JP2010276771A - Image forming apparatus - Google Patents

Abstract

Provided is an image forming apparatus capable of reusing used paper (backing paper) on which an image is formed on one side with a simple setting without leaking confidential information.
A CPU 300 of an image forming apparatus 150 forms a read image on a white surface of a back paper (S1320), reverses the back paper in a reverse conveyance path after image formation (S1340), reverse Scanning the printed backing paper with a line scanner (S1350), determining the printing area of the scanning surface of the backing paper (the surface that was originally printed), and information in the determined printing area becomes unrecognizable. A program including a step of creating dummy data to be overwritten and a step of printing dummy data is executed.
[Selection] Figure 6

Description

  The present invention relates to an image forming apparatus that forms an image on a recording sheet by an electrophotographic method or the like, and in particular, the other side of a used recording sheet that has been printed or copied on one side can be easily set, and The present invention relates to an image forming apparatus that can be reused without leaking confidential information.

  In offices, the reduction of recording paper has been promoted by promoting paperless printing that displays printing images on a screen of a computer or the like while avoiding printing on paper media. However, while the number of recording sheets can be reduced in this way, a large amount of recording sheets are used in many offices where office work is mainly performed. In view of the current situation, in order to reduce recording paper as much as possible from a viewpoint different from paperless printing, recording paper used inside the office has already been used with one side printed or copied. Reuse of the back side of paper has been done. In this way, even a used recording sheet printed on one side can be reused by using the other blank side, so that the consumption of the recording sheet and the cost can be reduced. it can.

  In order to reuse a used recording sheet on which one side is printed (hereinafter, such a recording sheet may be referred to as a “backing paper”), for example, as a copy sheet, the used recording sheet is used. After collecting the paper, it is necessary to sort the recording papers according to their sizes or align the unprinted side so that it faces one side. In addition, since there are cases where recording paper that has been reused and has already been printed on both sides is included and collected, it is necessary to remove such recording paper after use of both sides. Furthermore, recording paper with confidential information printed on the back side should not be reused in order to prevent leakage of confidential information, although such reuse is permitted under the condition that it is not taken out of the office.

  It would be very time consuming to manually process such a recording paper to be reused by size or to discard a paper that cannot be reused. Furthermore, when processing manually, if confidential matters are printed, they should be discarded without being reused, but this may be overlooked, and confidential information may be leaked. In relation to such a problem, there are known techniques described below.

  Japanese Laid-Open Patent Publication No. 2000-159410 (Patent Document 1) discloses a paper sorting apparatus that automatically sorts used paper for each size and cuts inappropriate paper to avoid leakage. The sheet sorting apparatus includes a sheet feeding unit that feeds stacked sheets one by one, and a conveyance path that is arranged continuously to the sheet feeding unit and conveys the sheet. The transport path includes a paper size detection unit that detects the size of the paper and a reading unit that reads both front and back sides of the paper. Based on the detection size by the paper size detection unit and the image analysis of the front and back sides of the paper by the reading unit, the paper is transferred to each sorting destination via the conveyance path, and is collected or discarded.

  According to this paper sorting device, even when papers of different sizes are used or unused surfaces are randomly stacked, paper suitable for reuse can be collected according to its size. Compared with sorting by work, work efficiency is greatly improved. In addition, since the paper on which the confidential information is printed is automatically cut, it is possible to avoid inadvertent leakage of confidential matters.

  Japanese Laid-Open Patent Publication No. 59-502140 (Patent Document 2) discloses a method for efficiently and economically printing already printed content when a long folded strip-shaped printing paper used as an output paper of a computer is reused. A method for making it unrecognizable is disclosed. This method is a method applied to the reuse of a strip-shaped printing paper in which information is printed on one side of a series of papers connected to each other. This method prints a character-based disturbance pattern over almost the entire print area on one side, regardless of the position of the printed content. The density of the disturbing pattern is characterized in that it is sufficient to make the printed content unrecognizable.

  According to this method, information already printed on one side of the paper is easily and reliably erased, and the paper can be reused by printing on the other side without obtaining that information. Can be saved.

JP 2000-159410 A JP 59-502140 A

  However, all of the above-described known techniques use a dedicated processing device different from the image forming apparatus to align the recording paper to be reused or make the information on the printing surface unrecognizable. For this reason, such a dedicated processing apparatus must be prepared separately from the image forming apparatus (for example, a multifunction peripheral). The introduction of such a dedicated device may increase the total cost, while saving money by reusing used paper with one side printed. Of course, if the processing is performed manually without introducing such a dedicated device, as described above, it is very time-consuming, or the confidential material is overlooked and reused.

  Therefore, according to the present invention, when the used paper on which one side is printed is reused, it can be reused with simple settings and without leaking confidential information without using a dedicated processing device. An object of the present invention is to provide an image forming apparatus.

  An image forming apparatus according to the present invention is based on an image forming unit for forming an image on a used recording sheet on which one side is printed, a scanning unit for scanning the recording sheet, and a result of scanning. The creation means for creating overwritten data that makes it impossible to recognize the information printed on one side of the used image, and the image is formed so as to overwrite the used one side and form an image based on the created overwrite data. Control means for controlling the forming means.

  According to this image forming apparatus, when used recording paper (back paper) printed on one side is used, the printed information is recognized on the used one side (printed side already printed). An image is formed using the overwriting data (image data) which becomes impossible. For this reason, confidential information that has already been printed on the backing paper is made unrecognizable by the overwriting data using the image forming apparatus without using a dedicated processing apparatus, so that confidential leakage can be avoided.

  In this image forming apparatus, as an operation mode, a back paper mode in which an image is formed on an unused side of a used recording paper on which one side is printed, and a recording on which both front and back sides are unused by inverting the front and back of the recording paper. A double-side mode in which images are formed on both sides of the paper can be provided. In this case, the image forming apparatus can be configured to further include means for not permitting the selection of the duplex mode when the backing paper mode is selected based on a user request.

  According to this image forming apparatus, when the backing paper mode using the backing paper is selected, the selection of the duplex mode using both sides of the recording paper is not permitted. This prevents the user from selecting the duplex mode wrongly and using the backing paper to form a necessary image on the used side of the backing paper (printed surface already printed). Can do.

  The image forming apparatus is configured to further include means for setting the operation mode to the back paper mode when it is determined that one side of the recording paper is printed based on the scanned result. be able to.

