JPH04204862A - Double sided copying method in copying machine - Google Patents

Abstract

PURPOSE:To facilitate carrying control by shifting the timings of light irradiation during image formation according the set values of the binding margins for the front and back of a sheet, which values are set arbitrarily within the prescribed range, and not changing the timing when a document is carried. CONSTITUTION:This copying machine is provided with the copying machine main body 1, a recycling type document feeder (RDF) 2 which automatically feeds the document, a stapler 3, and a reversing device 10. First side and second side are shifted from each other in image formation area, by changing the timing of light irradiation during copying according to the set values of binding margins for the front and rear surfaces where values are set arbitrarily within the prescribed range, the timing when a document is carried are not changed irrespective of the set values of the binding margins. Thus, the carrying control of the recycling type document feeder which carries the document is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a double-sided copying method in a copying machine equipped with a circulating document feeder (RDF).

[Conventional technology]

A double-sided copying method for such a copying machine is described, for example, in Japanese Patent Publication No. 16976/1983.

According to the document, double-sided copying is performed in the following order.

i) - Copying every other set of documents onto one side of the paper fed from the paper tray, and storing the paper in the intermediate tray to perform first side copying.

ii) Next, on the other side of the paper that is fed from the intermediate tray and on which the first side has been copied, the second side of the original that has not been copied in the - set of originals is copied, and the second side of the original is alternately copied. Copying is performed on the first side of the paper fed from the paper tray.

in) The paper fed from the intermediate tray and with copies on both sides is conveyed to the discharge port, and the paper fed from the paper tray is conveyed to the intermediate tray.

[Problem to be solved by the invention]

If a binding margin is provided when performing such double-sided copying, as shown in FIG. It is necessary to move it before and after.

However, since the position of the original image formed on the photoreceptor does not change, it is necessary to shift the exposure timing in order to move the image.

FIG. 1O shows the timing.

The position P is the position where the original image is formed on the photoreceptor.

If the image is exposed at equal intervals so that the paper and the image match, no image shift will occur, but if the exposure is performed when the position of the photoreceptor corresponding to the leading edge of the paper reaches point B, the image at that time will be A. Since the image is formed from dots, the image lags behind the paper. Conversely, if exposure is performed at the 0 point, the image will advance.

In conventional copying machines, when an automatic document feeder is used to transport originals, the originals are fed and ejected in accordance with this exposure timing, but in such a case, the originals are transported at regular intervals. The disadvantage is that the control becomes complicated.

SUMMARY OF THE INVENTION An object of the present invention is to provide a copying apparatus that is easy to control by keeping the document conveyance timing constant even in the above-described case.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a method for forming N copies of double-sided images from a single-sided original by circulating an original through an original circulation path N+1 times in a copying machine, and in the first circulation of the original, For every other continuous document, first side copying is performed by forming an image on the paper fed from the paper tray and storing it in the intermediate tray. During the second to Nth document circulation, 1 For the originals on which no image was formed in the second circulation, a second side copy is performed in which an image is formed on the paper fed from the intermediate tray and the image is discharged to the outside, and the first side copy is also performed. In the circulation, only the second side is copied to form a double-sided image of part N, and at that time, each of the above-mentioned values is set according to the setting value of the binding bar width that is arbitrarily set within a predetermined range for the front and back sides of the paper. A double-sided copying method characterized by shifting the timing of light irradiation during image formation and not changing the timing of document transport.

[For production]

The double-sided copying method according to the present invention shifts the timing of light irradiation when copying the first side and when copying the second side, depending on the setting value of the binding bar width that is arbitrarily set within a predetermined range for the front and back sides. The image forming area is alternately shifted by , and the document conveyance timing is not changed regardless of the setting value of the binding frame width.

Therefore, the conveyance control of the circulation type document feeding device that conveys the document becomes easy.

[Example] Hereinafter, an example of the present invention will be specifically described based on the drawings.

FIG. 1 is an internal configuration diagram showing an example of a copying machine embodying the present invention.

In this figure, 1 is the main body of the copying machine, 2 is a circulating document feeder (hereinafter abbreviated as "rRDF") that automatically feeds documents, 3 is a stapling device, and 10 is a reversing device.

The copying operation when these are used will be explained below.

The copying operation is started by making the necessary settings on the operating section provided on the copying machine main body 1 and then pressing the start key.

The RDF 2 has a document tray 201, and the document placed there is fed by a document feed belt 202, passes through a document conveyance path 203, and is conveyed onto the contact glass 101 of the copying machine main body 1.

