JP2011183592A - Image processor, image processing method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processor capable of reusing used paper while keeping easiness in information specification and safety for information. <P>SOLUTION: The controller 100 of a multifunction machine 1 comprises: a new printing information generation part 101 functioning as a printable area designating means; an overwrite pattern decision part 102 for deciding a pattern to be used out of a plurality of accumulated patterns; a paper supply controller 103 functioning as a paper control means; an already printed surface determination part 104 for determining an already printed surface from individual sensor signals obtained from a first sensor 71 and a second sensor 72; a printing mode decision part 105 for deciding a printing mode according to determination of the already printed surface by the individual sensors; an overwrite printing information generation part 106 for generating data for overwrite printing; and a printing controller 107 functioning as a printing control means, a printing inhibition means and a transmissive paper printing inhibition means. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image processing apparatus capable of double-sided printing of paper, an image processing method, and a program for realizing the method.

Currently, many image processing devices such as copiers are equipped with a double-sided printing function as a standard feature in consideration of environmental issues, and the back of used paper that has been printed once to save paper. Opportunities to use are also increasing.
However, among the papers, there are special papers such as material papers. Even if this is not the case, a printed surface (printed surface) may be loaded into the paper feed stage by mistake with an unprinted surface, or paper with dirt or scratches may be mixed. In such a case, double-sided printing should not be performed, but if double-sided printing is performed without noticing, paper will be wasted.

  In order to solve this problem, various ideas have been made for the use of a backing paper or the like of paper having an image printing surface. For example, an image processing apparatus that checks the type and state of paper, detects used paper, and automatically discharges paper is known (see Patent Document 1).

  Also, there is an image processing apparatus that performs printing prohibition, discharge of printing paper, processing to replace the printed area of the printing target surface with a registered pattern when a printed area is detected in the printing target area of the paper to be printed. (See Patent Document 2).

  In addition, if the back paper is mixed or the reverse paper is mixed in the back paper, only the back paper or only the reverse paper is separated and printing is not performed on them. In some cases, an image processing apparatus is also known that reverses the reverse side of the paper and prints it on the white paper surface (see Patent Document 3).

  In the image processing apparatuses described in Patent Documents 1 to 3, when there is a printed area on the back paper, processing such as ejection and printing stop is performed as it is. Further, in the image processing apparatus described in Patent Document 2, if there is a printed area on the same surface as the printing surface, and the printed area and the print target area to be printed do not overlap, the printed area is displayed. In order to distinguish it from an unprinted area, replacement with a pattern is also performed.

In the image processing apparatuses described in Patent Documents 1 to 3, when the backing paper is used, it is possible to newly print on the front surface or an unprinted portion. By reducing printing mistakes when using the backing paper, etc. The paper saving effect can be realized.
However, when distributing materials using backing paper, there is a problem that it is not easy to know on which side the information of the material is printed. More importantly, if the printed surface is output as it is without being processed, the printed information can be easily identified, and there is a problem in terms of information security. For example, since a paper on which confidential information and important information are printed is mistakenly used as a backing paper, a situation occurs in which important information is distributed even to people who are not permitted to browse.

  In order to avoid this, it is conceivable to obfuscate the existing printed surface by uniformly overwriting it with black solid coating or the like. However, even if information is overwritten uniformly with the same pattern, it is possible to identify even the information of the target area once obfuscated by the method of applying light to the paper or seeing it through the light.

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to make it possible to reuse printed paper while ensuring the safety of information already printed in the image processing apparatus. is there.

The invention of the present application is an image processing apparatus capable of double-sided printing on a sheet, the preprinted surface specifying means for specifying the preprinted surface of the supplied paper, and the paper specified by the preprinted surface specifying means A printing unit that performs printing on a printable surface; and an obfuscation printing unit that performs printing of a plurality of overwrite patterns on an already printed surface of a sheet specified by the already printed surface specifying unit. An image processing apparatus.
Another invention of the present application is an image processing method capable of double-sided printing on paper, and is specified in an already-printed surface specifying step for specifying an already-printed surface of a supplied sheet, and the already-printed surface specifying step A printing process for performing new printing on the printable surface of the paper, an obfuscation printing process for printing a plurality of overwrite patterns on the existing print image of the already printed surface of the paper specified in the already printed surface specifying process, An image processing method characterized by comprising:
According to another invention of the present application, the computer prints on a printable surface specifying unit for specifying the preprinted surface of the supplied paper and the printable surface of the paper specified by the preprinted surface specifying unit. And an obfuscation printing control unit for printing a plurality of overwriting patterns on an existing print image on an already printed surface of a sheet specified by the already printed surface specifying unit. It is a program.

