JP5058094B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus such as an MFP (Multi Function Printer).

  In order to save resources and reduce costs, an increasing number of users use the non-printing side, which is the back side of paper that has already been printed on only one side, for image formation (so-called “back paper printing” or “back paper printing”). . In general, there are many prints on only one side, and most of them are discarded without being permanently stored. By performing such backing paper printing, it is possible to save a considerable amount of paper consumption.

  On the other hand, incidents of leakage of confidential information such as personal information occur frequently, and security awareness is increasing. The leakage of confidential information is performed in the form of electronic data, and there are many cases that result from the leakage of the paper itself on which confidential information (confidential documents) is printed.

  In such a situation, the problem in the case of performing the above-described backing paper printing is the leakage of confidential information already printed on the back side, not the information on the newly printed surface. When printing on paper, there are few users who check the information already printed on the back side, and if the newly printed information is not particularly sensitive, it may be discarded without being shredded. Because there are many. As a result, there is a fear that confidential documents may be leaked unintentionally.

  From such a background, a technique has been proposed in which a confidential area is filled when a document already printed on the back side is a confidential document at the time of backing paper printing (see, for example, Patent Document 1).

FIG. 1 is a diagram showing a print example of a confidential document surface in the conventional confidential document backing paper printing. (A) is an example in which partial filling is performed. When a predetermined net-like pattern NE is added to the character string CR of the imaged paper PP, the black solid pattern image BL is printed on top of it. By doing so, confidential information is filled. (B) is an example in which the entire page is filled, and when the imaged paper PP is marked with the “confidential” code CD, the black solid pattern image BLH is printed over the entire page. The secret information is filled in.
JP 2001-228751 A

  With the above-described conventional technology, it is possible to prevent leakage of confidential information by painting the confidential area on the back side of the paper when printing on the back paper, but it is possible to fill a solid pattern even where it is not necessary for security protection. Therefore, there is a problem that toner is consumed wastefully. In other words, even if it is a confidential document, it is necessary to cover the entire surface with a solid pattern for a space between characters or a character that is separated even by a single character (for example, characters such as “I” and “tsu”). This is because a large amount of toner is consumed if the solid pattern is crushed to those portions.

  The present invention has been proposed in view of the above-described conventional problems, and an object of the present invention is to provide an image forming apparatus capable of suppressing the consumption of toner more than before while preventing leakage of confidential documents. It is to provide.

In order to solve the above problems, in the present invention, at the time of printing a document, an overprinting image creation / acquisition means for creating an overprinting image based on an image to be printed or obtaining from a print request source, and And an overprinting image recording means for recording the created or acquired overprinting image in association with the paper to be printed , wherein the overprinting image shifts the image to be printed in a predetermined direction. The gist of the image forming apparatus created by this is as follows. The present invention can also be configured as an image formation control method or an image formation control program.

  In the image forming apparatus of the present invention, when a document is printed, an image for overprinting based on the image to be printed is created or acquired from a print request source, and the image for overprinting corresponds to the paper to be printed. Keep a record. Then, at the time of backing paper printing, an overprinting image recorded in association with the paper to be printed is acquired, and the overprinting image is printed over the already printed surface of the paper. As a result, unlike the conventional solid pattern, the overprint image can be made fully illegible according to the content of the confidential document even though it contains non-printed parts, preventing the leakage of confidential documents. However, the amount of toner consumption can be suppressed as compared with the conventional case.

  Hereinafter, preferred embodiments of the present invention will be described.

<Overview of overprinting on confidential documents>
FIG. 2 is a diagram showing a print example of the confidential document surface in the confidential document backing paper printing according to the embodiment of the present invention.

  In this embodiment, as shown in FIG. 2A, when a confidential document is newly printed, a document image for overprinting based on the document image of the confidential document is printed separately from the normal printing of the confidential document. The QR code 303 as a symbol image including information is printed at the four central positions of the upper, lower, left and right edges of the sheet. As a method of creating a document image for overprinting included in the QR code 303, when the image is roughened by lowering the resolution of the content to be printed on the paper surface, the content to be printed on the paper surface is subjected to expansion processing (for the pixel to be printed). There are cases where the processing for printing all eight surrounding pixels is performed a predetermined number of times, or the resolution reduction and expansion processing are performed together. Image data of QR code 303 is generated by converting the created document image for overprinting into a QR code pattern. Since the data amount of the overprint document image is generally large, it is desirable to perform compression using a predetermined compression algorithm. In addition, the QR code 303 includes data indicating the position information of the top, bottom, left, and right of the four locations on the sheet. Data indicating position information in the upper, lower, left and right directions may be additionally printed with a mark or the like instead of being included in the QR code 303 as information. As will be described later, the data indicating the position information is used to match the orientation of the overlapped document image with the orientation of the paper.

