JPH05173385A - Image forming device - Google Patents

Abstract

PURPOSE:To prevent the output of an unproper copy even in the case where a document of a different size is mixed when both-side copies are taken from one-side documents by cancelling the setting of the mode only when the document of the different size is detected. CONSTITUTION:A sheet feed roller is tuned on, a pick-up roller 12b and a separation roller 12c are driven and the lowest one of documents D on a sheet feed tray 12a is taken out and sent to an exposure position. During the carrying of the document D, its size is detected by a resist sensor 12g and a size sensor 12h. The detected size of the document and the size of a sheet set first are compared in a processor. When they do not match, the both-side copy mode is cancelled. Then, a proper cassette is selected and a normal copy operation is performed by the one-side copy mode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a one-sided original for making a double-sided copy using an automatic document feeder, for example.
The present invention relates to an image forming apparatus such as a copying machine having a double-sided mode.

[0002]

2. Description of the Related Art In recent years, a copying machine equipped with an automatic document feeder capable of continuously feeding a large number of documents has been put into practical use and has become widespread.

An automatic document feeder of this type takes out a large number of set documents one by one in order, conveys them to the exposure position of the document placing table, and discharges the exposed documents onto a sheet discharging table. It is supposed to do.

Further, it is possible to obtain a double-sided copy from a large number of single-sided originals by utilizing the automatic original feeding device and the automatic double-sided device. That is, a single-sided original is automatically fed by the automatic original feeder, and the original image read from the original is first printed on the front surface (first surface) of the paper.
To form. Then, without ejecting this paper, the automatic double-sided device re-feeds the paper with the front and back reversed, and forms the image of the next original on the back surface (second surface) of the paper. By repeating this process, a double-sided copy is obtained in which the images of the respective originals are formed on both sides of each sheet. Usually, in a copying apparatus capable of obtaining a double-sided copy from a single-sided original, this double-sided copy is performed by setting a mode (single / double-sided copy mode).

In the conventional copying apparatus, when a single-sided original is set in the automatic document feeder and the print key is turned on after setting the mode of single / double-sided copying, the mode is kept until the end of the final copy unless the clear key is turned on. Is being continued. In this case, the copy operation is automatically repeated for the paper of the predetermined size fed from the paper cassette specified at the time of the first mode setting or the paper cassette selected according to the document size. ing. For this reason, it is customary to set single-sided originals of the same size in the automatic document feeder.

However, in the unlikely event that different-sized originals are mixed in a large number of single-sided originals of the same size, for example, if an A4-sized original is mixed in with an A3-sized original, A3 The A4 size document image is directly copied and output on either the front side or the back side of the size paper.

In particular, at the time of the first mode setting, the automatic paper selection function is designated, that is, it is designated to copy on the paper of a predetermined size fed from the paper cassette selected according to the document size. In this case, for example, when an A4 size original corresponds to an odd number of sheets, A
Only half of the image of the A3 size original is copied on the back surface of the 4 size paper. Conversely, for example, when an A4 size original corresponds to the even number of sheets, the image of the A4 size original is copied on the back surface of the A3 size paper.

As described above, when a double-sided copy is obtained from a single-sided original, if different-sized originals are mixed in the same-sized original, an improper copy may be output. It was

[0009]

As described above, in the prior art, when a double-sided copy is obtained from a single-sided original, when different-sized originals are mixed in the same-sized original, an improper copy is made. There was a problem that would be output.

Therefore, according to the present invention, when a double-sided copy is obtained from a single-sided original, an improper copy is output even if originals of different sizes are mixed in originals of the same size. An object of the present invention is to provide an image forming apparatus capable of preventing the above.

[0011]

In order to achieve the above object, in the image forming apparatus of the present invention, the images of one-sided originals sequentially placed at the exposure positions of the original placing table are subjected to image formation. In a device having a function of forming on both sides of a medium, a detecting means for detecting the size of the one-sided original and a releasing means for canceling the setting of the function when a different-sized original is detected by the detecting means. It is configured.

Further, in the image forming apparatus of the present invention, a placing means for sequentially taking out a large number of one-sided originals and placing them on the exposure position of the original placing table, and an original placed by the placing means. Detecting means for detecting the size of the document, first image forming means for sequentially forming document images of the document on both sides of the image forming medium when the document of a predetermined size is detected by the detecting means, and the detecting means. And a second image forming means for forming a document image of the document on only one side of the image forming medium when a document of a different size is detected.

Further, in the image forming apparatus of the present invention, a placing means for sequentially taking out a large number of one-sided originals and placing them on the exposure position of the original placing table, and an original placed on the placing means. Detecting means for detecting the size of the original, an image forming means for sequentially forming original images of the original on both sides of the image forming medium when the original of a predetermined size is detected by the detecting means, and different size by the detecting means. When a document is detected, the prohibition unit prohibits formation of a document image on any surface of the image forming medium.

