JP2020049878A - Image formation apparatus, image formation method and program - Google Patents

Abstract

To provide an image formation apparatus, an image formation method and program which can suppress input image data from being illegally accessed by a third party even when the maintenance operation is executed.SOLUTION: A compound machine 10 includes: RAM 113 which stores input data; and a control part 110 which forms an image on a recording sheet 30 on the basis of the input data. The control part 110 encodes the stored input data to make the encoded input data when it is determined that the maintenance operation prior to the image formation is executed, and performs the image formation on the basis of the decoded input data by decoding the encoded input data to make the decoded input data when it is determined that the maintenance operation is finished.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an image forming apparatus for forming an image on a sheet, an image forming method, and a program.

  2. Description of the Related Art Conventionally, various technologies relating to an image forming apparatus for forming an image on a sheet have been proposed.

  For example, an ink jet printer described in Patent Document 1 forms an image on a sheet by ejecting ink from a head provided on the carriage based on image forming data while reciprocating the carriage in a main scanning direction. After that, the operation of conveying the sheet at a constant pitch in the sub-scanning direction is repeated, so that an image is formed on the entire sheet.

JP 2005-349690 A

  By the way, in the above-mentioned conventional ink jet printer, a maintenance operation such as cleaning of a head may be executed before printing, in particular, but this maintenance operation generally requires time.

  Therefore, when the maintenance operation is performed, it takes time before printing is started, and during this time, there is a possibility that the input image data is illegally accessed by a third party.

  This danger may occur not only in an inkjet type image forming apparatus but also in an image forming apparatus of another type in which a maintenance operation is performed, for example, an image forming apparatus of an electrophotographic type.

  In view of the above, the present invention is directed to an image forming apparatus capable of preventing unauthorized access to input image data by a third party even when a maintenance operation is performed. , An image forming method, and a program.

  The invention according to claim 1, which has been made to solve this problem, includes a storage unit that stores input image data, an image forming unit that forms an image on a sheet based on the image data stored in the storage unit, Control means, when the control means determines that a maintenance operation prior to image formation by the image forming means is to be performed, encrypts the stored image data to obtain encrypted image data, and terminates the maintenance operation. If it is determined that the image data is decrypted, the encrypted image data is decrypted to obtain decrypted image data, and the image forming unit is controlled to form an image based on the decrypted image data.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the input image data is compressed image data, and the control unit sets the compressed image data to a predetermined size smaller than the data amount of the compressed image data. Decompressed to decompressed image data for each unit, encrypt the decompressed image data to encrypted image data, decrypt the encrypted image data to decrypted image data, control the image forming means, and An image is formed based on data.

  According to a third aspect of the present invention, in the image forming apparatus according to the second aspect, the control unit suspends the decompression of the subsequent compressed image data according to the data amount of the decompressed image data, and controls the subsequent compressed image data. Encrypting the data.

  According to a fourth aspect of the present invention, in the image forming apparatus according to the second aspect, when the control unit determines that the compressed image data of the second and subsequent pages is stored in the storage unit, the control unit determines that the second page is stored. The decompression of the compressed image data of the second and subsequent pages is suspended, and the compressed image data of the second and subsequent pages are encrypted.

  In order to solve this problem, the image forming method and the program according to the fifth and sixth aspects can be realized by the same technical idea as the first aspect.

  According to the invention of claim 1, 5 or 6, when it is determined that a maintenance operation prior to image formation is to be performed, the stored image data is encrypted. It is possible to reduce the risk of unauthorized access of input data used for image formation by a third party.

  According to the second aspect of the present invention, since the input image data is the compressed image data, a small-capacity storage unit can be used as the storage unit, thereby reducing the manufacturing cost of the entire image forming apparatus. it can. Further, since the decompressed image data is encrypted, the decompression process after decryption is not required, whereby image formation can be started quickly.

  According to the third aspect of the present invention, the decompression of the subsequent compressed image data is suspended according to the data amount of the decompressed image data, and the compressed image data is encrypted. Thus, the compressed image data can be encrypted as needed. In addition, since the encryption is performed on the compressed image data, a small-capacity storage unit can be used, and the manufacturing cost of the entire image forming apparatus can be reduced.

