exclusive OR operation.

[0037] In the method of the present invention, the additional data may be data based on information specifying each apparatus on which the image forming method is executed.

In the method of the present invention, horizontal scanning position information and vertical scanning position information in recording scanning by the image forming element are generated, and based on the information, a digital signal sequence based on the additional data is input to the input signal. You can also input to the terminal.

In the method of the present invention, it is also possible to generate position information on the image to which the additional data is to be added, and to generate a digital signal sequence based on the additional data based on the position information.

In the method of the present invention, the multi-valued image data includes at least data of yellow, cyan, and magenta colors. It is also possible to generate a digital signal sequence based on the additional data.

In the method of the present invention, the image forming device may be a light emitting device.

[0042]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a sectional view showing the structure of an image forming apparatus A according to one embodiment of the present invention.

In the image recording apparatus A, the sheet 102 fed from the sheet feeding section 101 has its leading end gripper 103.
f, and is held on the outer periphery of the transfer drum 103.

The latent images formed for each color on the image carrier 100 by the optical unit 107 are developed by developing units (Dy, Dc, Dm, Db) for each color, and are held on the outer periphery of the transfer drum 103. The image is transferred a plurality of times to the multi-color image on the sheet.

Thereafter, the paper 102 is transferred to the transfer drum 103.
The sheet is further separated and fixed by the fixing unit 104, and is discharged from the sheet discharge unit 105 to the sheet discharge tray unit 106.

Here, each developing unit (Dy, Dc, Dm, D
b) has rotating shafts at both ends thereof, each of which is held by the developing device selecting mechanism 108 so as to be rotatable about the shaft.

Each developing unit (Dy, Dc, Dm, D
In b), the rotation for selecting the developing device is performed while the posture is maintained constant. Then, after one of the selected developing units moves to the developing position, the solenoid 109a
As a result, the selection mechanism holding frame 109 moves about the fulcrum 109b, whereby the development device selection mechanism 108 and the development device are moved and positioned in the direction of the image carrier 100.

Next, the operation of the image forming apparatus A having the above configuration will be described.

First, the charger 111 shown in FIG.
The image carrier (photoconductor drum) 100 is uniformly charged to a predetermined polarity, and a first magenta latent image is formed on the photoconductor drum 100 by exposure with the laser beam L.

Next, in this case, the required developing bias voltage is applied only to the magenta developing device Dm to develop the magenta latent image, and the first toner image of magenta M is formed on the photosensitive drum 100. It is formed.

On the other hand, the transfer paper P is fed at a predetermined timing, and immediately before the leading end of the transfer paper P reaches the above-described transfer start position, the transfer bias voltage (+1.8 KV) of the opposite polarity (for example, plus polarity) to the toner. Is applied to the transfer drum 103, the first toner image on the photosensitive drum 100 is transferred to the transfer paper P, and the transfer paper P is
3 is electrostatically adsorbed on the surface of the substrate. Then, the photosensitive drum 10
From 0, the remaining magenta toner is removed by the cleaner 112 to prepare for the formation of a latent image of the next color to be printed and the development process.

Next, a second cyan latent image is formed on the photosensitive drum 100 by the laser beam L, and the second latent image on the photosensitive drum 100 is developed by the cyan developing unit Dc. Thus, a second toner image of cyan C is formed.

Then, the second toner image of cyan C is transferred to the transfer paper P in accordance with the position of the first toner image of magenta M previously transferred to the transfer paper P. In addition,
In the transfer of the second color toner image, a bias voltage of +2.1 KV is applied to the transfer drum 103 immediately before the transfer paper reaches the transfer portion.

Similarly, the third of yellow and black,
A fourth latent image is sequentially formed on the photosensitive drum 100,
Each is sequentially developed by the developing devices Dy and Db. Then, the position of the toner image is adjusted to the position of the toner image previously transferred to the transfer paper P, and the third and fourth toner images of yellow and black are sequentially transferred. As a result, on the transfer paper P,
The four color toner images are formed in an overlapping state.

In the transfer of the toner images of the third and fourth colors, bias voltages of +2.5 KV and +3.0 KV are applied to the transfer drum 103 immediately before the transfer paper reaches the transfer portion. The reason why the transfer bias voltage is increased each time the transfer of the toner image of each color is performed is to prevent a decrease in transfer efficiency.