[0014]

According to the present invention, the mode setting is canceled only when a document of a different size is detected by the above means,
After that, the mode can be automatically set again so that double-sided copying can be continued, so that images of different size originals are printed on either side of the image forming medium on which the same size original image is formed. It can prevent it from being formed.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 and 2 show a copying apparatus according to the present invention.

This copying apparatus comprises a copying machine body (PPC) 2
And an original conveying device (A which is provided on the upper surface of the PPC 2 so as to be freely opened and closed and automatically conveys an original D as an object to be read).
DF) 12, a paper P ejected from the PPC 2 as required, and a double-sided device (ADD) which sends the paper P into the PPC 2 again with the front and back reversed so as to perform double-sided copying.
70, and a multi-stage paper feeding device (PFP) 60 as a paper feeding carriage that also serves as a mounting table for mounting the PPC 2 and the ADD 70 and that feeds the paper P in the internal cassettes 62a, 62b, 62c into the PPC 2 There is. The PPC 2 has an original placing table (transparent glass plate) on which an original D is placed.
10 and an upper cover 10b surrounding the mounting table 10. The upper cover 10b is provided with an operation panel (described later) 18 to which an operation signal or the like is input by a user (user) operation.

Inside the mounting table 10, that is, inside the PPC 2, the exposure lamp 22 that illuminates the document D, the reflection plate 24 that condenses the illumination light generated by the lamp 22 onto the document D, and the document D. A first carriage 20 having a first mirror 26 for reflecting the reflected light of, and a second carriage 32 having a second mirror 32 and a third mirror 34 for further reflecting the reflected light from the document D reflected by the first carriage 20. The carriage 30 is arranged. The first carriage 20 is arranged movably in parallel with the mounting table 10 by a pulse motor (not shown) via a toothed belt (not shown).

The second carriage 30 is movably arranged via a toothed belt or the like (not shown) that drives the first carriage 20, is driven by the first carriage 20, and is also driven by the first carriage 20. It is designed to be moved at a speed of 1/2.

Below the first carriage 20 and within the plane including the optical axis of the reflected light that is folded back through the second carriage 30, a movable mechanism is provided through a drive mechanism (not shown), and the second carriage is provided. An imaging lens 36 is provided which imparts a converging property to the reflected light from the carriage 30 and moves the reflected light to form an image of the reflected light at a desired magnification.

Further, the reflected light is turned back and the photoconductor 40
A fourth mirror 38 that is movable along the optical axis by a driving mechanism (not shown) is arranged in order to form an image at a desired position in (3) and to correct the variation of the focal length due to the movement of the imaging lens 36. .. Needless to say, the reflected light is a character or figure written on the document D, that is, image information on the document D.

Below the lens 36, near the center of the PPC 2, the reflected light guided by the fourth mirror 38 is imaged to form a charge distribution pattern, that is, an electrostatic latent image. The body 40 is arranged.

Around the photosensitive member 40, a charging device 42 for charging the photosensitive member 40 with a predetermined electric charge, and the photosensitive member 4
The developing device 44 that visualizes the electrostatic latent image formed on 0 using toner (developer), and the toner image formed on the photoconductor 40 as an image forming medium supplied from a sheet feeding device described later. Of the transfer device 46 for transferring the image onto the copying paper P and the distribution of charges in the photoconductor 40,
A cleaning device 48 is arranged in order for returning the charging characteristic of 0 to the initial state and scraping off the residual toner. The transfer device 46 transfers the sheet P after transfer to the photoconductor 40.
And an AC voltage applying device 46a for separating the device.

Thus, the latent image formed on the photoconductor 40 is converted into a toner image by the developing device 44, whereby the image information contained in the document D is copied as a toner image, and the paper P Formed on.

That is, at the right side of the PPC 2, that is, at the position corresponding to the upstream in the rotation direction of the photoconductor 40,
A plurality of slots 50 into which paper cassettes described below are inserted
a and 50b are formed. These slots 50a, 5
0b includes paper cassettes (main body cassettes) 14a and 14b for supplying copy paper, postcards, OHP sheets, etc., which have a relatively small number of copies, which is a consumption amount of copy paper P, but are frequently used (copied). It is supposed to be installed.

The slot 50b, into which the main body cassette 14b should originally be inserted, is inserted into the main body cassette 14 described above.
A large capacity cassette (LCC) 14c capable of accommodating several times as many sheets P as a and 14b can be mounted. This LCC 14c is approximately 1500 to 2500
A cassette base 14d capable of accommodating a single sheet P of the same size and moved up and down in the direction of arrow A by a motor (not shown) causes the height of the uppermost sheet P to contact the sheet feed roller 51b. It is configured. Since the LCC 14c has a motor (not shown) for urging the cassette base 14d, it is electrically connected to the slot 50b via a drawer connector (not shown).

