JPH10282856A - Device and method for forming image and storage medium storing image forming procedure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device, an image forming method by which security is maintained or a storage medium is made effective by erasing stored image data or the image data of a format with lapse of set time and the storage medium storing an image forming procedure. SOLUTION: When the stop state of printing work is confirmed (S801), the data stored in the storage medium is held as long as the stored time if the stop state is the interruption of the printing work caused by paper jam and the like. If the stop state is the finish of the normal printing work, this control action is finished. In the case of the abnormal stop state, the restart of the printing work is monitored. When it is judged that the printing work is not started again within the set time (S802), the image data is erased from the storage medium and the control action is finished (S804). In the case that the stop state is not abnormal, the printing work is started again by using the stored content (S803).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image forming apparatus, an image forming method, and a storage medium storing an image forming procedure.

More specifically, the present invention is applicable to, for example, a digital copying machine having an image data storage function.
The present invention relates to an image forming apparatus, an image forming method, and a storage medium storing an image forming procedure.

[0003]

2. Description of the Related Art Conventionally, by reading an image of a document to be printed and storing the image data in a storage medium such as a hard disk or a MOD (Magneto-optical storage device), image data can be saved / edited / multiple-sheet data. There is also known a function in which printing can be performed again by reading stored image data without rereading a document even if a trouble occurs during printing, and the like.

There is also known a technique in which a specific format is stored in a partial area of a storage medium, and is combined with another original and printed.

[0005]

In an image forming apparatus having an image storage medium as described above, when a printing operation is interrupted due to a paper jam or the like, the printing operation is restarted using the stored image data. There are things that are. However,
If the paper jam cannot be dealt with promptly, the image data will remain stored in the storage medium forever.

For this reason, when a paper jam is dealt with by a third party, for example, when the user leaves the image forming apparatus without taking measures to recover the paper jam, the image is viewed by the third party, and the confidential image is viewed. There is a disadvantage that leakage occurs.

[0007] In addition, if a format that is no longer used is stored for a long time without erasing, there is a disadvantage that the storage medium cannot be used effectively.

[0008] Therefore, an object of the present invention is given in view of the above points,
An image forming apparatus, an image forming method, and an image forming procedure in which stored image data or format image data are erased with the lapse of a set time to secure confidentiality or that a storage medium can be used are stored. It is to provide a storage medium.

[0009]

In order to achieve the above object, according to the first aspect of the present invention, an image of a document is read,
Image reading means for outputting document image data, image storage means for storing the document image data in a storage medium, image forming means for reading an image stored in the image storage means and forming an image, A set time storing means for storing the original image data; and an erasing means for erasing the stored document image data after the elapse of the set time.

In the present invention, the set time is input via an operation panel.

According to a third aspect of the present invention, the erasing means monitors the state of the printing operation, and when the operation is abnormally stopped, only when the printing operation is not resumed within the set time,
The document image data is deleted.

In the present invention, when the printing operation is restarted within the set time, an image is formed using the original image data stored in the image storage means.

According to a fifth aspect, the image forming means forms a visible image according to an electrophotographic process.

According to a sixth aspect, a format image such as a frame of a document is stored in a predetermined storage medium.

In a preferred embodiment, the format image is deleted from the storage medium after a predetermined time has elapsed.

In the present invention, after the predetermined set time has elapsed, only the original image data is stored in the image storage means.

In the ninth aspect, the image of the original is read, the original image data is output, the original image is stored, and the original image data is deleted after a predetermined time has elapsed.

According to a tenth aspect of the present invention, the state of the printing operation is monitored, and when the operation is abnormally stopped, the original image data is deleted only when the printing operation is not restarted within the set time.

In the eleventh aspect, when the printing operation is restarted within the set time, an image is formed using the stored original image data.

In the twelfth aspect, an image of a document is read, document image data is output, and the document image is stored.
The procedure for erasing the document image data after the elapse of a predetermined time is stored as a program.

As described above, according to the present invention, for example, when a printing operation such as a paper jam is interrupted, the image data disappears when a preset time elapses, so that the image processing apparatus is separated from the image processing apparatus. However, image data is not kept stored forever, and leakage of confidentiality can be suppressed.