  According to the fourth aspect of the present invention, when it is determined that the compressed image data of the second and subsequent pages is stored in the storage unit, the decompression of the compressed image data of the second and subsequent pages is suspended, and Since the compressed image data of the second and subsequent pages is encrypted, even if the compressed image data can be input for a plurality of pages, a small storage device can be used as the storage means. Manufacturing costs can be reduced.

FIG. 1 is a block diagram illustrating a part of a configuration of a multifunction peripheral that is an image forming apparatus according to an embodiment of the present disclosure. FIG. 2 is a diagram for describing an outline of data processing performed in the multifunction peripheral from reception of print data generated by a personal computer externally connected to the multifunction peripheral of FIG. 1 to output of a print result on recording paper. . FIG. 2 is a diagram illustrating a state of a printing operation performed by a printer unit of the multifunction peripheral in FIG. 1. 2 is a timing chart illustrating timings of operations executed by each component of the multifunction peripheral in FIG. 1. 3 is a flowchart illustrating a procedure of a printing process executed by a CPU of the multifunction peripheral in FIG. 6 is a flowchart illustrating a procedure that follows the printing process of FIG. 5.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  The image forming apparatus according to the present embodiment is built on a multifunction peripheral (MFC) 10, as shown in FIG. The multifunction peripheral 10 has a copy function, a printer function, a scanner function, a facsimile function, and the like. However, in the present embodiment, since the printer function is mainly used, the configuration of the printer unit 100 is described in detail in FIG. Have been.

  As shown in FIG. 1, the printer unit 100 records (prints) an image (including characters) on a recording sheet (an example of a “sheet”) 30 (see FIG. 3) by an ink jet recording method. ing.

  The recording paper 30 is placed in a tray (not shown), and is supplied one by one to a transport path (not shown) by a paper feed roller 140. The paper feed roller 140 rotates by transmitting a driving force of an ASF (auto sheet feeder) motor 121 by a drive transmission mechanism (not shown) configured by meshing a plurality of gears.

  The head 120 has a nozzle surface on which a plurality of nozzles are formed. Each nozzle is connected to an ink cartridge (not shown) that stores any one of magenta (MZ), cyan (CY), yellow (YL), and black (BK) inks.

  The head 120 is held on a carriage 130. The carriage 130 receives a driving force transmitted from a CR (carriage) motor 122 via a drive transmission mechanism (not shown), and together with the head 120, moves in the width direction of the recording sheet 30 (in the transport direction of the recording sheet 30, that is, in the auxiliary direction). (The main scanning direction orthogonal to the scanning direction).

  The head 120 ejects the ink supplied from the ink cartridge onto the recording paper 30 during the reciprocating process in the main scanning direction. As a result, an image is formed on the recording paper 30 conveyed along the conveyance path.

  The carriage 130 is provided with an optical linear encoder 131. The linear encoder 131 includes an elongated encoder strip (not shown) on which graduations are formed along the main scanning direction, and a read head (not shown) for reading graduations of the encoder strip by an optical sensor (not shown). Have. The read head is held by the carriage 130, and the optical sensor faces the scaled surface of the encoder strip. As the carriage 130 moves, the optical sensor moves relative to the scale of the encoder strip, and the output of the optical sensor changes. The read head transmits a change in the output of the optical sensor as a pulse signal to a control unit 110 described later.

  Image formation of the entirety of one recording sheet 30 is executed by being divided into a plurality of passes. The pass is a series of operations in which the carriage 130 starts running and the head 120 ejects ink onto the recording paper 30 while the carriage 130 is running. By executing one pass, an image is recorded in an area of the recording paper 30 corresponding to the width of the nozzles arranged in the sub-scanning direction. After each pass, the recording sheet 30 is transported by a predetermined amount by a transport roller pair (not shown) including a transport roller 141 and a pinch roller (not shown) and stopped, and the next pass is executed. That is, an image is formed on the recording paper 30 in order from the downstream side in the transport direction. Note that the transport roller 141 is rotated by a rotational driving force transmitted from a PF (paper feed) motor 123 via a drive transmission mechanism (not shown).

