JPH09325529A - Image forming device and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve productivity by increasing the number of image forming sheets per unit time by switching from one-face image forming processing to reverse face image forming processing in accordance with a previously set condition. SOLUTION: At the time of executing a skip both-face copying mode performing the reverse face image forming processing successively visualizing image data on one face of recording material after the one-face image forming processing successively visualizing the image data on the other face of the recording material is performed by an image forming means performing image forming processing visualizing the image data in a storing means on the recording material, switching from the one face image forming processing to the reverse face image forming processing is performed in accordance with the previously set condition (for instance the number of the image data or the number of sheets of the recording material or the like). The CPU circuit part 205 of an image forming device is constituted of a CPU 206, a ROM 207 and a RAM 208 or the like. A control program for the time of both-face copying is stored at the ROM 207.

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 such as a digital copying machine system for performing image processing of double-sided copying after storing image data in a storage device, and an image forming method of the image forming apparatus. is there.

[0002]

2. Description of the Related Art Conventionally, in a double-sided mode in which an image is formed on both sides of a recording sheet, an image is formed on one side of the recording sheet and then the recording sheet is inverted by a reversing mechanism to form an image on the other side. Is generally known, but a skip double-sided mode, which is more productive than this method, has been devised and put into practical use.

That is, the skip double-sided mode is a mode in which image data having different contents is sequentially formed on one side of the recording paper, and then predetermined image data having different contents is sequentially formed on the other surface of the recording paper. is there.

[0004]

However, in the image forming apparatus having the above-described skip double-sided mode, when the number of image data is small, if the reversing mechanism for reversing the recording paper spends a long time, the image is formed per unit time. There is a problem that the number of possible images cannot be increased.

In view of the above conventional problems, it is an object of the present invention to provide an image forming apparatus and an image forming method capable of improving the productivity by increasing the number of image formed sheets per unit time. .

[0006]

In order to achieve the above object, an image forming apparatus according to a first aspect of the present invention visualizes a storage unit for storing image data and the image data in the storage unit on a recording material. An image forming means for performing an image forming process, and the image forming means performs a one-sided image forming process for sequentially visualizing image data on one surface of the recording material, and then further forms on the other surface of the recording material. In an image forming apparatus that performs an image forming process on the opposite side for sequentially visualizing image data,
A switching control means for switching from the one-sided image forming process to the opposite-sided image forming process is provided according to a predetermined condition.

An image forming apparatus according to a second aspect of the present invention includes a storage means for storing image data, an image forming means for performing an image forming process for reading out the image data from the storage means and visualizing it on a recording material, and the recording means. A reversing mechanism for reversing the recording material, and the image forming means performs a single-sided image forming process for sequentially visualizing image data having different contents on one surface of the recording material, and then reversing the recording material by the reversing mechanism. In the image forming apparatus for performing the opposite-side image forming process for sequentially visualizing image data having different contents on the other side of the recording material, the opposite side from the single-sided image forming process according to a predetermined condition. A switching control means for switching to the surface image forming process is provided.

According to a third aspect of the present invention, in the image forming apparatus according to the second aspect of the present invention, the switching control means is provided from the one-sided image forming process to the opposite side according to the number of the image data or the number of the recording materials. The switching to the image forming process is performed. An image forming apparatus according to a fourth aspect of the present invention uses the switching control unit according to the third aspect of the invention, when the number of the image data is less than a predetermined number,
After repeating the single-sided image forming process a plurality of times, switching to the opposite-side image processing is performed.

An image forming apparatus according to a fifth aspect of the present invention performs the switching operation of the switching control means according to the second aspect of the invention only at the time of image forming processing for the second and subsequent copies of the image data composed of a plurality of copies. It is the one that is supposed to be executed.

According to a sixth aspect of the invention, an image forming apparatus switches the switching control means in the second aspect from the single-sided image forming process to the opposite-side image forming process according to the size of the recording material. Is to do.

An image forming method according to a seventh aspect of the present invention uses storage means for storing image data and image forming means for performing an image forming process for visualizing the image data in the storage means on a recording material. In the image forming method, a single-sided image forming process for sequentially visualizing image data on one side of a recording material is performed, and then an opposite-side image forming process for sequentially visualizing image data on the other side of the recording material is performed. Switching from the image forming process to the opposite side image forming process,
It is designed to be executed according to a predetermined condition.