Further, by setting a storage time for a format image, a format image that has not been used for a certain period can be erased, and the area of the storage medium can be effectively used. [Detailed description of the invention]

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

Embodiment 1 FIG. 1 is a sectional view showing an example of an image forming apparatus (digital copying machine) to which the present invention is applied. In this figure, 100
Is a copier body, and 180 is a circulating automatic document feeder (RD
F). Reference numeral 101 denotes a platen glass as a document table. Reference numeral 102 denotes a scanner, and a document illumination lamp 1
03, a scanning mirror 104 and the like. The scanner 102 is reciprocally scanned in a predetermined direction by a motor (not shown), and the reflected light of the document passes through the lens 108 via the scanning mirrors 104 to 106 to form an image on the CCD sensor 109. Reference numeral 120 denotes an exposure control unit including a laser and a polygon scanner, and an image sensor unit CC.
A laser beam 129 which is converted into an electric signal by the D sensor 109 and modulated based on an image signal on which predetermined image processing described later has been performed irradiates the photosensitive drum 110.

Around the photosensitive drum 110, a primary charger 112, a developing device 121, a transfer charger 118, a cleaning device 116, and a pre-exposure lamp 114 are provided.

In the image forming section 126, the photosensitive drum 110 is rotated by a motor (not shown) in the direction of the arrow shown in the figure, and after being charged to a desired potential by the primary charger 112, the exposure control section 120 Is applied to form an electrostatic latent image. The electrostatic latent image formed on the photosensitive drum 110 is developed by the developing device 121 and is visualized as a toner image.

On the other hand, in the upper cassette 131, the transfer paper fed from the lower cassette 132 by the pickup rollers 133 and 134 is fed to the main body via the paper feed rollers 135 and 136 and the registration roller 137. Then, the visualized toner image is transferred to transfer paper by the transfer charger 118. After the transfer, the photosensitive drum 110 is cleaned of residual toner by the cleaning device 116, and the residual charge is erased by the pre-exposure lamp 114.

The transfer paper after the transfer is charged to a pre-fixing charger 139,1.
The toner image is recharged by 40, sent to the fixing device 141, fixed by pressure and heat, and discharged out of the main body 100 by the discharge roller 142.

The main body 100 is equipped with a paper deck 150 capable of feeding, for example, 4000 transfer papers. The lifter 151 of the paper deck 150 rises according to the amount of transfer paper so that the transfer paper always contacts the paper feed roller 152. Also, it can accommodate 100 transfer papers,
A multi-hand feed unit 153 is provided.

Further, in FIG. 1, reference numeral 154 denotes a paper discharge flapper, which switches the path between the double-side recording side or the multiple recording side and the paper discharge side. The transfer paper fed from the paper discharge roller 142 is switched by the paper discharge flapper 154 to a double-side storage side or a multiple recording side. Reference numeral 158 denotes a lower transport path, which reverses the transfer paper sent from the paper discharge roller 142 through the reversing path 155 and turns the transfer paper
Lead to 6. Reference numeral 157 denotes a multiplex flapper for switching the path between double-sided recording and multiplexed recording. When the flapper is tilted to the left, the transfer paper is directly guided to the lower transport path 158 without passing through the reversing path 155.

Reference numeral 159 denotes a paper feed roller for feeding the transfer paper to the photosensitive drum 110 through the path 160. 16
Reference numeral 1 denotes a discharge roller that is disposed near the discharge flapper 154 and discharges the transfer sheet switched to the discharge side by the discharge flapper 154 to the outside of the apparatus. During double-sided recording (double-sided copying) or multiple recording (multiplexed copying), the discharge flapper 15
4 upward and transport the copied transfer paper to the transport path 15.
Re-feed tray 156 in the state of being turned upside down through 5,158
To be stored. At this time, during double-sided recording, the multiplex flapper 157 is tilted rightward. At the time of multiplex printing, the transfer sheets stored in the re-feed tray 156 are guided to the registration rollers 137 of the main body via the path 160 by the feed rollers 159 one by one from below.

When the transfer sheet is inverted and discharged from the main body, the discharge flapper 154 is raised, the flapper 157 is tilted rightward, and the copied transfer sheet is transported to the transport path 155 side. Thereafter, the trailing end of the transfer paper is
, The sheet is conveyed to the second feed roller 162a side by the reversing roller 163, and the transfer paper is turned over by the discharge roller 161 and discharged out of the apparatus.