On the other hand, the image (toner image) formed on the photoconductor 40 is transferred to the left side surface portion of the PPC 2,
A discharge tray 16a on which the fixed copied sheets P are stocked is arranged.

Inside the PPC 2, the photoconductor 40
At the position corresponding to the upstream side of the sheet cassette 14
First and second paper feed rollers 51a and 51b for pulling out the paper P one by one from a, 14b or LCC 14c are provided. In addition, these first and second paper feed rollers 51
A pair of first and second transport rollers 52 for feeding the pulled-out sheet P toward the photoconductor 40 is provided at the tip of the a and 51b.
a and 52b are provided. Further, feeding paths 53a and 53b are provided at the ends of the first and second conveying roller pairs 52a and 52b, respectively, and the PF
A connecting / feeding path 53c constituted by a pair of guide plates is provided so that the sheet P supplied from P60 or ADD 70 can be fed toward the photoconductor 40. Then, the inclination of the paper P is corrected immediately before the photoconductor 40, the leading edge of the image on the photoconductor 40 and the leading edge of the paper P are aligned, and the paper P is fed at the same speed as the rotation speed of the photoconductor 40. A pair of timing rollers 54 are arranged.

In addition, at the position corresponding to the downstream side of the photoconductor 40 of the PPC 2, the toner image on the photoconductor 40 is transferred, and the paper P on which the toner is electrostatically adhered is placed. A carrying device 56 for carrying is provided. Also,
A fixing device 58 is arranged in front of the carrying device 56.

The fixing device 58 is a hollow cylinder, and accommodates a heater lamp 58b for heating itself therein, and in order to melt and fix the toner transferred to the paper P, the outer circumference of the photoconductor 40 is fixed. A heat roller 58a driven at the same peripheral movement speed as the surface movement speed;
The heat roller 58a is pressed against the heat roller 58a.
a and a pressure roller 58c that applies pressure to the paper P and melts and fixes the toner. Further, ahead of this, there is provided a discharge roller pair 16 for discharging the copied paper P having the toner image fixed by passing through the fixing device 58 to the outside of the PPC 2.

The PFP 60 includes a plurality of internal cassettes 62.
friction rollers 64a, 64b, 64c which have a, 62b, 62c, and draw out the paper P one by one from the respective internal cassettes 62a, 62b, 62c,
And a series of feeding paths 66a, 66b, 66c for guiding the paper P drawn out by the friction rollers 64a, 64b, 64c into the PPC 2 respectively.

This series of feeding paths 66a, 66b, 66c
Are the internal cassettes 62a, 62 in the PFP 60.
It is also used for transporting the paper P from b and 62c, and also for transporting the paper P from a cassette located below the currently selected cassette. For example, the paper P from the innermost cassette 62c at the bottom is sequentially passed through the feeding paths 66c, 66b, 66a, and the ADD 7
It is sent toward the photoconductor 40 in the PPC 2 via the relay unit 80 provided in the 0.

Further, the feeding paths 66a, 66b and 66c are
Either one of the pair of guide plates is movable,
As a result, even if a paper jam occurs, it can be easily removed. That is, when the paper P is jammed in the feeding paths 66a and 66b, L
Since the right side surface of the PFP 60 can be opened by removing the CC 14c, the feeding paths 66a, 66
The guide plate on the right side of b can be moved by the user in the direction of arrow B. Further, when the paper P is jammed in the feeding path 66c, the guide plate on the right side of the feeding path 66c can be similarly moved by the user in the direction of arrow C.

The relay unit 80 is the PPC of the PFP 70.
It is added when the device is mounted on the No. 2 and is incorporated into one end of the ADD 70 for the purpose of preventing the device from becoming large. The relay unit 80 has a connecting path 80a that forms a paper path connecting unit and a feed roller pair 80b, and can be opened and closed by removing the LCC 14c mounted in the slot 50b. Thus, even if a paper jam occurs, it can be easily removed. That is, when the sheet P is jammed in the relay unit 80, the right side surface of the ADD 70 can be opened in the arrow E direction by removing the LCC 14c.
The inside of the relay unit 80 can be exposed.

The ADD 70 distributes the fixed paper P discharged by the discharge roller 16 to the discharge tray 16a or to the inside of the ADD 70. The distribution gate 71 discharges the paper P distributed in the discharge tray 16a direction. A pair of paper discharge rollers 72 for discharging paper onto the tray 16a, and a conveyance path 7 for receiving and conveying the paper P distributed in the ADD 70 by the distribution gate 71.
0a, a storage section 70b for temporarily stacking the paper P guided in the transport path 70a, an ADD pickup roller 70c for appropriately taking out the paper P stacked in the storage section 70b, and an ADD pickup roller 70c. It is configured by a paper feed system 70d including an ADD paper feed roller, an ADD separation roller, and an ADD registration roller for guiding the formed paper P into the PPC 2.

