JPH0446357A - Image forming device - Google Patents

Abstract

PURPOSE:To detect overlapping-carry each time a document is circulated by providing an intermediate tray with a recycle lever when a skip-mode is executed in the time when a single-sided document is copied on both sides of a sheet. CONSTITUTION:RDF document is read at every other sheet and carried to the intermediate tray 203 while its image is transferred onto a sheet. When the carry of the last transfer sheet is finished, the recycle lever 218 is put into the on-position. Then, each document is circulated again; while sheets are alternately fed from a cassette and the intermediate tray, the image is transferred onto the front of the cassette sheet and the back of the intermediate-tray sheet. If the recycle sensor 47 is turned on before the document is circulated, it indicates that sheets are overlappingly carried at the time of intermediate-tray- sheet-feeding. Therefore, the copying operation is stopped at the same time that a warning by means of, for example, an alarm display is given. In addition, when the recycle sensor 47 is turned off after the document is circulated, it indicates that sheets are overlappingly carried at the time of cassette-sheet- feeding. Therefore, the sheets are ejected without being subjected to retransfer, and the copying operation is stopped at the same time that a warning by means of, for example, the alarm display is given.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image forming apparatus, and more particularly, to an image forming apparatus such as a copying machine or a laser printer, and particularly to an apparatus having a duplex function.

[Conventional technology]

Conventionally, a circulation-type document feeder (hereinafter referred to as RDF) feeds a stack of documents set on a tray one by one from the last page to the exposure position, and returns the documents to the same tray after exposure. ) is known in combination with a device such as a copying machine.

In such a device, when forming multiple copies of images using RDF, images are formed on both the front and back sides of transfer paper from a single-sided original to obtain one copy from two originals in the single-sided original/double-sided copy mode. Yes, and when the output from the number of copies setting means performs image formation for multiple copies, the image is formed on every other document while determining the number of documents during the first circulation in a circulation sort mode in which the document is circulated multiple times. The document is stored in the intermediate tray, and during the second and subsequent circulations, images are formed while alternately feeding the paper from the paper cassette and the intermediate tray. During the final circulation, images are formed while feeding every other document from the intermediate tray. Image formation was performed using an image forming mode (hereinafter referred to as skip mode).

However, if a double feed occurs when forming images for multiple copies using this method, this double feed will be detected only after the last copy has been created, making it difficult to identify the position where the double feed occurred. There was a fear that this would result in the creation of many incomplete parts.

〔the purpose〕

The present invention has been made in view of the above points, and its purpose is to form images on both the front and back sides of transfer paper from a single-sided RDF original to obtain one copy from two originals. When performing the above-mentioned skip mode in the copy mode, by providing a recycle lever on the intermediate tray, it is possible to detect double feeding each time the document is circulated, thereby making it possible to complete the sections other than the area where the double feeding occurred as set. The objective is to provide an image forming apparatus that can.

[Summary of the invention]

In order to achieve the above purpose, by providing a recycle lever in the intermediate tray that can detect one cycle of originals, images are formed on both the front and back sides of transfer paper for single-sided originals, and one-sided copy is obtained from two originals. When the double-sided copying mode is in effect and the output from the number of copies setting means is to form images for multiple copies, in the circulation sort mode in which the originals are circulated multiple times, the number of originals is determined during the first circulation and the originals are placed every other sheet. An image is formed on the document and stored in the intermediate tray. During the second and second circulation, images are formed while alternately feeding the paper from the paper feed cassette and the intermediate tray. During the final circulation, the image of the document is stored in the intermediate tray every other sheet. When operating in a skip mode in which an image is formed on a sheet of paper fed from a tray, double feeding can be detected every time an original is circulated.

[Embodiments of the invention]

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

In the skip mode mentioned above, by circulating the original,
If the number of originals is N, then N, N-2, N4, etc.
Every other document is read, an image is formed on a sheet of paper fed from a cassette, and the sheet of paper is conveyed to an intermediate tray. After this operation is completed, as shown in FIG. 2, the recycle motor is started, and the recycle lever 309 is rotated by the lever rotating bin to press the top of the document bundle S. At the same time, the recycle lever 218 is also rotated by the recycle motor to press against the top of the sheet, as shown in FIG. The lever 218 is rotated via the lever rotation pin 45. This first cycle determines whether the manuscript has an odd or even number of pages. From the second circulation to the copy circulation, if the number of originals is an even number, sheets of paper are fed from the cassette and images are formed again for the originals of N, N-2, N-4, etc. Transferred to the intermediate tray, and during that time N-1°N-3,
The originals of N-5, . After this is completed, if there is no double feeding, the recycle lever 218 falls to the chain line position under its own weight in FIG. 1. The recycle sensor 47 detects one circulation of the document bundle S by detecting the end surface 46a of the flag 46 that is displaced as the recycle lever 6 moves.