FIG. 2 is a block diagram of the image forming apparatus shown in FIG.

In the figure, the image reading unit 201 has a C
It is configured by the CD sensor 109, the analog signal processing unit 202, and the like. Here, the original image formed on the CCD sensor 109 via the lens 108 is
Is converted into an analog electric signal. The image information converted into an analog signal is converted into an analog-to-digital signal (A
/ D conversion), shading correction (variation of a sensor for reading a document, and correction of light distribution characteristics of a document illumination lamp) and scaling processing are performed, and the result is input to an electronic sorter unit 203.

The electronic sorter unit 203 performs correction processing necessary for an output system such as gamma correction, smoothing processing, edge enhancement, other processing, processing, and the like.
4 is output.

The printer 204 includes the exposure control unit 120, the image forming unit 126, and the transfer sheet transfer control unit shown in FIG. 1, and records an image on a transfer sheet according to an input image signal.

The CPU circuit unit 205 includes the CPU 20
6, ROM 207, RAM 208, etc.
It controls the image reading unit 201, the electronic sorter unit 203, the printer unit 204, and the like, and controls the sequence of the apparatus in a comprehensive manner.

FIG. 3 is a block diagram showing a detailed configuration of the electronic sorter unit 203. The image sent from the image reading unit 201 is input as luminance data,
01 is sent. The logarithmic conversion unit 301 stores an LUT (Look Up Table) for converting the input luminance data into density data, and outputs a table value corresponding to the input data, thereby obtaining the luminance. Convert the data to concentration data.

Thereafter, the density data is sent to the binarizing section 302. In the binarizing unit 302, the multi-valued density data (8 bits) is binarized (1 bit), and the density value becomes “0” or “255”. That is, since 8-bit density data is converted to 1-bit density data, the amount of image data stored in the memory is reduced.

However, when the image is binarized, the number of gradations of the image is changed from 256 gradations to two gradations. Therefore, image data having a large number of halftones, such as a photographic image, is generally significantly deteriorated. Therefore, it is necessary to perform pseudo halftone expression using binary data. Here, an error diffusion method is used as a method for pseudo-halftone expression using binary data. This method uses “25” when the density of a certain image is larger than a certain threshold.
It is assumed that the density data is "5", and if it is equal to or less than a certain threshold value, the data is binarized as being "0" density data, and the difference between the actual density data and the binarized data is used as an error signal. Of pixels. The distribution of the error is performed by multiplying a weight coefficient on a matrix prepared in advance by an error generated by the binarization and adding the multiplied error to surrounding pixels. As a result, the density average value of the entire image is stored, and the halftone can be represented in a pseudo binary manner.

The binarized image data is supplied to the control unit 303.
Sent to In the control unit 303, according to a command from the main body,
The entire image of the document to be copied is temporarily stored in the image storage unit 304, or image data is sequentially read from the image storage unit 304 and output.

The image storage unit 304 has a SCSI controller and a hard disk (memory), and writes image data to the hard disk according to a command from the SCSI controller. The plurality of image data stored on the hard disk are output in an order according to the editing mode specified by the operation unit (see FIG. 4) of the copying machine. For example, in the case of sorting, the originals are sequentially read from the last page to the first page of the bundle of originals, and are temporarily stored in the hard disk. And
The image data of the document once stored is read from the hard disk in order from the last page to the first page, and this is repeated and output plural times. Thereby, it can play the same role as a sorter having a plurality of bins.
In addition, since images can be saved, multiple copies can be printed without reading the original multiple times, and when resuming printing due to a paper jam, the stored original must be read. Disappears.

The image data read from the image storage unit 304 is sent to the smoothing unit 305. The smoothing unit 305 first converts 1-bit data into 8-bit data, and sets the image data signal to a state of “0” or “255”.

The converted image data is obtained as a sum of values obtained by multiplying a predetermined coefficient on a matrix by the density value of a neighboring pixel, and is replaced with a weighted average value. As a result, the binary data is converted into multivalued data in accordance with the density value of the neighboring pixels, and an image quality closer to the read image can be reproduced.

