JPH09149165A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To read a new job by quickly reserving an idle area in a memory area. SOLUTION: When a memory is occupied fully for reading in a job 3, a job 2 being an image output job maximizing an idle capacity per unit time of the memory is executed with higher priority among jobs in an output waiting state, then a print job 2 replaces a print job 1. Thus, the memory is made idle faster to terminate the reading job 3 as soon as possible thereby reducing the total copy time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus capable of simultaneously executing an image forming operation and an image reading operation for a plurality of originals.

[0002]

2. Description of the Related Art As a conventional copying machine having a multi-job function capable of simultaneously executing an image forming operation and an image reading operation, for example, as shown in Japanese Patent Laid-Open No. 4-305777, an output set for each job is set. A copying machine is disclosed which refers to the number of sheets to determine a job to be processed and preferentially outputs a job having a small number of output sets.

[0003]

By the way, in the above-described copying machine having the multi-job function, when a plurality of jobs are registered and waiting for output, when an original of a new job is read. Memory full (image memory that stores scanned image data is full)
May occur. In this case, as described above, in the control for determining the job to be first output only by determining the number of output sets, even if the copy output ends and the corresponding portion of the image memory is erased, the memory area of the image memory becomes empty. Since the capacity cannot be predicted, it is not possible to secure the free capacity for reading a new job,
There has been a problem that the reading of new jobs keeps waiting.

An object of the present invention is to provide an image forming apparatus capable of quickly securing a free space in a memory area of the image memory and enabling a new job to be read even when the image memory is in a memory full state. Is to provide.

[0005]

An image forming apparatus according to claim 1 is an image forming apparatus capable of simultaneously performing an image forming operation and an image reading operation of a plurality of originals, and an image reading apparatus for reading an image of an original. Means and setting means for setting copying conditions for the image data read by the image reading means,
Storage means for storing a plurality of sets of image data read by the image reading means and copying conditions set by the setting means, and storage of each set per unit time based on the information stored in the storage means Calculating means for calculating the free space of the means, judging means for judging the maximum set of the free capacity of the storage means per unit time calculated by the calculating means, and image data in the storage means during the image reading operation. And a control means for executing the copy operation of the set discriminated by the discriminating means when the storage becomes impossible.

With the above arrangement, even if the image data cannot be stored in the storage means during the image reading operation, the copy operation of the set that maximizes the free space of the storage means per unit time is preferentially executed. Therefore, it is possible to quickly secure the free space of the storage means and read a new job. Therefore, the reading time for a new job is shortened, and as a result, the time until the job currently being read can be output is shortened. As a result, it is possible to shorten the time until the end of printing for the entire multi-job, reduce the waiting time of the operator, and improve the productivity.

[0007]

1 is a sectional front view showing the overall construction of a copying machine 1 according to an embodiment of the present invention. Referring to FIG. 1, a copying machine 1 is a digital copying machine including an image reader IR and a page printer PRT.

The main body of the image reader IR is a scanning system 10 for decomposing an original document placed on a document table glass 18 into pixels and reading the same. Quantization of photoelectric conversion signals output to the scanning system 10 and various image forming modes. An image signal processing unit 20 for performing signal processing according to the above, and a memory unit unit 30 for storing image data corresponding to a document. An automatic double-sided document feeder (hereinafter referred to as "ADFR") 500, which is an additional device that also serves as a document cover, is attached to the upper part of the main body so that it can be opened and closed with its rear end as a fulcrum.

The scanning system 10 is a line scanning type image reading mechanism, and is an image composed of a scanner 19 having a document irradiation lamp 11 and a mirror 12, fixed mirrors 13a and 13b, a condenser lens 14, and a CCD array. It is composed of a sensor and a scan motor M2 that drives the scanner 19. The image signal processing section 20 and the memory unit section 30 will be described later.

The ADFR 500 conveys the document set on the document stacker 510 onto the platen glass 18 by a paper feed roller 501, a separation roller 502, a separation pad 503, an intermediate roller 504, a registration roller 505, and a conveyor belt 506. Then, the read document is discharged onto the document discharge tray 511 by the discharge rollers 509. The ADFR 500 is provided with a document scale 512, a document sensor SE50 for detecting the presence or absence of a document, a document size sensor SE51, and a discharge sensor SE52.