  According to this image forming apparatus, when it is determined that one side of the recording paper is printed, the operation mode is automatically set to the back paper mode. As a result, even if the user has forgotten to set the back paper mode even though the back paper is used, the front and back of the recording paper can be reversed in the image forming apparatus as necessary. Necessary images can be formed on the unused surface.

  The creation means in this image forming apparatus can be configured to include means for creating data that covers information printed on a used single side.

  According to this image forming apparatus, since information already printed on the back paper is covered with the overwrite data and cannot be recognized, it is possible to avoid leakage of confidential information.

  Further, the creating means can be configured to include means for creating data that covers information printed on a used single side, except for a single color area printed on one side.

  According to this image forming apparatus, an area filled with a single color does not need to cover information with overwrite data (in this case, the overwrite data is randomly arranged characters or the like), and thus does not form an image. For this reason, wasteful consumption of toner or the like can be suppressed while avoiding secret leakage.

  In this image forming apparatus, in order to form an image on both sides of an unused recording sheet, the recording sheet is printed on the basis of the scanning result based on the reversing means for inverting the front and back of the recording sheet. In the case where it is determined that an image is formed on the surface of the recording sheet, it is possible to include means for reversing the front and back of the recording paper by the reversing means before forming the image on the recording paper.

  According to this image forming apparatus, when the backing paper is used, if it is detected that an image has already been formed on the surface on which the image is to be formed by the image forming means, the reversing means is used. The recording paper is reversed so that the blank surface of the recording paper becomes the surface on which the image is formed. For this reason, even if the front and back sides of the back paper are mistakenly set in the paper tray of the image forming apparatus, the paper is automatically reversed, so that the back paper can be set in the paper tray without trouble.

  The image forming apparatus further includes means for discharging the recording paper without forming an image when it is determined that both sides of the recording paper are printed based on the scanned result. Can be configured.

  According to this image forming apparatus, when it is detected that images have already been formed on both sides of the backing paper, the recording paper is forcibly discharged. For this reason, even if the recording paper that has already used both sides is mistakenly set in the paper tray of the image forming apparatus, the paper is automatically discharged, so that the backing paper can be set in the paper tray without bothering human hands.

  The scanning unit of the image forming apparatus includes a unit that is provided upstream of the position where the image forming unit is disposed in the conveyance direction of the recording paper and that scans a surface on which an image is formed by the image forming unit. Can be configured. Here, the scanning means can be constituted by a line scanner.

  According to this image forming apparatus, the line scanner as a scanning unit is provided on the upstream side in the conveyance direction of the recording paper so as to scan the surface on which the image is to be formed. Therefore, the image forming unit forms an image. Prior to this, it is possible to detect whether the surface of the recording paper on which an image is to be formed has already been used. Based on the detection result, the recording paper can be reversed or forcibly discharged.

  The image forming means in this image forming apparatus can be configured to include means for recognizing an image on an unused surface of a used recording sheet on which one side is printed.

  According to this image forming apparatus, based on image data obtained by scanning a document, image data received by a facsimile function, or print data created by a computer, a necessary image is printed on an unused side (blank side) of a backing paper. It can be formed to be recognizable.

  According to the present invention, when reusing used paper on which one side is printed, an image that can be reused without using a dedicated processing device, with simple settings, and without leaking confidential information. A forming apparatus can be provided.

1 is a perspective view illustrating an appearance of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a simplified internal configuration of the image forming apparatus illustrated in FIG. 1. FIG. 2 is a control block diagram illustrating a hardware configuration of the image forming apparatus illustrated in FIG. 1. FIG. 4 is a flowchart (No. 1) showing a control structure of a copy processing program executed by the CPU of FIG. 3. FIG. FIG. 4 is a flowchart (No. 2) showing a control structure of a copy processing program executed by the CPU of FIG. 3. FIG. FIG. 4 is a flowchart (No. 3) showing a control structure of a copy processing program executed by the CPU of FIG. 3. FIG. FIG. 4 is a flowchart (No. 4) showing a control structure of a copy processing program executed by the CPU of FIG. 3. FIG. It is a figure which shows the printing state of the surface already used in the back paper. FIG. 9 is a diagram illustrating a determination result of an area where print data is present in FIG. 8. It is a figure (example 1) which shows an example of dummy data. It is a figure (the 2) which shows an example of dummy data. FIG. 9 is a diagram illustrating a result of black and white reversal of an area where print data is present in FIG. FIG. 10 is a third diagram illustrating an example of dummy data; It is a figure which shows the state which printed dummy data on the back paper image of FIG.

  An image forming apparatus according to an embodiment of the present invention will be described. In the following description, the same parts are denoted by the same reference numerals. Their functions and names are also the same. Therefore, detailed description thereof will not be repeated. In the present embodiment, an electrophotographic image forming apparatus (MFP (Multifunction Peripheral)) will be described. However, the present invention is not limited to this, and used paper (one-side printed) ( Any paper that can be reused as recording paper can be used.

[Image forming apparatus]
FIG. 1 is a diagram illustrating an external configuration of the image forming apparatus 150. FIG. 2 is a diagram illustrating a simplified internal configuration of the image forming apparatus 150. FIG. 3 is a control block diagram of the image forming apparatus 150.

  1 and 2, the image forming apparatus 150 includes a document reading unit 152, an image forming unit 154, a paper feeding unit 156, and a paper discharge processing device 158. The document reading unit 152 includes an automatic document feeder 152A.

  Hereinafter, the internal configuration of the image forming apparatus 150 will be described by describing the operation in the copy mode. Note that copying means printing on a recording sheet based on image data obtained by scanning a document. Therefore, hereinafter, “image formation”, “printing”, and “copying” may be described as synonymous. .

  In the image forming apparatus 150, an image of an original is read as image data by the original reading unit 152, and the read image data is input to a CPU (Central Processing Unit) 300 including a microcomputer shown in FIG. Here, various types of image processing are performed on the image data, and the image data is output to the image forming unit 154.

  When the original is read by the original reading unit 152, the original is placed on the original placement table (contact glass) 152C by the user's hand and read by the original reading unit 152 in a stationary state, or the automatic original conveyance is performed. There is a case where the document automatically conveyed by the apparatus 152A is read in the document reading window 152B. In order to cope with this, the document reading unit 152 provided on the upper part of the image forming apparatus 150 is provided with a document mounting table 152C made of a transparent contact glass on which the document is mounted, and above the document mounting table 152C. The automatic document feeder 152A is attached. As described above, the image forming apparatus 150 according to the present embodiment includes the automatic document conveying device 152A that automatically conveys the document to the position of the document reading window 152B of the document reading unit 152.