The smoothed image data is supplied to the γ correction unit 30.
6 is input. When outputting density data, the γ correction unit 306 performs conversion using an LUT in consideration of printer characteristics, and adjusts output according to the density value set by the operation unit (see FIG. 4).

FIG. 4 is a plan view showing an example of an operation panel of the image forming apparatus (digital copying machine) shown in FIG.
In the key group 600, reference numeral 601 denotes an asterisk (*) key, which is used by an operator (user) when setting a binding margin, setting a size of a document frame eraser, and collating an ID. An all reset key 606 is pressed when returning to the standard mode. Reference numeral 602 denotes a remaining heat key, which is depressed when the machine of the copying machine main body 100 is set to the preheat state and when the preheat state is released. The preheating key 602 is also pressed when returning from the auto shut-off state to the standard mode.

A copy start key (copy start key) 605 is pressed to start copying.

A clear stop key 604 functions as a clear key during standby (standby) and as a stop key during copying and recording. The clear stop key 604 is pressed to cancel the set number of copies. Also used to release the * (asterisk) mode. The clear stop key 604 is also pressed when interrupting continuous copying. When the key 604 is pressed, the copying operation is stopped after the copying is completed.

A numeric keypad 603 is used when setting the number of copies, setting an * (asterisk) mode, and inputting an ID (for example, a six-digit code). A job mode memory key 619 allows a user to register and call a frequently used job mode. Here, four types of registrations M1 to M4 can be registered for each section (individual).

Reference numerals 611 and 612 denote copy density keys which are depressed when manually adjusting the copy density. 613 is A
The E key is pressed when automatically adjusting the copy density in accordance with the density of the original, or when canceling the AE and switching the density adjustment to manual (manual).

Reference numeral 607 denotes a cassette selection key, which is pressed to select the upper cassette 131, the lower cassette 132, and the paper deck 150. Also, RDF
When a document is placed on 180, APS (automatic paper selection) can be selected with the cassette selection key 607. When APS is selected, a cassette of sheets having the same size as the original is automatically selected.

Reference numeral 610 denotes an equal-size key, which is depressed when making a copy of the same size (original size). An automatic scaling key 616 is pressed when automatically reducing or enlarging the image of the original according to the size of the specified transfer sheet. 617 and 618
Is a zoom key used to designate an arbitrary magnification between 64% and 142%. Reference numerals 608 and 609 denote fixed size scaling keys, which are pressed when designating reduction / enlargement of the fixed size.

Reference numeral 626 denotes a double-sided key which is depressed to make double-sided copying from a single-sided original, double-sided copying from a double-sided original, and single-sided copying from a double-sided original. A binding margin key 625 can create a binding margin of a designated length on the left side of the transfer sheet. A photo key 624 is pressed when copying a photo document. A multiple key 623 is pressed to create (combine) an image on the same side of a sheet (copy paper) from two originals.

Reference numeral 620 denotes a document frame erasing key which is pressed when the user uses the frame erasing of a fixed size document, and the size of the document at that time is set by the asterisk key 601.

Reference numeral 621 denotes a sheet frame erasing key, which is pressed when erasing a document frame in accordance with the size of a cassette.

Reference numeral 622 denotes a continuous page copy key, which is depressed when copying the left and right pages of the document on separate sheets.

Reference numeral 614 denotes a paper discharge method (staple, sort,
If a stapler that can be used to staple the recorded sheets is connected, the staple mode and the sort mode can be selected or canceled, and the sorting tray (sorter) or electronic sorter When connected, the user can select or cancel the sort mode or group mode.

A paper folding selection key 615 is used to select and cancel a Z-fold that folds a recorded sheet of A3 or B4 size into a Z-shaped cross section and a half-fold that folds the paper in half.

Reference numeral 627 denotes an interrupt key. When pressed during copying, its function is interrupted and a new copy (hereinafter referred to as interrupt copy) is enabled. If the button is pressed during the interrupt copy mode setting, the interruptable state is released.

Reference numeral 628 denotes a reservation key for canceling the registration of the reservation copy. When the reservation key 628 is pressed, a copy mode different from the already set copy mode can be set. Here, a copy mode to be registered is set, and when the setting is completed, the reservation setting key 629 is pressed. Thus, the set copy mode is stored in the RAM.