  Then, when the paper is used as the back paper next time, the QR code 303 on the surface on which the confidential information is printed is read, and the information included in the QR code 303 is read to obtain a document image for overprinting. As shown in (b), the overprint document image is printed over the surface on which the confidential information is printed. Thereafter, the sheet is reversed by the duplex unit in the apparatus, and normal printing is performed on the non-printing surface. Ordinary printing on the non-printing surface of the paper may be performed first, and the paper image may be reversed to print the document image for overprinting. Furthermore, only the printing on the already printed surface of the document image for overprinting may be performed, and normal printing on the back surface may be performed separately.

  FIG. 3 is a diagram showing another example of a document image for overprinting, in which a document image for overprinting is created by shifting the document image of a confidential document in a predetermined direction. This method may be used alone, or may be used in combination with either or both of the resolution reduction and expansion processing described above. FIG. 3A shows a character part “A” which is a part of the document image of the confidential document. As shown in (b), an image shifted by one pixel in the right direction and the downward direction is used as a document image for overprinting. Then, by superimposing and printing the document image for overlap printing (b) on the document image (a), the original character “A” can be made indistinguishable as shown in (c).

  The coarseness of resolution, the number of expansion processes, or the setting and setting of the degree of image shift are adjusted according to the security level, etc., so that the document image for overprinting conforms to the image of the confidential document being printed, Crush the original image to make it invisible. By doing so, it is possible to prevent secret leakage while suppressing wasteful consumption of toner. In the present invention, not only characters but also images such as photographs and graphs can be made invisible by overprinting a document image for overprinting.

  FIG. 4 is a diagram showing an example of the relationship between the toner consumption by the resolution and the security in the overprinting.

  (A) shows an example of a printed character string, and a broken-line frame is shown for convenience in evaluating toner consumption.

  (B) shows a case where all areas with character strings are crushed with a solid pattern as in the prior art. In this case, the amount of toner consumed in the broken line frame is set to 100%.

  On the other hand, the present invention is applied to (c) to (g).

  (C) is an example in which characters are crushed at the highest resolution. This image has a toner consumption of 73% compared to the prior art, and it is difficult to identify the written contents.

  (D) is an example in which characters are crushed at the next highest resolution. This image has a toner consumption of 59% compared to the prior art, and it is difficult to identify the written contents.

  (E) is an example in which characters are crushed at the next highest resolution. This image has a toner consumption of 54% compared to the prior art, and it is difficult to identify the written content, but the atmosphere is at a level that can be transmitted.

  (F) is an example in which characters are crushed at the next highest resolution. This image has a toner consumption of 36% compared to the prior art, and the written contents can be identified.

  (G) is an example of squashing characters with the smallest resolution. This image has a toner consumption of 32% compared to the prior art, and the written contents can be identified.

  As can be seen from these, as the resolution increases (coarse), the toner consumption increases, but the security increases. FIG. 4 shows an example of the relationship between the toner consumption by the resolution and the security. However, when the expansion process is performed a predetermined number of times alone, when the image shift is performed alone, or when these are performed in combination, etc. The relationship between toner consumption and security varies depending on how the document image for printing is created. Therefore, by setting the processing method according to the security level required for the confidential document, it is possible to arbitrarily determine the optimum toner usage amount while preventing leakage of the confidential document. That is, it is not only important to reduce the toner consumption uniformly, but it is also important to balance security and the user's intention.

  The image already formed on the paper is not particularly limited and may be any image. For example, from the viewpoint of confidentiality, customer information, employee information, contract related information, tax related information, Examples include confidential information such as R & D related information, confidential information such as confidential information, or images that include confidential information.

  The image forming apparatus only needs to be able to form a document image for overprinting. For example, in addition to an apparatus capable of forming an arbitrary image such as a copying machine, a printer, and a fax machine, a predetermined function is added to the image forming apparatus. It may be a dedicated device for forming on printed paper.

  Further, the reason why the QR code 303 is printed at the four central positions at the top, bottom, left and right edges of the sheet as shown in FIG. 2A is to reduce the number of QR code readers for reading the QR code 303. The cost can be reduced. That is, by setting the QR code 303 at the four central positions at the top, bottom, left, and right ends, the QR code 303 can be detected if the QR code reader is located at one central position regardless of the orientation and size of the paper, thereby reducing costs. . Note that the position of the QR code 303 is not limited to the four central positions of the sheet, but may be changed according to the application, and the QR code 303 may be arranged on the sheet at any number of positions. Therefore, when there is no limitation on the arrangement and number of QR code readers and the paper orientation can be detected by other methods, one QR code 303 can be used, and the QR code 303 includes position information. There is no need to let them. For example, the direction of the paper can be detected from the relative position on the paper from which the QR code 303 is detected by arranging the QR code 303 at a position where the paper is biased. Further, the direction of the paper can be detected by reading the printing surface of the paper and performing character recognition.