  That is, the method of reading a document in the image forming apparatus 150 provided with such an automatic document feeder 152A is roughly divided into the two types described above. The user places the document on the document table 152C, scans the scanner unit while the document is stationary, reads the document, and when the scanning is completed, the user takes out the document (this scan is called “OC scan”). ”), A scanner unit that is stationary at the document reading window 152B while the document is being transported by the automatic document transport device 152A (the scanner unit may be the same as or different from the scanner unit of the OC scan). No.) is a type of reading a document (this scan may be described as “SPF scan”).

  Furthermore, in the latter type (SPF scan), after scanning the first side (front side) of a double-sided document, it is also possible to scan the second side (back side) by reversing and feeding the document by the automatic document feeder 152A. It is.

  The automatic document feeder 152A included in the image forming apparatus 150 according to the present embodiment is a document on which a document (which may be one sheet or two or more document bundles) is placed (set). A tray, a document presence / absence sensor for detecting whether or not there is a document on the document tray (this document may be described as “SPF document”), a feed roller as a driving roller, and two or more sheets A separation roller that separates the originals one by one from the original bundle, and a plurality of original transport rollers that transport the separated originals. The plurality of document conveying rollers are provided in the conveying path and the reverse conveying path.

  The conveyance path is a conveyance path for conveying the first surface of the double-sided document from the document tray to the position of the document reading window 152B. The reverse conveyance path is the second surface after the first surface of the double-sided document is read. Is a conveyance path for conveying the document to the position of the document reading window 152B.

  In such a conveyance path and a reverse conveyance path, a document is detected, and the CPU 300 controls rotation (forward rotation, reverse rotation, and stop) of the conveyance roller and also controls switching between the conveyance path and the reverse conveyance path. Therefore, a plurality of document conveyance sensors are provided.

  Further, the automatic document feeder 152A places a document discharge roller for discharging a document whose first surface or both sides have been read from the position of the document reading window 152B, and a document discharged from the automatic document feeder 152A. A document discharge tray.

  The automatic document feeder 152A included in the image forming apparatus 150 according to the present embodiment has such a configuration and has a function of conveying a document by reversing the front and back. The present invention provides such an automatic document feeder 152A. It is not limited to the image forming apparatus provided with In particular, it may be one that does not have a reverse conveyance path.

  As shown in FIG. 1, the automatic document feeder 152A (upper portion of the document reading unit 152) is configured to be pivoted obliquely upward, and in the case of OC scanning, the upper side of the document placing table 152C is opened. Thus, the user can manually place a document (this document may be described as “OC document”) on the document placing table 152C by hand.

  The image forming unit 154 prints an image of a document indicated by image data on a recording sheet. The image forming unit 154 includes a photosensitive drum 222, a charging device 224, a laser scan unit (hereinafter referred to as “LSU”) 226, and the like. The image forming apparatus includes a developing device 228, a transfer device 230, a cleaning device 232, a fixing device 234, a static elimination device (not shown), and the like.

  The image forming unit 154 is provided with a main conveyance path 236 and a reverse conveyance path 238 through which the recording sheet passes, and the recording sheet fed from the sheet feeding unit 156 is conveyed along the main conveyance path 236. . The paper feeding unit 156 pulls out the recording paper stored in the paper tray (paper cassette) 240 or the recording paper placed on the manual feed tray 242 one by one and feeds the recording paper to the main transport path 236 of the image forming unit 154. To send to. The image forming apparatus 150 includes a plurality of paper trays 240, and can set a back paper on at least one of the paper trays 240 therein. In addition, when setting the backing paper on the paper tray 240, it may be set regardless of the front and back of the backing paper (although copy processing efficiency is reduced when using the backing paper), both sides are already set. The recording papers printed on may be mixed.

  While the recording paper is being conveyed along the main conveyance path 236 of the image forming unit 154, the recording paper passes between the photosensitive drum 222 and the transfer device 230, and further passes through the fixing device 234 to be recorded. Printing on paper is performed.

  The photosensitive drum 222 rotates in one direction, and its surface is cleaned by the cleaning device 232 and the static eliminator and then uniformly charged by the charging device 224.

  The LSU 226 modulates a laser beam based on the image data to be printed, and repeatedly scans the surface of the photosensitive drum 222 in the main scanning direction with the laser beam to form an electrostatic latent image on the surface of the photosensitive drum 222. To do.

  The developing device 228 develops the electrostatic latent image by supplying toner to the surface of the photosensitive drum 222, and forms a toner image on the surface of the photosensitive drum 222.

  The transfer device 230 transfers the toner image on the surface of the photosensitive drum 222 onto a recording sheet that passes between the transfer device 230 and the photosensitive drum 222.

  The fixing device 234 includes a heating roller 248 for heating the recording paper and a pressure roller 250 for pressing the recording paper. The recording sheet is heated by the heating roller 248 and pressed by the pressure roller 250, whereby the toner image transferred onto the recording sheet is fixed on the recording sheet.

  A branching claw 244 is disposed at a connection position between the main conveyance path 236 and the reverse conveyance path 238. When printing is performed only on one side of the recording paper, the branch claw 244 is positioned, and the recording paper from the fixing device 234 is guided to the paper discharge tray 246 or the paper discharge processing device 158 by the branch claw 244.

  When printing is performed on both sides of the recording paper, the branching claw 244 is rotated in a predetermined direction, and the recording paper is guided toward the reverse conveyance path 238. The recording sheet passes through the reverse conveyance path 238, is reversed on the front and back, and is conveyed again to the main conveyance path 236. During the re-conveyance of the main conveyance path 236, printing on the back surface is performed and the recording paper is discharged. The paper is guided toward the paper tray 246 or the paper discharge processing device 158.

  By using the reverse conveyance path 238 configured as described above, the front and back of the recording paper can be automatically reversed inside the image forming apparatus 150.

  The recording paper printed as described above is guided toward the paper discharge tray 246 or the paper discharge processing device 158 and discharged to the paper discharge tray 246, or on each paper discharge tray 168 of the paper discharge processing device 158. Discharged to either.