Reference numeral 630 denotes an ID key for registering an ID.
Used for correction, erasure, and collation.

Reference numeral 631 denotes a job correction key, which is pressed when the user wants to correct a job while reading a document or storing document data in the hard disk of the electronic sorter.

Reference numeral 632 denotes a document reading key,
Just read and store all the documents set in the hard disk of the electronic sorter (do not print)
Key to set the state of

In the display group 700 shown in FIG.
Reference numeral 01 denotes an LCD (liquid crystal) type message display for displaying information relating to copying. For example, one character is composed of 5 × 7 dots, a message of 40 characters, and fixed-size scaling keys 608, 609, 1x key 61
0, the copy magnification set by the zoom keys 617 and 618 can be displayed. The display 701 is a translucent liquid crystal, and normally turns on a green backlight.

Reference numeral 703 denotes a color development display, which is turned on when a sepia developer is set. A copy number display 702 displays the number of copies or a self-diagnosis code. Reference numeral 705 denotes a used cassette display, which indicates which of the upper cassette 131, the lower cassette 132, and the paper deck 150 is selected. An AE display 704 is turned on when AE (automatic density adjustment) is selected by the AE key 613. Reference numeral 709 denotes a preheating indicator, which is a two-color LED of green and orange, which lights green when ready (when copying is possible) and lights orange when waiting (when copying is impossible).

Reference numeral 708 denotes a double-sided copy display which is turned on when one of double-sided copy from a double-sided original and double-sided copy from a single-sided original is selected.

A power lamp 710 is turned on when a power switch is turned on. Reference numeral 711 denotes an interrupt indicator, which lights when an interrupt copying mode is set and during interrupt copying. A reservation registration display 712 lights when a reservation copy is registered.

Next, the control procedure in this embodiment is as follows.
This will be described with reference to FIG.

First, in step S800, a storage time is set using a numeric keypad before a copy operation. The setting need not be performed if this time is already stored.

In step S801, the stop of the printing operation is monitored. If the stop is confirmed in step S801,
If the reason is that the printing operation is interrupted due to a paper jam or the like, the data stored in the storage medium is held for the time stored in step S800. If the normal printing operation has ended, this control ends.

In step S802, restart of the printing operation is monitored. If it is determined in step S802 that the printing operation is not restarted within the set time, step S80 is performed.
Then, the control is moved to 4, and the image data is deleted from the storage medium, and the control is terminated. If not, the process advances to step S803 to resume printing using the stored content. Then, the process returns to step S801 to monitor the stop of printing. By doing so, it becomes possible to cope with the second and third interruptions.

FIG. 6 is a flowchart showing a modified example of the above step (FIG. 5). In this figure, first, in step S1800, a storage time is set from the operation panel using a numeric keypad or the like before a copy operation. The set value is stored on the RAM. Therefore, this operation does not necessarily have to be performed every time, and the setting does not have to be performed as long as the time is stored.

In step S1801, it is monitored whether or not copying has been started. In step S1802, a printing operation is performed.

In step S1803, the stop of the printing operation is monitored. When the stop is confirmed in step S1803, if the reason is the interruption of the printing operation caused by the abnormal stop due to a paper jam or the like and if the recovery is recoverable, the print medium is stored in the storage medium for the time stored in step S1800. Retain saved data.

The stoppage of the recoverable printing operation is caused, for example, when the printing operation is stopped due to a paper jam or when the printing paper runs out. The non-recoverable suspension of the printing operation includes, for example, the suspension of the printing operation due to a failure of the storage medium.

If the normal printing operation is completed, this control is completed. If the stop is abnormal, step S1
At 805, the restart of the printing operation is monitored.

If it is determined in step S1805 that the printing operation is not to be resumed within the set time, the process proceeds to step S1805.
At 1807, the image data is erased from the storage medium, and the control ends. In this way, by erasing the data in step S1807, leakage of confidential documents and the like does not occur.

If the printing operation is restarted within the set time in step S1805, printing is restarted using the contents saved in step S1803. Then, the process returns to step S1801 to monitor printing stop. By doing so, it becomes possible to cope with the second and third interruptions.

According to the first embodiment described above, when the printing operation is interrupted, it is possible to avoid a state in which the image is stored forever, so that the confidentiality can be maintained.