Thereupon, the entire surface of the document is irradiated with light by the flash lamp 102. The power source 103 of the flash lamp 102 is charged with electric charge prior to flashing, and emits light at a predetermined timing.

The reflected light from the original is reflected by the first mirror 104. Through lens 105. The belt photoreceptor 107 is exposed by the second mirror 106 .

The belt photoreceptor 107 is uniformly charged with a charge by a charger 108, and forms an electrostatic latent image by exposure.

The electrostatic latent image on the belt photoreceptor 107 has unnecessary charges removed by an eraser 109, is developed by a developer 110, and is sent to a transfer section.

The developed original image is then transferred onto transfer paper by a transfer charger 111. This transfer paper is placed in the paper feed tray 11.
2, 113, 114, or double-sided tray 124, is conveyed along the conveyance unit 115, and is transferred to the belt photoconductor 107 by registration rollers 116 in synchronization with the document image on the belt photoconductor 107. It is sent between the transfer charger 111 and the transfer charger 111 .

The transfer paper on which the image has been formed is separated from the belt photoreceptor 107 by a separation charger 120 and transferred to the conveyor belt 107.
17 and is fixed by a fixing device 118.

In duplex mode, which copies on both sides of the transfer paper, press duplex switching claw 1.
21 is switched to the duplex tray 124 side, the transfer paper is sent to the duplex tray 124 from the duplex entrance path 123, and is temporarily stored in the duplex tray.

Further, in the single-sided mode in which copying is performed on one side of the transfer paper, the double-sided switching claw 121 is switched to the paper ejection side, and the paper is conveyed to the ejection switching claw 122. If a peripheral device such as the stapling device 3 is connected to the copying machine main body 1 and a peripheral device such as the stapling device 3 is connected to the copying machine main body 1, the ejection switching claw 122 feeds the transfer paper to the peripheral device side, and if not, it feeds the transfer paper to the main body tray. Switch to the 119 side,
The transfer paper is discharged to the main body tray 119.

After the transfer paper is separated, the belt photoreceptor 107 is neutralized by a charger 125, and untransferred toner is removed by a cleaning device 126, in preparation for the next copy.

The document on the contact glass 101 is transferred to the document conveyor belt 2.
04, the document is sent out after the light irradiation is completed, and is returned to the document tray 201 again by the document discharge roller 206. The document discharge roller 206 is capable of forward and reverse rotation, and to make the front and back sides of the document the same as the original state, after the trailing edge of the document passes the document branching claw 205, the document discharge roller 206 is rotated in the reverse direction. If the document is to be ejected through the normal rotation conveyance path 207 and in the reverse direction, the document ejection roller 206 is driven as it is, and the document is ejected from the reverse conveyance path 208 .

In this embodiment, a stabilizing device 3 is connected as a peripheral device via a reversing device 10, and when this device is used, the paper ejected from the copying machine main body 1 is transferred to the reversing device 10.
If necessary, the sheet is reversed and sent to the stabilizing device 3, passes through the staple conveying section 302, and is once accumulated in the stable unit 303.

A predetermined number of sheets of paper are sequentially stacked, and the stapling unit 303 is driven to staple the stacked sheets, and then pass through the stable output section 304 to the output tray 3.
It will be discharged on 05.

Since the belt photoreceptor 107 of the copying machine main body 1 has a seam, the image forming areas on the belt are determined to be equally spaced for each size, avoiding the seam of the belt photoreceptor 107.

FIG. 2 shows a belt photoreceptor 107 cut at seam S and unfolded.
FIG. 3 is a diagram showing an example of the arrangement of image forming areas (segments) in FIG.

In this example, five A4 segments indicated by dashed lines, four B4 segments indicated by broken lines, and three A3 segments indicated by two-dot chain lines are determined to be equally spaced. M is a synchronization mark.

FIG. 3 is a mechanism and control block diagram of the main parts for forming an image on the belt photoreceptor 107 and forming a toner image on the transfer paper conveyed from the tray.

The operation will be explained below.

Like the vanguard, in order to avoid seams during image formation, it is necessary to determine the image forming area on the belt photoreceptor 107 prior to image formation.

Therefore, the end of the belt photoreceptor 107 has a seam S (
A synchronization mark M (FIG. 2) is provided at a certain distance from the synchronization mark M (FIG. 2), and is detected by a mark sensor 410.

In order to determine the image forming area, the belt photoreceptor 107
It is necessary to drive the mark M to detect this mark M. For this purpose, a drive signal from the output boat 402 is input to the motor control circuit 404, and the photoreceptor drive motor 408 is driven.