  According to the present invention, printed paper or the like can be reused while concealing important information printed on an existing image printing surface.

1 is a side view schematically showing an internal configuration of a multifunction machine that is an example of an image processing apparatus according to an embodiment. It is a pseudo program example showing what kind of processing is performed corresponding to four patterns generated by the combination of the first sensor and the second sensor. FIG. 2 is a functional block diagram illustrating an outline of a configuration of a multifunction machine. It is a figure which shows an example of an overwriting pattern. It is a figure which shows an example of the data (character) for overwriting printing. It is a figure which shows an example of the existing print image (character). It is an example which printed the data for overwriting printing on the existing print image. It is a figure which shows the example of an overwriting pattern (figure). It is a figure which shows the example of the data (graphics) for overwriting printing. It is a figure which shows the example of the existing print image (figure) on the already printed surface of paper. It is a figure which shows the example (graphic) which printed the data for overwrite printing on the existing print image.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a side view schematically showing an internal configuration of a multifunction machine as an example of the image processing apparatus according to the present embodiment.
As shown in FIG. 1, the multifunction device 1 has functions such as a facsimile function, a copy function, a printer function, and a scanner function, and a main body 2 and a stack disposed on the left side of the main body 2 in the drawing. A tray 3, a document reading unit 5 disposed on the upper portion of the main body unit 2, and a document feeding unit 6 disposed above the document reading unit 5 are provided.

  An operation unit 47 is provided at the front part of the multifunction machine 1. The operation unit 47 displays a start key 471 for a user to input a print execution instruction, a numeric keypad 472 for inputting the number of copies to be printed, operation guide information for various copying operations, and the like. A display unit 473 formed of a liquid crystal display or the like having a touch panel function, a reset key 474 for resetting setting contents set in the display unit 473, and a stop key 475 for stopping a printing (image forming) operation being executed. And a function switching key 477 for switching between a copy function, a printer function, a scanner function, and a facsimile function.

  The document reading unit 5 includes a scanner unit 51 including a CCD (Charge Coupled Device) sensor and an exposure lamp, a document table 52 formed of a transparent member such as glass, and a document reading slit 53. The scanner unit 51 is configured to be movable by a driving unit (not shown). When reading a document placed on the document table 52, the scanner unit 51 moves along the document surface at a position facing the document table 52, and scans the document image. The acquired image data is output to the control unit described later. When reading a document fed by the document feeding unit 6, the document moves to a position facing the document reading slit 53, and synchronizes with the document feeding operation by the document feeding unit 6 via the document reading slit 53. The image of the original is acquired and the image data is output to the control unit.

  The document feeding unit 6 includes a document placing unit 61 for placing a document, a document discharge unit 62 for discharging a document whose image has been read, and a document placed on the document placing unit 61. A document transport mechanism 63 including a paper feed roller (not shown), a transport roller (not shown) and the like for feeding the paper one by one to a position facing the document reading slit 53 and discharging it to the document discharge section 62 is provided. .

  The document conveying mechanism 63 further includes a sheet reversing mechanism (not shown) that reverses the document and reversely conveys the document to a position facing the document reading slit 53, and from the scanner unit 51 via the document reading slit 53, a double-sided image of the document. Can be read.

  The document feeding unit 6 is provided so as to be rotatable with respect to the main body unit 2 so that the front side thereof can move upward. By moving the front side of the document feeder 6 upward to open the upper surface of the document table 52, the operator can place a read document, for example, a book in a spread state, on the upper surface of the document table 52. It has become.

  The main body 2 is transported from a plurality of paper feed cassettes 461, a paper feed roller 462 that feeds recording paper (paper) P from the paper feed cassette 461 one by one and transports it to the recording unit 40, and a paper feed cassette 461. And a recording unit 40 for forming an image on the recording paper P.

