JP2008035376A - Optical writing device, image forming apparatus, and optical writing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve an unauthorized copying prevention function by making a dot diameter of an unauthorized copying prevention pattern when it is printed out, close to that in other model. <P>SOLUTION: An optical writing device which superimposes an unauthorized copying prevention pattern onto an output image and performs optical writing on a photo conductor using a light emitting element array unit LPH includes a line memory which accumulates output images for n lines, a pattern matrix forming section 501-32 which forms an image matrix of n×n with respect to image data read out from the line memory, and a pattern recognizing and output image forming section 501-33 which recognizes an input image for each image matrix formed in the pattern matrix forming section 501-32 and, when a relevant unauthorized copying prevention pattern is recognized, corrects the output image for each picture element of the unauthorized copying prevention pattern and regulates the size of an isolated dot pattern of unauthorized copying prevention. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical writing device equipped with an illegal copy prevention function, a copying machine equipped with the optical writing device, an image forming apparatus such as a digital multi-function peripheral having a copying function, and these devices. The present invention relates to an optical writing method to be corrected.

  A copying machine that is currently in general use is equipped with an illegal copy prevention function. The illegal copy prevention function superimposes an illegal copy prevention pattern on an image output by a printer, and when the superimposed image is read under a certain condition when the superimposed image is read, This is a function for handling and not copying the image. An important element of this function is that an image on which a pattern of an illegal copy prevention pattern printed on a certain model is superimposed is read by another model and recognized as an illegal copy prevention image.

On the other hand, for example, an invention described in Patent Document 1 is known as an image forming apparatus provided with another type of illegal copy prevention function. According to the present invention, whether or not copying can be performed on a thermoreversible printing medium having a thermoreversible recording layer capable of displaying and erasing visible information by reversibly changing a coloring state and a staining state by heat energy. Embedded information including copying authority, confidentiality expiration date, and print medium characteristics is read and analyzed during copying, and the result is used for copying control.
JP 2004-237678 A

  By the way, the A0 wide-width machine currently uses an LED writing head (hereinafter referred to as LPH) when forming an electrostatic image on the photosensitive member, and LD writing is used depending on other process conditions. Compared to other models, the dot shape of one dot is generally large and vertically long, and an image on which an illegal copy prevention pattern output by a wide-width machine is superimposed can be copied by another model.

  Also, even if trying to control the size of this illegal copy prevention pattern with a thinning function, etc., thinning in the horizontal direction is currently effective, but in the vertical direction, the effect of satisfying the illegal copy prevention pattern standard is not effective. If the control cannot be performed and the control in the vertical direction is performed, the entire image is affected. Therefore, the control in the vertical direction cannot be performed. Furthermore, since the dot diameter of LPH itself is a general-purpose component, it cannot be changed. In addition, there is a problem that it is difficult to actually change the process system in consideration of the influence of side effects.

  Therefore, the problem to be solved by the present invention is to realize the illegal copy prevention function by bringing the dot diameter at the time of printing output of the illegal copy prevention pattern close to the diameter of other models.

In order to solve the above-described problem, the first means is an optical writing apparatus that superimposes an illegal copy prevention pattern on an output image and performs optical writing on a photoconductor using a light emitting element array unit. A storage unit that accumulates n lines at a time, a matrix generation unit that generates an n × n (n is an integer greater than or equal to 2) image matrix for image data read from the storage unit, and a matrix generation unit The input image is recognized for each image matrix, and when the corresponding illegal copy prevention pattern is recognized, the output image is corrected for each pixel of the illegal copy prevention pattern to control the size of the isolated dot pattern for preventing illegal copy. Control means to
It is characterized by having.

  The second means arbitrarily sets, from the outside, a dot pattern that is recognized as an isolated dot pattern for preventing unauthorized copying when the first means performs pattern recognition using the image matrix generated by the matrix generation means. A setting means is provided.

  A third means is characterized in that, in the first or second means, the input image is a binary or multi-valued image.

  According to a fourth means, in any one of the first to third means, an external control means for controlling the correction amount of each pixel of the isolated dot pattern from the outside is provided.

  A fifth means is characterized in that, in the fourth means, the adjustment is performed by an output control means for controlling an output of a light emitting element corresponding to each pixel of the isolated dot pattern.