  In addition to the QR code 303, the symbol image printed on the paper may be a bar code, magnetic information carried on a magnetic tape affixed to a predetermined position on the printed paper, or the like. When a magnetic tape is used, a magnetic sensor or the like is used as the reading unit. Further, it is possible to record a document image for overprinting on an RFID tag that is affixed to a sheet or embedded in the sheet. The RFID tag is a small IC chip provided with a data recording function and a wireless communication function, and can write and read data.

  FIG. 5 is a diagram illustrating an example in which an RFID tag is used for recording on a sheet. FIG. 5A illustrates a state in which an RFID tag 303 ′ is attached to four central positions of upper, lower, left, and right ends of the sheet. ) Shows a state in which the RFID tag 303 'is embedded at the four central positions of the upper, lower, left and right edges of the paper. Similar to the QR code 303 described above, the number of RFID tags 303 'is not limited. Note that when the RFID tag 303 ′ is used, it is necessary to separately detect the front and back sides of the paper because the reading can be performed regardless of the front and back sides of the paper when printing on the back side. For example, it is possible to detect whether or not the print surface is obtained by roughly reading an image on the surface of the paper.

  Further, the case where the document image for overprinting is recorded on the QR code 303 or the RFID tag 303 ′ has been described. In short, the document image for overprinting may be recorded in association with the paper to be printed. Thus, the document image for overprinting may be recorded in another location. FIG. 6 is a diagram showing an example in which a document image for overprinting is held in the image forming apparatus. A sheet ID for identifying a sheet is recorded on the QR code 303 or the RFID tag 303 ′ on the sheet, and the sheet ID corresponds to this sheet ID. Thus, the document image for overprinting is recorded in the storage device in the image forming apparatus 100.

  Further, as information to be put on the paper surface as a symbol image, it is conceivable to put an expiration date in addition to putting data of a document image for overprinting. Confidential information, such as publicly-documented documents, is often unclassified after a certain period of time, so such information has an expiration date, and when it expires, it prints over the document image for overprinting. Therefore, printing can be performed as a normal backing paper, and wasteful consumption of toner can be suppressed.

  Further, instead of placing the overprint document image on the symbol image such as the QR code 303, the overprint document image may be generated by reading the image of the printed paper at the time of printing on the back paper. In this case, an image reader installed in a copier or FAX can be used. In other words, once the information on the printed paper is read, a document image for overprinting is formed only in a high-density part, and the operator inserts the printed paper again so that the document image for overprinting is superimposed on that part. Can be printed.

<Device configuration>
FIG. 7 is a functional block diagram showing a configuration example of the image forming apparatus according to the embodiment of the present invention.

  In FIG. 7, the control system of the image forming apparatus 100 having the function of a digital copying machine includes a controller control system 120 that accepts designation of an image forming operation and sets the image forming operation, and an engine that controls driving of each unit 150 of the printer engine. The control system 130 is divided. Specifically, the controller control system 120 is responsible for image formation, user interface, mode setting, control of applications such as copying and printers, and the like.

  The controller control system 120 mainly includes an image forming unit 121 composed of an ASIC (Application Specific Integrated Circuit) that performs image forming processing, a CPU (Central Processing Unit) 122 that performs various processing operations, and a control program in a fixed manner. From a stored ROM (Read Only Memory) 123, a RAM (Random Access Memory) 124 that temporarily stores various information, a non-volatile storage device 125 that stores setting information of operating conditions of the digital copying machine, and an external communication device 9 A transmission / reception interface 126 that transmits and receives information via a network 8 such as a LAN (Local Area Network), an operation panel 110 and an I / O (Input / Output) interface 127 that provides an interface such as serial communication, and an engine control system 130 It consists of an external interface 128 etc. that performs communication, and these are low It is connected by Le communication bus.

  The controller control system 120 receives designation of an image forming operation from the operation panel 110 or the external communication device 9, sets the image forming operation, and transmits the set image forming operation to the engine control system 130.

  The engine control system 130 includes a CPU 131 that mainly performs various processing operations, a ROM 132 that permanently stores a control program, a RAM 133 that temporarily stores various information, an external interface 134 that communicates with the controller control system 120, An I / O interface 135 that reads information from each part 150 of the printer engine, and a non-volatile storage device 136 that stores minimum setting information related to operating conditions necessary for starting the preparation operation of the printer engine after the power is turned on. Etc., which are connected by a local communication bus.