  The recording unit 40 outputs an optical beam or the like based on the image data acquired by the scanner unit 51 to expose the photosensitive drum 43, and a developing unit 44 that forms a toner image on the photosensitive drum 43. A transfer unit 41 that transfers the toner image on the photosensitive drum 43 to the recording paper P, a fixing unit 45 that heats the recording paper P to which the toner image is transferred and fixes the toner image on the recording paper P, and a recording unit Transport rollers 463, 464, etc. that are provided in the paper transport path in 40 and transport the recording paper P to the stack tray 3 or the discharge tray 48.

  Further, when forming images on both sides of the recording paper P, the recording unit 40 forms an image on one side of the recording paper, and then nips (nips) the recording paper P with the conveying roller 463 on the discharge tray 48 side. It is assumed that In this state, the conveyance roller 463 is reversed to switch back the recording paper P, and the recording paper P is sent to the paper conveyance path L to be conveyed again to the upstream area of the recording unit 40. After the formation, the recording paper P is discharged to the stack tray 3 or the discharge tray 48.

The first sensor 71 and the second sensor 72 are arranged opposite to each other so as to sandwich the recording paper P as a pre-printed surface (surface on which an image is already printed) detection unit. The installation positions of the second sensors 71 and 72 are, for example, on the downstream side of the joining position of the sheet conveyance path from the sheet feeding cassette 461 and the sheet feeding stack 461 ′.
The processing of this embodiment is performed using the preprinted surface detection signals of the first sensor 71 and the second sensor 72.
That is, for example, when one of the first and second sensors 71 and 72 detects the preprinted surface, it operates in the back paper use mode, and when both sensors do not detect the preprinted surface, When both sensors detect the back paper, the operation is performed in the non-printable mode, and for example, the paper whose both surfaces are determined to be printed is discharged onto the stack tray 3.

FIG. 2 is a pseudo program example showing what processing is performed on the four patterns generated by the combination of the first sensor 71 and the second sensor 72.
As shown in FIG. 2, the paper determined as one of the following four types of printed surface determination patterns by the first sensor 71 and the second sensor 72 is processed in each operation mode.

(1) Operation mode when both sides are determined as preprinted surfaces Since both of the sheets are determined as preprinted surfaces, they cannot be newly printed. Therefore, the following two operation modes can be considered.
(I) In the first operation mode, the paper whose printed surface is determined on both sides is discharged as it is. Although the stack tray 3 or the discharge unit 48 is a discharge destination of the paper determined to be the printed surface on both sides, it is not possible to newly print to the stack tray 3 than to the discharge unit 48. It is easy to judge.
(Ii) As a second operation mode, a sheet that is determined to be an already printed surface on both sides is ejected by overwriting a pattern on an existing printed image on both sides. In this operation mode, since both sides are overwritten, it is easy to determine that new printing cannot be easily performed regardless of the discharge unit.

(2) Operation mode when both sides are not determined as already printed sides New printing is performed by the recording unit 40 as normal printing.

(3) Operation mode when the first sensor 71 side is determined as an already printed surface The developing unit 44 that forms a toner image on the photosensitive drum 43 in the sheet conveyance path in the recording unit 40, and the photosensitive drum 43, a transfer unit 41 that transfers the toner image on the recording paper P to the recording paper P, and a fixing unit 45 that heats the recording paper P to which the toner image has been transferred and fixes the toner image on the recording paper P. A new print operation is performed and then overwritten.
That is, the conveyance roller 463 is reversed and the recording paper P is switched back, whereby the opposite side of the paper is sent to the recording unit 40, and the already printed surface is reversed to the printing side. The existing print image on the inverted paper is obfuscated by overwriting some existing patterns. At this time, depending on the performance of the first sensor 71, it is possible to calculate and obtain an existing print image area in the already printed surface, and to overwrite only the existing print image area with the existing pattern.