According to an eighth aspect of the present invention, there is provided an image forming method, storage means for storing image data, image forming means for performing image forming processing for reading image data from the storage means and visualizing it on a recording material, and the recording means. Using a reversing mechanism for reversing the material, a single-sided image forming process for sequentially visualizing image data having different contents is performed on one surface of the recording material, and then the reversing mechanism reverses the recording material, In an image forming method for performing an opposite side image forming process for sequentially visualizing image data having different contents on one side, switching from the single sided image forming process to the opposite side image forming process is performed according to a predetermined condition. It was designed to be executed.

An image forming method according to a ninth invention is the image forming method according to the eighth invention, wherein switching from the one-sided image forming process to the opposite-side image forming process is performed depending on the number of image data or the number of recording materials. It is designed to be executed accordingly.

According to a tenth aspect of the present invention, in the ninth aspect of the present invention, when the number of the image data is smaller than a predetermined number, the one-sided image forming process is repeated a plurality of times and then the opposite side is formed. Switching to image processing is performed.

An image forming method according to an eleventh invention is the image forming method according to the eighth invention, wherein switching from the one-sided image forming process to the opposite-side image forming process is performed by two copies of the image data composed of a plurality of copies. This is executed only during the image forming process after the eyes.

In the image forming method according to the twelfth invention, in the eighth invention, the switching from the one-sided image forming processing to the opposite-side image forming processing is executed according to the size of the recording material. is there.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of an image forming apparatus according to an embodiment of the present invention.

In the figure, reference numeral 100 is a copying apparatus main body, and 180 is a circulating automatic document feeder (RDF). Reference numeral 101 is a platen glass as a document placing table, 102 is a scanner, which is composed of a document illumination lamp 103, a scanning mirror 104, and the like. The scanner is reciprocally scanned in a predetermined direction by a motor (not shown), and the reflected light of the document is scanned by the scanning mirrors 104 to 106.
An image is formed on the CCD sensor 109 through the lens 108 via the.

Reference numeral 107 denotes an exposure control section composed of a laser, a polygon scanner, etc., which is a laser beam which is converted into an electric signal by the image sensor section 109 and is modulated based on an image signal which is subjected to a predetermined image processing described later. The photosensitive drum 110 is irradiated with 129. Around the photoconductor drum 110, a primary charger 112, a developing device 121, a transfer charger 11
8, a cleaning device 116, and a pre-exposure lamp 114 are provided.

In the image forming unit 126, the photosensitive drum 110 is rotated in the direction of the arrow shown in the figure by a motor (not shown), and is charged to a desired potential by the primary charger 112, and then the exposure controller 120. The laser beam 129 from is emitted 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, the transfer paper fed from the upper cassette 131 or the lower cassette 132 by the pickup rollers 133 and 134 is sent to the main body by the paper feed rollers 135 and 136, and is fed to the transfer belt by the registration roller 137. The visualized toner image is transferred to the transfer charger 1.
The image is transferred to transfer paper by 18. After the transfer, the cleaner device 116 cleans the residual toner from the photosensitive drum, and the pre-exposure lamp 114 erases the residual charge.

The transfer sheet after the transfer is separated from the transfer belt 130, the toner image is recharged by the pre-fixing chargers 139 and 140, and the toner image is sent to the fixer 141 to be fixed by pressurization and heating, and the discharge roller 142. It is discharged to the outside of the main body 100.

Reference numeral 138 denotes an adsorption charging device for adsorbing the transfer paper sent from the registration roller 137 to the transfer belt 130, and 139 is used for rotating the transfer belt 130 and at the same time forms a pair with the adsorption charging device 138. , Transfer belt 1
A transfer belt roller that attracts and charges the transfer paper to 30.

The main body 100 is equipped with a deck 150 capable of storing, for example, 4000 transfer papers. The lifter 151 of the deck 150 rises according to the amount of transfer paper so that the transfer paper always contacts the paper feed roller 152. Also, a multi-manual feed 15 capable of accommodating 100 sheets of transfer paper
3 are equipped.