That is, the paper P sorted in the ADD 70 is again re-worn with the PPC while the front and back sides thereof are reversed.
Will be sent within 2. As a result, an image is formed on the second surface of the paper P, and finally one paper P
Two-sided copying is performed on both sides. The paper P on which the double-sided copying has been performed is sorted by the sorting gate 71 in the direction of the discharge tray 16 a, and is discharged by the discharge roller 72 to P.
It is discharged to the outside of the PC 2 and is stocked on the discharge tray 16a. FIG. 3 shows a configuration example of the operation panel 18.

On the operation panel 18, a print key 18a for inputting a copy start signal, numeric keys (ten keys) 18b of "0" to "9" used for setting the number of copies and inputting a data signal, and copy. It includes a clear key 18c for interrupting the operation or returning data being input to "0", and an all clear key 18d for stopping all copying operations and returning the set copy mode to the initial state.

Input data (for example, the number of copies and copy magnification) can be displayed on the operation panel 18, and at the same time, the operation procedure of the PPC 2, the paper P or toner replenishment timing, an error message, etc. Is displayed on the liquid crystal display device (L
The CD) 18e and the monitor LED 18f for displaying the operating state of the PPC 2, such as the position of the selected cassette or paper jam, are assembled together.

Further, on the operation panel 18, in addition to a mode key 18g for setting a copy mode such as double-sided copying from a single-sided original, a cassette selection key for selecting a cassette accommodating a desired paper size. 18h etc. are prepared. Next, a basic copying operation in the above copying apparatus will be described.

For example, when the copy conditions such as the number of copies, copy magnification and paper size are selected through the operation panel 18, and a copy start signal is input from the print key 18a, the document is placed on the document table 10. The read document D is illuminated by the light from the exposure lamp 22 at the time of reading, that is, when the first carriage 20 moves forward.

The reflected light from the document D passes through the slit area formed by the reflecting plate 24 and is guided to the first mirror 26, whereby it is reflected toward the second mirror 32 of the second carriage 30. The reflected light guided to the second mirror 32 is reflected again by the third mirror 34, guided to the lens 36 that has been moved to a position that provides a desired magnification, and is converted into focused light here. After that, an image is formed on a predetermined position of the photoconductor 40 to which a predetermined charge has been given in advance via the fourth mirror 36. That is, the reflected light from the document D is converted into an electrostatic pattern on the surface of the photoconductor 40 by slit exposure and becomes a latent image.

The image formed as a latent image on the photoconductor 40 is guided to the developing area as the photoconductor 40 is rotated at a desired moving speed. In this developing area, the toner is supplied from the developing device 44, whereby the toner is selectively attached to the latent image and developed.

In parallel with the series of operations up to this point, according to the designated paper size or document size and image magnification,
The cassette containing the paper P of the optimum size is selected from the paper cassette 14a, the LCC 14c, or one of the internal cassettes 62a, 62b, and 62c.
Then, by the corresponding paper feed rollers 51a, 51b or friction rollers 64a, 64b, 64c,
One sheet of paper P is pulled out from the selected cassette. This sheet of paper P is conveyed by the respective conveyance rollers 52.
a, 52b between the respective feeding paths 53a, 53b or between the feeding paths 66a, 66b, 66c via the relay unit 80 and the connecting feeding path 53c, and the upstream side in the rotation direction of the photoconductor 40. From the photoconductor 40 and the transfer device 46.
It is fed to the transfer area formed between

The paper P fed to the transfer area is temporarily stopped by the timing roller 54 immediately before that. After that, the leading edge of the image and the leading edge of the sheet P are aligned with each other based on the movement of either the first carriage 20 or the second carriage 30 in the sub-scanning direction, and the sheet is fed toward the photoconductor 40. It

On the other hand, the toner image formed on the photoconductor 40 is rotated at a desired speed, and the photoconductor 40 and the transfer device 4 are rotated.
When the sheet P is guided to the transfer area defined between the sheet P and the sheet 6, the sheet P from the timing roller 54 is attracted (adhered) by the electric charge remaining on the photoconductor 40.
Then, the paper P is passed through the transfer area as the photoconductor 40 rotates.

At this time, charges having the same polarity as the charges already applied to the photoconductor 40 (for forming a latent image) are supplied to the photoconductor 40 and the paper P from the transfer device 46. As a result, the toner attached to the photoconductor 40 is transferred to the paper P.

The paper P on which the toner is transferred is transferred to the transfer device 4
When the AC voltage is applied from the AC voltage applying device 46a formed integrally with the toner supply unit 6, the toner is released from the attraction with the photoconductor 40, and the toner is sent to the carrying device 56. Then, the toner is fixed (fixed) to the paper P by passing between the heat roller 58 a and the pressure roller 58 c via the transport device 56.

The photosensitive member 40 after the paper P is separated
Is further rotated and its surface is cleaned by the cleaning device 48.
To be cleaned. That is, the photoconductor 40
The residual toner is removed by the cleaning device 48, and the charge distribution pattern on the surface is returned to the initial state via a neutralization lamp (not shown), so that the next copying is possible.