An encoder 409 is integrally attached to the photoreceptor drive motor 408 and outputs a number of pulses proportional to the moving distance of the belt photoreceptor 107.

The pulse signal is input to the motor control circuit 404,
The signal is used to rotate the photoreceptor drive motor 408 at a constant speed, and is also input to the frequency divider 406, frequency-divided at a predetermined division ratio, and then input to the CPU 401, where the number is counted. Since this signal is proportional to the amount of movement of the photoreceptor, the image forming area is determined by this count value (CNT).

Next, completion of the copy sequence will be explained.

When the leading value of the aforementioned segment of the belt photoreceptor 107 reaches a predetermined position, a sequence operation starts, and a counter for sequence control starts operating.

This counter performs a count-up operation in response to a pulse signal from the frequency dividing circuit 406, but is not cleared by the mark M detection signal, and continues to perform a count-up operation until the sequence is completed.

When the counter starts operating and its value reaches the value of CNT 1, a signal is output from the output boat 402 to the power pack 405, the charger 108 operates, and the belt photoreceptor 10
7 is uniformly charged.

Next, when the count value reaches CNT2, the output port 40
2, a charge start signal is input to the flash power supply 103, and in order to light up the flash lamp 102, a capacitor in the flash power supply 103 is charged with electric charge.
By sending a flash signal to a flash power source 103, a flash lamp 102 is turned on, and a document set on a contact glass 101 is irradiated with light to expose a belt photoreceptor 107. This flash signal is output when the count value is CNT3.

When the belt photoreceptor 107 further rotates and the leading edge of the image reaches the position of the eraser 108 (=CNT4), the part corresponding to the eraser image turns off, and the rear end of the image reaches the position of the eraser 109 (=CNT5). When it reaches , the eraser is fully turned on, the excess charge on the photoreceptor is erased, and an electrostatic latent image is left only on the original image.

This electrostatic latent image is developed by a developing device 110, and
It is transferred onto the paper sent from 12, 113, and 114.

In order to synchronize with the original image, paper begins to be transported at different timings depending on which paper feed tray is selected.

That is, transport is started at CNT-LOW for the lower tray 112, CNT-MID for the middle tray, and CNT-HIGH for the upper tray.

The paper onto which the original image has been transferred passes through a conveyor belt 117,
The image is fixed by the fixing device 118.

The double-sided switching claw 121 operates at CNT6, and switches so that the paper is transported to the double-sided tray side in the case of double-sided copying, and to the paper ejection side in the case of single-sided copying.

The discharge switching claw 122 is operated by the CNT 7 and switches whether the paper is discharged to the main body tray 119 or to the peripheral device side. The sequence operation ends when the paper is ejected. When using RDF2, flash lamp 1
Before 02 lights up, it is necessary to convey the original set on the original placing table 201 to the contact glass 101.

Therefore, the value of the sequence counter mentioned above is CNT F
When EED occurs, serial boat 407, which is a communication device,
A command is given to the RDF control circuit 6 through the RDF control circuit 6 to start conveying the document. Furthermore, the original after exposure is returned to the original placing table 201 again in response to an original ejection command.

FIG. 4 is an internal configuration diagram of the RDF 2, and its operation will be explained below.

Before the document set on the document tray 201 is fed from the lower side by the document feed belt 202, the partition claw 210 is once retracted to the upper left side of the document, and then reappears to be placed on top of the document. Noru.

The original fed in this state passes through the original transport path 203, is sent to a predetermined position on the contact glass 101, and is irradiated with light.

After the light irradiation, the original is sent to the left by the original transport belt 204, and is moved to the contact glass 1 by the original branching claw 205.
01 and is picked up from the top surface of the document ejection roller 20.
6 into the reversing conveyance path 208.

When the front and back sides of the original are the same as when they were fed, when the trailing edge of the original is detected by the reversal sensor 211, the original discharge roller 206 starts to rotate in reverse, and the original continues to advance along the trailing edge in the previous direction. The document is sent to the normal rotation conveyance path 207 with the leading edge in the direction, and is returned to the document tray 201 through the document discharge port 209.

Furthermore, it is possible to turn the front and back sides of the paper without changing the direction of movement while leaving the drive as it is. At this time, the original that has been fed and returned and the original that has not been fed are clearly distinguished by the partition mold 210 that is provided so as to be able to move forward and backward, so that the end of the original can be detected.