For example, when copying a plurality of originals, the operator sets the originals so that their surfaces face upward. Each original on the original stacker 510 is pulled out one by one from the lowermost original, and is set accurately at a reading position on the original platen glass 18 with its front surface facing downward.
Then, in the case of the single-sided original mode, after the reading is completed, the original is conveyed to the left in the drawing, and is discharged such that the upper surface becomes the front surface. Further, in the double-sided original mode, the original fed to the left after the front side reading is finished is turned upside down by the reversing roller 507 and returned to the reading position on the original platen glass 18, and after the back side reading is finished. It is sent to the left again and discharged.

The page printer PRT includes a print processing unit 40 for outputting an exposure control signal, a print head 60 using a semiconductor laser 62 as a light source, a developing / transferring system 70A including a photosensitive drum 71 and its peripheral devices, and a fixing roller pair 84. An electrophotographic process based on the image data transferred from the image reader IR. The electrophotographic process includes a fixing / discharging system 70B having a discharging roller 85 and the like, a circulation type sheet conveying system 70C including a re-feeding unit 600, and the like. To print the copied image. Below the page printer PRT, two sheet cassettes 80a and 80b capable of storing several hundred sheets of paper, sheet size sensors SE11 and SE1.
2, and a sheet feeding roller group.

The laser beam emitted from the semiconductor laser 62 is deflected in the main scanning direction by the polygon mirror 65,
Main lens 69 and various mirrors 67a, 68, 67c
, And is guided to the exposure position of the photosensitive drum 71. The surface of the photosensitive drum 71 is uniformly charged by the charger 72. The latent image formed by the exposure passes through the developing device 73 and becomes a toner image, and the toner image is transferred onto the sheet by the transfer charger 74 at the transfer position (copy position).
Then, the sheet is separated from the photosensitive drum 71 by the separation charger 75, is sent to the fixing roller pair 84 by the conveyor belt 83, and is discharged face up.

The re-feeding unit 600 is attached to the side surface of the page printer PRT as an additional device for automating double-sided copying, and temporarily stores the paper discharged from the main body of the page printer by the discharge roller 85, and switches it. It has the function of carrying the paper back and sending it back to the page printer body.

In the single-sided copy mode, the sheet passes through the sheet re-feeding unit 600 and is discharged onto the sheet discharge tray 621. On the other hand, in the duplex copy mode,
The left end of the switching claw 601 is moved upward by a solenoid (not shown), and the sheet discharged from the discharge roller 85 reaches the forward / reverse roller 603 through the transport roller 602. When the trailing edge of the sheet reaches the sheet sensor SE61, the forward / reverse roller 603 reverses. As a result, the paper is returned to the main body of the page printer. The returned sheet passes through the horizontal conveyance rollers 86a, 86b, 86c in order and is sent to the timing roller 82 to stand by. Here, when a plurality of paper sheets are continuously fed, the paper sheets are sequentially conveyed at a predetermined paper interval so as not to overlap each other, and are fed to the re-feeding unit 600. Since the length of the sheet conveying path is constant, the number of sheets N in one circulation (the maximum number of circulating sheets) N by the re-feeding unit 600 and the horizontal conveying rollers 86a, 86b, 86c depends on the sheet size.

FIG. 2 is a plan view of the operation panel OP, and FIG. 3 is a view showing an example of the operation screen. Referring to FIG. 2, on operation panel OP, a liquid crystal touch panel 91 for displaying status and designating various modes, a numeric keypad 92 for inputting numerical conditions for copying (number of sheets, magnification, etc.), and numerical conditions for standard values. Clear key 93 for returning to the default mode, panel reset key 94 for initializing the copy mode, stop key 95 for instructing copy stop, start key 96 for instructing copy start, single-sided original or double-sided original An original designation key 100 for designating whether or not a copy mode key 101, a copy mode key 101 for switching between double-sided copy and single-sided copy, a finishing mode key 102 for designating necessity of electronic sorting, and a reservation mode key 103. It is arranged.