As described above, the paper P on which the image of the document D is copied is discharged by the discharge roller 16 to the discharge tray 16a.
Is ejected with the copy side facing up (upward).
This process is repeated until the copy operation for all copies is completed.

In the case of double-sided copying, the front side (first
The paper P having the image copied on the surface) is sent again to the transfer area in the PPC 2 via the ADD 70. Then, after the image of the same document D or the next document D is copied to the back surface (second surface), it is similarly discharged onto the discharge tray 16a. FIG. 4 shows a schematic configuration of the ADF 12 described above.

The ADF 12 has a supply section S for sequentially separating the set originals D and supplying them one by one, and an original D supplied from the supply section S on the original placing table 10, that is, P.
A transport unit T that transports the document D on the document mounting table 10 to the reversal discharge unit R after transporting to the exposure position (image reading position) of the PC 2 and the document D transported from this transport unit T. It is provided with the reversal discharge part R which can be reversed or discharged as it is, if necessary. This ADF12
Is provided so as to be openable and closable with respect to the document placing table 10, and also serves as a document placing table cover.

The supply section S is configured by stacking a plurality of documents D in a sheet feed tray 12a, a pickup roller 12b for taking out the documents D set on the sheet feed tray 12a one by one, and a pickup roller 12b for taking out the documents. Separation roller 12c for sending the printed document D, separation pad 12d in contact with this separation roller 12c, and separation roller 12c
A pair of aligning rollers 12e is provided for aligning and transporting the document D sent by.

Then, the separation roller 1 of the paper feed tray 12a
On the side 2c, an empty sensor 12f for detecting the presence or absence of the document D, a registration sensor 12g in front of the aligning roller pair 12e, and a size for detecting the size of the document D behind the aligning roller pair 12e. Each sensor 12h is provided.

The transport section T has belt rollers 12i, 12
An endless conveyor belt 12k for conveying the document D, which is hung over j and supplied along the original placing table 10, and belt pressing rollers 12m for pressing the conveying belt 12k to the original placing table 10 are provided, respectively. ing.

The reversing and discharging section R receives the document D conveyed from the conveying section T, reverses its front and back, and conveys it.
, And a discharge roller 12p for guiding the document D to the discharge tray 12o. The discharge sensor 12 is provided in the middle of the reversing roller group 12n.
q is provided.

Further, the discharge roller 12p and the reversing roller group 1
A flapper 12r is provided between 2n, ..., By driving this flapper 12r, the document D from the transport section T is sent back to the transport section T, or the document D from the transport section T is guided to the discharge tray 12o. Or Normally, the document D from the transport section T
Is guided to the paper discharge tray 12o, and is driven by a flapper solenoid described later.

In the case of 12s, the apparatus 12 is the original placing table 1
An automatic document feeder (ADF) open sensor for detecting opening / closing with respect to 0, 12t is a supply unit S
A cover open sensor for detecting the opening / closing of the open / close cover that covers the cover 10 and a document stopper 10a for positioning the document D on the document table 10. Figure 5
FIG. 4 shows an arrangement example of various electric components in the ADF 12.

In the figure, 12f is the empty sensor, 12g is the registration sensor, 12h is the size sensor, 12q is the discharge sensor, and 12s is the ADF.
The open sensor 12t is the cover open sensor.

Further, 12u is a conveyance motor clock sensor, 12v is a paper feed motor clock sensor, 12w is a weight solenoid, 12x is a shutter solenoid, and 12y.
Is a flapper solenoid, and 12z is an electromagnetic clutch.
Further, 12 ₁ is a feed motor, 12 ₂ is a conveyance motor, and 1
2 ₃ is a logic PC board, and 12 ₄ is a drive PC board. FIG. 6 shows a main part of a control system in the ADF 12 and the PPC 2 described above.

In the figure, 121 is a main processor that mainly controls the PPC 2, 122 is an ADF processor that mainly controls the ADF 12, and these interface signals (to be described later) are exchanged with each other. There is.

The input switch 1 such as various keys on the operation panel 18 is input to the main processor 121 via an input interface 123 such as a data selector.
24, and other various detectors (switches, sensors, etc.) 125 required for control are connected.

In the main processor 121, a driver 127 that drives a display unit 126 such as various display devices on the operation panel 18, an exposure lamp 22 and a heater lamp 58.
a lamp control unit 128 for controlling b, a driver 130 for driving various drive systems (main motor, clutch, etc.) 129, a high-voltage power supply unit 13 for driving various chargers 131
2, and a driver 13 that drives the solenoids 133
4 etc. are connected.

The ADF processor 122 includes the empty sensor 12f, the registration sensor 12g, the size sensor 12h, the discharge sensor 12q, and the ADF open sensor 1.
The 2s, the copper open sensor 12t, and the like are connected via the input interface 141.