  In the paper discharge processing device 158, there are cases in which a plurality of recording sheets are sorted (sorted) into the respective discharge trays 168 and discharged, the recording sheets are punched, and the recording sheets are stapled. For example, when creating a plurality of printed materials, each recording sheet is sorted and discharged to each paper discharge tray 168 so that a part of the printed material is allocated to each paper discharge tray 168. In addition, punched processing or stapling processing is performed on each recording sheet on the paper discharge tray 168 to create a printed matter.

  Such an image forming apparatus 150 further includes the following configuration. As shown in FIG. 2, the recording passing through the main transport path 236 is closer to the paper tray 240 (upstream in the transport direction of the recording paper) than the photosensitive drum 222 in the main transport path 236 of the image forming apparatus 150. A line scanner 410 that scans one side (first side, front side) of the paper is provided. The line scanner 410 is provided so as to face the surface of the recording paper passing through the main conveyance path 236, and scans the recording paper as indicated by arrows. When the recording paper approaches the line scanner 410 in the main transport path 236 by a sensor (not shown), a reading start signal is transmitted from the CPU 300 to the line scanner 410, and the surface of the recording paper is scanned. The surface of the recording paper scanned by the line scanner 410 is a surface on which an image is formed by the image forming unit 154 and is a surface facing (facing) the photosensitive drum 222.

  The image forming apparatus according to the present embodiment is (1) a line scanner that has been printed on the front surface (printing surface) of the image forming unit 154 when a backing paper is used as a recording paper for forming an image. When detected by 410, the recording paper is reversed upside down using the reverse conveyance path 238. (2) When the line scanner 410 detects that printing has already been performed on both sides, the recording paper is forcibly ejected. (3) When the backing paper is used, the dummy data is overwritten and printed so that the printed content cannot be recognized on the already printed surface. As described above, in the image forming apparatus 150 according to the present embodiment, the backing paper can be used effectively without using a dedicated processing device, without manpower, and avoiding leakage of confidential information. It has the feature of being able to.

  Such a feature is realized by a hardware configuration (particularly, the reverse conveyance path 238 and the line scanner 410) in the image forming apparatus 150, and hardware and software for controlling the image forming apparatus 150. Hereinafter, the hardware configuration (control block diagram) included in the image forming apparatus 150 or the document reading unit 152 for executing this control will be described, and then the software configuration (program) will be described.

[Hardware configuration (control block)]
Referring to FIG. 3, image forming apparatus 150 is a case where operation device 166 capable of setting related to a copy function, a facsimile function, and a scanner function, ROM 306 for storing a program and the like, and a case where power is cut off. Also includes a hard disk 302, which is a non-volatile storage area capable of storing programs, data, and the like, and a RAM (Random Access Memory) 308 for providing a storage area when executing the program.

  The image forming apparatus 150 further includes a document reading unit 152, an image forming unit 154, a FAX communication unit 155, an operation device 166, a ROM 306, a hard disk 302, and a bus 310 connected to the RAM 308, and an image formation connected to the bus 310. CPU300 for implement | achieving the general function as an apparatus is included.

  The ROM 306 stores programs and data necessary for controlling the operation of the image forming apparatus 150. The CPU 300 controls the image forming apparatus 150 according to the program and data stored in the ROM 306 and executes control related to each function of the image forming apparatus 150.

  As shown in FIG. 3, a public line is connected to the FAX communication unit 155 of the image forming apparatus 150 for transmission and reception of image data, and a network line is connected to a network I / F (interface) 304. A personal computer or the like that uses the image forming apparatus 150 as a network compatible printer is connected to the network line.

  The RAM 308 provides a function as a working memory that temporarily stores the results of calculation and processing by the CPU 300, a function as a frame memory that stores image data, and a function as a memory that stores dummy data described later. .

  Control of document reading unit 152, image forming unit 154, plate-like operation panel 170 and display panel 172 of operation device 166, ROM 306, hard disk 302, and RAM 308 is performed by CPU 300 executing predetermined programs.

  The operation device 166 includes a plate-like operation panel 170 provided with a hardware key that is a numeric keypad and other various operation buttons arranged in a region on the right side of the surface of the operation device 166, and the operation device 166. And a display panel 172 configured from a small touch panel integrated liquid crystal display device disposed in the left region from the center. The operation panel 170 and the display panel 172 are held in one housing, and the operation device 166 is configured to be integrated as a whole.

  In the operation device 166, the display panel 172 displays the status of the image forming apparatus 150, the facsimile destination designation status, the job processing status, and the like. A selection button is displayed on the display area of the liquid crystal display device of the display panel 172. When the area where the selection button is displayed is pressed with a finger, the touch panel detects the pressed position. By collating the display position of the selection button with the position where the touch panel is pressed on the program, function setting, operation instruction, and the like of the image forming apparatus 150 are performed.

  The image forming apparatus 150 further includes a backing paper processing unit 400 for properly reusing the backing paper in the image forming apparatus 150. This backing paper processing unit 400 creates dummy data for creating the above-described line scanner 410 and dummy data to be printed so that the printed content is unrecognizable on the printing surface already printed when used for backing paper. Part 420. The dummy data creation unit 420 creates dummy data that is given only to an area where the image data detected by the line scanner 410 exists, or a black area (a blacked-out portion that is originally determined as information). Dummy data is created so that it will not be assigned. The dummy data creation unit 420 may be configured as hardware, but is realized by software in the present embodiment.

Software configuration
As described above, the image forming apparatus 150 according to the present embodiment uses the backing paper effectively without using a dedicated processing device, without manpower, and avoiding leakage of confidential information. A process having the feature of being able to perform is executed. Such processing is realized by software executed using the hardware configuration described above. The software configuration will be described below.

  4 to 7 are flowcharts showing the control structure of the copy processing program executed by the image forming apparatus 150. FIG. The CPU 300 of the image forming apparatus 150 executes a program that realizes a general function as a network-compatible image forming apparatus connected to a network line in parallel with such a copy processing program. However, the program is not directly related to the essential part of the present invention, and details thereof will not be described here. In this image forming apparatus 150, the image formed on the backing paper is not only based on image data obtained by scanning a document, but also based on image data received by a facsimile function or print data created by a computer. It doesn't matter.