  FIG. 3 shows how an image is formed on the recording paper 30. In the figure, each arrow indicates that the head 120 moves forward or backward from one end to the other end in the main scanning direction. Then, the path from the start point to the end point of each arrow corresponds to one pass. In other words, the rectangular position described as (1) (however, the half-width (1) corresponds to “Ichimaru” in the drawing. The same applies to the following) is the position of the head 120 that has completed the first pass printing process. Is shown. Similarly, the rectangular positions described in (2) to (6) (however, the half-width (2) to (6) respectively correspond to “nimaru” to “rokuromaru” in the drawings. The same applies hereinafter). 3 also shows the position of the head 120 after the printing process of the second to sixth passes. In the present embodiment, since the image formation for one sheet of the recording paper 30 is performed in five passes, the sixth pass corresponds to the printing process of the next page. Of course, the number of passes required for forming an image for one recording sheet 30 is not limited to five passes, and may be more or less. Further, it differs depending on the size of the recording paper 30.

  Returning to FIG. 1, the control unit 110 controls the operation of the entire MFP 10. The control unit 110 includes a central processing unit (CPU) 111, a read only memory (ROM) 112, a random access memory (RAM) 113, an electrically erasable and programmable read-only memory (EEPROM) 114, and an application specific integrated circuit (ASIC) 115. As a microcomputer. The components 111 to 115 are interconnected by an internal bus 116.

  The ROM 112 stores a program and the like for the CPU 111 to control various operations including image forming control of the MFP 10. The RAM 113 is used as a storage area for temporarily storing data, signals, and the like used when the CPU 111 executes the programs, or as a work area for data processing. The EEPROM 114 stores settings, flags, and the like that should be retained even after the power is turned off.

  An ASF motor 121, a CR motor 122, a PF motor 123, a head 120, a linear encoder 131, and a liquid crystal panel 150 are electrically connected to the ASIC 115. The ASIC 115 incorporates a drive circuit for controlling each of the motors 121 to 123.

  The ASIC 115 receives a pulse signal output from the linear encoder 131. The control unit 110 calculates the moving distance and position of the carriage 130 based on the pulse signal from the linear encoder 131, and controls the CR motor 122 so that the calculated moving distance and position match the target moving distance and position. Rotate. As described above, in the present embodiment, the moving distance and the position of the carriage 130 are controlled to indirectly control the moving distance and the position of the head 120. However, the moving distance and the position of the head 120 itself are directly controlled. , The moving distance and position of the head 120 itself may be directly controlled.

  The liquid crystal panel 150 is provided, for example, on the front of the multifunction peripheral 10 and displays various information necessary for operation. In the present embodiment, a touch panel type liquid crystal panel 150 is employed, so that the liquid crystal panel 150 also plays a role as an input device for inputting operation information.

  The multifunction device 10 is connected to a personal computer (PC) 20, as shown in FIG. In this embodiment, a LAN (local area network) connection is used as the connection mode. However, the present invention is not limited to this, and other connection modes such as an Internet connection and a USB (universal serial bus) connection may be used. Is also good.

  When a user instructs printing of an image (including a document) displayed on a display (not shown) of the PC 20, (a print driver (print driver) of) the PC 20 prints the specified image. The data 200 is generated and output to the MFP 10.

  When the print data 200 is output from the PC 20, the MFP 10 inputs the print data 200 and temporarily stores the print data 200 in the input data storage area 113a secured on the RAM 113. The print data 200 stored in the input data storage area 113a is hereinafter referred to as "input data".

  In this embodiment, the print data 200 is composed of print information indicating bibliographic items of the print data 200 and data obtained by compressing dot data for each print line for each color.

  As examples of the print information, as shown in FIG. 2, “data format” indicating the data format of the print data 200, “paper size” indicating the size of the recording paper 30 on which the print data 200 is printed, and the type of paper medium ( A “paper medium” indicating a normal copy paper, an inkjet dedicated paper, a film, etc.), a “compression format” indicating a compression method used for compression, and the like.

  The dot data indicates whether or not ink is ejected for each dot for each print line of each color, and includes each print line of each color of magenta (MZ), cyan (CY), yellow (YL), and black (BK). Is represented as a collection of dot data for Further, the dot data is compressed by the compression method indicated by the above-mentioned "compression format" command.

  Hereinafter, an image forming process executed by the MFP 10 configured as described above will be described with reference to FIGS.

  FIG. 4 illustrates operations performed by the components (mechanisms) of the multifunction peripheral 10, specifically, “print data analysis processing”, “print data decompression processing”, “cleaning operation”, “pre-print operation”, and “supply operation”. The timing of "paper-print-discharge" is shown. However, since the “pre-print operation” and the “paper feed to print to paper discharge” operation are not necessary for explaining the features of the present invention, specific operation items and operation timings included in the respective operations are Not shown. FIG. 4 also does not show the operation items executed on the PC 20 side and their operation timings.