The main cause of the decrease in the transfer efficiency is that when the transfer paper separates from the photosensitive drum 100 after the transfer, the surface of the transfer paper is charged to the opposite polarity to the transfer bias voltage by air discharge (the transfer paper is carried). This is because the charged electric charge is slightly accumulated on the surface of the transfer drum). This is because the charged electric charge is accumulated every transfer. When the transfer bias voltage is constant, the transfer electric field decreases every transfer.

When the transfer of the fourth color is completed, when the leading edge of the transfer paper reaches the transfer start position (including immediately before and immediately after), an AC voltage of 5.5 KV (effective value, the frequency of which is 500 Hz) Then, a DC bias voltage of +3.0 KV having the same polarity and the same potential as the transfer bias voltage applied during the transfer of the fourth toner image is superimposed and applied to the charger 111.

The reason why the charger 111 is operated when the leading edge of the transfer paper reaches the transfer start position during the transfer of the fourth color is to prevent transfer unevenness. In particular, in the transfer of a full-color image, even if slight transfer unevenness occurs, it is easy to notice as a color difference, and it is necessary to apply a required bias voltage to the charger 111 to perform a discharge operation as described above. Becomes

Thereafter, when the leading end of the transfer paper P on which the four color toner images are superimposed and transferred approaches the separation position, the separation claw 113 is moved.
Approach, the leading edge thereof comes into contact with the surface of the transfer drum 103, and the transfer paper P is separated from the transfer drum 103. Then, the leading end of the separation claw 113 keeps the contact state with the surface of the transfer drum 103 until the rear end of the transfer paper P leaves the transfer drum 103, and thereafter returns to the original position away from the transfer drum 103.

As described above, the charger 111 transfers the transfer paper P
When the leading end of the transfer paper reaches the transfer start position of the final color, the operation is performed until the rear end of the transfer paper is separated from the transfer drum 103, and the accumulated charge (opposite polarity of the toner) on the transfer paper is eliminated. In addition to facilitating separation of the transfer paper, air discharge during separation of the transfer paper is reduced.

When the rear end of the transfer paper reaches the transfer end position (the exit of the nip formed by the photosensitive drum 100 and the transfer drum 103), the transfer bias voltage applied to the transfer drum 103 is turned off. (Installation potential). At the same time, the bias voltage applied to the charger 111 is turned off.

The transfer paper P thus separated is then conveyed to the fixing device 104, where the toner image on the transfer paper is fixed, and then discharged onto the discharge tray 115.

Next, the operation of laser beam scanning in the image forming apparatus A will be described.

The optical unit 107 as a driving means is
Semiconductor laser device 12 as image forming element (light emitting element)
0, a polygon mirror 121, a scanner motor 122, a lens 123, and a mirror 125. Then, when the recording paper P is fed and its leading end is detected, an image signal VDO for one page is output to the semiconductor laser device 120 in synchronization with the detection.

The light beam L is modulated by the image signal VDO and is emitted toward the polygon mirror 125 rotated by the scanner motor 122 so that the lens 123
The light is guided to the photosensitive drum 100 by the mirror 125. When the light beam L is emitted, the light beam L is detected by a detector (not shown) arranged on the scanning axis, and a beam detection signal BD serving as a horizontal synchronization signal is output. As a result, the photosensitive drum 100 is scanned and exposed by the light beam L in synchronization with the BD signal, and an electrostatic latent image is formed.

FIG. 2 is a block diagram showing a schematic configuration of a print system using the image forming apparatus A. As shown in FIG. 1, the printer 2 (image forming apparatus A) includes a printer controller 3 for developing image information in a predetermined description language sent from the host computer 1, a printer control unit 404, and a signal processing unit 402. And a printer engine.

The host computer 1 also sends out bit data such as RGB read by an image reader or the like.

The image processing unit 401 in the printer controller 3 converts the RGB image into a YMCK image and performs pulse width modulation and dither processing on the multi-valued image data, thereby obtaining a VDO as a 1-bit image data sequence. Generate signal 6.