(4) Operation mode when the second sensor 72 side is determined as the preprinted surface In this case, the print side surface of the recording unit 40 is a preprinted surface on which an image has already been printed. For this reason, the existing print image is overwritten on the existing print image by using the developing unit 44, the transfer unit 41, and the fixing unit 45 in the paper conveyance path in the recording unit 40, thereby making this existing print. Obfuscate the image. At this time, depending on the performance of the second sensor 72, it is possible to calculate an existing print image area in the already printed surface and overwrite only the existing print image area with the existing pattern.
Next, the conveyance roller 463 is reversed and the recording paper P is switched back to reverse the unprinted surface to the printing side. Next, the reversed paper is sent to the recording unit 40 to perform normal printing, that is, new printing operation.

  As the first sensor 71 and the second sensor 72, for example, a CIS (Contact Image Sensor) sensor or a CCD sensor can be used. The first sensor 71 and the second sensor 72 read each sheet from when the sheet is taken out from the paper feed cassette 461 to when printing is performed, and sequentially determine the printed surface. Since the direction of the preprinted surface of the paper (the direction of the preprinted surface) is dynamically changed, it is necessary to switch between pattern printing to be printed on the preprinted surface and normal printing according to the surface of the paper. By using these first and second sensors 71 and 72, even if the front and back sides are mixed, the printed surface and the unprinted surface on the opposite side are specified, and normal (new) printing is performed without error. be able to.

FIG. 3 is a functional block diagram illustrating an outline of the configuration of the multifunction machine 1.
As shown in FIG. 3, the multifunction device 1 is provided with a control unit 100 that controls the entire operation. The control unit 100 includes the scanner unit 51, the recording unit 40, a conveyance roller 46, a paper feed roller, and the like. 462, the operation part 47, the display part 473, the 1st sensor 71, the 2nd sensor 72, RAM80, and ROM90 are connected.

  The control unit 100 includes a new print information generation unit 101 as a printable area designating unit, an overwritten pattern determination unit 102, a paper feed control unit 103 as a paper control unit, a first sensor 71, and a second sensor. 72, a preprinted surface determination unit 104 that determines a preprinted surface from each sensor signal obtained from 72, a print mode determination unit 105 that determines a print mode from the preprinted surface determination of each sensor, and overprint printing And an overprint print information generation unit 106 for generating the data of the print data, and a print control unit 107 as a print control unit, a print prohibition unit, and a transparent paper print prohibition unit. Each of the units 101 to 107 is realized by, for example, reading a program stored in the ROM 90 into the control unit 100 and executing it.

The new print information generation unit 101 generates print information to be newly printed from the printer language. In the copy operation, the scanned image data is subjected to image processing according to instructions from the operation unit 47, for example, reduction / reduction. Enlargement processing or processing 2 pages into 1-page print data. The generated new print information is temporarily stored in the storage area of the RAM 80.
Here, the new print information generation unit 101, the overwritten pattern determination unit 102, the overwritten print information generation unit 106, and the print control unit 107 constitute an obfuscated printing unit of the present invention.
The obfuscation printing unit performs printing control of a plurality of print patterns held in a storage device such as the RAM 80 on the printed surface after specifying the printed surface of the paper on which the image is printed on one side. . As a printing method, a method of printing each pattern in several times may be used, or a plurality of patterns may be combined and the combined image printed on the printed surface of the paper.
In addition, although there are patterns such as characters and figures as a plurality of print patterns held in the storage device such as the RAM 80, they are separately held as a character pattern holding unit and a graphic pattern holding unit, respectively. When printing, the print control unit 107 calls the respective holding units to perform print processing.

FIG. 4 is a diagram showing an example of a pattern overwritten on an existing print image by the obfuscated printing unit.
The overwriting pattern determination unit 102 determines data to be overwritten on an existing print image on the already printed surface from the overwriting pattern as shown in FIG. 4, and selects several types of overwriting patterns. The pattern can be selected by selecting a pattern set registered in advance using, for example, a GUI (Graphical User Interface) of the operation unit 47 and the display unit 473. The selected overwrite pattern is temporarily stored in a storage area different from the new print information in the RAM 80.

  The paper feed control unit 103 sequentially feeds the recording paper P by a paper feed roller 462 installed at the exit of the paper feed cassette 461 or a paper feed roller 462 ′ installed at the exit of the paper feed stack 261 ′. The operation of the paper feed roller 462 is controlled.