  A sixth means is characterized in that, in the fourth means, the adjustment is performed by a transfer speed control means for controlling a transfer speed of image data to a light emitting element corresponding to each pixel of the isolated dot pattern.

  A seventh means is an output control means for controlling the output of the light emitting element corresponding to each pixel of the isolated dot pattern in the fourth means, and the image data to the light emitting element corresponding to each pixel of the isolated dot pattern. A transfer rate control unit that controls a transfer rate, and a selection unit that selects each of the control units, wherein the selection unit is one of the output control unit and the transfer rate control unit based on whether it is a binary input or a multi-value input. It is characterized in that the adjustment is performed by selecting the above.

  The eighth means is characterized in that the image forming apparatus includes the optical writing device according to any one of the first to seventh means.

  A ninth means is an optical writing method in which an illegal copy prevention pattern is superimposed on an output image and optical writing is performed on a photoconductor using a light emitting element array unit, and a small image matrix is obtained from an input image using a line memory. A generation step for generating the image, a recognition step for recognizing an illegal copy prevention pattern by referring to the image matrix generated in the generation step as needed, and a unit for one pixel when the illegal copy prevention pattern is recognized in the recognition step. And a control step of controlling the size of the entire isolated dot pattern for preventing unauthorized copying by controlling the light quantity of the pixels, and correcting the unauthorized copy preventing pattern.

  A tenth means is an optical writing method in which an illegal copy prevention pattern is superimposed on an output image and optical writing is performed on a photoconductor using a light emitting element array unit, and the output image is stored in a storage means for every n lines. A storage step of generating, and a generation step of reading out the output image data stored in the storage step from the storage unit and generating an n × n (n is an integer of 2 or more) image matrix for the read image data; The input image is recognized for each image matrix generated in the generating step, and when the corresponding illegal copy prevention pattern is recognized, the output image is corrected for each pixel of the illegal copy prevention pattern to prevent unauthorized copy. And a control step for controlling the size of the isolated dot pattern, wherein the illegal copy prevention pattern is corrected.

  In the embodiments described later, the light emitting element array units LPH (1) 503-1, LPH (2) 5032-2, LPH (3) 503-3, the storage means in the line memory 501-21, and the matrix generation means in the pattern. In the matrix generation unit 501-32, the control unit is in the pattern recognition and output image generation unit 501-33, the setting unit is in the CPU provided in the system control device 302, and the external control unit is in the operation unit 400 and the system control device 302. The output control means corresponds to the LED writing control circuit 502, the transfer speed setting means corresponds to the delay control / LPH transfer section 502-3, the selection means corresponds to the CPU, and the image forming apparatus corresponds to the copying section 200. To do.

  According to the present invention, when the unauthorized copy prevention pattern is recognized, the size of the isolated dot pattern for preventing unauthorized copying is controlled by correcting the output image for each pixel of the unauthorized copy preventing pattern. An illegal copy prevention function can be realized by making the dot diameter at the time of print output close to the diameter of other models.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a schematic configuration of an image forming apparatus according to an embodiment of the present invention. In the figure, an image forming apparatus according to the present embodiment includes a document reading unit 100 as a reading unit that reads a document, an image information storage unit 300 as a storage unit that stores image information of a read document, and stored images. A copying unit 200 that executes a series of processes for copying information to transfer paper, a writing unit 500 that writes an image when copying, a system control device 302 that controls these, and an operation that performs key input to the system control device It is comprised from the operation part 400 etc. as a means.

  FIG. 2 is a diagram showing a mechanical configuration of the image forming apparatus according to the embodiment of the present invention. The image forming apparatus includes a copying unit 200 and an image reading unit 100. The image reading unit 100 is mounted on the copying unit 200, and these are integrated. The copying unit 200 has a sheet feeding unit at the bottom and an image forming unit at the top.

  When the operator inserts a document from the insertion port 10 of the image reading unit 100, the document is conveyed between the contact sensor (CIS-Contact Image Sensor) 101 and the white roller 23 by the rotation of the roller 21. The document being conveyed is irradiated with light by the LED element attached to the contact sensor 101, and the reflected image forms an image on the contact sensor 101 to read document image information.