  In FIG. 4, each strip-shaped frame indicates the timing at which the mechanism described at the left end, that is, the component executes the operation indicated by the item described at the right side thereof. In the figure, “0” on the bottom time axis indicates a point in time when the user presses a print button (not shown) displayed on the display of the PC 20 by, for example, a mouse click. That is, the period from “0” to the start of “print data analysis [input data]” indicates the timing at which the PC 20 generates the print data 200 and outputs the print data 200 to the multifunction device 10 in response to a print instruction from the user. ing.

  When the PC 20 starts outputting the print data 200 to the multifunction peripheral 10, the CPU 111 of the multifunction peripheral 10 receives the data and stores it in the input data storage area 113a of the RAM 113 as described above. Starts the printing process.

  In the printing process, first, the CPU 111 determines whether there is a page to be printed (step (S) 1). This determination is inserted in order to determine whether or not one page has been printed in step 14 of FIG. 6 described later and whether there is any more pages to be printed.

  As a result of the determination in step 1, when the CPU 111 determines that there is no page to be printed, the CPU 111 ends the print processing. On the other hand, when the CPU 111 determines that there is a page to be printed, the processing proceeds to step 2. At the start of the printing process, there is usually a page to be printed. At this time, the CPU 111 determines “YES” in step 1 and proceeds to the next step 2.

  In step 2, the CPU 111 determines whether or not the print setting information of the input data has been analyzed. If it is determined that the analysis has not been completed, the CPU 111 waits until the analysis is completed. On the other hand, as a result of the determination in step 2, when the CPU 111 determines that the print setting information of the input data has been analyzed, the CPU 111 determines from the analysis result whether or not it is necessary to perform a maintenance operation before printing ( Step 3). As a result of this determination, when the CPU 111 determines that it is not necessary to perform the maintenance operation before printing, the CPU 111 prints one page of the page (step 14 in FIG. 6), while performing the maintenance operation before printing. When it is determined that the maintenance process needs to be performed, the maintenance process is started (step 4).

  Specifically, the operations included in the maintenance process started in step 4 include a cleaning operation of the nozzles of the head 120, a print color adjustment (calibration), and the like. In the timing chart shown in FIG. 4, a cleaning operation is exemplified as the maintenance operation.

  Next, the CPU 111 determines whether or not the input data has been analyzed for a predetermined amount or more (step 5). Here, “analysis” includes, in addition to the processing performed in the “print data analysis processing” (see FIG. 4), the processing performed in the “print data decompression processing” (see FIG. 4), ie, decompression of the input data. And generating output data. Further, the determination in step 5 is based on the processing of the following steps 9 and 10 (FIG. 6), that is, when there is the following input data before decompression, the encryption processing for the input data before decompression is performed by the input data after decompression. (Output data) is inserted for the purpose of performing according to the data amount. In the present embodiment, the “predetermined amount” is a data amount for one page. Of course, it is not limited to this data amount.

  In FIG. 4, the item “input data encryption” belonging to “cleaning operation” is determined to be “YES” in the determination in step 9 and the input data before decompression is encrypted in the processing in step 10. Is shown. The process proceeds from step 5 to step 9 when the input data has been analyzed for a predetermined amount or more, that is, for one page or more, as described above. Therefore, at this time, the input data for two pages or more is stored in the input data storage area 113a, and at the timing of the “input data encryption”, the input data for one page has been analyzed. The input data from the next page that has not been analyzed is encrypted.

  As a result of the determination in step 5, when the CPU 111 determines that the input data has not been analyzed by a predetermined amount or more, the CPU 111 analyzes the input data in a predetermined unit (step 6). Here, the “analysis” includes the decompression processing of the input data as described above. In the present embodiment, the “predetermined unit” is a unit of one pass, that is, a unit of a data amount of input data for generating output data used for one-pass printing.

  In FIG. 4, the item “Print data decompression [input data → output data]” indicates the generation timing of the output data (1) to (5) generated by the processing of step 6 described above. As shown in the figure, the output data (1) to (5) are generated in units of one pass.

  Of course, the “predetermined unit” is not limited to this, and may be another unit such as a color unit, a line unit, or a page unit.