Further, in FIG. 1, reference numeral 154 is a paper discharge flapper, which switches the path between the double-sided 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-sided recording side or a multiple recording side. Further, reference numeral 158 denotes a lower conveyance path, which reverses the transfer paper sent from the paper discharge roller 142 through the reversing path 155 and guides it to the re-feed tray 156.

Reference numeral 157 denotes a multiple flapper that switches between double-sided recording and multiple recording paths. By tilting this 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 126 through the path 160. 161 is arranged near the paper ejection flapper 154,
It is a discharge roller that discharges the transfer paper switched to the discharge side by the discharge flapper 154 to the outside of the machine.

At the time of double-sided recording (double-sided copying) or multiplex recording (multiplex copying), the paper discharge flapper 154 is raised and the copied transfer paper is stored in the re-feed tray 156 via the transport paths 155 and 158. . At this time, when recording on both sides,
The multiple flapper 157 is tilted to the right, and when multiple recording is performed, the multiple flapper 157 is tilted to the left. The transfer sheets stored in the re-feed tray 156 are guided from the bottom one by one to the registration rollers 137 of the main body via the path 160 by the sheet feed roller 159. When the transfer sheet is reversed and discharged from the main body, the discharge flapper 154 is raised upward, the flapper 157 is tilted to the right, the copied transfer sheet is conveyed to the conveying path 155 side, and the rear end of the transfer sheet is moved to the first position. After passing through the first feed roller 162, the second reverse roller 163
To the feed roller side of the
The transfer paper is turned over and ejected outside the machine.

FIG. 2 is a view showing the operation section of the image forming apparatus in this embodiment.

In the figure, numeral 451 is a ten-key,
Used to set the number of images to be formed and to enter numerical values for mode settings. A clear / stop key 452 is used to stop the set number of image formations and the set image formation operation. Reference numeral 453 denotes a reset key, which is used to return the set number of image formations, the operation mode, the selected paper feed mode, and the like to predetermined values. 454 is a start key,
By pressing the start key 454, the image forming operation is started.

Reference numeral 469 is a display panel composed of a liquid crystal or the like, and the display contents are changed according to the setting mode in order to facilitate detailed mode setting. In this embodiment, the cursor keys 466 to 468 move the cursor on the display panel 469, and the OK key 464 determines the setting. This setting method can be configured by a touch panel.

A paper type setting key 471 is set when an image is formed on a recording material thicker than the standard. Paper type setting key 4
When the cardboard mode is set by 71, the LED 470
Is controlled to light up. In the present embodiment, only the setting of the thick paper mode is possible, but the function can be extended as necessary so that the mode for OHP or other special paper can be set.

Reference numeral 475 denotes a double-sided mode setting key, for example, "single-sided mode" for single-sided output from a single-sided original, "single-sided mode" for double-sided output for a single-sided original, and "double-sided output for double-sided original". Both-both mode ", 2 from two-sided original
It is possible to set four types of two-sided mode, that is, a "two-sided mode" for outputting one side of a sheet. The LEDs 472 to 474 are turned on in accordance with the set double-sided mode, and the “single-single mode” is set.
, All of the LEDs 472 to 474 are turned off, only the LED 472 is turned on in the “single-both mode”, only the LED 473 is turned on in the “both-both mode”, and LE in the “both-single mode”.
Control is performed so that only D474 is turned on.

FIG. 3 is a block diagram showing the arrangement of the image forming apparatus of this embodiment.

In the figure, the image reading unit 201 is
An original image formed by the CCD sensor 109, the analog signal processing unit 202 and the like and formed on the CCD sensor 109 via the lens 108 is converted by the CCD sensor 109 into an analog electric signal. The converted image information is
Input to the analog signal processor, sample and hold,
After dark level correction and the like, analog / digital conversion (A / D conversion) is performed.

The digitized signal is input to the electronic sorter unit 203 after being subjected to shading correction (variation of sensors for reading a document and correction of light distribution characteristics of a document illumination lamp) and scaling processing. The external I / F processing unit 209 expands image information input from an external computer and inputs the image information to the electronic sorter unit 203 as image data.