  As shown in FIG. 1, the contact sensor 101 converts the formed original image into an analog electric signal, and the electric signal is amplified by an image amplification circuit 102. The A / D conversion circuit 103 converts the image signal amplified by the image amplification circuit 102 into a multi-value digital image signal for each pixel. This digital image signal is output in synchronization with the clock output from the synchronization control circuit 106 by the A / D conversion circuit 103, and the shading correction circuit 104 causes distortion due to the light amount unevenness of the LED element, the sensitivity unevenness of the contact sensor 101, and the like. Correct. The digital image information corrected by the shading correction circuit 104 is converted into digital recording image information by the image processing circuit 105 and then written in the image memory unit 301 as a storage unit in the image information storage unit 300. The reading control circuit 107 controls the synchronization control circuit 106 and the like in the reading unit 100, and the scanner driving device 108 drives and controls a motor and the like that rotate the roller 21 and the white roller 23 in the reading unit 100.

  The system control device 302 controls a series of processes for forming an image on the transfer paper based on the image information written in the image memory unit 301, and the writing unit 500 has a function of optically writing an image to the copying apparatus 200. Have. More specifically, the system control device 302 controls the entire image forming apparatus. The image control unit 502, the synchronization control circuit 106, the image memory unit 301, the image conversion unit 501, and the LED writing control unit (circuit) 502 perform image processing. Data transfer is controlled, and the drive control circuit 504 is driven by a motor or the like via the scanner driving device 108 and the printer driving device 303 to smoothly control the document and transfer paper conveyance.

  In the writing unit 500, the image signal transferred from the image memory unit 301 by the synchronization signal clock is received by the image conversion unit 501 and directly passed to the LED writing control circuit 502, or after being subjected to density conversion, and received by the LED writing control circuit 502. The data is divided into LED array unit 1, 2, and 3, and necessary image correction is performed, and the LED arrays 503-1 to 503-3 of the LED array unit 503 as the light-emitting element array unit are infrared. Convert to light and output.

  On the other hand, the charging device 24 shown in FIG. 2 is a charging device called a scorotron charger with a grid for uniformly charging the drum-shaped photoconductor 25 as an image carrier to −2500 V, and the photoconductor photoconductor 25 is not shown. It is rotationally driven by a motor. The LED array unit 503 includes LED array units 503-1, 50-2, and 503-3 arranged one-dimensionally and a plurality of LED elements arranged in an array in the main scanning direction. Based on the image information, the LEDs of the LED array units 503-1 to 503-3 emit light and irradiate the photosensitive member 25 with the light via the SELFOC lens array which is an optical element.

  When the photoconductor 25 is irradiated with light based on digital image information from the LED array unit 503, the charge on the surface flows to the ground due to a photoconductive phenomenon and disappears. Here, in the LED array unit 503, the LED element does not emit light when the image density of the original is low, and the LED element emits light when the image density of the original is high. Thereby, an electrostatic latent image corresponding to the density of the original image is formed on the light irradiation portion on the photosensitive member 25. The electrostatic latent image on the photosensitive member 25 is developed by the developing device 27 to become a toner image. In the developing device 27, since the toner inside is negatively charged by stirring and a bias of −700 V is applied, the toner adheres only to the light irradiation portion on the photoconductor 25.

  On the other hand, the transfer paper as a sheet-like recording medium is selectively fed to the registration roller 31 from the three paper feed bases 28, 29, 30 and the manual feed unit, and is sent out at a predetermined timing by the registration roller 31 to the photosensitive member 25. The transfer paper on which the toner image on the photoconductor 25 is transferred by the transfer charger 32 as a transfer means at this time is then separated from the photoconductor 25 by the separation charger 33 and is fixed by the conveying belt 34. 35, where the toner is fixed. The transfer paper on which the toner is fixed is discharged out of the apparatus by discharge rollers 36 and 37.

  FIG. 3 is a block diagram showing the flow of image data in the writing unit 500. In the drawing, a writing unit 500 includes an image conversion unit 501, an LED writing control unit 502, an LED array unit (1) 503-1, an LED array unit (2) 503-2, an LED array unit (3) 503-3 (hereinafter referred to as “LED array unit (1) 503-1”). LPH).