  Next, the CPU 111 determines whether there is output data to be encrypted (step 7 in FIG. 6). As a result of this determination, when the CPU 111 determines that there is output data to be encrypted, the CPU 111 encrypts the output data (step 11) and then proceeds to step 8 while determining that there is no output data to be encrypted. If so, step 11 is skipped and the process proceeds to step 8.

  In FIG. 4, items “output data encryption (1)” to “output data encryption (5)” belonging to “cleaning operation” respectively correspond to the encryption of the output data (1) to (5) by the processing in step 11 described above. FIG. As shown in the figure, immediately after the decompression of the output data (1) to (5) is completed, each of them is encrypted.

  On the other hand, as a result of the determination in step 5 in FIG. 5, when the CPU 111 determines that the input data has been analyzed by a predetermined amount or more, the process proceeds to step 9 in FIG. Since the processing performed in steps 9 and 10 has been described above, a description thereof will be omitted.

  After the processes in steps 9 and 10, CPU 111 proceeds to step 8.

  In step 8, the CPU 111 determines whether the maintenance process started in step 4 is completed. As a result of this determination, when the CPU 111 determines that the maintenance process is still continuing, the process returns to step 5 in FIG. 5 described above, and when it is determined that the maintenance process is completed, the process proceeds to step 12.

  In step 12, the CPU 111 decrypts the encrypted output data. In the following step S13, if the input data is encrypted, it is decrypted.

  Then, the CPU 111 prints one page of the recording paper 30 based on the unencrypted output data (step 14), and then returns the process to step 1 (FIG. 5).

  As described above, the MFP 10 of the present embodiment includes the RAM 113 that stores input data, and the control unit 110 that forms an image on the recording paper 30 based on the input data.

  If the control unit 110 determines that a maintenance operation prior to image formation is to be performed, the stored input data is encrypted to be encrypted input data. The encrypted input data is decrypted as decrypted input data, and an image is formed based on the decrypted input data.

  As described above, in the MFP 10 according to the present embodiment, when it is determined that the maintenance operation is to be performed, the input data is encrypted. Thus, the risk of unauthorized access can be reduced. Here, specific examples of unauthorized access to data include reading, falsification, copying, and retrieval of the data via a network.

  Incidentally, the input data is an example of “input image data”. The RAM 113 is an example of a “storage unit”. The control unit 110 is an example of a “generation unit” and a “control unit”.

  In the present embodiment, the input data is compressed dot data, and the control unit 110 decompresses the compressed input data for each predetermined unit smaller than the data amount of the compressed input data to generate output data. The output data is encrypted to generate encrypted output data, the encrypted output data is decrypted to obtain decrypted input data, and an image is formed based on the decrypted input data.

  As described above, in the MFP 10 of the present embodiment, since the input data is the compressed dot data, a small-capacity RAM 113 can be used, thereby reducing the manufacturing cost of the entire MFP 10. be able to. In addition, since the output data is encrypted, the decompression process after decryption is not required, so that image formation can be started quickly.

  Further, in the present embodiment, the control unit 110 suspends the decompression of the subsequent compressed input data and encrypts the compressed input data according to the data amount of the output data (steps 5 and 6 in FIG. 5 and FIG. 6). 9 and 10), the input data can be encrypted according to the data amount of the output data. Further, since the encryption is performed on the compressed input data, a small-capacity RAM 113 can be used, thereby reducing the manufacturing cost of the entire MFP 10.

  Further, in the present embodiment, the decompression of the subsequent compressed input data is suspended, and the criterion for determining whether to encrypt the compressed input data is that the data amount of the output data is equal to or larger than a predetermined amount ( (See step 5 in FIG. 5). In the present embodiment, as described above, the data amount for one page is exemplified as the “predetermined amount” (see the item “input data encryption” belonging to “cleaning operation” in FIG. 4).

  As described above, in the present embodiment, when the CPU 111 of the control unit 110 determines that the compressed input data of the second and subsequent pages is stored in the RAM 113, the CPU 111 decompresses the compressed input data of the second and subsequent pages. The compressed input data of the second and subsequent pages is encrypted. As a result, even if input data for a plurality of pages can be input, a small-capacity RAM 113 can be used, so that the manufacturing cost of the entire MFP 10 can be reduced.

  Note that the present invention is not limited to the above embodiment, and various changes can be made without departing from the gist of the present invention.