  Referring to FIG. 4, in step (hereinafter, “step” is described as “S”) 1000, CPU 300 of image forming apparatus 150 (hereinafter, simply referred to as “CPU 300”) determines whether or not the copy mode is selected. judge. At this time, when the copy button in the main menu displayed on the operation panel 170 of the image forming apparatus 150 is pressed, the CPU 300 determines that the copy mode has been selected. If the copy mode is selected (YES in S1000), the process proceeds to S1010. If not (NO in S1000), the process returns to S1000 and waits until the copy mode is selected. When a mode other than the copy mode is selected, programs (scanner program, facsimile program, print program, etc.) other than this flowchart are executed.

  In S1010, CPU 300 displays a copy setting menu on display panel 172. In S1020, CPU 300 determines whether or not the size setting of the document to be copied has been input. If document size setting is input (YES in S1020), the process proceeds to S1130. If not (NO in S1020), the process proceeds to S1030.

  In S1030, CPU 300 determines whether or not a magnification setting for a document to be copied has been input. If the magnification setting is input (YES in S1030), the process proceeds to S1130. If not (NO in S1030), the process proceeds to S1040.

  In S1040, CPU 300 determines whether or not a tray setting indicating a tray in which a recording sheet to be used as a copy sheet is set is input. If the tray setting is input (YES in S1040), the process proceeds to S1050. If not (NO in S1040), the process proceeds to S1080.

  In S1050, CPU 300 determines whether or not the tray on which the back paper is set is set. If the tray on which the backing paper is set is set (YES in S1050), the process proceeds to S1080. If not (NO in S1050), the process proceeds to S1060.

  In S1060, CPU 300 displays a duplex printing menu on display panel 172. In S1070, CPU 300 determines whether or not a double-sided print setting for printing on both sides of the recording paper has been input. If the duplex printing setting is input (YES in S1070), the process proceeds to S1130. If not (NO in S1070), the process proceeds to S1080.

  In S1080, CPU 300 determines whether or not a duplex scan setting indicating scanning of both sides of a document printed on both sides has been input. If the duplex scan setting is input (YES in S1080), the process proceeds to S1130. If not (NO in S1080), the process proceeds to S1090.

  In S1090, CPU 300 determines whether the number of copies to be printed has been input. If the number of copies is input (YES in S1090), the process proceeds to S1130. If not (NO in S1090), the process proceeds to S1100.

  In S1100, CPU 300 determines whether or not a sort setting for sorting when copying a plurality of copies has been input. If sort setting is input (YES in S1100), the process proceeds to S1130. Otherwise (NO at S1100), the process proceeds to S1110.

  In step S1110, the CPU 300 determines whether or not format-printed paper settings for using a format-printed paper on which ruled lines or the like have been printed from the beginning as copy paper have been input. If formatted paper setting is input (YES in S1110), the process proceeds to S1130. If not (NO in S1110), the process proceeds to S1120.

  In S1120, CPU 300 determines whether or not black overwriting prohibition setting indicating that dummy data is not added to the black region (the blacked-out portion) is input for the dummy data to be printed on the already printed surface of the backing paper. Determine whether. If black overwrite prohibition setting is input (YES in S1120), the process proceeds to S1130. If not (NO in S1120), the process proceeds to S1140.

  In S1130, CPU 300 stores the set items in RAM 308. Thereafter, the process proceeds to S1140.

  In S1140, CPU 300 determines whether or not the copy start button has been pressed by the user. At this time, if a start button (either a hardware key or a software key) provided on the operation device 166 of the image forming apparatus 150 is pressed, the CPU 300 determines that the copy start button has been pressed. If the copy start button is pressed (YES in S1140), the process proceeds to S1150. If not (NO in S1140), the process returns to S1020 and waits for further input of settings for the copy process. If the user does not press the copy start button after a predetermined time has elapsed since the copy setting menu was displayed on the display panel 172, it may be processed as a timeout error. Also, default settings are applied to items that are not set by the user when the copy start button is pressed.

  Referring to FIG. 5, in S1150, CPU 300 determines whether or not an SPF document is detected. At this time, the CPU 300 determines that the SPF document has been detected when the document is detected by the document presence / absence sensor that is provided on the document tray of the automatic document feeder 152A of the image forming apparatus 150 and detects the SPF document. If an SPF document is detected (YES in S1150), the process proceeds to S1160. If not (NO in S1150), the process proceeds to S1230.

  In S1160, CPU 300 controls automatic document feeder 152A to automatically convey the SPF document set on the document tray to document reading window 152B. In S1170, CPU 300 controls document reading unit 152 to scan the first surface of the SPF document, and temporarily stores the image data formed on the first surface in RAM 308.

  In S1180, CPU 300 determines whether or not double-sided scanning is set. At this time, the CPU 300 makes a determination based on the content of the copy setting item stored in the RAM 308. If duplex scanning is set (YES in S1180), the process proceeds to S1190. Otherwise (NO in S1180), the process proceeds to S1210. In S1190, CPU 300 controls automatic document feeder 152A to pull the SPF document whose first surface is scanned into the reverse conveyance path, and reverses the front and back to automatically convey it to document reading window 152B. In S1200, CPU 300 controls document reading unit 152 to scan the second surface of the SPF document and temporarily store the image data formed on the second surface in RAM 308.

  In S1210, CPU 300 controls automatic document feeder 152A to discharge the SPF document scanned on the first surface or the SPF document scanned on the first and second surfaces from the position of document reading window 152B. Eject to paper tray.

  In S1220, CPU 300 determines whether or not an SPF document is further detected. At this time, the CPU 300 further detects a document by a document presence / absence sensor that is provided on the document tray of the automatic document feeder 152A of the image forming apparatus 150 and detects the SPF document (that is, a plurality of sheets on the document tray). When an original bundle consisting of originals is set), it is determined that an SPF original is detected. If an SPF document is further detected (YES in S1220), the process proceeds to S1160. If not (NO in S1220), the process proceeds to S1250.

  In S1230, CPU 300 controls document reading unit 152 to scan the OC document placed on document placement table 152C, and temporarily stores the image data formed on the OC document in RAM 308. At this time, for example, when the “reading start” button provided on the operation panel 170 of the image forming apparatus 150 is pressed, the CPU 300 controls the document reading unit 152 to execute the OC scan.

  In S1240, CPU 300 determines whether or not the end of scanning of the OC document has been input. At this time, for example, when the “reading end” button provided on the operation panel 170 of the image forming apparatus 150 is pressed, the CPU 300 determines that the scanning end of the OC document has been input. When the end of scanning of the OC document is input (that is, when scanning of all the OC documents is completed), the process proceeds to S1250. If not (NO in S1240), the process returns to S1230 to scan the next OC document.