In the electronic sort, the same document is M (M ≧ 2).
This is a function of repeating M times the operation of printing the original of each page M times to make a duplicate of M copies in the case of multi-copy printing one by one and a plurality of originals (for example, three pages). . In non-electronic sort mode,
Each original is printed M sheets in the reading order.

When the operator depresses (turns on) the reservation mode key 103 while the reading job of the previous job is completed and the printing screen Q10 for displaying "printing" is displayed on the liquid crystal touch panel 91. The input mode becomes the reservation mode, and as shown in FIG. 3, the mode setting and the reading start of the next original reading can be designated even while the previous job is outputting.

FIGS. 4 and 5 show the control unit 10 of the copying machine 1.
FIG. 3 is a block diagram showing a configuration of a 0. The control unit 100 has 8
Each of the CPUs 101 to 108 is configured mainly, and each of the CPUs 101 to 108 is provided with a ROM 111 to 118 storing a program and a RAM 121 to 128 serving as a work area for executing the program. The CPU 106 is provided in the memory unit section 30.

The CPU 101 controls input signals and display from various operation keys of the operation panel OP. CPU1
02 controls each part of the image signal processing unit 20, and C
The PU 103 controls the driving of the scanning system 10. CPU
104, a page printer PRT including a print processing unit 40
Control the whole of.

The CPU 105 performs processing for adjusting the overall timing of the control unit 100 and setting operation modes. Therefore, the CPU 105 performs serial communication with another CPU to transmit and receive commands and reports required for control.

CPU 106 controls storage and reading of image information. CPU 107 controls document conveyance by ADFR 500. And the CPU 108
Controls the re-feed unit 600.

FIG. 6 is a block diagram showing the configuration of the image signal processing section 20. The image signal processing unit 20 includes an A / D conversion unit 21, an image processing unit 22, an image monitor memory 23, and a timing control unit 24 that outputs a synchronization signal for the operation of each of these units.

The A / D converter 21 includes an image sensor 16
Are converted to 8-bit (256 gradation) image data. The image processing unit 22 performs image processing such as shading correction, MTF correction, gamma correction, and scaling processing, and outputs the processed image data D2 as read information. The image monitor memory 23 is used for storing sample data for shading correction.

FIG. 7 is a block diagram showing the structure of the memo unit section 30. The memory unit unit 30 includes a bus switching unit 301, a binarization processing unit 302, a multi-port image memory 304, a code processing unit 305 having a compressor 311 and an expander 312, a multi-port code memory 306, a rotation process. It has a unit 308, a multi-value quantization processing unit 309, and the above-mentioned CPU 106 that controls these units, and is configured to compress and store image information in order to reduce the memory capacity. The image memory 304 has a capacity capable of storing image data for two pages read at a resolution of 400 dpi.

In the memory mode copy in which the image read by scanning the original is temporarily stored, the binarization processing section 302 of the memory unit section 30 is operated by the image signal processing section 20 via the bus switching section 301. Bit image data D2 is input. The binarization processing unit 302 uses, for example, a dither method or the like to generate multivalued image data D2
Is converted into binary image data within a recoverable range. The binarized image data is temporarily written to the image memory 304.

The code processor 305 reads and compresses the image data written in the image memory 304 to generate code data (compressed data), and writes the code data in the code memory 306. The code processing unit 305 reads out the code data to be printed from the code memory 306 and decompresses the code data.
The obtained image data is written into the image memory 304. The compressor 311 and the decompressor 312 are configured to be operable independently of each other and in parallel in order to improve the copy speed, and between these and the code memory 306, data is not shown in the DMA controller. By D
It is designed to be transferred by MA.

When the image data for one page is reproduced by decompression, the data is read from the image memory 304, subjected to rotation processing if necessary, and then the multivalued processing unit 309 performs multivalued image processing. Restored to data. Then, the multivalued image data is used as exposure control data in the print processing unit 4
0 is transferred.

The code memory 306 is managed by a management table MT1 provided in the RAM 126 when the document image is temporarily stored. FIG. 8 is a diagram showing the relationship between the management table MT1 and the code memory 306.