  The preprinted surface determination unit 104 determines the preprinted surface from the individual sensor signals obtained from the first sensor 71 and the second sensor 72. The preprinted surface is individually determined from the information of the individual sensors. judge. Based on the first sensor 71 and the second sensor 72 that detect the printed surface of the paper, and the sensor signal (printed surface detection signal) detected by the first sensor 71 and the second sensor 72 The printed surface determination unit 104 that performs surface determination constitutes a printed surface specifying unit of the present invention.

  The print mode determination unit 105 determines the print mode from the already printed surface determination of the individual sensors 71 and 72. Four operation modes are determined by a combination of the printed surface determination patterns of the individual sensors, and the operation outline of each mode is as described in the example of the program shown in FIG.

<Example of applying characters to an overwritten pattern>
FIG. 5 is a diagram illustrating an example of data (characters) for overwriting printing.
The overwrite print information generation unit 106 generates data for overwrite print as shown in FIG. The generated overprint data is temporarily stored in a storage area of the RAM 80 where the new print information and the overwrite pattern are different. The overprint printing data is overwritten and printed on an existing print image by using the print control unit 107.

  The print control unit 107 controls printing process by the recording unit 40, conveyance of the recording paper P by the conveyance roller 43 and the like, reversal, and paper discharge. Note that the multifunction device 1 is connected to a personal computer (PC) or the like via an interface (not shown), and can transmit and receive data to and from these.

FIG. 6 is a diagram illustrating an example of an existing print image (character), and FIG. 7 is an example of printing data for overprint printing on an existing print image.
Specifically, when an existing print image as shown in FIG. 6 is present on the backing paper, the overprint printing data shown in FIG. 4 stored in the RAM 80 by the print control unit 107 for this existing print image. Is read and printed, and an output as shown in FIG. 7 can be obtained. This series of processing can obfuscate existing print images.

When the first sensor 71 and the second sensor 72 are simple preprinted surface determination sensors, for example, when a sensor device that determines a preprinted surface when a non-white area exists on the reading surface is used. 8 is used for overwriting the graphic pattern shown in FIG. 8 below, considering that the character pattern shown in FIG. 7 is used for overwriting and that the graphic printing is printed on the printed surface. And the character overwriting printing data generated by combining the character overwriting printing data shown in FIG. 7 may be used.
As a simple printed surface determination sensor, a sensor that irradiates light to the determination target surface and detects the reflection of the light, a non-contact type sensor that reads the image, or a non-white surface of the printed surface may be used. Alternatively, a contact-type sensor that obtains the contact thickness between the white paper and the non-white portion where toner is accumulated may be used.

<Example of figure applied to overwriting pattern>
Next, an example in which an overwriting pattern using figures is applied will be described. The application of the overwriting pattern to the graphic is the same as the overwriting pattern printing using the character, but the overwriting pattern to be applied is different from the character.

FIG. 8 is a diagram showing an example of an overwriting pattern (graphics), and FIG. 9 is a diagram showing an example of data (graphics) for overwriting printing.
Similar to the example of the overprint pattern printing process using the above characters, the overwrite pattern determination unit 102 converts the overprint pattern shown in FIG. 8 into an existing print image on the already printed surface in the case of a graphic pattern. Data to be overprinted is determined, and several overwriting patterns are selected. These patterns can be selected by, for example, selecting a pattern set registered in advance using the GUI of the operation unit 47 and the display unit 473 or the like. The selected overwriting pattern is temporarily stored in a storage area different from the new print information in the RAM 80.

  The overwrite print information generation unit 106 generates overwrite print data as shown in FIG. The generated overprint printing data is temporarily stored in a storage area different from the new print information in the RAM 80 and the overwritten pattern selected by the overwritten pattern determining unit 102. The overprint printing data (FIG. 9) is overwritten on the existing print image by the print control unit 107.

FIG. 10 is a diagram showing an example of an existing print image (graphics) on the already printed surface of the paper, and FIG. 11 is an example in which the data for overprint printing of FIG. 9 is printed on the existing print image of FIG. FIG.
For example, when there is an existing print image as shown in FIG. 10 on the already printed surface of the paper, the print control unit 107 overlays the existing print image as shown in FIG. By reading out and printing the writing print data, an output as shown in FIG. 11 can be acquired. Through a series of these processes, it is possible to obfuscate existing print images.