The operation of the recycle lever is the same even in the case of an odd number, but
After the second circulation, first, the transfer paper on which the image of the N document was formed in the first circulation is re-fed from the intermediate tray, but no image is formed by the entire surface erasing means controlled by the blank LED. When the number of originals is odd, reverse ejection as described below is performed. In the final circulation, image formation is performed in the same manner as in the case of refeeding paper from the intermediate tray for the smallest number of copies from the second circulation.

Incidentally, the motor 42 of the recycle lever 218 is activated upon detection of a signal for completing one circulation of the original, and places the lever 218 on the sheet of the intermediate tray. The completion of one circulation of the original is detected by the operation of the recycle lever 309.

FIG. 2 shows the internal configuration of an embodiment of the image forming apparatus of the present invention. In Fig. 2, 100 is a main body that has an image reading function and an image recording function, and 200 is a main body that has a double-sided processing function that turns the recording medium (paper) over during double-sided recording, and performs multiple recordings on the same recording medium. A pedestal with a multiplex recording function, 300 a circulating document feeder (hereinafter referred to as RDF) that automatically feeds originals, and 400 a collation device with a stable (hereinafter referred to as a stable router); Each of the 200 to 400 devices can be used in combination with the main body 100 as desired.

A1 main body (100) In the main body 100, 101 is a document table glass on which a document is placed, and 103 is an illumination lamp (exposure lamp) for verifying the document.
, 105, 107, and 109 are scanning reflection mirrors (scanning mirrors) that change the optical path of reflected light from the original, respectively, and 111
113 is a lens having focusing and zooming functions, and 113 is a fourth reflecting mirror (scanning mirror) that changes the optical path. 11
5 is an optical system motor that drives the optical system; 117.119.
121 are sensors, respectively.

131 is a photosensitive drum, 133 is a main motor that drives the photosensitive drum 131, 135 is a high voltage unit, 137 is a blank exposure unit, 139 is a developing device, 141 is a transfer charger, 147 is a separation charger, and 145 is a cleaning device. be.

151 is the upper cassette, 153 is the lower cassette, 171
1 is a manual paper feed slot, 155 and 157 are paper feed rollers, 1
59 is a registration roller.

Further, 161 is a conveyor belt that conveys the recording paper on which an image has been recorded to the fixing side, 163 is a fixing device that fixes the conveyed recording paper by heat fixing, and 167 is a sensor used in double-sided recording.

The surface of the photosensitive drum 131 described above is made of a seamless photoconductor using a photoconductor and an electric conductor. The motor 133 starts rotating in the direction of the arrow in the figure. Next, when the predetermined rotational control and potential control processing (preprocessing) of the drum 131 are completed, the original placed on the original platen glass 101 is illuminated by the illumination lamp 103 that is integrated with the first scanning mirror 105. The reflected light from the original is transmitted to the first scanning mirror 105 and the second scanning mirror 105.
Scanning mirror 107, third scanning mirror 109, lens 11
1 and a fourth scanning mirror 113 to form an image on the drum 131.

The drum 131 is corona charged by a high pressure unit 135. After that, the image illuminated by the illumination lamp 103 (
The original image) is exposed to slit light, and an electrostatic latent image is formed on the drum 131 using a known Carlson process.

Next, the electrostatic latent image on the photosensitive drum 131 is transferred to a developing device 139.
The toner image is developed by a developing roller 140 and visualized as a toner image, and the toner image is transferred onto a transfer paper by a transfer charger 141 as described later.

That is, the upper cassette 151 or the lower cassette 1
The transfer paper in 53 or the transfer paper set in the manual paper feed port 171 is fed into the main unit by a paper feed roller 155 or 157, and the leading edge of the latent image and the leading edge of the transfer paper are aligned. Thereafter, the transfer paper passes between the transfer charger 141 and the drum 131 and is discharged to the outside of the main body 100.