  Image information created by the image forming unit 121 of the controller control system 120 is sent from the external interface 128 of the controller control system 120 to the external interface 134 of the engine control system 130, and is sent from the engine control system 130 to the write control unit 140. Image is printed.

  Each unit 150 of the printer engine includes various motors 151, a clutch 152, a solenoid 153, a fixing heat source 154, various sensors 155, a duplex unit 156, and the like.

  FIG. 8 is a diagram illustrating a configuration example of the sheet conveyance path of the image forming apparatus.

  In FIG. 8, the image forming apparatus 100 can perform double-sided printing on a sheet. As a characteristic configuration, the image forming apparatus 100 is supplied from a confidential tray 301 and a confidential tray 301 that can store confidential documents. A QR code reader 302 that detects the QR code 303 of the sheet, a secret tray lock 304 that locks the secret tray 301, and a duplex unit 306 that reverses the sheet are provided. Note that the present invention can be applied by manually replacing paper even if double-sided printing is not possible in the course of a series of operations due to paper reversal by the duplex unit 306. In addition to the backing paper printing, the double-sided printing function is not necessary when only the confidential information erasing process is performed by simply performing the overprinting on the paper on which the confidential information is printed.

  In FIG. 8, when a confidential document is newly printed, the sheet is conveyed from the sheet feeding tray 300 via the sheet feeding roller 201 by the main body relay roller 202, passes through the registration roller 203, and then transferred by the transfer roller 204. The confidential document and the QR code 303 including the overprint document image created by the image forming unit 121 (FIG. 7) are printed, fixed by the fixing roller 205, and discharged from the discharge tray via the discharge roller 207. The paper is discharged to 307.

  Subsequently, when the confidential document printed as described above is used as a backing paper, the paper on which the confidential document is printed is placed in the confidential tray 301 and locked by the confidential tray lock 304. As a result, the user can safely store the paper in the confidential tray 301 without putting the confidential document on the shredder. In addition to the problem that the shredder takes up space and is expensive, it is difficult to deink (process that separates the toner from the paper) in the recycling process for the paper on which the shredder is applied. Therefore, these problems can be solved.

  When the confidential document is printed as the backing paper, the QR code 303 printed on the paper in the confidential tray 301 is detected by the QR code reader 302, and the overprint document image included in the QR code 303 is converted to the controller control system. 120 is reproduced. The overprint document image is sent to the engine control system 130 via the external interface 128, sent from the engine control system 130 to the write control unit 140, and the overprint document image is printed over the paper by the transfer roller 204. The

  Thereafter, the sheet is conveyed to the duplex unit 306 by the fixing sheet discharge roller 206, and the sheet is nipped by the refeed roller 211. In this state, the re-feed roller 211 is reversed to switch back the sheet, and the sheet is transferred through the lateral transport roller (drive) 212, the lateral transport roller (middle) 213, and the lateral transport roller (right) 214 in order. Then, the sheet is conveyed again to the upstream area of the transfer roller 204, and after the image is printed on the other surface by the transfer roller 204, the sheet is conveyed to the sheet discharge roller 207 and is conveyed to the sheet discharge tray 307.

  Here, the reason why the QR code reader 302 is arranged in the confidential tray 301 is to transmit data to the controller control system 120 before the conveyance starts in order to shorten the time for reading the QR code 303 when printing. It is. Therefore, if it is not necessary to consider the reading time, the QR code reader 302 may be arranged at another location. For example, when the QR code reader 302 is placed immediately before the registration roller 203, the time for reading the QR code 303 on the paper is increased, but a confidential document is put in a tray other than the confidential tray 301. In addition, it is possible to recognize that the document is a confidential document and perform appropriate processing. Further, if the QR code reader 302 is arranged on both sides (up and down direction in the figure) with the sheet just before the registration roller 203 in between, the confidential document is a confidential document even if it is put in the confidential tray 301 by mistake. I can recognize that. In this case, the document to be printed first is printed by the transfer roller 204 and then reversed by the duplex unit 306, the overprint document image is printed over the confidential document by the transfer roller 204, and the discharge tray is discharged by the discharge roller 207. Transport to 307.

  Further, in the present embodiment, the case where the document image for overprinting is printed on the print surface which is a confidential document first is exemplified. However, as described above, the document to be printed first is printed on both sides. The image may be reversed by the unit 306, and the document image for overprinting may be printed over the confidential document and discharged. In this case, if the backing paper is not a confidential document, the reversal by the duplex unit 306 and subsequent processing are not performed.