  In the present embodiment, description has been made by taking characters and figures as an example of the pattern to be overwritten on the existing print image on the preprinted surface of the paper, but more specifically, (1) specifying the preprinted surface (2) one or more character patterns that combine documents, words, and numerical values, and (3) one or more character patterns that frequently appear during printing on the printed surface of the sheet specified by the means. It is possible to use a graphic pattern that uses one or more graphics that frequently appear during printing of the printed surface of the sheet specified by the printed surface specifying means.

Here, in the case of using a pattern of characters or graphics having a high appearance frequency, a character registration unit and a graphic registration unit for registering those characters and graphics are required. The character registration unit and the graphic registration unit may use, for example, a method of interactively setting characters and graphic patterns using a display device provided in the multifunction device 1, or print characters and graphic patterns to be registered in advance. A method of scanning the paper including the printed characters and graphic patterns using a scanner, reading the paper as electronic data, and holding the scanned characters and graphic patterns in the character and graphic pattern holding unit such as the RAM 80 described above. It may be used. In this case, the multifunction device 1 needs a reading unit using a scanner.
Further, when the character pattern group is interactively changed by mode setting or the like, a mode setting unit for selecting a mode is required.

  In addition, when using one or more character patterns that combine documents, words, and numerical values, it is possible to change numerical values randomly or change characters each time each pattern is printed. The multi-function device 1 requires a random number generator that randomly selects a pattern.

  A plurality of patterns such as characters and figures used in the obfuscation printing means are accumulated in a storage device such as the RAM 80 as a pattern printed in the past, and these accumulated image patterns are used as composite patterns. It is possible to print on the preprinted surface of the paper. In this case, it can be configured by adding a print data holding unit for holding rasterized data as a printing target. At this time, it is conceivable to hold data obtained by mixing a plurality of print data. However, when mixing the data, for example, a mix data generation unit that performs an operation using a logical expression such as an exclusive OR is necessary.

Further, in the present embodiment, both the first sensor 71 and the second sensor 72 are used for the printed surface determination, but either one may be used for cost reduction. When only one of the first sensor 71 and the second sensor 72 is mounted, use of the backing paper is set in the paper feed cassette 461 or the display unit 473, and one of the sensors must detect the printed surface. For example, the back side that is not detected by the sensor is the already printed side with the existing print image.
Further, both the first sensor 71 and the second sensor 72 may not be used for the printed surface determination unit. A designating means for designating the direction of the printed surface, for example, a switch provided in the paper feed cassette 461 or the like is used to specify the printed surface of the paper. In this case, it is necessary to match the direction of the printed surface of all the sheets (here, the “direction of the printed surface” means the direction in which the printed surface of the sheet faces) and store it in the paper feed cassette 461. . Here, the printed surface determination unit 104 that performs the printed surface determination based on the designation unit and the designation signal of the designation unit constitutes a printed surface specifying unit of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... MFP, 2 ... Main-body part, 3 ... Stack tray, 5 ... Document reading part, 6 ... Document feeding part, 40 ... Recording part, 46, 463, 464・ ・ ・ Conveyance roller, etc. 47 ・ ・ ・ Operating part 51 ・ ・ ・ Scanner part 71 ・ ・ ・ First sensor 72 ・ ・ ・ Second sensor 80 ... RAM 90 ... ROM , 100 ... Control unit, 101 ... New print information generation unit, 102 ... Overwrite pattern determination unit, 103 ... Paper feed control unit, 104 ... Preprinted surface determination unit, 105 Print mode determination unit, 106... Overprint print information generation unit, 107... Print control unit, 462.