Further, the ADF processor 122 includes a paper feed motor 12 ₁ for driving the pickup roller 12b and the separation roller 12c, a conveyor belt 12k of the conveyor T, an aligning roller 12e, and a reversing roller 12.
n, ..., A transport motor 12 ₂ for driving the paper discharge roller 12p, an electromagnetic clutch 12z for transmitting the drive from the transport motor 12 ₂ to the aligning roller 12e,
Drivers 151, 152 for driving the flapper solenoid 12y for driving the flapper 12r, respectively.
153 and 154 are connected.

Further, a first pulse generator 142 and a second pulse generator 143 are connected to the ADF processor 122. The first pulse generator 142 is for generating a clock pulse by a rotary encoder attached to the paper feed motor 12 ₁ . Second pulse generator 14
3 is for generating clock pulses by a rotary encoder attached to the carry motor 12 ₂ . Here, the main processor 121 and the ADF processor 122
The interface signal transmitted to and received from will be described.

The interface signals are exchanged between the main processor 121 and the ADF processor 122 by an asynchronous serial communication system. in this case,
The interface signal transmitted from the main processor 121 to the ADF processor 122 is a control signal group (DF-TxD) from the main processor 121 to the ADF 12.
Transferred through 160. Similarly, the interface signal transmitted from the ADF processor 122 to the main processor 121 is a state signal group (DF-R
xD) 161 is transmitted.

There are seven interface signals from the main processor 121 to the ADF processor 122. For example, a double-sided / single-sided selection signal (ORG) output for setting the double-sided original conveyance mode or the single-sided original conveyance mode.
-ROTH), a document feed signal (ORG-IN) output to start the replacement operation of the document D, the document table 1
A document discharge signal (ORG-OUT) output to discharge the document D on 0, a mode signal (MODE) output to notify whether the ADF 12 is in the normal document transport mode or the test mode, When the ADF 12 is in the test mode state, a coded signal is transmitted, and a test code signal (TEST) is output to perform various test operations. When the ADF 12 is in the normal document transport mode, it is transported. Adjustment code signal (ADJUST), which is output to adjust the carry amount of the document D to be read, A
An aging signal (AGIN) output to cause the DF12 to operate at the same timing as when a document is conveyed without a document.
G) and so on.

Also, an interface signal (ADF1 from the ADF processor 122 to the main processor 121
10 signals, for example, a document set signal (ORG-RDY) indicating whether or not the document D is set on the paper feed tray 12a, a jam signal (DF-JAM) indicating a jam state, Paper feed motor 12 of ADF12
Error signal indicating that the operation abnormality occurs in _one or conveying motor 12 ₂ (DF-ERR), encodes the contents of the error or jam when this error signal or jam signal (DF-JAM) is output PPC
2 error code signal (ERR-COD), ADF
12 outputs a DF operation signal (DF-AC) from the start of the replacement operation of the original D to the end of the detection of the original size.
T), a document stop signal (ORG-STP) indicating that the document D is set at the exposure position, a DF open signal (DF-OPN) indicating the open / close state of the open / close cover of the transport section T of the ADF 12 or the supply section S, A document size signal (SIZE0, SIZE) for indicating the document size with a 4-bit code.
1, SIZE2, SIZE3), an original front / back signal (ORG-FACE) that indicates whether the first surface of the original D is set downward or the second surface is set downward at the exposure position during the conveyance operation of the double-sided original. ), The advance signal (PRE-F) for indicating whether or not the document D is at the advance position.
ED) etc. Next, an outline of the operation of the ADF 12 in the above-mentioned configuration will be described by taking single-sided sheet passing as an example.

First, when the power switch 2a is turned on,
After the lapse of a predetermined time, the PPC 2 becomes ready (copyable). At this time, the main processor 121
The print key 18a provided on the operation panel 18 is ready to be received, and the main processor 121 and the ADF
Interface signals between the processors 122 can be transmitted and received to and from each other.

In this state, it is assumed that the document D is set on the paper feed tray 12a. Then, the empty sensor 12f is turned on, and the presence of the document is detected. As a result, the ADF processor 122 outputs the “H” level ORG-RDY signal to the main processor 121. Here, when the print key 18a is turned on, the ORG-IN signal is output from the main processor 121.

The ADF processor 122 uses this ORG-I
When the N signal is received, the DF-ACT signal turns on and the ORG
-The STP signal is turned off, and the operation of conveying the document D by the ADF 12 is started. That is, after receiving the ORG-IN signal, first, the paper feed motor 12 ₁ is turned on for a fixed time. As a result, the pickup roller 12b and the separation roller 12c are driven, and the document D set on the paper feed tray 12a is separated. After that, the shutter solenoid 12x is turned on, and the sheet feeding motor 12 ₁ is turned on again.
When is turned on, the first sheet of the document D is taken out from below and is conveyed to the aligning roller 6.