After the transfer, the drum 131 continues to rotate, and its surface is cleaned by a cleaning device 145 composed of a cleaning roller and an elastic blade.

B. Pedestal (200) The pedestal 200 can be separated from the main body 100 and includes a deck 201 that can store 2000 sheets of transfer paper and an intermediate tray 203 for double-sided copying. In addition, the deck 201 glue lid 2 can hold 2000 sheets.
05 rises according to the amount of transfer paper so that the transfer paper always comes into contact with the paper feed roller 207.

Further, 211 is a paper flapper that switches between the double-sided recording side, the multi-recording side, or the reverse discharge route and the discharge side route; 212 is a switchback roller for reverse discharge;
Reference numeral 3 designates a reversing paper ejecting flapper that switches the path between the double-sided recording side or multi-recording side and the reversing ejecting path, and when it rotates to the right, the transfer paper is transferred to the switchback roller 2141.
: Guide<.

215 is a conveyance path of a conveyor belt, and 217 is an intermediate tray dust for holding down the transfer paper. The transfer paper that has passed through the paper discharge flapper 211 and the transport paths 214 and 215 is turned over and stored in the intermediate tray 203 for double-sided copying. Reference numeral 219 denotes a multiplex flapper that switches between double-sided recording and multiplex recording, and is disposed between conveyance paths 214 and 215, and guides the transfer paper to multiplex recording conveyance path 221 by rotating upward. Reference numeral 223 is a multiple sheet discharge sensor that detects the end of the transfer sheet passing through the multiple flapper 219. A paper feed roller 225 feeds the transfer paper to the drum 131 through a path 227. 229 is a discharge roller that discharges the transfer paper to the outside of the machine.

During double-sided recording (double-sided copying) or multiplex recording (multiple overlapping copying), first raise the paper discharge flapper 211 of the main body 100 upwards, and move the copied transfer paper to the conveyance path 2 of the bediskle 200.
14 and stored in the intermediate tray 203 via 215. At this time, the multiplex flapper 219 is lowered during double-sided recording, and the multiplex flapper 219 is raised during multiplex recording.

This intermediate tray 203 can store up to 99 sheets of transfer paper, for example. The transfer paper stored in the intermediate tray 203 is pressed down by an intermediate tray weight 217. In addition, in the skip mode mentioned above, the recycle lever 2
18, document circulation is detected.

During the next back-side recording or multiplex recording, the transfer paper stored in the intermediate tray 203 is moved one by one from the bottom to the path 2 by the action of the paper feed roller 225 and the weight 217.
27 to the registration rollers 159 of the main body 100.

In addition, at the time of reversal discharge, the reversal discharge flapper 213 is rotated to the right to guide the transfer paper to the switchback roller 212, and then, when the transfer paper has sufficiently reached the switchback roller 212, the switchback roller 212 is reversed.
The transfer paper is discharged to the outside of the machine by a paper discharge roller 229.

C, RDF (circulating document feeder) (300) RDF
In 300, 301 is a stacking tray on which a bundle of originals 302 is set. First, for single-sided originals, half-moon roller 3
04 and a separation roller 303 from the bottom of the document bundle 302, and the separated documents are transferred to the platen glass 10 by a conveyance roller 305 and a full-surface belt 306.
The sheet is conveyed to the exposure position No. 1 through bus e. After copying is completed, the original on the platen glass 101 passes through paths ■ and ■ and is transported to the large transport roller 3.
07, the paper is sent to passes ■,
8, the document is returned to the uppermost surface of the document bundle 302 again.

Reference numeral 309 denotes a recycle lever for detecting document circulation. When the document feed starts, the recycle lever 309 is placed on top of the document stack, and the documents are fed one after another until the trailing edge of the final document passes through the recycle lever 309. One circulation of the original is detected by the original falling onto the stacking tray 301 due to its own weight.

Next, in the case of a double-sided document, as described above, the document is guided from bus e, from The original is conveyed and stopped on the platen glass 101 by the full-surface belt 306 through (2). That is, the configuration is such that the rotation of the large transport roller 307 causes the document to be reversed along the routes of buses 1 to 3.

Also, pass through the document bundle 302 one by one~■~■~■~■
It is also possible to count the number of originals by transporting the originals through the recycle lever 309 until one cycle is detected.