  The secret tray lock 304 attached to the secret tray 301 may be a physical key, but may also be a password type key using an electronic key or the like, or a key based on fingerprint authentication.

  In addition, by separating the discharge destination of the paper discharged to the paper discharge tray 307 between the confidential document and the non-confidential document, the user can visually check whether the confidential information is really crushed. You may be able to.

<Print processing operation>
FIG. 9 is a flowchart showing an example of processing when a confidential document is printed.

  In FIG. 9, when the confidential document printing process is started in step S101, the communication device 9 on the user side performs printing on the dialog box of the printer driver displayed by specifying the document to be printed and instructing printing. For each document, specify “is it a confidential document?”, “What is the security level if it is a confidential document”, and the like. Thus, in step S102, the image forming apparatus 100 receives image information including various designations from the communication device 9 via the network 8 via the transmission / reception interface 126 of the controller control system 120. At this time, the designation of the confidential document or the security level may be automatically set on the image forming apparatus 100 side instead of being designated by the user. In this case, the controller control system 120 of the image forming apparatus 100 stores the correspondence between the document type (confidential report, customer information, etc.), the confidential document, and the security level in the ROM 123 or the like, and based on the received image information. Whether it is a confidential document and if it is a confidential document, the security level is determined and set. An example of setting the security level will be described later.

  In addition, it is possible to specify all or part of the confidential area of the document to be printed. If the confidential document is printed only on a part of the paper, such as the personal name, the user can specify the range. It can be specified by dragging with etc. Furthermore, the controller control system 120 may re-detect only a portion where there is printing within the range, so that overlapping printing is applied only to that portion, so that the amount of toner used can be suppressed.

  Subsequently, in step S103, the image forming unit 121 of the controller control system 120 renders the received image information so as to be a document that the user wants to print, and creates a document image. Rendering refers to imaging information related to print contents given as numerical data by calculation.

  In step S104, the CPU 122 of the controller control system 120 determines whether the document to be printed is a confidential document from the image information. This is determined according to the designation by the user that the document is a confidential document or the type of document. If the object to be printed is not a confidential document, the document image is printed on the sheet by the transfer roller 204 in step S112 and conveyed to the sheet discharge tray 307 by the sheet discharge roller 207. In step S113, the printing process is terminated.

  If the CPU 122 of the controller control system 120 determines that the document to be printed is a confidential document, the CPU 122 detects the security level in step S105. This determination is made based on the contents automatically set on the controller control system 120 side according to the security level designation by the user or the document type. Subsequently, in accordance with the detected security level, the CPU 122 determines the resolution and the number of expansion processes for roughening the pixels in step S106.

  FIG. 10 is a flowchart showing a processing example of security level detection and resolution / expansion processing determination corresponding to steps S105 and S106 of FIG. In FIG. 10, when processing is started in step S121, the security level is initialized to "0" in step S122, and addition is performed according to the title of the print requester in step S123. For example, “1” is not added for “general”, “1” is added for “manager”, and “2” is added for “officer”. The title of the print requester is acquired by referring to the user database or the like from the ID of the print requester.

  Subsequently, in step S124, addition according to the document type is performed. For example, no addition is made for “general document”, “1” is added for “specification document”, “2” is added for “confidential document”, and “customer information document” is added. Add "2". The document type is acquired by referring to information added to the document or a document management database.

  Subsequently, in step S125, addition according to the user setting is performed. For example, no addition is performed for “no confidential information”, “1” is added for “confidential information”, and “2” is added for “confidential information”.

  Subsequently, details of the resolution reduction / expansion processing corresponding to the security level are acquired in step S126. For example, when the security level is “0”, there is no resolution reduction and no expansion processing (600 dpi, expansion processing: 0 times), and when the security level is “1”, there is no resolution reduction and expansion processing (600 dpi, expansion processing: 2). If the security level is “2”, the resolution is reduced and no expansion processing is performed (200 dpi, expansion processing: 0 times). If the security level is “3”, the resolution is decreased and expansion processing is performed (200 dpi, expansion processing). : When the security level is “4”, the resolution is reduced and no expansion processing is performed (100 dpi, expansion processing: 0 times). When the security level is “5”, the resolution is decreased and expansion processing is performed (100 dpi, When the security level is “6”, the resolution is lowered and the expansion process is performed (50 dpi, expansion process: 4 times). And a process is complete | finished by step S127.