After a certain period of time has passed since the registration sensor 12g was turned on by the leading edge of the conveyed document D, the paper feed motor 1
2 ₁ is stopped. At this time, the leading edge of the document D has reached the position of the aligning roller 12e and is aligned by the aligning roller 12e.

[0072] Subsequently, the conveying motor 12 ₂ is rotated forwardly,
The transport belt 12k, the reversing rollers 12n, ..., And the paper discharge roller 12p are rotated in the discharge direction. This allows
The document discharge operation is performed. This is in consideration of the case where a document remains on the mounting table 10.

When the operation of discharging the remaining original document is completed, the electromagnetic clutch 12z is turned on at a proper timing, so that the first aligning roller 12
The document D that has been conveyed to the position e is the conveyance belt 12k.
Sent to. At this time, the document D has a size sensor 12h for detecting the width of the document D in the direction perpendicular to the document transport direction.
Is passed through. When the trailing edge of the document D passes through the registration sensor 12g, the signals SIZE0 to SIZE3 are set and the DF-ACT signal is set to the "L" level.

From this point, the first pulse generator 44
By counting the pulses from, the transport amount of the document D is counted. The trailing edge of the document D is a left end of the document stopper 10a, a certain amount, for example, the amount that has been conveyed to the position of 10mm is counted, the conveyance motor 12 ₂ is stopped.

[0075] After a certain time, by now being reversed conveying motor 12 _2, the document D is abutted to the left edge of the document stopper 10a, it is set to an exposure position on the document table 10. When the document D is set at the exposure position,
The ORG-STP signal is set to "L" level.

This ORG-STP signal is output to the main processor 121 at a fixed time before the end of the carrying operation, and 1
The end of the conveyance operation of the first document D is notified. this is,
The original scanning system (first carriage 20) of the PPC2 is OR
The start is started by outputting the G-STP signal, but this is performed in order to shorten the time from the start start point of the original scanning system to the original scanning point.

In this way, by accepting the "L" level ORG-STP signal from the ADF processor 122, the copy operation by the PPC 2 is started. That is, when the conveyance of the first document D is completed, the document D is read by the first carriage 20 as described above.

In the meantime, the ADF 12 carries out a first-out conveyance operation for conveying the second original D to the aligning roller 12e under the same control as the first original conveying operation. Then, the second document D is waited at the first-out position closer to the exposure position.

When the reading of the first document D is completed,
The ORG-IN signal is output from the main processor 121 to the ADF processor 122. Then, the ADF 12 starts the transport operation of the second document D from the first-out position. At this time, the first document D has a length (for example, A
If the size is shorter than (4 sizes), the step conveyance operation is performed.

This step-conveying operation means that when the original D being conveyed to the exposure position is replaced with the next original D, the original D being conveyed to the exposure position is ejected from the sheet ejection tray 12.
It is an operation of transporting the sheet to the step position (intermediate position) where the leading end reaches the sheet ejection sensor 12q between the exposure position and the sheet ejection tray 12o without ejecting the sheet to the sheet ejection position o and waits there. In addition, if you do not consider the appearance,
It can be performed regardless of the size of the original.

By performing this step transport operation,
The document D to be conveyed to the exposure position next can be started to be conveyed when the document D at the exposure position reaches the step position before the document D can be discharged to the discharge tray 12o. Therefore, the time required for exchanging the original can be shortened.

Further, the first document D is
If the size is longer than the predetermined length, the above-described step conveyance operation is not performed, and the electromagnetic clutch 12z is reached when the document D at the exposure position reaches the position where it can be discharged to the discharge tray 12o. Is turned on and the aligning roller 12e is driven. As a result, the document D that has been waiting at the first-out position is sent to the exposure position.

It should be noted that when the third document D is transported to the exposure position during the step transport operation, and when the second document D is transported to the exposure position during the operation in which the step transport is not performed, the document after the document is transported to the exposure position. In the replacement operation, a discharge operation of discharging the exposed document D onto the discharge tray 12o is performed at the same time.

Further, in the discharge operation at the time of this document replacement, depending on the size of the document D at the step position or the exposure position and the distance from the step position to the paper discharge roller 12p, or the distance from the exposure position to the paper discharge roller 12p. When the distance to be determined is transported to (the front end of the document D to be discharged is the distance that is discharged onto a predetermined distance discharge tray 12o), the rotational speed of the conveying motor 12 ₂ is lowered. Then, the conveyance speed of the document D to be discharged is reduced, and control is performed so that the discharged document D is aligned on the discharge tray 12o.

Such an original exchange operation is performed by a series of originals D,
When the original D on the paper feed tray 12a is exhausted, the empty sensor 12f is turned off. Then, the ORG-RDY signal from the ADF processor 122 is set to the “L” level, and the main processor 121 is notified of that.