In the electronic sorter section 203, correction processing necessary for the output system such as γ correction, smoothing processing, edge enhancement, and other processing and processing are performed, and the printer section 20.
4 is output. The printer unit 204 includes an exposure control unit 12 including a laser and the like described with reference to the cross-sectional configuration diagram of FIG.
0, an image forming unit 126, a transfer paper conveyance control unit, and the like, and records an image on the transfer paper according to an input image signal.

Further, the CPU circuit unit 205 includes the CPU 20.
6, the ROM 207, the RAM 208, and the like, and 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. Here, in the ROM 207, FIGS.
Also, a control program relating to processing unit control during double-sided copying shown in the flowchart of FIG. 10 is stored.

FIG. 4 is a block diagram showing the detailed arrangement of the electronic sorter unit 203.

The image sent from the image reading unit 201 is input as the data of the brightness of B1ack, and the log
Sent to conversion section 301. The log conversion unit 301 uses an LU for converting the input brightness data into density data.
T is stored, and the luminance data is converted into density data by outputting a table value corresponding to the input data.

Thereafter, the density data is sent to the binarizing section 302. The binarizing unit 302 binarizes the multivalued density data, and the density value becomes “0” or “255”. 8b
The image data of it is binarized and converted into 1-bit image data of “0” or “1”, and the amount of image data stored in the memory becomes small. However, when the image is binarized, the number of gradations of the image changes from 256 gradations to 2 gradations.
Image data having many halftones such as a photographic image is generally significantly deteriorated when binarized. Therefore, it is necessary to perform pseudo halftone expression using binary data. Here, 2
The error diffusion method is used as a method of pseudo-intermediate representation with value data.

In this method, if the density of a certain image is greater than a certain threshold value, the density data is "255", and if it is less than a certain threshold value, the density data is "0". This is a method of distributing the difference between the actual density data and the binarized data as an error signal to surrounding pixels. The distribution of the error is performed by multiplying a weighting coefficient on a matrix prepared in advance with the error generated by the binarization and adding it 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 sent to the control unit 303.
Sent to Also, input from an external I / F processing unit,
Since the image data from the computer has been processed as binary image data by the external I / F processing unit, it is sent to the control unit 303 as it is. In the control unit 303, an image of a document to be copied is displayed in the image storage unit 30 according to a command from the main body.
4, or all of the 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 in 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 of the copying machine. For example, in the case of sorting, the document is read from the DF in order from the last page to the first page of the document bundle, and temporarily stored in the hard disk. Then, the image data of the temporarily stored original is read from the hard disk in order from the last page to the first page, and this is repeated a plurality of times for output. This allows it to play the same role as a sorter with multiple pins.

The image data retrieved from the image storage unit 804 is sent to the smoothing unit 305. In the smoothing unit 305, first, the 1-bit data is converted into 8-bit data, and the image data signal is set to the state of “0” or “255”. The converted image data is replaced with a weighted average value obtained by the sum of the coefficients on a predetermined matrix and the density values of neighboring pixels. As a result, the binary data is converted into multi-valued data according to the density value of the neighboring pixels.
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 the density data, the γ correction unit 306 performs conversion by the LUT in consideration of the characteristics of the printer and adjusts the output according to the density value set by the operation unit.

FIG. 5 is a diagram showing the configuration of the control unit 303 of this embodiment.

The image memory unit 501 is composed of a memory such as DRAM, and through the memory access control unit 502, a video write signal from the binarization unit 302, a video read signal to the smoothing unit 305, and an image storage unit 304. The image input / output signal is accessed. The memory access control unit 502 generates a DRAM refresh signal for the image memory unit 501, and arbitrates signals from the binarization unit 302, the smoothing unit 305, and the image storage unit 304 to the image memory unit 501. .

Further, according to an instruction from the processing control unit 503, a write address, a read address, a read direction, etc. for the image memory unit 501 are controlled. As a result, the processing control unit 503 arranges a plurality of original images in the image memory unit 501 to perform layout and outputs the images to the printer unit, a function of cutting out only a part of the image, and outputting the image.
Controls the image rotation function.

Next, the operation of the image forming apparatus having the above-described structure during double-sided copying will be described.