The code memory 306 is divided into memory areas of 32 Kbyte units, and in consideration of enabling simultaneous control of writing (reading) and reading (printing), each area is divided. Stores code data for each page.

The management table MT1 includes a code memory 30.
6, the page number of the image data (original image number) P given to the writing order (original scanning order)
N, the number of the concatenated area, and various additional information necessary for compression / expansion processing such as the compression method and the data length are stored, and the code memory 306 is dynamically managed based on these information. It is like this.

"Pre-concatenation" in FIG. 8 (a) indicates the forward connection of the area of every 32 Kbytes in each page, and when it is "00", it corresponds to one page. This indicates the first storage area of data, and if other than "00", indicates the number of the area connected before that. Similarly, "post-connection" indicates the last area when it is "FF", and indicates the number of the area which is connected later when it is other than "FF".

When the CPU 106 reads out the image data from the image memory 304 and compresses the image data, the CPU 106 stores the management table MT1.
, While controlling the compressor 311 to store the information in the code memory 306. When outputting image data, code data is read from the code memory 306 by the reverse operation. The information in the management table MT1 is erased when the information of the corresponding page is accurately read and copying of the number M (copies) M designated by the operator is completed.

Next, the operation sequence of the copying machine 1 in the memory mode will be described focusing on the flow of request command (Q), report (A), or data exchanged among the CPUs 101 to 106.

FIG. 9 is a diagram showing a schematic sequence of a memory mode write operation. In memory mode write operation,
The image data is transferred from the image signal processing unit 20 to the image memory 304.

First, C which manages the entire sequence
The PU 105 requests the CPU 106 to prepare memory. In response to this, the CPU 106 sets to the internal hardware a bus connection state for transferring the image data D2 from the image signal processing unit 20 to the image memory 304,
Setting of a mode for binarization processing (for example, error distribution method, threshold value for background erasure, binary threshold value, etc.), start address of writing area to image memory 304, XY length information, etc. Set.

Upon completion of these settings and preparation, the CPU 106 notifies the CPU 105 of completion of memory preparation. CPU 105 is CPU 106, 10
When the reading is requested to the CPU 2, the CPU 102 causes the CPU 1 to
03 request scan.

The scan is started by the CPU 103,
When the scanner 19 reaches the image area of the document, the CPU 10
The read data (image data D2) is transferred from the image signal processing unit 20 to the memory unit unit 30 in accordance with the image processing mode set in Step 2.

When the scan is completed, the CPUs 102 and 106
When the completion of reading is notified from the CPU 105, the CPU 105
Request data compression to U106. In response to this, the CPU 106 sets the read address from the image memory 304, the XY length information, the write address to the code memory 306, the mode of the compressor 311 (for example, the MH system), etc., and activates each unit. . As a result, the compression process is performed, and the code data is stored in the code memory 306.

When the compression process is completed, the CPU 106 notifies the CPU 105 of the completion of compression. At this time, if the code memory 306 is full, the compression completion report to which the parameter indicating that compression is impossible is added to the CPU.
Sent to 105. This allows the CPU 105 to know that the code memory 306 has reached the memory full state.

FIG. 10 is a diagram showing a schematic sequence of a memory mode read operation. In the memory mode reading operation, image data is read from the image memory 304, and a copy image is printed on a sheet based on the image data.

The CPU 105 requests the CPU 106 to expand the data. The CPU 106 uses the code memory 30.
6, read address, data amount, write address to image data 304, XY length information, and decompressor 31.
The second mode (for example, MH system) is set to start each unit. As a result, decompression processing is performed and the image data is written in the image memory 304.

When the expansion processing is completed, the CPU 105
The CPU 106 is requested to prepare the memory for reading the image data from the image memory 304. In response,
The CPU 106 sets to the internal hardware a bus connection state for outputting the image data D3 from the image memory 304 to the print processing unit 40, a setting for rotation processing,
Start address and XY of read area of image memory 304
Make settings such as length information.