  (1) In the above embodiment, the start timing of the maintenance process is adopted as the timing for encrypting the input data and the output data (see step 4 in FIG. 5 and steps 10 and 11 in FIG. 6). However, the present invention is not limited thereto, and a timing before a predetermined second before starting the maintenance process may be adopted. In the above embodiment, the timing for ending the maintenance processing is adopted as the timing for decrypting the encrypted input data and output data (see steps 8, 12, and 13 in FIG. 6). Instead, a timing before or after a predetermined second to end the maintenance process may be adopted.

  (2) In the above embodiment, the print data 200 generated by the PC 20 is composed of print information indicating bibliographic items of the print data 200 and data obtained by compressing dot data for each print line for each color. However, the present invention is not limited to this, and the PC 20 may generate and output image data described in a page description language (PDL).

  (3) In the above embodiment, the color MFP 10 is employed as the image forming apparatus. However, the present invention is not limited to this, and a monochrome MFP may be employed. Further, the present invention is not limited to the form of the multifunction peripheral, but may be a form of a printer having only a printing function. Of course, the printer may be either one capable of color printing or one capable of only monochrome printing. In the above-described embodiment, the printer unit 100 employs an apparatus that records an image on a sheet by an inkjet recording method. However, the invention is not limited to this, and an image forming apparatus of another method in which a maintenance operation is performed, for example, An electrophotographic image forming apparatus may be employed (the same applies to a single printer). As a specific maintenance process when an electrophotographic image forming apparatus is employed, there is a preparatory rotation performed when an image on the photosensitive drum is defective. Of course, the present invention is not limited to this as long as it falls within the category of maintenance processing.

  (4) In the above embodiment, whether to suspend the decompression of the subsequent compressed input data is determined based on the data amount of the output data. However, the present invention is not limited to this, and the determination is performed based on the free space of the RAM 113. You may make it. As a result, a small-capacity RAM 113 can be used, so that the manufacturing cost of the entire multifunction peripheral 10 can be reduced.

  10 MFP, 100 printer unit, 110 control unit, 111 CPU, 112 ROM, 113 RAM, 115 ASIC, 120 head, 121 ASF motor, 122 CR motor, 123 PF motor, 130 carriage, 131 linear encoder.

Claims (6)

Storage means for storing input image data;
Image forming means for forming an image on a sheet based on the image data stored in the storage means,
Control means,
The control means includes:
When it is determined that a maintenance operation prior to image formation by the image forming unit is to be performed, the stored image data is encrypted to be encrypted image data,
If it is determined that the maintenance operation is to be terminated, the encrypted image data is decrypted into decrypted image data,
Controlling the image forming means to form an image based on the decoded image data;
An image forming apparatus comprising: The input image data is compressed image data,
The control means includes:
The compressed image data is decompressed for each predetermined unit smaller than the data amount of the compressed image data as decompressed image data,
Encrypting the decompressed image data into the encrypted image data;
Decrypting the encrypted image data as the decrypted image data,
Controlling the image forming means to form an image based on the decoded image data;
The image forming apparatus according to claim 1, wherein: The control means includes:
According to the data amount of the decompressed image data, suspending the decompression of the subsequent compressed image data, and encrypting the subsequent compressed image data,
The image forming apparatus according to claim 2, wherein: The control means includes:
When it is determined that the compressed image data of the second and subsequent pages is stored in the storage unit,
Suspending the decompression of the compressed image data of the second and subsequent pages,
Encrypting the compressed image data of the second and subsequent pages,
The image forming apparatus according to claim 2, wherein: An image forming step of forming an image on a sheet based on the input image data stored in the storage means,
And a control step.
In the control step,
If it is determined that a maintenance operation prior to image formation in the image forming step is performed, the stored input image data is encrypted to be encrypted image data,
If it is determined that the maintenance operation is to be terminated, the encrypted image data is decrypted into decrypted image data,
Controlling the image forming step, forming an image based on the decoded image data,
An image forming method comprising: On the computer,
Image forming processing for forming an image on a sheet based on the input image data stored in the storage means,
Control processing;
Is a program that executes
In the control processing,
If it is determined that a maintenance operation prior to image formation by the image forming process is performed, the stored input image data is encrypted to be encrypted image data,
If it is determined that the maintenance operation is to be terminated, the encrypted image data is decrypted into decrypted image data,
Controlling the image forming process, forming an image based on the decoded image data,
A program characterized by that:

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