First, prior to the description of the present embodiment, a general operation during double-sided copying will be described.

FIG. 6 and FIG. 7 are flow charts showing the processing unit control at the time of general double-sided copying. The processing of FIG. 6 and FIG. 7 is called and executed at regular time intervals or as required by the main sequence.

In FIG. 6, an image is formed on the transfer paper fed from the cassette and is stacked on the double-sided tray 156. Therefore, in step 1001, it is determined whether or not there is a transfer sheet in the cassette to be fed. If there is a transfer sheet in step 1001, the process proceeds to step 1002. Step 1001
If there is no transfer paper, the process is interrupted with a paper out alarm. At this time, a display indicating the interruption is displayed on the operation unit.

In step 1002, the document is conveyed by the DH 180 onto the platen glass 101. After that, the process proceeds to step 1003, the document on the platen glass 101 is scanned and read, and the image is written in the image memory 501. The image of the image memory unit 501 is stored in the storage means HD of the image storage unit.

Then, in step 1004, the image in the image memory 501 is formed on the transfer paper. This transfer sheet is conveyed and stacked on the double-sided tray 156 by the method described above. After forming an image in step 1004, step 100
Go to 5. In step 1005, step 1003
It is determined whether or not the original scanned and read was the final original.

If it is the final original in step 1005, the process proceeds to step 1009. If the document is not the final document in step 1005, the process proceeds to step 1006. In step 1006, the platen glass 101 is moved by the DH 180.
The next original is fed to the top. After that, the process proceeds to step 1007, the original on the platen glass 101 is scanned and read, and the image is written in the image memory 501. The image in the image memory 501 is stored in the storage means HD of the image storage unit.

Then, the process proceeds to step 1008. In step 1008, it is determined whether or not the document scanned and read in step 1007 is the final document. If it is not the final manuscript in step 1008, step 1001
Return to If it is the final document in step 1008, the process proceeds to step 1009.

In step 1009, step 1003,
In step 1007, it is determined whether the image formation of all the images read has been completed. If the processing ends in step 1009, the process proceeds to step 1012 in FIG. Step 10
If the processing has not ended in 09, the process proceeds to step 1010. In step 1010, the image stored in the storage means HD of the image storage unit is read out and expanded in the image memory 501. At this time, the images corresponding to the back pages of the transfer sheets stacked on the intermediate tray are sequentially read.

In step 1011, the image memory 50
The image developed in No. 1 is image-formed on the transfer paper fed from the intermediate tray. The transfer sheet on which the image is formed in step 1011 is discharged by the above-described method. After the image formation is performed in step 1011, the process returns to step 1009, and it is determined whether or not all the image formation of the image formed in step 1011 is completed. Step 1 in FIG.
In 012, it is determined whether or not the copy number N designated by the operation unit has ended. If it is finished in step 1012, the exit is made. If it is not completed in step 1012, the process proceeds to step 1013.

At step 1013, it is judged whether or not there is a transfer sheet in the cassette to be fed. If there is a transfer sheet in step 1013, the process proceeds to step 1014. In step 1014, the images stored in the storage means HD of the image storage unit are sequentially read and developed in the image memory 501.
At this time, the images to be sequentially read are read in order of the images read by scanning the document in step 1003.

In step 1015, the image memory 50
The image developed in No. 1 is image-formed on the transfer paper fed from the cassette. This transfer paper is double-sided tray 1 by the method described above.
It is conveyed and loaded to 56. After image formation is performed in step 1015, the process proceeds to step 1016. Step 1
In 016, it is determined whether or not the image formation of all the images of the image read in step 1014 is completed. Step 1
If the processing ends in 016, the process proceeds to step 1018. If it is not completed in step 1016, the process returns to step 1013.

In step 1018, the image stored in the storage means HD of the image storage unit is read out and the image memory 50 is read.
Expand to 1. At this time, the images corresponding to the back pages of the transfer sheets stacked on the intermediate tray are sequentially read. Step 1
At 019, the image developed in the image memory 501 is formed on the transfer sheet fed from the intermediate tray. The transfer sheet on which the image is formed in step 1019 is discharged by the above-described method. After image formation is performed in step 1019, the process proceeds to step 1020, and it is determined whether or not all image formation in step 1019 is completed. Step 10
If all images are not finished in step 20, step 10
Returning to 18, the next image is read out. If all the images are finished in step 1020, the process returns to step 1012, and it is determined whether or not the copy number N designated by the operation unit is finished.