When reversing the original internally, after detecting the trailing edge of the original with the reversal sensor 211, the original ejection roller 206 is reversed to change the direction of travel, and the original duplex branching claw 212 is activated to transport the original again. This is made possible by feeding it into the channel 203.

FIG. 5 is a block diagram of an RDF control circuit that controls this RDF2.

This control circuit 6 includes a CPU 601. ROM602, RA
It is constituted by a communication interface 607 with the main body control circuit shown in FIG. 3.

Various sensors are connected to the input/output capotro o4, and a blower board 608, various motors, solenoids, etc. are connected to the input/output capotro 05.

FIG. 6 shows an operating section provided on the copying machine main body 1. As shown in FIG.

In this operation unit 5, 501 is a mode clear/preheating key, which serves as both a mode clear key and a preheating key.When this key is pressed, it becomes a mode clear key, and when it is kept pressed, it becomes a preheating key.

The mode clear key is used to return each mode to the standard mode, and the preheating key is pressed to put the machine into a preheating state and to cancel the preheating state.

502 is an interrupt key, which is pressed to perform an interrupt copy, and 503 is an enter key to change the zoom magnification.

Press when entering numerical values for dimension scaling and binding margin.

Reference numeral 504 denotes a copy start key (start key), which is pressed when starting a copying operation. This also serves as a ready/wait display; a green LED lights up when ready, and a red LED lights up when wait.

A numeric keypad 505 is used to set the number of copies, to change the zoom magnification in two dimensions, and to enter numerical values for the binding margin.

A clear/stop key 506 functions as a clear key during standby and as a stop key during copying. This clear key is pressed to cancel the set number of copies. The stop key is pressed to interrupt the copying operation, and the machine stops when the current copying operation is completed.

A guidance key 507 is pressed to display an explanation of basic operations, and a program registration key 508 allows the user to register frequently used modes. Here, 10 modes can be registered.

A program call key 509 is pressed to call a registered mode.

510 is a display unit, which is of an LCD type.

The display of this display unit 510 has touch keys arranged on its surface, which not only display functions but also function as selection keys.

Therefore, in this area, when a function is selected by pressing the function display area, the color of the display changes to indicate the selection. FIG. 7 shows details of this display section 510.

The display unit 510 will be explained below based on FIG.

511 is the message display, which displays information on the machine, such as "You can copy."

” [Please replenish paper. ” etc. will be displayed.

512 is a tray selection key, paper size and remaining amount display area, and the upper trays are displayed in order from left to right.

A middle tray, a lower tray, and a large capacity tray are shown.

Reference numeral 513 is an automatic paper selection key, and when this key is selected, a tray containing paper of the same size as the original is automatically selected.

A density adjustment key 514 is pressed when manually adjusting the copy density. Reference numeral 515 denotes an automatic density key, which is selected when automatically adjusting the copy density according to the background density of the original.

Reference numeral 516 is a same-size key, 517 is an enlargement key, and 518 is a reduction key, each of which is pressed when specifying a same-size copy or enlargement or reduction of a standard size.

519 is a zoom key, which is pressed to specify any magnification between 64% and 142%. Reference numeral 520 is a dimension magnification change key, and by pressing this key and inputting a dimension, a magnification is automatically calculated and set to that magnification.

Reference numeral 521 is a paper specification scaling key, which is used when it is desired to automatically reduce or enlarge the original image according to the specified paper size.

Reference numeral 522 denotes three duplex keys, which are respectively selected to convert a single-sided original to double-sided, to convert a double-sided original to double-sided, or to convert a double-sided original to single-sided.

Reference numeral 523 denotes a duplex mode message area, in which the copy creation status is displayed when the duplex mode function is selected.

524 has two binding margin keys, and when binding margin is required, 21m
If it is less than m, it can be set on either the left or right side. In addition, in the case of double-sided copying, settings can be made for the back side independently of the front side. Reference numeral 525 denotes a margin mode message area, in which the status of the margin is displayed when the margin mode function is selected.

Reference numeral 526 indicates three cover function selection keys, which are front cover, back cover, and double-sided bar selection keys.

527 is two stable selection keys that allow you to select one-place stop or two-place stop.

Next, a method of double-sided copying performed in the present invention will be explained. This method is used to make two or more double-sided copies from a stack of single-sided originals, and is a method in which front-side copies and back-side copies are alternately made for successive originals.

A bundle of originals placed on the original tray 201 of the RDF 2 shown in FIG. The image is transferred onto a sheet of paper sent from any one of 112 to 114.