FIG. 3 is an internal block diagram of the printer controller 3. As shown, an image developing unit 406 for converting printer language information sent from the host computer 1 into bitmap data, a page memory unit 407 for storing the data for one page, and RGB information sent from the page memory unit Is converted to YMCK information, and the VDO signal 6 converted to a pulse width corresponding to the multi-valued density
The image processing unit 401 generates The VDO signal 6 is one hard signal. The image processing unit 401
The printing dots are controlled by a clock signal corresponding to one dot of 600 dpi.

FIG. 4 is a time chart showing the VDO signal 6 sent from the printer controller 3, the BD signal 423 which is a horizontal synchronization signal sent from the engine to the printer controller, and the PSYNC signal 424 which is a vertical synchronization signal. . As shown in FIG. 4, in synchronization with the PSYNC signal 424, magenta data, cyan data,
Yellow data and black data are output in this order.

FIGS. 5, 12, and 14 are internal block diagrams of the signal processing unit 402 on the engine side, respectively. Particularly, in this embodiment, FIGS.
4 is a signal processing unit 402. Hereinafter, description will be made in order from the example of FIG.

V sent from printer controller 3
The DO signal 6 is sent to the laser drive circuit 500 via the OR circuit 414 and the AND circuit 415.

The image mask signal generation section 411 controls the control signal M for forcibly turning off the laser outside the printing area.
This block generates an ASK signal 419.

The MASK signal is "1" except for the print area, and "0" is the print area. The generation of the MASK signal
Upon receiving desired information from the CPU 412, the BD signal, P
Generated based on the SYNC signal.

The tracking pattern generation section 410 prints
This block generates a signal for printing with a yellow toner, which makes it difficult to visually recognize the dots representing the machine-specific numbers. The code is represented by the arrangement of this tracking pattern on the printed matter.

The tracking pattern generator 410 includes a clock signal CCLK output from a crystal oscillator 413 disposed on the engine side, a BD signal 423, and a PSYNC signal 42.
4 and a signal MKON for forcibly turning on the laser
Then, a signal MKOFF for forcibly turning off the laser is generated. These signals MKON and MKOFF are asynchronous with the VDO signal 6 sent from the printer controller 3.

Note that the tracking pattern arrangement information 421 is
The CPU 412 gives it to the tracking pattern generation unit 410. C
The PU 412 reads and codes a machine-specific number stored in the memory 420 to generate tracking pattern arrangement information 421.

The tracking pattern is added to the VDO signal 6 when printing the yellow plane, and is not added to the planes of other colors.

FIG. 6 shows a tracking pattern generator 410 shown in FIG.
It is an internal block diagram of.

The frequency of the clock CCLK of the crystal oscillator 413 is similar to the image transfer rate of the printer controller 3.

The frequency of the CCLK signal is converted to eight times by the multiplication circuit 434. The clock signal 445 whose frequency has been multiplied by 8 is supplied to shift registers 432 and 433,
The signal is output to the frequency divider 435. In the frequency divider 435, the crystal oscillator 4 is synchronized with the rising edge of the BD signal 423.
13. A clock PC synchronized with the BD signal at the same frequency as
Generate LK. FIG. 7 is a timing chart of these signals.
Shown in

Reference numeral 426 denotes an image clock PC in the main scanning direction.
This is a 4-bit counter for counting LK, which is started after resetting with the BD signal 423, and repeatedly counts up to 0h color Bh.

Reference numeral 427 denotes a 5-bit counter for counting the BD signal 423 in the sub-scanning direction, which is started after resetting by the PSYNC signal 424, and repeatedly counts from 0h to 1Fh.

The output signal 446 of these counters is information representing the coordinates of the print dot,
At 8,429, if it is determined that the position is the desired coordinate position,
If the coincidence signals 447 and 448 are set to “1”, the selector 4
30 and 431 indicate that the match signals 447 and 448 are “1” and A
The input, "0", selects the B input and outputs from Y.

The basic pixels of the tracking pattern have forced off dots on both sides of the forced on dot as shown in FIG. The multi-value information 443 indicating the forced ON dot is output from the selector 430 in FIG. FCh is output at the timing of printing the forced on-dot. Otherwise, 0 is output.
0h is output. The selector 431 outputs multi-value information 444 indicating a forced off dot. F8h is output at the timing of printing the forced off dot, and otherwise, 00h is output. The 8-bit signal output from each selector is converted into parallel-serial conversion circuits 432 and 433.
Then, it is converted into serial data and output.