Next, if there is a transfer sheet in step 1013, the process proceeds to step 1017. In step 1017, it is determined whether or not transfer sheets are stacked in the intermediate tray 156. Although not shown in the flowchart of FIG. 7, when it is determined whether or not the transfer papers in the intermediate tray 156 are stacked, the paper is fed from the paper feed cassette and is stacked in the image forming apparatus to be stacked on the intermediate tray 156. It is determined whether transfer sheets including the transfer sheet being conveyed are stacked on the intermediate tray 156.

If the transfer sheets are not stacked in step 1017, the process is interrupted as a paper out alarm. At this time, a display indicating the interruption is displayed on the operation unit. If the transfer sheets are stacked in the intermediate tray in step 1017, the process proceeds to step 1018 to form an image on the back surface of the stacked transfer sheets.

FIG. 8, FIG. 9 and FIG. 10 are flow charts of the processing section control during double-sided copying according to this embodiment. The processing of FIGS. 8 to 10 is called and executed at regular time intervals or as needed by the main sequence.

In FIG. 8, first, in step 1101, it is determined whether or not the copy key has been pressed by the operator. If not pressed, the process returns to step 1101 and waits until pressed. When the copy key is pressed by the operator in step 1101, although not shown, the internal management information for starting the copy is initialized, and the copy process according to the copy mode designated by the operator is performed. FIG.
Then, only the double-sided copy mode processing is shown after step 1102.

In step 1102, the document is conveyed by the DH 180 onto the platen glass 101. After that, the process proceeds to step 1103, the original on the platen glass 101 is scanned and read, and the image is written in the image memory 501. The image in the image memory 501 is stored in the storage means HD of the image storage unit. Then, in step 1104, 1 is added to the document number management information S inside the control.

In step 1105, it is determined whether or not the original of the image read in step 1103 is an odd number. If it is an odd number in step 1105, the process proceeds to step 1106. If it is not an odd number in step 1105, the process proceeds to step 1107. In step 1106, the image read in step 1103 and written in the image memory 501 is formed on a transfer sheet, and the process proceeds to step 1107.

In step 1107, step 1103
It is determined whether or not the original read in is the final original. If it is not the final original in step 1107, the process returns to step 1102 and is repeated until all originals are processed. Step 1
If the document is the final document at 107, the process proceeds to step 1108.

In step 1108, it is determined whether the number S of originals is larger than a predetermined number "X". In the present embodiment, X is a value of 4 sheets. When it is not larger than X in step 1108, the process proceeds to step 1109. If it is larger in step 1108, the process proceeds to step 1110.

In step 1109, the value of the circulation number "C" which is the internal control management data is set to 3, and the process proceeds to step 1113 of FIG. In step 1110, it is determined whether the number S of originals is larger than a predetermined number "Y".
In the present embodiment, Y is a value of 6 sheets. Step 1110
If it is not greater than Y, the process proceeds to step 1111. If it is larger in step 1110, step 1112
Move to.

At step 1111 the value of the circulation number "C" which is the internal control management data is set to 2, and the routine proceeds to step 1113 of FIG. In step 1112, the value of the circulation number “C” which is the internal control management data is set to 1, and the process proceeds to step 1113 of FIG. FIG. 9 step 111
At 3, it is determined whether the copy number N designated by the operation unit is equal to or less than the circulating copy number C. C at step 1113
If not, the process proceeds to step 1116. If the set number of copies N is less than or equal to C in step 1113, the process proceeds to step 1114, the circulation number of copies C is set to the value of N, the final copy number flag which is the internal management information is set in step 1115, and the process proceeds to step 1116. Transition.

In step 1116, the circulation number C is subtracted from the number N, the value of C is set in the back side circulation number "D", and the process proceeds to step 1117. In step 1117, the circulation number C is set to the temporary processing variable C ′ and it is determined whether C ′ is larger than 1. If it is not larger in step 1117, the process proceeds to step 1121 in FIG. If it is larger in step 1117, the process proceeds to step 1118.