When these settings are completed and the preparation is completed and the notification is received, the CPU 105 causes the CPU 106, 1
Print request to 04. CPU 104 to C
A paper feed report is sent to the PU 105 to inform the paper conveyance state, and then the image data D3 read from the image memory 304 is output to the print processing unit 40 to perform printing.

Upon completion of printing, the CPU 106, C
The PU 104 sends a print completion report and an eject completion report to the CPU 105. The CPU 105 that has received these reports, if necessary,
A memory clear request or the like is issued to 06.

Next, the output job switching control when the memory is full in the multi-job will be described. FIG.
FIG. 1 is a diagram for explaining output job switching control when the memory is full.

As shown in FIG. 11A, in the conventional multi-job control, the job 1 is continuously printed even if the memory is full while the job 3 is being read. Therefore, for example, when the number of copies of the job 1 is very large, it is not possible to expect the memory to be free due to the output of the job 1, and as a result, the printing of the job 1 ends and the job 2 ends.
Job 3 could finally be read in the middle of printing. As a result, after the completion of printing job 2, a waiting time D occurs until the start of printing job 3, and the time from the start of reading job 1 to the end of printing job 3 is increased by the waiting time D in the figure. .

On the other hand, in the copying machine according to the present embodiment described above, when the memory is full during the reading of job 3, when the memory capacity of job 2 is larger than the memory capacity of job, when the printing of job 1 starts. By switching to the print of job 2, the memory can be freed quickly. Therefore, the reading of the job 3 can be completed early and the total copy time can be shortened.

Regarding the switching of the output job when the above-mentioned memo full occurs, the job management table is created at the time when the reading of the original is finished for each job. FIG. 12 is a diagram showing an example of the job management table.

Referring to FIG. 12, document type (single-sided or double-sided) and number of sheets, copy type, paper size, number of copies,
Calculate the free memory capacity per unit time from the memory usage. For example, in job 1, the document type is single-sided, the number of sheets is 10, the copy type is single-sided, the sheet size is A4T (297), the number of copies is 100, and the memory usage is 2n.
In this case, the free memory capacity per unit time is calculated by system speed x number of documents x number of copies x amount of memory used / paper size. Therefore, for example, 160 x 10 x 100 x 2/2
Calculated at 97. Similar calculations are performed for other jobs. Regarding the memory usage used here, the average memory usage per original is used by referring to the code memory.

Next, the free memory capacity per unit time when the paper discharge option is installed will be described. For example, when the finisher is used, it has a shift function and a stapling function of a shift tray for sorting in electronic sort. In order to use these functions, mechanical drive time is required at the timing of shifting or stapling, so the paper interval is made longer than the normal length to avoid jamming. Therefore, when the electronic sort using the shift function or the staple sort using the staple function is set in the finishing mode, the free memory capacity per unit time shown in FIG. 12 is calculated in consideration of these as well.

For example, if the paper interval in the staple sort is set to be 200 mm longer than the normal time, if Job 1 shown in FIG. 12 is in the staple mode, the number of copies is 100, so the paper interval of 99 times is longer than usual. It will be long. Therefore, considering the above conditions,
Memory free capacity per unit time is 160 × 10 × 100
It can be calculated by × 2 / (297 + 200 × 99).

It should be noted that the above-described consideration of the sheet interval when the sheet discharge option is installed is an example, and, for example, in consideration of the length of the circulation conveyance path and the number of sheets conveyed on the circulation conveyance path, The free memory capacity may be calculated.

Next, the operation of the copying machine 1 will be described in more detail, focusing on the control that is a feature of the present invention, based on the flowchart. FIG. 13 shows C which controls the operation panel OP.
It is a main flowchart of PU101.

When the power is turned on, the CPU 101 first makes initial settings for initializing the RAM 121, registers and the like (# 11). After that, an internal timer that defines the length of one routine is set (# 12), a key input process that accepts a key operation (# 13), a panel display process that performs a display according to the operation (# 14), and other processes ( # 15),
And the waiting of the internal timer (# 16) is repeatedly executed. In addition, communication with another CPU is performed as an interrupt process at an appropriate time.