D. Stable router (collation device with stable) (
400) The stable sorter 400 has a fixed non-sort tray 411 with 20 bins and performs collation.

In the sort mode, the copied sheets are sequentially ejected from the paper ejection roller 229 of the main body, enter the conveyance roller 401 of the sorter 400, pass through the conveyance path 403, and are ejected from the ejection roller 405 to each bin of the tray 412. Each time, each bin is moved up and down by a bin shift motor (not shown) to collate the bins. Further, when the skip mode is selected and a stable signal is input from the main body 100, the stabilizing device 420 stabilizes the sheets in each bin while moving the sheets one bin at a time using the bin shift motor.
(taple) and go.

E. Control device (800) FIG. 3 shows an example of the configuration of the control device 800 of the embodiment shown in FIG. In FIG. 3, 801 is a central processing unit (CPU) that performs arithmetic control for executing the present invention, and uses, for example, a 16-bit microcomputer. 803
is a read-only memory (ROM) in which a control procedure (control program) according to the present invention is stored in advance;
PU801 controls each component device stored in this ROM803. Reference numeral 805 denotes a random access memory (RAM) which is a main storage device used for storing input data and as a working storage area.

807 is an output signal transfer interface (
Ilo), 809 is an interface for inputting input signals such as the image tip sensor 121 and transmitting the input signals to the CPU 801, and 811 is a key group 600 and a display group 700.
This is an interface that controls input and output. These interfaces 807.809.811 use input/output circuit ports 8255, for example.

Note that the display group 700 uses, for example, LEDs (light emitting diodes) and LCDs (liquid crystal displays). The key group 600 is each key, and the CPU (8
It is structured as shown in 01.

[Embodiment 1] Next, an example of the recycle lever operation when the present invention is applied to a copying machine will be described based on FIG. 4.

When the skip mode is used in the single-sided original-double-sided copy mode using RDF, the following operation occurs.

First, as described above, every other RDF document is read and transferred onto a sheet while the sheet is conveyed to the intermediate tray 203 (5-1).

When the last transfer sheet has been conveyed to the intermediate tray, the recycle lever is turned on (5-2). Next, the original is passed through the second cycle, and as described above, while feeding alternately from both the cassette and intermediate tray, the front side is transferred to the cassette paper, and the back side is transferred to the intermediate tray paper.5-3) Determine whether the manuscript has completed one cycle (5-4).

If the recycle sensor is on before the original is cycled (5-5)
If the paper is fed from the intermediate tray, double feeding may have occurred (5-8), so a warning (5-8) such as an alarm display or alarm sound will be displayed after the transfer paper currently being copied is ejected.
-10) and the copying operation ends. Also, when the recycle sensor is off after the document cycle, double feeding may have occurred when feeding the paper from the cassette, so feed the paper from the intermediate tray until the recycle sensor turns on and try to eject the paper without retransferring.
-7) At the end, the copying operation is ended with a warning (5-10) such as an alarm display or alarm sound.

The above operations are repeated until the set number of copies is completed unless double feeding occurs. (5-9).

[Other Embodiment 2] Next, an example of the recycle lever operation when the present invention is applied to a copying machine will be described based on FIG.

When the skip mode is used in the single-sided original-double-sided copy mode using RDF, the following operation occurs.

First, as described above, the sheet paper is conveyed to the intermediate tray while transferring every other RDF original (6-1).

When the last transfer sheet has been conveyed to the intermediate tray, the recycle lever is turned on (6-2). Next, as described above, feed paper alternately from the cassette and intermediate tray (6-3).
, it is determined whether the manuscript has completed one cycle (6-4).

If the recycle sensor is turned on (6-5) before printing the original
If this occurs, it is considered that double feeding occurred when feeding paper from the intermediate tray, so after the transfer paper currently being copied is ejected, end this cyclical copying operation (6-8) and shift the sorter by one bin. and open it (6-10) to perform the next copying operation. Also, the recycle sensor is turned off after the original is circulated.
In this case, it is thought that double feeding occurred when feeding paper from the cassette, so feed the paper from the intermediate tray until the recycle sensor turns on, eject it without retransferring it (6-7), shift the sorter by one bin, and then Performs a cyclic copying operation.