Coordinate data (437 and 438) for printing the tracking pattern set in the coincidence circuit is represented by C (not shown).
Preset from PU.

Next, the signal processing section 402 according to an embodiment of the present invention shown in FIG. 12 will be described.

The difference from the example of FIG.
In the preceding stage of 01, tracking is not performed by AND or ORing the tracking pattern, but by using a terminal (here, forced lighting ON, forced OFF port OFF) of the laser driving circuit 501 for forcibly controlling the laser. The pattern is superimposed on the image signal.

In the example of FIG. 12, the image signal 6 sent from the printer controller 3 is the operation signal / VDO.
And VDO.

FIG. 13 shows the tracking pattern generator 5 of FIG.
02 is an internal block diagram of FIG. In the case of this figure, since the tracking pattern is generated by the clock of the crystal oscillator 413, the jitter of one clock of the clock is used as the tracking pattern.
Have. Further, since the dots constituting the tracking pattern are also controlled in units of one dot, a PS conversion circuit is not required. As described above, the example of FIG. 12 has a simple configuration and can be realized at low cost.

Next, the signal processing unit 402 according to an embodiment of the present invention shown in FIG. 14 will be described.

In this embodiment, as shown in the embodiment of a laser beam printer in which laser scanning in the main scanning direction is performed by two or more lasers (here, two lasers), a laser driving circuit for driving each laser is shown. An exclusive OR (EX-OR: exclusive OR) circuit 507 and 508 for superimposing a tracking pattern are provided at a stage preceding 505 and 506, respectively.

FIG. 15 is an internal block diagram of the tracking pattern generators 503 and 504. In this example, since the tracking pattern is expressed by inverting the image data VDO 513 and 514, the output signal is MKOT 511.
And 512 only.

FIG. 8 is a diagram schematically showing an area of a unit representing a machine-specific number by a tracking pattern. FIG.
As shown in the figure, a predetermined code is expressed by nine patterns in a region within a broken line, and two patterns among them are reference patterns. Depending on the position of the remaining seven patterns,
It represents a code of "3" (2 bits), and a total of 14 bits are represented by 7 patterns. Converted to a decimal number, the number is from 0 to 16383. FIG. 8 represents the number 11384. This pattern is repeated in the main scanning direction and the sub-scanning direction.

FIG. 9 shows MKON which is a multi-level signal of the tracking pattern dot generated by the tracking pattern generating section 410.
[7: 0], MKOFF [7: 0] 444 are shown as an example.

In FIG. 9, MKON [7: 0] is FC
In the case of h, 11111100B is converted into serial data and output to the OR circuit 414 (not shown) as MKON. In other words, 6/8 dots of one dot divided into eight are forcibly printed. On the other hand, MKOFF [7: 0] is F
In the case of 8h, 111111000B is converted into serial data and output to the AND circuit 415 (not shown) as MKOFF.

That is, 5/5 of the division of one dot into eight
Eight dots are forcibly printed. For 00h, VDO
The signal 6 is output to the laser driver through. The tracking pattern is printed every four lines.

FIG. 10 is an image diagram in which the tracking pattern shown in FIG. 9 is mixed into the image signal VDO6 and printed. This figure shows V output from the printer controller.
FIG. 9 is a diagram when DO data 6 and a tracking pattern are in phase. That is, the control clock of the image processing unit 401 of the printer controller 3 and the tracking pattern generation unit 41
This is the case where the frequency of the control clock CCLK of 0 is completely the same. The VDO signal is a diagram in which a uniform intermediate density is printed.

FIG. 11 shows a case where the synchronization between the VDO data 6 output from the printer controller and the tracking pattern does not match. That is, the frequency of the control clock of the image processing unit 401 of the printer controller 3 does not completely match the frequency of the control clock CCLK of the tracking pattern generation unit 410. FIG. 11 shows that the control clock CCLK of the tracking pattern generation unit 410 is
FIG. 11 is a diagram in the case of a frequency which is 1.5 times lower than the frequency of the control clock No. 01.