  Subsequently, returning to FIG. 9, the image forming unit 121 converts the document image into the determined resolution in accordance with the determined resolution and the number of expansion processes, performs the expansion process for the determined number of expansion processes, Create a document image for overprinting. Here, the document image for overprinting may be created as a color image, but it can be said that a monochrome image is more suitable for the purpose of erasing by overprinting on already printed characters.

  Subsequently, in step S108, the image forming unit 121 compresses the document image for overprinting to create compressed data.

  Subsequently, in step S109, the image forming unit 121 places the position information of the upper, lower, left, and right on the compressed data, and renders the image to print the QR code 303 at the four central corners of the paper surface to create a symbol image.

  In step S110, the image forming unit 121 generates a composite image by combining the document image of the confidential document to be printed and the symbol image.

  In step S <b> 111, the composite image is printed on a sheet by the transfer roller 204 and conveyed to the sheet discharge tray 307 by the sheet discharge roller 207. In step S113, the printing process is terminated.

  In step S107 and step S108, resolution conversion, expansion processing, and compression processing are performed on the image forming apparatus 100 side. However, these processing is performed on the communication device 9 side that instructs printing, and data of the processing result is converted into image data. It may be transmitted to the forming apparatus 100, and the image forming apparatus 100 may receive this by the transmission / reception interface 126 of the controller control system 120, and may be connected to the rendering of the symbol image by the image forming unit 121 in step S 109. Alternatively, the communication device 9 instructing printing may perform all the processes up to the creation of the composite image, and the image forming apparatus 100 may simply print the received composite image.

  FIG. 11 is a flowchart showing another example of processing at the time of printing a confidential document, in which the communication device 9 side performs all processing up to creation of a composite image.

  In FIG. 11, when processing is started in step S131, the driver of the communication device 9 accepts setting of image information to be printed from the user in step S132.

  In step S133, the driver renders the image information so that the user wants to print a document and creates a document image.

  Subsequently, in step S134, the driver determines whether the document to be printed is a confidential document from the image information. This is determined according to the designation by the user that the document is a confidential document or the type of document. If the object to be printed is not a confidential document, the document image is transmitted to the image forming apparatus 100 in step S143. The image forming apparatus 100 prints on the paper by the transfer roller 204 in step S144, and the paper discharge roller 207 discharges the document image. Transport to paper tray 307. In step S145, the printing process is terminated.

  If it is determined that the document to be printed is a confidential document, the driver detects the security level in step S135. This is determined based on the contents automatically set on the driver side according to the security level designation by the user or the document type. Subsequently, according to the detected security level, in step S136, the driver determines the resolution and the number of expansion processes for coarsening the pixels.

  Subsequently, in step S137, the driver converts the document image into the determined resolution according to the determined resolution and the number of expansion processes, and performs the expansion process for the determined number of expansion processes to create a document image for overprinting. .

  Subsequently, in step S138, the driver compresses the document image for overprinting to create compressed data.

  Subsequently, in step S139, the driver places the positional information on the top, bottom, left, and right on the compressed data, and renders the image to print the QR code 303 at the four corners at the center of the paper surface to create a symbol image.

  Subsequently, in step S140, the driver combines the document image and the symbol image of the confidential document to be printed to create a combined image.

  In step S141, the composite image is transmitted to the image forming apparatus 100. In step S142, the composite image is printed on a sheet by the transfer roller 204, and is conveyed to the discharge tray 307 by the discharge roller 207. In step S145, the printing process is terminated.

  FIG. 12 is a flowchart showing an example of processing when printing on the back paper.

  In FIG. 12, when the back paper printing process is started in step S201, the image forming apparatus 100 is connected from the communication device 9 to the network in step S202 by specifying a document to be printed by the communication device 9 on the user side and instructing printing. 8, the image information is received by the transmission / reception interface 126 of the controller control system 120.

  In step S203, the image forming unit 121 of the controller control system 120 renders the received image information so as to be a document that the user wants to print, thereby creating a document image.

  In step S204, the CPU 122 of the controller control system 120 determines whether the QR code reader 302 has detected the QR code 303 on the paper. If the QR code 303 is not detected, the sheet is reversed by the duplex unit 306 in step S214, the document image is printed on the sheet by the transfer roller 204 in step S215, and conveyed to the sheet discharge tray 307 by the sheet discharge roller 207. To do. In step S216, the printing process is terminated.

  When the QR code 303 is detected, in step S205, the image forming unit 121 develops information embedded in the QR code 303 and creates (reproduces) a document image for overprinting.

  In step S206, the image forming unit 121 recognizes the position information of the QR code 303 from the information obtained by developing the QR code information.