FIG. 14 is a main flowchart of the CPU 104 which controls the page printer PRT. CP
After performing the initial setting (# 41), U104 sets the internal timer (# 42) and controls the developing / transfer system (# 4).
3), control of conveyance system (# 44), control of fixing system (# 4)
5), control of print processing unit (# 46), other processing (# 46)
47) and waiting of the internal timer (# 48) are repeatedly executed.

FIG. 15 is a CP for controlling the control of the copying machine 1.
16 is a main flowchart of U105, and FIG. 16 is a main flowchart of the CPU 106 that controls the memory unit section 30.

First, referring to FIG. 15, the CPU 105
After the initial setting (# 5), the internal timer is set (# 52), the input data analysis process for checking the input data from another CPU (# 53), and the operation mode is determined according to the operation content. Mode setting process (# 54), command setting process for setting a command according to the mode (# 5
5), the output data set (# 56) for holding the command at the communication port, other processing (# 57), and waiting for the internal timer (# 58) are repeatedly executed.

Next, referring to FIG. 16, the CPU 106
After initial setting (# 61), command reception processing (# 62), status transmission processing (# 63), image memory writing processing (# 64), compression control processing (# 65), decompression control processing (# 66), image memory reading process (# 6
7) and other processing (# 68) are repeatedly executed.

FIG. 17 is a flowchart of the command setting process (# 55) shown in FIG. If there is a document, the process for the memory writing operation is performed (# 550, # 55).
1). On the other hand, if there is no document, the write state, which is a variable indicating the write state transition, is cleared (0) (# 55
2).

Next, it is determined whether or not there is a print job (# 553). When there is a print job, the processing for the job switching operation which is the subject of the present invention is performed (# 555), and the memory reading operation is further performed (# 557). On the other hand, if there is no print job, the read state, which is a variable indicating the read state transition, is cleared (0) (# 559).

FIG. 18 is a flowchart of the memory write operation (# 551) shown in FIG. In this routine, check the first write state (# 5500),
The following processing is executed according to each state (“0” to “3”).

First, when the write state is "0", it is checked whether or not there is a start request in response to the start key 96 being turned on (# 5501). If there is a start request, the current read job number is registered in N (# 550).
3). Next, the number of written pages PW corresponding to the job number
(N) is initialized (# 5505). Next, the write state is set to "1" and updated (# 5507).

Next, when the write state is "1", the read command is registered in the command dedicated buffer (Q buffer) (# 5510). A command-dedicated buffer is prepared in advance for each command, and each command is transferred from the command-dedicated buffer to the communication port in the above-mentioned output data set (# 56 in FIG. 15). Next, the write state is set to "2" and updated (# 5513).

Next, when the write state is "2", if the read completion report (read completion A) is received, it is checked whether the memory is full (# 5520, # 552).
1). If the memory is not full, the compression command for the read image is registered in the command-dedicated buffer, and the write state is set to "3" to update (# 5523, # 552).
5). On the other hand, if the memory is full, it waits for the free space of the memory due to switching of print jobs.

Finally, when the write state is "3" and the compression completion report (compression completion A) is received, the number of write pages PW (N) corresponding to the job number is updated by 1 (# 5530, # 5531), write state is "1"
And the next document reading is repeated (# 553
3).

FIG. 19 is a flowchart of the job switching operation (# 555) shown in FIG. First, it is determined whether or not the memory is full (# 570). In the case of the memory full, a unit time is output from the registered job waiting for output by referring to the job management table shown in FIG. The print job number x is set to the job number having the maximum free memory capacity, and the read state is set to “0” (# 571).

On the other hand, if the memory is not full, the read page number PR (x) of the job currently being output is the write page number PW.
It is determined whether or not it matches (x) (# 573). If they match, it is determined that the output of the job number x is completed, the print job number x is updated, and the read state is set to "0". Yes (# 575). On the other hand, if the number of read pages PR (x) does not match the number of written pages PW (x), the current job is continuously printed.

FIG. 20 is a flowchart of the memory read operation (# 557) shown in FIG. Also in this routine, the read state is first checked (# 560
0), the following processing is executed according to each state (“0” to “3”).

First, when the read state is "0", the read page number PR (x) of the image data in job number x
Is set to the initial value "1" and the read state is set to "1"(#
5601, # 5602).