  Referring to FIG. 6, in S1250, CPU 300 controls image forming unit 154 to feed and convey the sheet. At this time, the CPU 300 sets 0 to an inversion flag (this flag assumes a value of 0 or 1).

  In S1260, CPU 300 determines whether or not format-printed paper is set. At this time, the CPU 300 makes a determination based on the content of the copy setting item stored in the RAM 308. If formatted paper has been set (YES in S1260), the process proceeds to S1320. Otherwise (NO at S1260), the process proceeds to S1270.

  In S 1270, CPU 300 controls backing paper processing unit 400 to face one side (first side, front side, photosensitive drum 222) of the recording paper passing through main transport path 236 by line scanner 410. Scan).

  In S1280, CPU 300 determines whether there is print data on the scan surface of the recording paper. If there is print data on the scan surface of the recording sheet (YES in S1280), the process proceeds to S1290. If not (NO in S1280), the process proceeds to S1320.

  In S1290, CPU 300 determines whether or not the inversion flag is 0 (whether it has not been inverted yet or has been inverted). When the reversal flag is 0, the recording paper is not yet reversed, and when the reversal flag is 1 other than 0, the recording paper is already reversed. If the reverse flag is 0 (YES in S1290), the process proceeds to S1300. If not (NO in S1290), the process proceeds to S1310.

  In step S <b> 1300, the CPU 300 controls the image forming unit 154 to reversely convey the sheet using the reverse conveyance path 238. At this time, the CPU 300 sets 1 to the inversion flag. Thereafter, the process returns to S1270.

  In step S1310, the CPU 300 controls the image forming unit 154 so that the recording sheet is discharged to either the discharge tray 246 or each discharge tray 168 of the discharge processing device 158 as an invalid sheet that has already been duplex printed. To do. Thereafter, the process returns to S1250.

  In S1320, CPU 300 controls image forming unit 154 to print on the transported recording paper based on the data temporarily stored in RAM 308.

  In S1330, CPU 300 determines whether a back paper tray is set. At this time, the CPU 300 makes a determination based on the content of the copy setting item stored in the RAM 308. If the backing paper tray is set (YES in S1330), the process proceeds to S1340. If not (NO in S1330), the process proceeds to S1370.

  In S <b> 1340, CPU 300 controls image forming unit 154 to reversely convey the paper using reverse conveyance path 238. In S 1350, CPU 300 controls backing paper processing unit 400 to face one side (first side, front side, photoconductor drum 222) of the recording paper passing through main transport path 236 by line scanner 410. Scan). At this time, an image already formed when the back paper is set on the paper tray 240 is scanned, and the scanned image data is temporarily stored in the RAM 308. In S1360, CPU 300 determines whether there is print data on the scan surface of the recording paper. If there is print data on the scan surface of the recording sheet (YES in S1360), the process proceeds to S1400. If not (NO in S1360), the process proceeds to S1450.

  In S1370, CPU 300 determines whether or not double-sided printing is set and there is temporarily stored image data for the next page. At this time, the CPU 300 makes a determination based on the contents of the copy setting item stored in the RAM 308 and the temporarily stored image data. If duplex printing is set and there is temporarily stored image data for the next page (YES in S1370), the process proceeds to S1380. If not (NO in S1370), the process proceeds to S1450.

  In S <b> 1380, CPU 300 controls image forming unit 154 to reversely convey the sheet using reverse conveyance path 238. In S1390, CPU 300 controls image forming unit 154 to print on the transported recording paper based on the data temporarily stored in RAM 308. Thereafter, the process proceeds to S1450.

  Referring to FIG. 7, in S1400, CPU 300 starts printing on the recording paper (backing paper) on which an image has already been formed when print data is present on the scanning surface of the recording paper, that is, when set on paper tray 240. When an image is formed, an area (for example, FIG. 9) having print data (for example, FIG. 8) on the surface opposite to the new printed surface (the surface on which the image has already been formed as the backing paper) is displayed. judge.

  In S1410, CPU 300 controls backing paper processing unit 400 to create dummy data of the determined area size. At this time, for example, dummy data (eg, FIG. 10) composed of random hiragana and oblique lines is created so as to cover at least this region. The created dummy data (eg, FIG. 11) is temporarily stored in the RAM 308.

  In S1420, CPU 300 determines whether or not black overwriting prohibition indicating that dummy data is not added to a black region (a blacked-out portion) is set for dummy data. At this time, the CPU 300 makes a determination based on the content of the copy setting item stored in the RAM 308. If black overwrite prohibition is set (YES in S1420), the process proceeds to S1430. If not (NO in S1420), the process proceeds to S1440.

  In S1430, CPU 300 deletes the black print data area from the created dummy data and creates new dummy data. At this time, for example, the CPU 300 extracts a black print data area (RGB data (0, 0, 0)) from the back paper image data (eg, FIG. 8) and outputs black and white. The result of inversion (example: FIG. 12) and AND (logical product) operation with dummy data (example: FIG. 11) is used as new dummy data (example: FIG. 13). The newly created dummy data is also temporarily stored in the RAM 308.

  In S1440, CPU 300 controls image forming unit 154 and, based on dummy data (eg, FIG. 11 or FIG. 13) temporarily stored in RAM 308, the conveyed recording paper (this recording paper is Dummy data is printed on the side opposite to the side on which the new image is formed (the side on which the image has already been formed when set on the paper tray 240) (eg, the backing paper image in FIG. 8). When the dummy data is printed on, the state shown in FIG. 14 is obtained).

  In S 1450, CPU 300 controls image forming unit 154 to discharge the recording sheet to either discharge tray 246 or each discharge tray 168 of discharge processing device 158.

  In S1460, CPU 300 determines whether all pages per copy have been printed. For example, when the document is a set of three sheets (referred to as a single-sided document), it is determined that all pages per copy have been printed when the printing of the three sheets is completed. When all pages per copy are printed (YES in S1460), the process proceeds to S1470. If not (NO in S1460), the process returns to S1250 to print the next page.