The replacement and flow of image data in the writing unit 500 is as follows.
1) First, image data 301-1 of EVEN ODD is simultaneously sent from the image information storage unit 301.
2) The transferred image data is subjected to pattern recognition by the image conversion unit 501 and image correction is performed as necessary.
3) Next, in the LPH control unit 502, the main scanning data output from the image conversion unit 501 is divided and written into one line of data in three group A SRAMs (502-1A) of the image data RAM unit.
4) Next, the image data for one line written in the three SRAMs (502-1A) of the group A are simultaneously read.
5) During reading in the SRAM A group (502-1A), the second line performs a toggle operation for writing to the SRAM B group (501-1B). Selection control of the SRAM group 502-1 is executed by the address control unit 502-2.
6) The image data of each LPH read from the SRAM 502-1 is once transferred to the SDRAM 502-4 and read again, but each LPH of LPH (1) 503-1 is shifted in the sub-scanning direction due to the mechanical layout. Therefore, the data of LPH (2) 503-2 and LPH (3) 503-3 is used as the displacement amount of each LPH with LPH (1) 503-1 as a reference. Read with a corresponding time delay. This read control is performed by the delay control / LPH transfer unit 502-3.
7) Finally, the image data is transferred from the delay control / LPH transfer unit 502-3 to the LPHs 1, 2, and 3.
As shown in the block diagram of FIG. 4, the image conversion unit 501 includes a GATE control unit 501-1, a memory control unit 501-2, an image recognition unit (unauthorized copy prevention pattern correction unit) 501-3, and a density conversion processing unit 501-. 4 and main / sub trim processing section 501-5. Each density conversion mode of the density conversion unit 501 is set by a register dense_r [2: 0]. The setting of denser_r [2: 0] and each density conversion are as shown in FIG.

  In the GATE control unit 501-1, LSYNC_0 passed to the image information storage unit 301 according to the image output mode set according to normal output, print mode other than 1.5 times density conversion, or 1.5 times density conversion mode is set. Generate. Further, since LSYNC from the image information storage unit is thinned out in the density conversion mode, it is necessary to interpolate LSYNC when passing it to the LED image writing control unit 502, and this processing is performed here. In addition to LSYNCy, generation of dummy FGATE is also performed in this block.

The memory control unit 501-2 generates a group of lines in the sub-scanning direction of the image matrix in accordance with the selected output image mode. The main functions are as follows.
(A) Mask data write / read The line memory 501-21 is read and written in two-pixel parallel (EVEN-ODD).
The image data of 21600 dots per line is written to the line memory 501-21 having an address of 0 to 10799 and a width of 5 bits for each PLSYNC_N.
When there is no assertion of PFGATE_N and PLGATE_N, the masked data is written to the line memory 501-21.
If the assertion of PLGATE_N does not occur within 32 clocks from PLSYNC_N, the writing to the line memory 501-21 is forcibly started.
As a result, before the PFGATE_N is asserted, the eight line memories 501-21 are filled with mask data (= 0).

(B) Image data write The mask data is released during the enable period of PFGATE_N and PLGATE_N, and the image data is written into the memory.
(C) Data Read and Image Matrix Generation Data is read from the line memory 501-21 every plsync_n (PLSYNC_N is interpolated to obtain an interval of 600 dpi).
The matrix size at each magnification is as shown in FIG.

  At the time of printer output (single density) and normal image output, a line group used for a 7 × 7 pixel matrix is generated by the image matrix generation unit 501-22 of the memory control unit 501-2, and an illegal copy prevention pattern is generated. If the correction function is enabled, the data is sent to the next block, the unauthorized copy prevention pattern unit 501-3, and otherwise the data is passed to the density conversion unit 501-4. At the time of 1.5 times density conversion, three types of pattern matrices are generated as shown in FIG. After that, the necessary matrix is referred to in each mode.

  The read / write operation of the line memory 501-21 is performed by the line memory control unit (write / read / block switching) 501-23, and one of the eight line memories as shown in FIG. Line memory 3) A write operation is performed, and line data is read from seven memories not performing the write operation, and image data for an image matrix for seven lines in the sub-scanning direction is secured. Details of the memory read / write timing chart are shown in FIGS. 7A and 7B.

  In the image conversion unit 501, a CPU (not shown) can set various registers from the CPU I / F. In addition, since an instruction is input to the CPU from the operation unit 400, the register can be set by an instruction input from the operation unit 400, and various corrections can be performed by the register setting. This indicates that a dot pattern correction instruction can be given from the outside.