At step 1118, the image stored in the storage means HD of the image storage section is read out and the image memory 5 is read.
Then, the image is formed on the transfer paper. At this time, the odd-numbered original images of the originals read in step 1103 are sequentially read in the order in which they are read until the final original.
01 is read and an image is formed. Then, step 11
19, the value of C ′ is decremented by 1, and step 1120
Move to.

In step 1120, it is determined whether the value of C'is greater than zero. If it is greater than zero, the process returns to step 1117. If it is not greater than zero in step 1120, the process proceeds to step 1121 in FIG.

In step 1121, images on the back side are sequentially formed on the back side of the transfer papers stacked on the intermediate tray 156. At this time, the original images which are not the odd-numbered originals read in step 1103 are sequentially read out to the image memory 501 up to the final original in the order of reading, and images are formed. After that, the process proceeds to step 1122, the value of the circulation number D for the back surface is decremented by 1, and the process proceeds to step 1123.

In step 1123, it is determined whether the value of D is larger than zero. Step 1 if greater than zero
Returning to step 121, the back side image formation is repeated. Step 1
When it is not larger than zero in 123, the process proceeds to step 1124, and it is determined whether or not the final copy number flag is set. If not set in step 1124, the process returns to step 1113, and image formation is repeated up to the number N of copies set by the operation unit. If it is set in step 1124, the image forming operation is ended.

In this embodiment, the mode in which two single-sided originals are copied onto both sides of the transfer paper has been described, but the same can be done in the mode where both sides of the original are copied onto the transfer paper. Further, in the present embodiment, the transition timing from the front side image formation to the back side image formation is determined according to the number of originals. However, according to the paper size of the transfer paper, or the number of originals and the paper size of the transfer paper. May be determined from both. For example, although not shown, the length of the transfer paper is 210 m.
When it is longer than m, the circulation number "C" is forcibly set to 1.

The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of a single device. Further, it goes without saying that 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 apparatus, the system or apparatus can enjoy the effects of the present invention.

[0080]

As described above in detail, according to the first and seventh inventions, the switching from the one-sided image forming process to the opposite-sided image forming process is performed according to a predetermined condition. By setting such conditions, it is possible to increase the number of images formed per unit time and improve productivity.

According to the second and eighth aspects of the invention, in the case of sequentially forming image data of different contents on both sides of the recording material, switching from the single-sided image forming process to the opposite-side image forming process is predetermined. Since the process is performed according to the conditions, it is possible to increase the number of image forming sheets per unit time and improve the productivity by setting appropriate conditions.

According to the third and ninth inventions, the switching from the one-sided image forming process to the opposite-side image forming process is performed according to the number of image data or the number of recording materials. The number of image forming sheets per unit time can be increased according to the number of sheets or the number of recording materials, and the productivity can be improved.

According to the image forming apparatus of the fourth and tenth aspects, when the number of image data is less than the predetermined number, the one-sided image forming process is repeated a plurality of times and then the other-side image processing is switched. Therefore, in the skip double-sided mode, even when the number of image data is less than the predetermined number, the time spent by the reversing mechanism for reversing the recording paper can be effectively utilized, and the productivity is further improved. It becomes possible.

According to the fifth and eleventh inventions, the switching from the one-sided image forming process to the opposite-sided image forming process is executed only during the second and subsequent image forming processes of the image data composed of a plurality of copies. Since this is done, the time spent in the reversing mechanism for reversing the recording paper can be used more effectively,
It is possible to further improve productivity.

According to the sixth and twelfth inventions, the switching from the one-sided image forming process to the opposite-sided image forming process is performed according to the size of the recording material. The number of images formed per unit time can be increased, and productivity can be improved.

[Brief description of drawings]

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

FIG. 2 is a diagram illustrating an operation unit of the image forming apparatus according to the embodiment.

FIG. 3 is a block diagram showing a configuration of an image forming apparatus according to an embodiment.

FIG. 4 is a block diagram showing a detailed configuration of an electronic sorter unit 203.