  In S1470, CPU 300 determines whether the set number of copies has been printed. For example, if the document is a set of 3 sheets (referred to as a single-sided document) and printing of 3 copies is requested, it is determined that the set number of copies has been printed after 9 sheets (3 sheets × 3 copies) have been printed. If the set number of copies is printed (YES in S1470), this process ends. At this time, a copy completion message may be output to the display panel 172. If not (NO in S1470), the process returns to S1250 to print the next copy.

[Operation]
A copy operation in image forming apparatus 150 according to the present embodiment based on the above-described structure and flowchart will be described. In the description of this operation, a case where three copies of A4 size double-sided originals are copied on the back paper will be described as an example. In preparation for the copying operation, an A4 size backing paper is set in one of the paper trays 240, and the setting of the paper tray is set as “size: A4” and “type: backing paper”.

  The image forming apparatus 150 is set to the copy mode (YES in S1000), and three A4 size double-sided originals are placed on the original tray.

  Various items (original size, magnification, paper tray, double-sided printing, double-sided scanning, number of copies, sorting, formatted printed paper, black overwriting prohibition) for copy processing are set (S1020 to S1120), and the set items are It is stored in the RAM 308 (S1130).

  In the description of this operation, for example, A4 is set as the document size, 100% is set as the magnification, the paper tray is set as the back paper tray, double-sided scanning is set, and the number of copies is set to 1 and sorting is valid. It is set that the paper is not formatted and printed, and black overwriting prohibition is set. Note that double-sided printing cannot be set when the backing paper tray is set as the paper tray. That is, if YES in S1050, the processes of S1060 and S1070 are not performed.

  When such setting is completed, the copy start button is pressed (YES in S1140). Three double-sided originals (SPF originals) placed on the original tray are detected by the original presence sensor (YES in S1150), and the first SPF original is automatically sent to the original reading window 152B by the automatic original feeder 152A. The first surface scanned after being transported is temporarily stored in the RAM 308 (S1160, S1170).

  Since double-sided scanning is set (YES in S1180), the SPF document scanned on the first surface is drawn into the reversal conveyance path, and the front and back of the document are reversed and automatically conveyed to the document reading window 152B (S1190). ), The second side of the SPF document is scanned, and the scanned image data of the second side is temporarily stored in the RAM 308 (S1200). Thereafter, the first double-sided document scanned on both sides in this manner is discharged to the document discharge tray (S1210).

  Furthermore, even after the first SPF scan is completed, the second double-sided document and the third double-sided document placed on the document tray are still detected by the document presence / absence sensor (YES in S1220). The SPF scan is continued. The first side of the second double-sided original is scanned, and the scanned image data of the first side is temporarily stored in the RAM 308 (S1170), and the second side of the original is scanned and scanned. The two-side image data is temporarily stored in the RAM 308 (S1200). Further, similarly, the third double-sided document is scanned. In this way, until the double-sided original is not detected (NO in S1220), the second double-sided original and the third double-sided original are scanned on both sides in the same manner as the first double-sided original. The document is discharged to the document discharge tray (S1210).

  When scanning an OC document, when the “reading start” button is pressed, the OC document placed on the document placement table 152C is scanned, and the scanned image data is temporarily stored in the RAM 308. (S1230). This OC scan is repeated until the “reading end” button is pressed (YES in S1240).

  When such a scanning operation is completed, one sheet of back paper is fed from the paper tray 240 (S1250). In order to shorten the processing time, printing may be started while the document is scanned. One surface (first surface, surface, surface opposite to the photosensitive drum 222) of the recording paper passing through the main conveyance path 236 is scanned by the line scanner 410 (S1270).

  If there is no data on the scan surface as a result of scanning the recording paper by line scanner 410, it is determined that the recording paper is correctly set and conveyed (NO in S1280).

  As a result of the scanning of the recording paper by the line scanner 410, if there is data on the scanning surface (that is, the surface on which image formation is to be performed is not already blank) and has not yet been reversed, the recording paper is recorded using the reversing conveyance path 238. Are reversed (YES in S1280, YES in S1290, S1300).

  As a result of scanning the recording paper by the line scanner 410, if there is data on the scan surface (that is, the surface on which image formation is to be performed is not already a blank sheet), and the image has already been reversed (that is, an image has already been formed on both sides). The recording sheet is discharged as an invalid sheet to either the discharge tray 246 or each discharge tray 168 of the discharge processing device 158 (YES in S1280, NO in S1290, S1310). Note that a discharge tray dedicated to invalid paper may be provided in order to clearly separate from normally printed recording paper.

  If it is determined that the side on which image formation is to be performed is blank (NO in S1280), the image forming unit 154 causes the image to be printed on the conveyed recording paper based on the data temporarily stored in the RAM 308. Is formed (S1320). At this time, the first side image of the first double-sided original is printed at a magnification of 100% on the blank side of the backing paper.

  Thus, the recording paper on which the image is printed on the white paper surface is reversed using the reverse conveyance path 238 (YES in S1330, S1340). One side of the recording paper passing through the main conveyance path 236 by the line scanner 410 (the side opposite to the side printed earlier and the side already printed when used as the backing paper) is scanned. The scanned image data is temporarily stored in the RAM 308 (S1350).

  In the explanation of this operation, since the back paper tray is set as the paper tray to be used, it is determined that there is data on the scan surface as a result of scanning the recording paper by the line scanner 410 (YES in S1360). As a result of the scanning of the recording paper, an area having image data is determined (S1400). Dummy data is created so as to cover the area with the image data, and is temporarily stored in the RAM 308 (S1410). At this time, data in which random hiragana and oblique lines are embedded is created as dummy data, but there is no particular limitation as long as the printed information cannot be recognized. The dummy data itself may be in color, but in the present embodiment, it is monochrome data. Furthermore, the range in which the dummy data is embedded is limited to a range in which there is an image already printed on the back paper.

  Here, since black overwriting prohibition is set (YES in S1420), the black area portion is extracted from the image data already printed on the backing paper, binarized, and reversed in black and white. The result of the logical product operation with the dummy data created and stored in the RAM 308 is created as new dummy data (S1430). It should be noted that as a countermeasure against the deviation between the scan position by the line scan 410 and the print position by the image forming unit 154, a method of reducing the deletion range using an 8-neighbor reduction filter or the like can be applied.

  Using the dummy data stored in the RAM 308, printing is performed so as to overwrite the surface on which the image has already been printed on the backing paper (S1440). Thereafter, the printed recording paper is discharged to either the paper discharge tray 246 or each paper discharge tray 168 of the paper discharge processing device 158 (S1450).