Next, when the read state is "1", the data corresponding to the read page number PR (x) is fetched from the management table MT1, the decompression command is registered in the command dedicated buffer, and the read state is set to "2". Yes (# 5610,
# 5612).

Next, if the decompression completion report is received when the read state is "2" (YE at # 5620).
S), a print command is registered in the command-dedicated buffer for paper feeding, and the read state is set to "3"(# 56).
21, # 5623).

Finally, if the print completion report is received when the read state is "3" (Y in # 5630).
(ES) Since the printing of one sheet is completed, the number of read pages PR (x) is updated (+1) and the read state is returned to “1” (# 5631 and # 5632) for the next print.

When a memory full state occurs during multi-job execution by the above processing, the job number with the maximum memory free space per unit time is set as the print job number from among the job numbers waiting for output. Since the job is preferentially executed, the waiting time for reading a new document due to the memory full can be shortened as much as possible, and the reading start time of the next job can be shortened. As a result, it is possible to shorten the time until the end of printing for the entire multi-job, shorten the waiting time for the operator, and improve the productivity.

[Brief description of the drawings]

FIG. 1 is a sectional front view showing the overall configuration of a copying machine according to an embodiment of the present invention.

FIG. 2 is a plan view of an operation panel.

FIG. 3 is a diagram showing an example of an operation screen.

FIG. 4 is a first block diagram showing a configuration of a control unit of the copying machine shown in FIG.

5 is a second block diagram showing a configuration of a control unit of the copying machine shown in FIG.

FIG. 6 is a block diagram illustrating a configuration of an image signal processing unit.

FIG. 7 is a block diagram illustrating a configuration of a memory unit.

FIG. 8 is a diagram showing a relationship between a management table and a code memory.

FIG. 9 is a diagram showing a schematic sequence of a memory mode write operation.

FIG. 10 is a diagram showing a schematic sequence of a memory mode read operation.

FIG. 11 is a diagram for explaining output job switching control when a memory full occurs.

FIG. 12 is a diagram showing an example of a job management table.

FIG. 13 is a main flowchart of the CPU 101 that controls the operation panel.

FIG. 14 is a main flowchart of a CPU 104 that controls a page printer.

FIG. 15 is a main flowchart of a CPU 105 that controls the control of the copying machine.

FIG. 16 is a CPU 106 that controls the memory unit.
5 is a main flowchart of FIG.

FIG. 17 is a flowchart of the command setting process shown in FIG.

18 is a flowchart of the memory write operation shown in FIG.

19 is a flowchart showing the job switching operation shown in FIG.

20 is a flowchart showing a memory read operation shown in FIG.

[Explanation of symbols]

 1 Copier IR Image Reader PRT Page Printer 10 Scanning System 20 Image Signal Processing Section 30 Memory Unit Section 40 Printing Processing Section 500 ADFR 60 Printer Head 70A Developing / Transfer System 70B Fixing / Discharging System 70C Paper Conveying System 302 Binarization Processing Section 304 image memory 305 code processing unit 306 code memory 308 rotation processing unit 309 multi-value processing unit 101 to 108 CPU 111 to 118 ROM 121 to 128 RAM

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Tanaka 2-13-13 Azuchi-cho, Chuo-ku, Osaka, Osaka International Building Minolta Co., Ltd. (72) Hidenobu Nakamura 2-3, Azuchi-cho, Chuo-ku, Osaka No. 13 Osaka International Building Minolta Co., Ltd.

Claims (1)

[Claims] 1. An image forming apparatus capable of simultaneously performing an image forming operation and an image reading operation for a plurality of originals, comprising image reading means for reading an image of an original, and image data read by the image reading means. Setting means for setting copying conditions; storage means for storing a plurality of sets of image data read by the image reading means and copying conditions set by the setting means; Of the free capacity of the storage means per unit time of each set based on the information, and the maximum capacity of the free capacity of the storage means per unit time calculated by the calculation means Determination means for determining whether the image data cannot be stored in the storage means during the image reading operation. An image forming apparatus, comprising: a control unit that executes a copy operation of a computer.