  FIG. 8 is a block diagram showing details of the unauthorized copy prevention pattern correction unit 501-3. The illegal copy prevention pattern correction unit 501-3 selects the illegal copy prevention pattern correction function by selecting presence / absence of illegal copy prevention and whether the input image is binary or multi-valued by the pattern matrix generation unit register (hcopyset). In this case, an image matrix is generated using the image data for 1 to 7 lines obtained from the line memory 501-21 in the previous stage as an illegal copy prevention pattern, and pattern recognition is performed on the image matrix to correct the image. Done. The illegal copy prevention pattern correction unit 501-3 generates a delay matrix 501-31 including seven lines provided with three FFs for each line, and a pattern matrix generation in which data delayed by the delay unit 501-31 is input. Unit 501-32 and a pattern recognition and output image generation unit 501-33.

  FIG. 9 shows a breakdown of register settings for the hcopyset. As can be seen from FIG. 9, when the value of hcopyset [1: 0] is 1, the image has no illegal copy prevention correction control, and when it is 2, the image has binary copy prevention control. It indicates that image data is multivalued with unauthorized copy prevention correction control.

  Here, details of generation of the 7 × 7 image matrix will be described. FIG. 8 shows a configuration of the unauthorized copy prevention pattern correction unit 501-3 at this time, and FIG. 10 shows a timing chart when the image matrix is generated.

  As shown in FIG. 8, data mx_data0-6 [9: 0] for EVEN / ODD 2 pixels, which are output from the line memory 501-21, are delayed by 3 times each by the FF of the delay unit 501-31, thereby obtaining 8 pixels. It becomes possible to refer to the data. Since the output from the line memory 501-21 is for 7 lines, it is possible to refer to data of a total of 7 × 8 pixels at a time. The illegal copy prevention pattern correction control actually performs pattern conversion using the 7 × 8 pixel image matrix generated by the pattern matrix generation unit 501-32. Basically, the image matrix to be referenced is 7 × 7 pixels, and in this system, image control is performed in parallel with EVEN / ODD. Therefore, the generated image matrix has two pixels in the first half main scanning direction and the second half 7 pixels. By referencing separately, it is possible to generate both EVEN / ODD pixels at once.

  The pattern recognition performed by the illegal copy prevention pattern correction unit 501-3 and the pattern recognition performed by the output image generation unit 501-33 is as shown in FIG. 11 with respect to the image matrix created by the pattern matrix generation unit 501-32 in the previous stage. As a matching pattern, the pattern is recognized as a matching pattern in which 10 patterns are set in the registers inpat1-1 [4: 0] to impat10-49 [4: 0]. This corresponds to each pixel of the image matrix generated by Impat1-1 to impat1-49. By setting a conceivable pattern of an isolated dot pattern for preventing unauthorized copying in this register centering on the pixel of interest, it is possible to correct only the unauthorized copy preventing pattern, not the entire image.

  In the case of matching, data in registers outpat1 [4: 0] to output10 [4: 0] set in pairs with each input matching pattern is output. In the multi-value mode, the value set in the output register outpat for the input data may be converted as it is and transferred to the LPH 503. In the binary mode, the pixel is shot twice in the sub-scanning direction. Since the correction operation is performed in the pseudo multi-value mode, it is handled as a maximum of four values. Therefore, pattern matching is performed by referring to the lower 1 bit of the input data. As shown in FIG. 12, when the output mode is 00, writing is performed for both the first line and the second line when the sub-scan is performed twice. In the case of 01, only the first line is written. In the case of 10, the second line is written. In the case of 11, the first line and the second line are written. A total of four patterns are output and set, and finally the illegal copy prevention pattern correction operation is performed.

  In order to perform the double hit, it is necessary to double the transfer rate of the image data. When the dot size is increased in this way, for each pixel of the isolated dot pattern output, when image data is transferred to the issuing element array unit at a predetermined transfer speed x, m of X (m is The size of the isolated dot pattern can be controlled by performing pseudo-multi-value writing in the sub-scanning direction at a transfer rate mx of (positive integer) times.