JP 2004-279760 A JP 2003-112439 A JP-A-9-213991

Claims (19)

An image processing apparatus capable of duplex printing on paper,
A preprinted surface specifying means for specifying the preprinted surface of the supplied paper;
Printing means for performing printing on the printable surface of the paper specified by the printed surface specifying means;
An image processing apparatus comprising: an obfuscated printing unit that prints a plurality of overwrite patterns on an already printed surface of a sheet specified by the already printed surface specifying unit. The image processing apparatus according to claim 1,
The obfuscation printing unit prints a plurality of character patterns or a plurality of graphic patterns on an existing print image of a preprinted surface of a sheet specified by the preprinted surface specifying unit so as to overlap each other. Image processing device. The image processing apparatus according to claim 2,
2. The image processing apparatus according to claim 1, wherein the plurality of character patterns use a plurality of characters and sentences that frequently appear in a printed matter on a printed surface of a sheet specified by the printed surface specifying means. In the image processing device according to claim 2 or 3,
The image processing apparatus, wherein the plurality of character patterns are one or more character patterns obtained by combining documents, words, and numerical values. The image processing apparatus according to any one of claims 2 to 4,
The image processing apparatus, wherein the plurality of graphic patterns are graphic patterns using one or more graphics that frequently appear during printing of the printed surface of the sheet specified by the printed surface specifying means. . The image processing apparatus according to any one of claims 1 to 5,
Having image storage means for storing images printed in the past as patterns;
The plurality of print patterns that the obfuscated printing unit prints so as to overlap the existing print image on the already printed surface of the paper is a composite pattern of the plurality of image patterns accumulated by the image accumulation unit. Image processing device. The image processing apparatus according to any one of claims 1 to 6,
The obfuscation printing unit prints a dot pattern on an already printed surface of the paper. The image processing apparatus according to claim 1,
The preprinted surface specifying means includes designating means for storing preprinted surfaces of all sheets in a paper cartridge in the same direction and designating the direction of the preprinted surface by a preprinted surface direction setting unit. Image processing device. The image processing apparatus according to claim 1,
The image processing apparatus according to claim 1, wherein the already-printed surface specifying unit includes a sensor that sequentially determines an existing print image on the sheet with a sensor before image printing is performed. An image processing method capable of duplex printing on paper,
A preprinted surface identifying step for identifying the preprinted surface of the supplied paper;
A printing process for performing new printing on the printable surface of the paper specified in the printed surface specifying process;
An image processing method comprising: an obfuscated printing step of printing a plurality of overwriting patterns on an existing printed image of an already printed surface of a sheet specified in the already printed surface specifying step. The image processing method according to claim 10,
In the obfuscation printing step, a plurality of character patterns or a plurality of graphic patterns are printed so as to overlap each other on an existing print image of a preprinted surface of a sheet specified by the preprinted surface specifying step. Image processing method. The image processing method according to claim 11,
The image processing method according to claim 1, wherein the plurality of character patterns use a plurality of characters and sentences that frequently appear in a printed matter on a printed surface of a sheet specified by the printed surface specifying step. The image processing method according to claim 11 or 12,
The image processing method, wherein the plurality of character patterns are one or more character patterns obtained by combining documents, words, and numerical values. The image processing method according to any one of claims 11 to 13,
The plurality of graphic patterns are graphic patterns using one or more graphics that frequently appear in a printed matter on the printed surface of the paper specified by the printed surface specifying step. . 15. The image processing method according to claim 10, wherein:
Having an image storage step of storing images printed in the past as patterns;
The plurality of overlapping print patterns to be printed on the existing print image on the preprinted surface of the paper specified in the preprinted surface specifying step is a composite pattern of the plurality of image patterns accumulated in the image accumulation step. An image processing method. The image processing method according to any one of claims 10 to 15,
An image processing method comprising: printing a plurality of print patterns overlapping each other on a print surface of a printed surface of a sheet specified by the already-printed surface specifying step, and further printing a dot pattern. The image processing method according to any one of claims 10 to 16,
In the image processing method, the preprinted surface specifying step stores the preprinted surfaces of all sheets in a paper cartridge in the same direction, and designates the direction of the preprinted surface by a preprinted surface direction designating unit. The image processing method according to any one of claims 10 to 16,
In the image processing method, the preprinted surface specifying step sequentially determines the preprinted surface of the paper with a sensor before performing image printing. A printed surface identifying means for identifying a printed surface of the supplied paper;
Print control means for performing printing on the printable surface of the paper specified by the printed surface specifying means; and
Obfuscated printing control means for printing a plurality of overwrite patterns on the existing print image of the already printed face of the paper specified by the already printed face specifying means;
Program to function as.

Images