The above operations are repeated until the set number of copies is completed (6-9). After completing the set number of copies, if double feeding occurs on the way (6-
12) A warning (6-13) such as an alarm display or an alarm sound indicating the occurrence of double feeding shall be given, and the position of the portion where double feeding has occurred shall be indicated by shifting the sorter by one bin.

[Other Embodiment 3] Next, an example of a duplex sequence operation when the present invention is applied to a copying apparatus will be described based on FIG.

When the skip mode is used in the single-sided original-double-sided copy mode using RDF, the following operation occurs.

First, as described above, the RDF original is transferred to the intermediate tray while being transferred every other sheet (7-1).

When the last transfer paper has been conveyed to the intermediate tray, the recycle lever is turned on (7-2). Next, as described above, while feeding paper from the cassette and intermediate tray (7-3), it is determined whether or not the document has completed one cycle (7-4).

If the recycle sensor is on before the original is cycled (7-5)
If this occurs, double feeding may have occurred when feeding paper from the intermediate tray, so after the transfer paper currently being copied is ejected, this cycle of copying operation should be terminated.7-8), and the sorter position where it was ejected should be 7-10) and perform the next circular copying operation. Also, if the recycle sensor is off after the document cycle, double feeding may have occurred when feeding the cassette, so feed the paper from the intermediate tray until the recycle sensor turns on and eject it without retransferring.7-7) , stores the discharged sorter position (7-10)L, and performs the next circulation copying operation.

The above operations are repeated until the specified number of copies is completed (7-9). Here, the designated number of copies is (set number of copies) + (number of times of double feeding).

In other words, the copying operation is ended when the set number of copies has been successfully completed. After finishing, if double feeding occurs on the way (7-1
2) A warning (7-13) such as an alarm display or sound indicating that a double feed has occurred is displayed and the bin/bin of the sorter where the double feed has occurred is
The numbers will be displayed (7 to 14).

〔Effect of the invention〕

A single-sided original that creates one copy from two originals by forming images on both the front and back sides of a transfer paper from a single-sided RDF original.
When using the above-mentioned skip mode in the double-sided copy mode, by providing a recycle lever on the intermediate tray, it is possible to detect double feeding each time a document is circulated.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of the intermediate tray and recycle lever, (a
) is a plan view, and (b) is a front view. FIG. 2 is a sectional view showing the internal configuration of the entire embodiment, FIG. 3 is a block diagram showing the circuit configuration of the control device of the embodiment, FIG. 4 is the operation sequence of the first embodiment, and FIG. 5 is the operation of the second embodiment. Sequence FIG. 6 shows the operation sequence of the third embodiment. 203...Intermediate tray 218...Recycle lever 300...Circulating original feeder 2ρ3 zf Figure 3 S (heavy change sequence of 彎2) Figure 41 (heavily added sequence of -11) dance) Figure 6

Claims (2)

[Claims] (1) A circulation-type automatic document transport device that automatically feeds multiple originals placed on a document placement table to an image reading position, and after reading, ejects the documents to return them to the document placement table; and image reading. an image reading means for reading an image of a document at a position, an image recording means for recording an image read by the image reading means, a mode input means for inputting an image forming mode, and a copy number setting for setting a required number of copies. and an intermediate tray for storing the sheet paper after image formation, and the mode input means forms images on both the front and back sides of the sheet paper for a single-sided original to obtain one copy from two originals. When the original-duplex copy mode is set and images are to be formed for the number of copies, a circular sort mode that circulates the original multiple times will form an image on every other original while determining the number of originals during the first circulation. During the second to nth (number of copies) circulation, images are formed while alternately feeding the paper from the paper cassette and the intermediate tray, and during the final circulation, images of the document are created every other sheet. In an image forming apparatus that has an image forming mode that forms images on sheets of paper fed from an intermediate tray, a recycle lever is installed on the intermediate tray to detect one circulation of originals to detect double feeding, and when double feeding is detected, An image forming apparatus characterized by performing a predetermined treatment. (2) The predetermined action is to compare the number of sheets fed to the intermediate tray and the number of sheets fed from the intermediate tray during document circulation, and if the former is less than the latter, double feeding is detected. The present invention is characterized in that it detects the sheet paper left on the intermediate tray, and discharges the sheet paper without transferring it, and when the former is more than the latter, double feeding is detected and the circulation operation is terminated. An image forming apparatus according to claim 1.