  FIG. 13 and FIG. 14 show images of correction for preventing unauthorized copying in the case of binary and multivalue. In these figures, if the input pattern is binary, the inputs 1-11 to 13, the inputs 18 to 20, and the inputs 25 to 27 are set to 1, otherwise all are set to 0, and if the input pattern is multi-value, the inputs 1-11 to 13 are set. , Inpat18 to 20, and inpat25 to 27 are set to 1f, and the others are all set to 0. As can be seen from these figures, in this embodiment, it is possible to control the size of dots only for a specific isolated pattern.

  Although not shown, the density conversion processing unit 501-4 at the subsequent stage of the illegal pattern preventing copy correction unit 501-3 includes a smoothing processing unit, a 1.5-fold density conversion processing unit, an image selector, and a format conversion unit. In the density conversion unit, each density conversion mode is selected, and processing corresponding to that is performed. That is, first, when the through mode is selected, the image is simply passed through and output. Further, each mode of single density, 1.5 times density, 2 times density, and 3 times density is provided, and when selected, necessary density conversion processing is performed on the input image and an image is output.

  A main / sub-scanning trim unit 501-5 further downstream from the density conversion processing unit 501-4 performs mask processing on the output data in the main / sub direction. With respect to the mask amount for the image in the main and sub directions, the value set in the register is referred to, and a mask corresponding to it is applied to output the image.

As described above, according to the present embodiment, the following effects can be obtained.
1) An output image is stored in a memory by n lines, an n × n image matrix is formed for image data from n of the n memories, and an input image is recognized for each image matrix, If the corresponding illegal copy prevention pattern is recognized, the output image is corrected for each pixel of the illegal copy prevention pattern to adjust the size of the illegal copy prevention isolated pattern. The recognition rate can be increased.

2) When performing pattern recognition using a reference image matrix formed using a line memory, it is possible to arbitrarily set an external dot pattern that is recognized as an isolated dot pattern for preventing unauthorized copying, and the input image is binary. However, since it is possible to cope with multi-values, it is possible to cope with changes in the isolated dot pattern superimposed on the image when the illegal copy prevention function is selected.

3) When performing pattern recognition using a reference image matrix formed using a line memory, it is possible to arbitrarily set a dot pattern that is recognized as an isolated dot pattern for preventing unauthorized copying from the outside. The value can also be handled, and the degree of pixel correction of the isolated dot pattern output can be adjusted from the outside accordingly, so it is possible to cope with the difference in dot shape that changes between machines and environments .

4) When performing pattern recognition with a reference image matrix formed using a line memory, it is possible to arbitrarily set a dot pattern that is recognized as an isolated dot pattern for preventing unauthorized copying, and in addition, an isolated dot pattern can be output. By controlling the size of the isolated dot pattern by controlling the light emission of the light emitting element of each pixel, it is possible to cope with the case of a multi-value system and a multi-value LPH.

5) When performing pattern recognition with a reference image matrix formed using a line memory, it is possible to arbitrarily set a dot pattern that is recognized as an isolated dot pattern for preventing unauthorized copying, and in addition, an isolated dot pattern can be output. When the image data is transferred to the issuing element array unit at a predetermined transfer speed x, each pixel is processed at a transfer speed mx that is m times X (m is a positive integer), and a large number of pixels are simulated in the sub-scanning direction. By controlling the size of the isolated dot pattern by writing in a digitized manner, it is possible to cope with the case where the image writing apparatus is a binary system and a binary LPH.

6) Since the correction method for preventing unauthorized copying can be selected by binary input or multi-value input, this correction function can be applied regardless of whether it is a binary system or a multi-value system. This correction function can be shared between different models.