The paper onto which the original image has been transferred is fixed by a fixing device 118, the conveyance path is changed by a double-sided switching claw 121, and the paper is first stored in a double-sided tray 124. The document on which no image is formed is only circulated within the RDF 2, and the page order is not changed (first side copying).

The first copy paper is stored in the duplex tray 124,
When paper feeding becomes possible and the second document circulation becomes possible after the last document is fed, the documents are fed one by one again.
The image of the original on which the image was not formed in the first side copying is formed on the belt photoreceptor 107, and the original image is transferred to the back side of the paper on which the first side has been copied, which is fed from the duplex tray 124 (
Copy of the second side).

As a result, the two i-documents are copied on both sides of the paper. Copying on the first side is also performed alternately with this second side copying, and the sheet on which the first side has been copied is conveyed to the duplex tray 124 as described above, and the other sheet on which the second side has been copied is transferred to the main body tray 124.
9 or is discharged to a reversing device 10. At this time, the paper is
The sheets are alternately sent from the double-sided tray 124 and one of the paper trays 112 to 114.

In the last original circulation, the original image on which the image was not formed in the first side copying is formed on the paper on which the first side has been copied stored in the duplex tray 124, and is discharged to the main body tray 119 or the reversing device 10. .

The above is the method for creating a double-sided copy from a single-sided original.

Next, a method for forming a binding margin during double-sided copying will be explained.

In the case of double-sided copying, the binding margin can be set independently for the front and back sides, so in the method of creating a double-sided copy from a single-sided original, the timing of light irradiation and original ejection during image formation is as shown in Figure 8. It comes to show.

The timing diagram in FIG. 8 represents the following four points.

(i) Light irradiation timing for one-sided copying (ii) Original output signal output timing for one-sided copying (■) Light irradiation timing for one-sided/double-sided copying (iv) Original for one-sided/double-sided copying Output timing of paper ejection signal In the case of single-sided copying, a document ejection command is given to the RDF control circuit 6 immediately after light irradiation, but in the case of single-sided/double-sided copying, as shown in (iii) of FIG. By shifting the timing of light irradiation, the image forming area is alternately shifted, and by erasing unnecessary charges with an eraser,
Create a binding margin on the paper that is fed at the same timing as one-sided copying.

(iv) In order to keep the timing of document conveyance constant,
This figure shows how a document discharge signal is output after a predetermined period of time after light irradiation.

〔Effect of the invention〕

If the double-sided copying method according to the present invention is applied, the document transport timing will not shift regardless of the binding margin setting, so the RD
The transport control of F becomes easier.

[Brief explanation of the drawing]

FIG. 1 is an internal configuration diagram showing an example of a copying machine embodying the present invention, FIG. 2 is a developed view showing an example of the arrangement of image forming areas on a belt photoreceptor, and FIG. 3 is an outline of the copying machine shown in FIG. 1. Fig. 4 is an internal configuration diagram of the RDF 2 in Fig. 1, Fig. 5 is a block diagram of the RDF control circuit, and Fig. 6 is a diagram of the copying machine main body 1.
7 is a layout diagram of the display section 510 of the operation section 5 in FIG. 6, FIG. 8 is a timing diagram of light irradiation and document ejection when making double-sided copies, and FIG. 9 is a binding margin. FIG. 1o is an explanatory diagram showing the positional relationship between the original image and the paper when double-sided copying is performed by providing the same. FIG. 1o is also an explanatory diagram of the timing at that time. 1... Copying machine main body 2... Circulating document feeder (RDF) 3... Stable device 5... Operation unit 6... RDF control circuit 10
... Reversing device 101 ... Contact glass 1
07...Belt photoreceptor 112-114...Paper feed tray 124...Double-sided tray 510...Display section 522
...Double-sided key 524...Binder key Fig. 2/Fig. 8 (1v)

Claims (1)

[Scope of Claims] 1. A method for forming N copies of double-sided images from a single-sided original by circulating the original in the original circulating path N+1 times in a copying machine, wherein in the first original circulation, the original is On the other hand, every other sheet of paper is fed from the paper tray, the image is formed on the paper, and the first side is copied, which is stored in the intermediate tray. For the document on which no image has been formed, a second side copy is performed in which an image is formed on the paper fed from the intermediate tray and the image is discharged to the outside, and the first side copy is also performed, and in the N+1th document circulation, Only the second side is copied to form a double-sided image of part N, and the binding margin width is arbitrarily set within a predetermined range for the front and back sides of the paper, and the binding margin width is set arbitrarily within a predetermined range for each of the above image formation. A double-sided copying method characterized by shifting the timing of light irradiation and not changing the timing of document conveyance.