  Subsequently, in step S207, the CPU 122 determines whether or not the position information of the QR code 303 indicates the right. If so, the overlapping print document image is rotated 90 degrees counterclockwise in step S208. If the QR code position information is not right, it is determined in step S209 whether or not the QR code 303 position information indicates below. If so, the overprint document image is counterclockwise in step S210. Rotate 180 degrees around. If the position information of the QR code 303 is not below, it is determined in step S211 whether the position information of the QR code 303 indicates the left, and if so, the document image for overprinting is reversed in step S212. Rotate 270 degrees clockwise. If the position information of the QR code 303 is not left, the overprint document image is not rotated.

  In step S 213, the overprint document image is printed by the transfer roller 204 so as to overlap the print surface of the paper on which the confidential document is printed. Subsequently, the sheet is reversed by the duplex unit 306 in step S214, and the document image to be printed is printed on the sheet by the transfer roller 204 in step S215, and conveyed to the sheet discharge tray 307 by the sheet discharge roller 207. In step S216, the printing process is terminated.

  FIG. 13 is a diagram showing the orientation of the paper and the state of rotation of the superimposed image, and more specifically shows the processing in steps S207 to S212 in FIG.

  In the above-described embodiment, when using a printed confidential document as a backing paper, the QR code 303 is detected regardless of the direction in which the paper is conveyed up, down, left, or right, and the overlapping is performed according to the location where the original image is printed. The document images for printing can be overlaid. By doing so, when the user sets a confidential document as a backing paper, the paper can be set without worrying about the orientation of the paper. FIG. 13 shows the method.

  First, when printing a confidential document, the QR code 303 is placed at the four upper, lower, left, and right central positions as shown in the broken line frame of “the direction of the paper in the confidential tray 301” shown in the lower part of FIG. It is arranged, and data showing the top, bottom, left and right is placed on each. In this way, if the QR code reader 302 is arranged at one central point, the QR code 303 can be detected regardless of the direction and size of the paper.

Subsequently, when the sheet is conveyed in the direction of the arrow in the figure and the images are overlapped by the transfer roller 204, the “printing surface” shown in the upper part of the broken line frame of “the image to be overlapped by the transfer roller 204” at the top of the drawing. If the original is superimposed in the direction of “the original image to be superimposed on”, the problem arises that the position where the images are superimposed does not match when the paper is turned upside down or set in the horizontal direction. Therefore, the data indicating the top, bottom, left, and right placed on the above-described QR code 303 is read by the QR code reader 302, and the data indicating the top, bottom, left, and right is detected by the image forming unit 121, and processing (rotation correction) is performed under the following conditions. Do.
• When the data indicates the upward direction, the “original image to be superimposed on the print surface” remains the same.
When the data indicates the downward direction, the “original image superimposed on the printing surface” is rotated 180 degrees counterclockwise.
When the data indicates the right direction, the “original image superimposed on the print surface” is rotated 90 degrees counterclockwise.
When the data indicates the left direction, the “original image superimposed on the printing surface” is rotated 270 degrees counterclockwise.

  After the above processing, the overprinted document image can be properly overlaid at the position where the confidential document is printed by printing the image as it is or rotated on the paper. it can.

<Summary>
The present invention has been described above by the preferred embodiments of the present invention. While the invention has been described with reference to specific embodiments, various modifications and changes may be made to the embodiments without departing from the broad spirit and scope of the invention as defined in the claims. Obviously you can. In other words, the present invention should not be construed as being limited by the details of the specific examples and the accompanying drawings.

