JP2011160357A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To relatively improve a security level while suppressing occurrence of delay of a following job caused by overwrite-erasing of image data. <P>SOLUTION: In an image forming apparatus 1, when ending an image output job, a data deletion section 33 overwrite-erases a part of image data by the image output job in a storage device 16. If all the image output jobs generated by a job management section 31 are completed, all or the remaining image data which have been overwrite-erased partially, are overwrite-erased. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image forming apparatus.

  In an image forming apparatus such as a printer or a multifunction peripheral, image data of an output image of each page is generated in a copy job, a print job, etc., temporarily stored in a storage device such as a hard disk drive, and the image data is read from the storage device While the output image is printed.

  In an image forming apparatus such as a multifunction machine equipped with a security function, image data remaining in the storage device is overwritten and erased after output of a copy job, print job, or the like (see, for example, Patent Documents 1 to 3). This prevents unauthorized acquisition of other person's document data remaining in the image forming apparatus. In overwriting erasing, first, meaningless data is overwritten on the entire image data, and then the data area is erased and released.

JP 2004-072138 A JP 2004-072139 A JP 2004-112629 A

  When overwriting is performed, access (writing) to the storage device continuously occurs. For this reason, when there is a subsequent job, there is a possibility that a delay occurs in the reading / writing of the image data of the subsequent job with respect to the storage device due to the overwriting erasure, and thus the processing of the subsequent job may be delayed. There is.

  In this regard, in the technique described in Patent Document 2 described above, the invalidation of the image data is interrupted when a subsequent job occurs. In this way, when the job continues, the image data is invalidated. This is not desirable in terms of security.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an image forming apparatus that can increase the security level while suppressing the delay of a subsequent job caused by overwriting deletion of image data. And

  In order to solve the above problems, the present invention is configured as follows.

  An image forming apparatus according to the present invention includes a job management unit that generates an output job, an image processing unit that generates image data based on the image output job, a storage device that stores image data, and reads image data from the storage device, An image output unit that performs printing based on the image data or transmits the image data, and at the end of the image output job, the storage unit erases a part of the image data by the image output job, and the job management unit And a data erasure unit for overwriting the entire image data or a part of the image data that has been partially overwritten when all of the generated image output jobs have been completed.

  As a result, at the end of the job, only part of the image data that can be executed in a short time is overwritten, and when there is no job, overwriting erasure of the entire area is completed. As a result, the delay of the succeeding job due to the above is suppressed, and the security level is relatively high.

  In addition to the image forming apparatus described above, the image forming apparatus according to the present invention may be configured as follows. In this case, when the value of the security level setting is the predetermined first value in the image output job, the data erasure unit stores the entire area of the image data by the image output job in the storage device at the end of the image output job. When overwriting is erased and the value of the security level setting is a predetermined second value, at the end of the image output job, a part of the image data by the image output job is overwritten and erased at the storage device. When all the image output jobs generated by the management unit have been completed, the entire area or the rest of the image data in which a part is overwritten is overwritten.

  As a result, if the security level is set high (in the case of the first value), the overwriting erasure is completed immediately at the end of the job, so the security level should be increased as necessary. Can do.

  The image forming apparatus according to the present invention may be configured as follows in addition to any of the image forming apparatuses described above. In this case, if no value is set in the security level setting in the image output job, the data erasing unit performs the image output by the image output job in the same manner as when the second value is set in the security level setting. Erase the data.

  The image forming apparatus according to the present invention may be configured as follows in addition to any of the image forming apparatuses described above. In this case, the data erasure unit releases the image data area in the storage device after the overwriting erasure of the entire image data is completed.

  As a result, the image data can be accessed even after a portion of the overwriting is erased, and the overwriting erasure of the entire image data is reliably performed.

  The image forming apparatus according to the present invention may be configured as follows in addition to any of the image forming apparatuses described above. In this case, when the total size of the image data stored in the storage device exceeds a predetermined percentage of the storage capacity of the storage device, the data erasure unit overwrites a part at the end of one of the image output jobs. Overwrite the entire image data or the rest.

  As a result, it is possible to prevent in advance that the job is stopped due to insufficient storage capacity.

  According to the present invention, in the image forming apparatus, the delay of the subsequent job due to the overwriting erasure of the image data is suppressed, and the security level is relatively high.

FIG. 1 is a block diagram showing a configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a flowchart for explaining the operation of the image forming apparatus shown in FIG.

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

  FIG. 1 is a block diagram showing a configuration of an image forming apparatus according to an embodiment of the present invention. The image forming apparatus 1 includes a printer 11, a scanner 12, a facsimile device 13, an operation panel 14, a network interface 15, a storage device 16, and an arithmetic processing device 17.