1 is a block diagram illustrating a schematic configuration of an image forming apparatus according to an embodiment of the present invention. 1 is a diagram illustrating a mechanical configuration of an image forming apparatus according to an embodiment of the present invention. It is a block diagram which shows the flow of the image data of the writing part in FIG. It is a block diagram which shows the structure of a writing part. It is a figure which shows the relationship between a magnification and matrix size. It is a figure which shows the control structure of the read-write operation | movement of a line memory. 7 is a timing chart (part 1) showing details of the memory read / write timing of FIG. 6; 7 is a timing chart (part 2) showing details of the memory read / write timing of FIG. 6; It is a block diagram which shows the detail of an unauthorized copy prevention pattern correction | amendment part. It is a figure which shows the breakdown of the setting of a pattern matrix production | generation part register | resistor (hcopyset). 6 is a timing chart showing timing at the time of image matrix generation in an unauthorized copy prevention pattern correction unit. It is a figure which shows the example of the matching pattern of the pattern recognition performed in a pattern recognition and an output image generation part. It is explanatory drawing of the correction | amendment operation | movement of an unauthorized copy prevention pattern. It is a figure which shows the image of the correction pattern of illegal copy prevention in the case of 2 values. It is a figure which shows the image of the correction pattern of illegal copy prevention in the case of multivalue.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Reading part 200 Copying part 300 Image information memory | storage part 301 Image memory part 302 System control apparatus 400 Operation part 500 Writing part 501 Image conversion part 501-2 Memory control part 501-21 Line memory 501-22 Image matrix production | generation part 501-23 Line memory control unit 501-3 Unauthorized copy prevention pattern correction unit 501-31 Delay unit 501-32 Pattern matrix generation unit 501-33 Pattern recognition and output image generation unit 502 LED write control unit (circuit)
503-1, 2, 3 LPH
504 Drive control circuit

Claims (10)

In an optical writing device that superimposes an illegal copy prevention pattern on an output image and performs optical writing on a photoreceptor using a light emitting element array unit,
Storage means for accumulating the output image by n lines;
Matrix generating means for generating an n × n (n is an integer of 2 or more) image matrix for the image data read from the storage means;
The input image is recognized for each image matrix generated by the matrix generation means, and when the corresponding illegal copy prevention pattern is recognized, the output image is corrected for each pixel of the illegal copy prevention pattern to prevent unauthorized copy. Control means for controlling the size of the isolated dot pattern;
An optical writing device comprising:   The image processing apparatus further comprises setting means for arbitrarily setting a dot pattern to be recognized as an isolated dot pattern for preventing unauthorized copying when pattern recognition is performed using the image matrix generated by the matrix generation means. Item 5. The optical writing device according to Item 1.   3. The optical writing apparatus according to claim 1, wherein the input image is a binary or multi-valued image.   The optical writing apparatus according to claim 1, further comprising an external adjustment unit that adjusts the degree of correction of each pixel of the isolated dot pattern from the outside.   The optical writing apparatus according to claim 4, wherein the adjustment is performed by an output control unit that controls an output of a light emitting element corresponding to each pixel of the isolated dot pattern.   5. The optical writing apparatus according to claim 4, wherein the adjustment is performed by a transfer rate control unit that controls a transfer rate of image data to a light emitting element corresponding to each pixel of the isolated dot pattern. Output control means for controlling the output of light emitting elements corresponding to each pixel of the isolated dot pattern, transfer speed control means for controlling the transfer speed of image data to the light emitting elements corresponding to each pixel of the isolated dot pattern, and Comprising a selection means for selecting each control means;
5. The optical writing apparatus according to claim 4, wherein the selection unit selects the output control unit or the transfer rate control unit based on whether the input is a binary input or a multi-value input and performs the adjustment. .   An image forming apparatus comprising the optical writing device according to claim 1. In an optical writing method in which an illegal copy prevention pattern is superimposed on an output image, and optical writing is performed on a photoconductor using a light emitting element array unit.
A matrix generation step of generating a small image matrix from an input image using a line memory;
A pattern recognition process for recognizing an illegal copy prevention pattern by referring to the image matrix generated in the matrix generation process as needed;
When the illegal copy prevention pattern is recognized in the pattern recognition step, a control step of controlling the size of the entire isolated dot pattern for preventing illegal copy by controlling the light amount of the pixel in units of one pixel, and
An optical writing method, wherein an illegal copy prevention pattern is corrected in the control step. In an optical writing method in which an illegal copy prevention pattern is superimposed on an output image and optical writing is performed on a photoconductor using a light emitting element array unit.
An accumulation step of accumulating the output image in a storage unit by n lines;
A matrix generation step of reading out the output image data accumulated in the accumulation step from the storage means, and generating an n × n (n is an integer of 2 or more) image matrix for the read image data;
The input image is recognized for each image matrix generated in the matrix generation step, and when the corresponding illegal copy prevention pattern is recognized, the output image is corrected for each pixel of the illegal copy prevention pattern to prevent unauthorized copy. A control process for controlling the size of the isolated dot pattern;
With
An optical writing method, wherein an illegal copy prevention pattern is corrected in the control step.

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