It is a figure which shows the example of printing of the confidential document surface in the conventional confidential document backing paper printing. It is a figure which shows the example of printing of the confidential document surface in confidential document backing paper printing by embodiment of this invention. It is a figure which shows the other example of the document image for overlap printing. FIG. 6 is a diagram illustrating an example of a relationship between a toner consumption amount and security according to resolution in overprinting. It is a figure which shows the example which used the RFID tag for the recording on paper. FIG. 3 is a diagram illustrating an example in which a document image for overprinting is held in an image forming apparatus. 1 is a functional block diagram illustrating a configuration example of an image forming apparatus according to an embodiment of the present invention. 3 is a diagram illustrating a configuration example of a sheet conveyance path of the image forming apparatus. FIG. It is a flowchart which shows the process example at the time of confidential document printing. It is a flowchart which shows the process example of the detection of a security level, and the determination of the resolution / expansion process frequency. It is a flowchart which shows the other process example at the time of confidential document printing. It is a flowchart which shows the process example at the time of backing paper printing. FIG. 6 is a diagram illustrating a state of paper orientation and a state of rotation of an image to be overlaid.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Image forming apparatus 110 Operation panel 120 Controller control system 121 Image forming part 122 CPU
123 ROM
124 RAM
125 Non-volatile storage device 126 Transmission / reception interface 127 I / O interface 128 External interface 130 Engine control system 131 CPU
132 ROM
133 RAM
134 External interface 135 I / O interface 136 Non-volatile storage device 140 Write controller 150 Printer engine components 151 Various motors 152 Clutch 153 Solenoid 154 Fixing heat source 155 Various sensors 156 Double-sided unit 201 Paper feed roller 202 Main relay roller 203 Registration roller 204 Transfer Roller 205 Fixing roller 206 Fixing paper discharge roller 207 Paper discharge roller 208 Vertical transport roller (upper)
209 Longitudinal conveying roller (medium)
210 Vertical transport roller (bottom)
211 Re-feed roller 212 Horizontal transport roller (drive)
213 Horizontal transport roller (middle)
214 Horizontal transport roller (right)
215 Confidential paper feed roller 216 Confidential vertical conveyance roller 217 Manual paper feed roller 218 Manual relay roller 300 Paper feed tray 301 Confidential tray 302 QR code reader 303 QR code 303 'RFID tag 304 Confidential tray lock 305 Manual feed tray 306 Duplex unit 307 Ejection Paper tray 8 Network 9 Communication equipment

Claims (15)

An image creating / acquisition means for creating an overprint based on an image to be printed or obtaining from a print request source when printing a document;
An image recording unit for overprinting that records the created or acquired image for overprinting in association with a sheet to be printed ;
The image forming apparatus, wherein the overprinting image is created by shifting the image to be printed in a predetermined direction . The image forming apparatus according to claim 1.
Wherein for superimposition printing image, The image forming apparatus characterized by being created by reducing the resolution of the image requested to be printed. The image forming apparatus according to claim 1, wherein:
The image forming apparatus, wherein the overprint image is further created by performing an expansion process on the image to be printed. The image forming apparatus according to any one of claims 1 to 3 ,
The image forming apparatus according to claim 1, wherein the overprinting image changes a difference from the image to be printed based on a security level required for the image to be printed. The image forming apparatus according to claim 4.
The security level is determined by a value obtained by adding a value corresponding to the job title of the print requester and adding a value corresponding to the document type to the initial value.
An image forming apparatus. The image forming apparatus according to any one of claims 1 to 5,
Overprint image acquisition means for acquiring an image for overlap printing recorded in association with a sheet to be printed at the time of printing on the back paper;
An image forming apparatus, comprising: a printing unit that prints the acquired image for overlapping printing on the already printed surface of the paper. The image forming apparatus according to any one of claims 1 to 6,
The image forming apparatus, wherein the image for overlap printing recorded in association with the paper is directly recorded on the paper. The image forming apparatus according to any one of claims 1 to 6,
The image forming apparatus, wherein the image for overlap printing recorded in association with the sheet is recorded in the image forming apparatus in association with a sheet identifier directly recorded on the sheet. The image forming apparatus according to any one of claims 7 and 8,
The image forming apparatus according to claim 1, wherein the direct recording on the sheet is performed by printing a symbol image on the sheet. The image forming apparatus according to any one of claims 7 and 8,
The image forming apparatus according to claim 1, wherein the direct recording on the paper is performed by recording information on an RFID tag provided on the paper. The image forming apparatus according to claim 6.
The image forming apparatus, wherein the overprinting image is created based on a read image from an already printed surface of the paper. Creating or acquiring an image for overprinting based on an image to be printed or obtaining an image for overprinting from a print request source when printing a document;
An image recording step for overprinting that records the created or acquired image for overprinting in association with a sheet to be printed ;
The image formation control method, wherein the overprint image is created by shifting the image to be printed in a predetermined direction . The image formation control method according to claim 12.
An overprinting image acquisition step of acquiring an overprinting image recorded in association with a paper to be printed at the time of backing paper printing;
An image formation control method comprising: a printing step of printing the acquired image for overlapping printing on the already printed surface of the paper. An image formation control program for an image forming apparatus,
A computer for controlling the image forming apparatus;
Creating or acquiring an overprinting image based on an image to be printed when printing a document or acquiring from a print request source
An image recording unit for overprinting that records the created or acquired image for overprinting in association with a sheet to be printed;
To function as,
The image forming control program is created by shifting the image to be printed in a predetermined direction . The image formation control program according to claim 14 ,
A computer for controlling the image forming apparatus;
Overprinting image acquisition means for acquiring an overprinting image recorded in association with the paper to be printed at the time of printing on the back paper;
A printing means for printing the acquired image for overprinting on the already printed surface of the paper;
An image formation control program for functioning as

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