FIG. 5 is a diagram showing a configuration of a control unit 303 of the embodiment.

FIG. 6 is a flowchart showing control of a processing unit at the time of general double-sided copying.

FIG. 7 is a flowchart continued from FIG. 6;

FIG. 8 is a processing unit control flowchart during double-sided copying according to the embodiment.

FIG. 9 is a continuation of the flowchart of FIG.

FIG. 10 is a flowchart continued from FIG. 9;

[Explanation of symbols]

 100 Copying Machine Main Body 180 Circular Automatic Document Feeder (RDF) 201 Image Reading Unit 203 Electronic Sorter Unit 204 Printer Unit 205 CPU Circuit Unit 209 External I / F Processing Unit

Claims (12)

[Claims] 1. A storage unit for storing image data, and an image forming unit for performing an image forming process for visualizing the image data in the storage unit on a recording material. In the image forming apparatus, after performing the one-sided image forming process of sequentially visualizing the image data on one side of the recording medium, and performing the opposite-side image forming process of further visualizing the image data on the other side of the recording material, An image forming apparatus comprising: a switching control unit that switches from the one-sided image forming process to the opposite-sided image forming process according to a condition. 2. A storage means for storing image data, an image forming means for performing an image forming process for reading out the image data from the storage means and visualizing it on a recording material, and a reversing mechanism for reversing the recording material. Then, by the image forming means,
After performing a single-sided image forming process of sequentially visualizing image data having different contents on one surface of the recording material, the recording material is inverted by the reversing mechanism, and image data having further different content on the other surface of the recording material. In the image forming apparatus for performing the opposite-side image forming processing for sequentially visualizing, the switching control means for switching from the single-sided image forming processing to the opposite-side image forming processing is provided according to a predetermined condition. A characteristic image forming apparatus. 3. The switching control means switches from the single-sided image forming process to the opposite-side image forming process according to the number of the image data or the number of the recording materials. 2. The image forming apparatus according to 2. 4. The switching control means, when the number of the image data is smaller than a predetermined number, repeats the single-sided image forming processing a plurality of times and then switches to the opposite-side image processing. The image forming apparatus according to claim 3. 5. The image forming apparatus according to claim 2, wherein the switching operation of the switching control unit is executed only during an image forming process for the second and subsequent copies of the image data composed of a plurality of copies. . 6. The image forming apparatus according to claim 2, wherein the switching control unit switches from the one-sided image forming process to the opposite-side image forming process according to the size of the recording material. . 7. The image data is sequentially recorded on one side of the recording material by using storage means for storing the image data and image forming means for performing an image forming process for visualizing the image data in the storage means on the recording material. An image forming method of performing a one-sided image forming process for visualization, and then performing an opposite-side image forming process for sequentially visualizing image data on the other side of the recording material, wherein the one-sided image forming process to the opposite-side image forming process are performed. An image forming method, characterized in that switching to processing is executed according to a predetermined condition. 8. A storage means for storing image data, an image forming means for performing image forming processing for reading image data from the storage means and visualizing it on a recording material, and a reversing mechanism for reversing the recording material. After performing a single-sided image forming process for sequentially visualizing image data having different contents on one surface of the recording material, the recording material is inverted by the inversion mechanism,
In an image forming method for performing an opposite side image forming process for sequentially visualizing image data having different contents on the other side of the recording material, switching from the one side image forming process to the opposite side image forming process is predetermined. An image forming method, characterized in that the image forming method is executed in accordance with specified conditions. 9. The image forming according to claim 8, wherein the switching from the one-sided image forming process to the opposite-side image forming process is executed according to the number of the image data or the number of the recording materials. Method. 10. The method according to claim 9, wherein when the number of the image data is less than a predetermined number, the one-sided image forming process is repeated a plurality of times and then the opposite-side image processing is performed. Image forming method. 11. The switching from the one-sided image forming process to the opposite-side image forming process is executed only during an image forming process of a second and subsequent copies of the image data composed of a plurality of copies. The image forming method according to claim 8. 12. The image forming method according to claim 8, wherein the switching from the one-sided image forming process to the opposite-side image forming process is performed according to the size of the recording material.