  Next, in the same manner, a new recording paper (second backing paper) is fed, and the second side image of the first double-sided document is printed on the white side of the second backing paper. Dummy data that makes it impossible to recognize an image detected by scanning the back side already printed on the back of the eye is printed on the back side of the second sheet and discharged.

  Further, similarly, a new recording paper (third backing paper) is fed, and the first side image of the second side of the double-sided original is printed on the white side of the third back side of the three sheets. Dummy data is printed on the back side of the third sheet so that the image detected by scanning the back side already printed on the back side of the eye becomes unrecognizable and discharged.

  Further, a new recording paper (fourth backing paper) is fed, and the second side image of the second double-sided document is printed on the white side of the fourth backing paper, and the fourth backing paper. Dummy data that makes it impossible to recognize an image detected by scanning the back side that has already been printed is printed on the back side of the fourth sheet and discharged.

  Further, a new recording paper (fifth backing paper) is fed, and the first side image of the third double-sided document is printed on the white side of the fifth backing paper, and the fifth backing paper. Dummy data that makes it impossible to recognize an image detected by scanning the back side that has already been printed is printed on the back side of the fifth sheet and discharged.

  In addition, a new recording paper (sixth backing paper) is fed, and the second side image of the third double-sided document is printed on the white side of the sixth backing paper. Dummy data that makes it impossible to recognize an image detected by scanning the back side that has already been printed is printed on the back side of the sixth sheet and discharged.

  As described above, according to the image forming apparatus according to the present embodiment, when a backing paper is used, it is confirmed by the line scanner that an image has already been printed on the surface to be printed in the image forming unit. If detected, the recording paper is reversed so that the blank paper surface of the recording paper becomes the surface on which the image is formed using the reverse conveyance path. In this case, if the line scanner detects that printing has already been performed on both sides of the backing paper, the recording paper is forcibly discharged. Further, when the backing paper is used, dummy data is printed on the already printed surface so that the printed content cannot be recognized. For this reason, in the image forming apparatus according to the present embodiment, the backing paper can be reused without using a dedicated processing device. In the image forming apparatus according to the present embodiment, even if the front and back sides of the back paper are mistakenly set in the paper tray, they are automatically reversed, and the double-sided printed back paper is automatically discharged. The backing paper can be set in the paper tray without any trouble. Furthermore, since confidential information already printed on the backing paper is made unrecognizable by dummy data, it is possible to avoid leakage of confidential information.

  In the above-described embodiment, if the recording paper is determined to be the backing paper as a result of scanning the recording paper by the line scanner 410, the backing paper tray is set even if the backing paper tray is not set by the user. As set, it may be automatically operated in the back paper use mode (the state in which the back paper tray is input).

  If the line scanner 410 is not installed, a “reverse image batch erase mode” is prepared. If this “reverse image batch erase mode” is designated, the automatic document feeder 152A is used to erase the image. The desired back paper is automatically conveyed to the original reading unit 152, and is collectively scanned at the position of the original reading window 152B, and dummy data for each page is created so as to cover the image area on the use surface of the back paper. After that, the scanned back paper is put together on the manual feed tray 242, and the dummy data for each page is overwritten on the used side of the back paper so that the back paper to be reused cannot be read (already It may be set in the paper tray (after the printed information cannot be recognized).

  Further, even if the line scanner 410 is opposed to the front surface of the recording paper and the line scanner 410 is opposed to the back surface of the recording paper, the front and back surfaces of the recording paper are scanned at once by the two line scanners 410. I do not care.

  The embodiment disclosed herein is merely an example, and the present invention is not limited to the above-described embodiment. The scope of the present invention is indicated by each of the claims after taking into account the description of the detailed description of the invention, and all modifications within the meaning and scope equivalent to the wording described therein are intended. Including.

DESCRIPTION OF SYMBOLS 150 Image forming apparatus 152 Document reading part 154 Image forming part 156 Paper feeding part 158 Paper discharge processing apparatus 166 Operation apparatus 170 Operation panel 172 Display panel 300 CPU
302 HDD
306 ROM
308 RAM
310 Bus 400 Backing paper processing unit 410 Line scanner 420 Dummy data generation unit

Claims (10)

Image forming means for forming an image on a used recording sheet on which one side is printed;
Scanning means for scanning the recording paper;
Based on the scanned result, creating means for creating overwritten data in which the information printed on the used single side becomes unrecognizable;
An image forming apparatus comprising: a control unit configured to control the image forming unit so as to form an image by overwriting the used single side based on the created overwrite data. In the image forming apparatus, as an operation mode, a back paper mode in which an image is formed on an unused side of a used recording sheet on which one side is printed, and a recording on which both sides of the recording sheet are unused by reversing the front and back sides of the recording sheet. A duplex mode that forms images on both sides of the paper,
The image forming apparatus according to claim 1, further comprising means for disallowing selection of the duplex mode when the backing paper mode is selected based on a user request.   The image forming apparatus further includes means for setting the operation mode to a backing paper mode when it is determined that one side of the recording paper is printed based on the scanned result. The image forming apparatus according to claim 2.   The image forming apparatus according to claim 1, wherein the creating unit includes a unit for creating data that covers information printed on the used one side.   The image forming apparatus according to claim 1, wherein the creating unit includes a unit for creating data that covers information printed on the used single side, except for a single color area printed on the single side. . The image forming apparatus includes:
Reversing means for reversing the front and back of the recording paper in order to form images on both sides of the recording paper where both front and back sides are unused,
If it is determined that an image is formed on the printed surface of the recording sheet based on the scanned result, before the image is formed on the recording sheet, the reversing unit The image forming apparatus according to claim 1, comprising means for reversing the front and back sides.   The image forming apparatus further includes means for discharging the recording paper without forming an image when it is determined that both sides of the recording paper are printed based on the scanned result. The image forming apparatus according to claim 1, further comprising:   The scanning means includes means for scanning a surface on which an image is formed by the image forming means, which is provided upstream of the position where the image forming means is disposed in the conveyance direction of the recording paper. The image forming apparatus according to claim 1.   The image forming apparatus according to claim 8, wherein the scanning unit is a line scanner. 10. The image forming unit according to claim 1, wherein the image forming unit includes a unit for recognizing an image on an unused side of a used recording sheet on which the one side is printed. Image forming apparatus.

Images