As another example of this embodiment, a crystal oscillator having a frequency different from the image transfer rate of the controller may be used. In the case of a crystal oscillator having a frequency several times the image transfer rate, a multiplication circuit 4
34 becomes unnecessary. Alternatively, the frequency may be lower than the image transfer rate, and a clock of a desired frequency may be generated by the multiplying circuit 434.

It goes without saying that the present invention also includes a combination of some of the above-described configurations as appropriate.

Further, both the forced on dot and the forced off dot have a size smaller than one dot.
It may be larger than one dot, such as 11/8 dot or 5/4 dot.

Further, PCLK output from frequency divider 435
However, it may be completely different from the image transfer rate. In this case, the size and the interval of the tracking pattern dots are different from the integral multiple of the image dots. When a code is extracted from the position of the tracking pattern dot, the determination is made not as an absolute size but as a printing interval ratio, so that this is established. By using a clock signal of a crystal oscillator used in another circuit, a new crystal oscillator is not required, and an inexpensive configuration can be realized.

The clock output from the crystal oscillator 413 is raised in frequency by the multiplication circuit 434 and then synchronized with the horizontal synchronizing signal to reduce the phase jitter of the tracking pattern dot to a fraction of one dot. However, the phase jitter may be set to one dot without using the multiplying circuit 434. In this case, since a multiplying circuit or the like is not required, it can be realized with an inexpensive configuration.

Further, a PS conversion circuit was used to divide a tracking dot into eight dots, but a PWM (Pulse Widget) was used.
th Modulation).

In FIG. 6, the counters 426, 4
27, matching circuits 428 and 429, selectors 430 and 43
1, PS circuits 432 and 433, a multiplication circuit 434, a frequency divider 435, an OR circuit 415 (not shown), and an AND circuit 416
May be built into the ASIC. In addition, an AND circuit is used as an OR circuit for mixing the VDO signal 6 with tracking dots, but a selector circuit may be used.

[0108]

As described above, according to the present invention,
A certain amount of information can be added to the image, and this can contribute to the tracking of crimes such as duplication of securities.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a structure of an image forming apparatus A according to an embodiment of the present disclosure.

FIG. 2 is a block diagram illustrating a schematic configuration of a print system using an image forming apparatus A.

FIG. 3 is an internal block diagram of the printer controller 3.

FIG. 4 shows a VDO signal 6, a BD signal 423 as a horizontal synchronization signal, and a PSYNC signal 424 as a vertical synchronization signal.
FIG. 4 is a diagram showing a time chart of FIG.

FIG. 5 is an internal block diagram of a signal processing unit 402 on the engine side.

FIG. 6 is an internal block diagram of the tracking pattern generation unit 410.

FIG. 7 is a diagram showing a time chart of PCLK signal generation in tracking pattern generation section 410.

FIG. 8 is a diagram schematically showing a unit area representing a machine-specific number by a tracking pattern.

9 shows MKON [7: 0] and MK, which are multi-level signals of tracking pattern dots generated by the tracking pattern generation unit 410. FIG.
FIG. 14 is a diagram illustrating an example of OFF [7: 0] 444.

FIG. 10 shows the tracking pattern shown in FIG.
FIG. 6 is an image diagram in which the image is mixed and printed.

FIG. 11 shows VDO output from a printer controller.
It is a figure in case data 6 and a tracking pattern are not synchronized.

FIG. 12 is an internal block diagram of another signal processing unit 402.

FIG. 13 is an internal block diagram of a tracking pattern generation unit 502.

FIG. 14 is an internal block diagram of yet another engine-side signal processing unit 402.

FIG. 15 is an internal block diagram of tracking pattern generation units 503 and 504.

FIG. 16 is a schematic view of a conventional multicolor light beam printer.

FIG. 17 is a block diagram of signal processing.

FIG. 18 is a timing chart showing a relationship between a TOPSNS signal and a VDO signal.

FIG. 19 is a block diagram showing a system configuration of a conventional printer.

FIG. 20 is a block diagram illustrating an internal configuration of an image processing unit 305.

FIG. 21 is a diagram showing a time chart of each signal.