  The printer 11 is an internal device that prints a document image based on print data. The scanner 12 is an internal device that optically reads a document image from a document and generates image data of the document image. The facsimile apparatus 13 is an internal apparatus that generates and transmits a facsimile signal from document data to be transmitted, and receives the facsimile signal and converts it into document data. The printer 11 is an image output unit that performs printing based on image data in the storage device 16 in a copy job or print job. The facsimile device 13 performs facsimile transmission of image data in the storage device 16 in a facsimile transmission job. An image output unit to be performed.

  The operation panel 14 is arranged on the surface of the casing of the image forming apparatus 1 and includes a display device that displays various types of information to the user and an input device that detects a user operation. For example, a liquid crystal display is used as the display device. A key switch, a touch panel, or the like is used as the input device.

  The network interface 15 is a circuit that is connected to a network (not shown) and performs data communication with other devices (such as the host device 2) connected to the network. The network interface 15 functions as a physical layer for network communication.

  The storage device 16 is a device capable of storing various data. The storage device 16 stores image data generated by image output jobs such as copy jobs, print jobs, facsimile transmission jobs, and scan jobs. As the storage device 16, a nonvolatile large-capacity storage medium such as a nonvolatile memory or a hard disk drive is used.

  The arithmetic processing unit 17 is a computer having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc., and loads a program from the ROM or a storage device (not shown) to the RAM. Various processing units are realized by executing the program by the CPU. In this embodiment, a job management unit 31, an image processing unit 32, and a data erasing unit 33 are realized in the arithmetic processing unit 17.

  The job management unit 31 is a processing unit that generates an image output job in accordance with user operation information obtained from the printer driver of the host device 2 and the operation panel 14.

  The image processing unit 32 is a processing unit that generates image data based on an image output job. The image processing unit 32 generates image data from print data such as PDL (Page Description Language) data supplied from the host device 2 for each image output job, or generates image data of a scan image obtained by the scanner 12. Or Further, the image processing unit 32 performs predetermined image processing on the image data, and stores the image data after the image processing in the storage device 16. The image processing unit 32 may store the image data in the storage device 16 after encryption or encoding (data compression).

  At the end of the image output job, the data erasing unit 33 overwrites a part of the image data of the image output job in the storage device 16 and all the image output jobs generated by the job management unit 31 are completed. In some cases, this is a processing unit for overwriting and erasing the entire area or the rest of the image data partially overwritten. In other words, the data erasure unit 33 overwrites the entire image data or the rest of the image data that has been partially overwritten when each job is completed when there is no subsequent job.

  In this embodiment, the data erasure unit 33, when the value of the security level setting is a predetermined first value (here, “high”) in the image output job, at the end of the image output job, When the image data by the image output job is completely overwritten and the security level setting value is a predetermined second value (here, “low”), at the end of the image output job, the image output job When the image data is simply overwritten and all the image output jobs are completed, the image data that has been overwritten is simply overwritten.

  That is, when the value of the security level setting is a predetermined first value (here, “high”), the entire image data of the image output job is overwritten when the image output job ends. On the other hand, when the value of the security level setting is a predetermined second value (here, “low”), at the end of the image output job, only a part of the image data of the image output job is stored in the storage device 16. When all the image output jobs that have been erased and have been generated by the job management unit 31 have been completed, the entire area or the rest of the image data that has been partially overwritten is overwritten.

  In simple overwrite erasure, meaningless data is overwritten at a predetermined location (or a predetermined percentage of the data area) of image data so that an image cannot be accurately obtained based on the image data. Is done. For example, if the image data is encrypted or encoded, partially meaningless data is overwritten to such an extent that the original image data cannot be decrypted. For example, meaningless data is overwritten intermittently at a predetermined interval from the top of the image data.

  It should be noted that only simple overwrite erasure does not release the image data area, but allows it to be continuously accessed.

  Next, the operation of the image forming apparatus will be described. FIG. 2 is a flowchart for explaining the operation of the image forming apparatus shown in FIG.

  First, when the user causes the image forming apparatus 1 to execute copying, printing, facsimile transmission, and the like, the user operates the host device 2 or the operation panel 14 to set the security level setting value (here, “high”). And “low”), and an execution command for image output such as copying, printing, and facsimile transmission is input.

  The host device 2 or the operation panel 14 detects these input operations, sets a security level value, and transmits an image output execution command to the job management unit 31 (step S1).