Embodiment 2 FIG. 7 is a flowchart showing a control procedure according to a second embodiment. The hardware configuration shown in FIGS. 1 to 4 is the same as that of the above-described embodiment.

First, in step S900, a format image data storage time is set and stored when a format image is recorded.

In step S901, the elapsed time since the last use of the format image is obtained.

In step S902, the elapsed time is compared with the storage time. If the elapsed time is longer than the storage time, the flow advances to step S903 to delete the format image data and end the control. If not, the process returns to step S901, and the image is kept stored.

According to the second embodiment described above, since the format image that has not been used for the preset time is erased, the storage medium can be effectively used.

The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of one device. Needless to say, the present invention can be applied to a case where the present invention is achieved by supplying a program to a system or an apparatus. In this case, by reading a storage medium storing a program represented by software for achieving the present invention into the system or the apparatus, the system or the apparatus can enjoy the effects of the present invention. Becomes

[0086]

As described above, according to the present invention, the stored image data or format image data is erased with the lapse of a set time, so that confidentiality can be ensured or the storage medium can be used. The image forming apparatus, the image forming method, and the storage medium storing the image forming procedure can be realized.

[Brief description of the drawings]

FIG. 1 is a cross-sectional configuration diagram of an image forming apparatus to which the present invention is applied.

FIG. 2 is a block diagram of the image forming apparatus shown in FIG.

FIG. 3 is a block diagram showing a detailed configuration of an electronic sorter unit shown in FIG.

FIG. 4 is a diagram showing an operation panel of the image forming apparatus shown in FIG.

FIG. 5 is a flowchart illustrating a control procedure according to the first embodiment.

FIG. 6 is a flowchart showing a modified example of FIG.

FIG. 7 is a flowchart illustrating a control procedure according to the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 100 Copier main body 120 Exposure control part 126 Image forming part 180 Recirculating automatic document feeder (RDF)

 ──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Hirohiko Tashiro 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Rieko Inoue 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inside (72) Inventor Akinobu Nishikata 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Tokuharu Kaneko 3-30-2, Shimomaruko 3-chome, Ota-ku, Tokyo Canon Inc. ( 72) Inventor Nobuo Sekiguchi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Noriaki Miyahara 3-30-2, Shimomaruko 3-chome, Ota-ku, Tokyo Canon Inc.

Claims (12)

[Claims] An image reading unit that reads an image of a document and outputs document image data; an image storage unit that stores the document image data in a storage medium; and an image that reads the image stored in the image storage unit. An image forming apparatus comprising: an image forming unit for forming; a set time storage unit for storing a set time; and an erasing unit for erasing the stored document image data after the lapse of the set time. 2. The image forming apparatus according to claim 1, wherein the set time is input via an operation panel. 3. The printing apparatus according to claim 1, wherein the erasing means monitors a state of the printing operation, and when the operation is abnormally stopped, only when the printing operation is not restarted within the set time.
An image forming apparatus for erasing the original image data. 4. The image forming apparatus according to claim 3, wherein when the printing operation is restarted within the set time, an image is formed using the document image data stored in the image storage unit. . 5. An image forming apparatus according to claim 1, wherein said image forming means forms a visible image in accordance with an electrophotographic process. 6. An image forming apparatus according to claim 1, further comprising storing a format image such as a document frame in a predetermined storage medium. 7. The image forming apparatus according to claim 6, wherein the format image is deleted from the storage medium after a lapse of a predetermined set time. 8. The image forming apparatus according to claim 7, wherein after the predetermined time has elapsed, only the original image data is stored in the image storage unit. 9. An image forming method comprising: reading an image of a document, outputting document image data, storing the document image, and erasing the document image data after a predetermined time has elapsed. . 10. The method according to claim 9, wherein the status of the printing operation is monitored, and when the operation is abnormally stopped, the document image data is deleted only when the printing operation is not restarted within the set time. Image forming method. 11. The image forming method according to claim 9, wherein when the printing operation is restarted within the set time, an image is formed using the stored document image data. 12. A program for reading a document image, outputting document image data, storing the document image, and erasing the document image data after a predetermined time has elapsed, as a program. A storage medium storing an image forming procedure characterized by the following.