FIG. 22 is a diagram showing a time chart when a PWM signal is generated by a PWM unit 353.

Claims (18)

[Claims] An image forming apparatus for forming an image related to multi-valued image data, wherein a digital signal sequence related to the multi-valued image data is input,
Driving means for driving an image forming element for image formation; and additional data generating means for generating a digital signal sequence based on predetermined additional data, wherein the driving means forcibly emits light from the image forming element. An image forming apparatus, wherein the additional data generating means inputs a digital signal sequence based on the additional data to the input terminal. 2. The image forming apparatus according to claim 1, wherein the input terminal is for forcibly turning on or off light emission of the image forming element. 3. An image forming apparatus for forming an image according to multi-valued image data, wherein said image forming apparatus comprises two or more image forming means, and each of said image forming means comprises Driving means for driving an image forming element, an additional data generating means for generating a digital signal sequence based on predetermined additional data, a digital signal sequence based on the multi-valued image data, and a digital signal sequence based on the additional data. Input means for inputting the superposed digital signal sequence to the driving means,
An image forming apparatus comprising: 4. The apparatus according to claim 3, wherein said input means executes an exclusive OR operation of a digital signal sequence based on said multi-valued image data and a digital signal sequence based on said additional data. Image forming device. 5. The image forming apparatus according to claim 1, wherein the additional data is data based on information that specifies each of the image forming apparatuses. 6. An apparatus for generating horizontal scanning position information and vertical scanning position information in print scanning by the image element, wherein the additional data generating means is configured to generate the horizontal scanning position information and vertical scanning position information based on the horizontal scanning position information and the vertical scanning position information. 2. A digital signal sequence based on the additional data is generated.
The image forming apparatus according to any one of claims 1 to 5, wherein 7. The apparatus according to claim 1, wherein said additional data generating means includes means for inputting position information on the image to which the additional data is to be added.
Item 10. The image forming apparatus according to item 1. 8. The multi-valued image data comprises at least data of yellow, cyan, and magenta colors, and the additional data generating means performs the above-mentioned multi-valued image data only for a digital signal sequence of the multi-valued image data for yellow. The image forming apparatus according to claim 1, wherein a digital signal sequence based on the additional data is generated. 9. The image forming apparatus according to claim 1, wherein the image forming element is a light emitting element. 10. An image forming method for forming an image related to multi-valued image data by using an image forming element for forming an image and a driving unit that drives the image forming element, wherein the driving unit includes: Having an input terminal for forcibly controlling light emission of the image forming element; inputting a digital signal sequence related to the multi-valued image data to the driving unit; and a digital signal sequence based on predetermined additional data. And inputting the data to the input terminal. 11. The image forming method according to claim 10, wherein the input terminal is for forcibly turning on or off light emission of the image forming element. 12. An image forming device for forming an image and driving means for driving the image forming device, comprising:
An image forming method for forming an image according to multi-valued image data, wherein for each of the driving units, a step of generating a digital signal sequence based on predetermined additional data; and for each of the driving units, Superposing a digital signal sequence related to multi-valued image data and a digital signal sequence based on the additional data, and inputting the superimposed digital signal sequence. 13. The digital signal sequence according to claim 12, wherein a digital signal sequence based on the multi-valued image data and a digital signal sequence based on the additional data are superposed by executing an exclusive OR operation. Image forming method. 14. The image forming apparatus according to claim 10, wherein the additional data is data based on information for specifying each apparatus on which the image forming method is executed. Method. 15. Generating horizontal scanning position information and vertical scanning position information in recording scanning by the image forming element,
15. The image forming method according to claim 10, wherein a digital signal sequence based on the additional data is input to the input terminal. 16. The digital camera according to claim 10, wherein position information on the image to which the additional data is to be added is generated, and a digital signal sequence based on the additional data is generated based on the position information. Item 2. The image forming method according to Item 1. 17. The digital signal sequence based on the additional data only for the digital signal sequence of the multi-level image data related to yellow, wherein the multi-valued image data includes at least data of yellow, cyan, and magenta colors. 17. The method according to claim 10, wherein
Item. 18. The image forming method according to claim 10, wherein the image forming element is a light emitting element.