  When the job management unit 31 of the image forming apparatus 1 receives an image output execution command from the host device 2 via the operation panel 14 or the network interface 15, it generates an image output job corresponding to the command (step S2). ). The generated image output job is added to the job matrix and processed in order.

  The job management unit 31 selects an image output job from the job matrix and executes the image output job (step S3). In the image output job, image data is appropriately generated by the image processing unit 32 and stored in the storage device 16, and then read from the storage device 16 and supplied to the printer 11, the facsimile device 13, and the like.

  When one image output job is completed, the data erasing unit 33 determines whether or not the security level value set for the job is “high” (step S4).

  If the security level value set for the job is “high”, the data erasure unit 33 completely erases the image data of the job at this point (step S5). Thereby, at this time, the area of the image data in the storage device 16 is released.

  On the other hand, if the security level value set for the job is not "High" (that is, if the security level value is "Low" or the security level value itself is not set), data At this point, the erasure unit 33 simply overwrites and erases the image data of the job, and registers this image data in a predetermined list (step S6). In the list, identification information of the area of the image data is registered. When image data is stored as a file on the file system, a file path including a file name is used as identification information. When the file system does not exist, the start address and size (or start address and end address) of the area are used as identification information.

  Then, the job management unit 31 determines whether or not there is a subsequent job (step S7). If there is a subsequent job, the job management unit 31 processes the job similarly (steps S3 to S6).

  On the other hand, if there is no subsequent job, the data erasure unit 33 refers to the above list, determines whether there is image data registered in the list (step S8), and registers in the list. If there is image data that has been deleted, the image data is completely overwritten and the registration of the image data that has been completely overwritten is deleted from the list (step S9). The area of the image data once deleted by simple overwriting is released at this point.

  As described above, according to the above-described embodiment, when the image output job is completed, the data deletion unit 33 overwrites a part of the image data of the image output job in the storage device 16 and the job management unit 31. When all of the image output jobs generated by the above are completed, the entire area or the rest of the image data partially overwritten is overwritten.

  As a result, at the end of the job, only part of the image data that can be executed in a short time is overwritten, and when there is no job, overwriting erasure of the entire area is completed. As a result, the delay of the succeeding job due to the above is suppressed, and the security level is relatively high.

  The above-described embodiments are preferred examples of the present invention, but the present invention is not limited to these, and various modifications and changes can be made without departing from the scope of the present invention. is there.

  For example, in the above embodiment, the data erasing unit 33 periodically determines whether the total size of the image data stored in the storage device 16 exceeds a predetermined ratio of the storage capacity of the storage device 16. When the total size of the image data stored in the storage device 16 exceeds a predetermined ratio of the storage capacity of the storage device 16, the entire area or the rest of the image data partially overwritten is overwritten at that time. You may do it.

  The present invention can be applied to security functions of, for example, a printer, a copier, and a multifunction machine.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 11 Printer (an example of an image output part)
13 Facsimile device (example of image output unit)
16 Storage Device 31 Job Management Unit 32 Image Processing Unit 33 Data Erasing Unit

Claims (5)

A job management unit for generating an image output job;
An image processing unit for generating image data by the image output job;
A storage device for storing the image data;
An image output unit for performing printing based on the image data in the storage device or transmitting the image data;
At the end of the image output job, in the storage device, a part of the image data by the image output job is overwritten and erased, and when all the image output jobs generated by the job management unit are completed, A data erasing unit for overwriting erasing the entire or remaining image data that has been overwritten;
An image forming apparatus comprising:   When the security level setting value is a predetermined first value in the image output job, the data erasing unit stores the entire area of the image data by the image output job in the storage device at the end of the image output job. When overwriting is erased and the value of the security level setting is a predetermined second value, at the end of the image output job, the storage device overwrites a part of the image data by the image output job, 2. The image formation according to claim 1, wherein when all of the image output jobs generated by the job management unit are completed, the entire or remaining part of the image data in which a part is overwritten is overwritten. apparatus.   When no value is set in the security level setting in the image output job, the data erasing unit uses the image output job in the same manner as when the second value is set in the security level setting. 3. The image forming apparatus according to claim 2, wherein the image data is erased.   The data erasing unit releases the area of the image data in the storage device after the overwriting erasure of the entire area of the image data is completed. 2. An image forming apparatus according to item 1.   When the total size of the image data stored in the storage device exceeds a predetermined ratio of the storage capacity of the storage device, the data erasing unit overwrites a part at the end of any of the image output jobs. 5. The image forming apparatus according to claim 4, wherein the entire area or the rest of the erased image data is overwritten.

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