On the other hand, when the ORG-OUT signal is output from the main processor 121 to the ADF processor 122, the document D being conveyed is discharged onto the discharge tray 12o. That is, when the ADF processor 122 receives the ORG-OUT signal, the two originals D, which are the step original and the final original at the exposure position, are ejected while the originals are exchanged in the step conveying operation. Be seen.

In this case, first, the distance determined by the size of the document D at the exposure position and the step position and the distance from the step position to the paper discharge roller 12p (the front end of the document D at the step position is a fixed distance, for example, Paper roller 12
When conveyed to a distance of) passing through p are performed, lowered rotational speed of the conveying motor 12 ₂ is, deceleration of the conveying speed of the document D is started. At this decelerated conveyance speed, the document D at the step position and the exposure position is ejected while being aligned on the ejection tray 12o.

Thus, the transport speed of the final document D is reduced simultaneously with the document D located at the step position. That is, the original document D other than the final document is decelerated after being conveyed by a predetermined amount from the step position. However, unlike the original document D that has been conveyed up to then, the conveying speed of the original document D is the same as that of the original document D. It is designed to decelerate in synchronism with the transport speed of. After that, a certain time after the trailing edge of the document D at the exposure position passes the ejection sensor 12q, the conveyance motor 1
2 ₂ is stopped.

On the other hand, when the originals are not exchanged in the step conveyance operation and the originals are discharged by the ORG-OUT signal, one of the originals D at the exposure position is discharged to the discharge tray 12.
The operation is the operation of transporting the document to O, and is performed under the same control as the document discharge operation at the time of document replacement in the case of not the step transport operation. As described above, the operation during single-sided document transportation is completed.
Next, the operation when the two-sided document is conveyed will be described.

The first document D is aligned with the aligning roller 12
The operation until the sheet is conveyed to the position e is the same as that when the one-sided original is conveyed. That is, when the leading edge of the document D is stopped at the position of the aligning roller 12e, the conveyor motor 12 ₂ is rotated in the forward direction so that the conveyor belt 12k, the reversing rollers 12n, ... The original is discharged by being rotated. This is in consideration of the case where a residual document exists on the document table 10.

When the discharging operation of the remaining original document is completed, the electromagnetic clutch 12z is turned on, and the original document D which has been transported to the position of the aligning roller 12e is fed to the transport belt 12k. At this time, the size sensor 12h for detecting the width of the document D in the direction perpendicular to the document transport direction,
Further, when the rear end of the document D passes through the registration sensor 12g, each signal of SIZE0 to SIZE3 is set.

After a lapse of a fixed time after the trailing edge of the document D passes through the registration sensor 12g, the electromagnetic clutch 12z is turned off, the flapper solenoid 12y is turned on, and the flapper 12r is set in the direction for reversing the document D. To be done.

As a result, the document D is conveyed on the document placing table 10 by the conveyor belt 12k, and after a certain time after the leading edge of the document D has passed the ejection sensor 12q (at this time, the leading edge of the document D is reversed. has reached between belt rollers 12j of discharge section R and the sheet discharge side), the conveying motor 12 ₂ is stopped. Then, after a predetermined time from the conveyance motor 12 ₂ is stopped, is started reverse rotation of the conveying motor 12 _2, the document D is conveyed to the document stopper 10a direction.

In the ADF 12, the DF-ACT signal is turned off a fixed time before the trailing edge of the document D reaches the document stopper 10a, and when the leading edge of the document D reaches the document stopper 10a, the ORG-STP signal is set. .. As a result, the carry motor 12 ₂ is stopped. Document D at this time
The transport amount of is determined by counting the pulses output from the first pulse generator 142 after the leading edge of the document D has passed the ejection sensor 12q.

When the ORG-STP signal is output, PP
At C2, the operation for reading the document D by the scanning system is started. Then, when this reading operation is completed,
In order to invert the document D, the ORG-IN signal is output from the main processor 121.

[0096] In ADF processor 122 receives the ORG-IN signal, the forward rotation of the conveying motor 12 _2,
As a result, the document D at the exposure position is started to be conveyed in the direction of the reverse discharge portion R. Then, the document D in the reverse discharge section R
After the reversing operation is performed, the reversed document D is conveyed to the exposure position.

While the inverted document D is being read, the first-out feeding operation of the second document D is performed. Then, by the next output of the ORG-IN signal, the document replacement operation is performed in the ADF 12. next,
The operation of the above configuration will be described. 7 and 8 show the flow of processing in the single / double-sided copy mode in which double-sided copy is obtained from a large number of single-sided originals of the same size.

For example, it is now assumed that the power switch 2a is turned on. Then, the PPC2, the ADF12, the PFP60, and the ADD7 are passed by a certain time.
0 or the like is set to the standby state.

In this state, a large number of originals D are set on the paper feed tray 12a of the ADF 12, and then the single / double-sided copy mode is set by the mode key 18g on the operation panel 18. In this case, by operating the mode key 18g several times, the setting of the mode and the lighting of the corresponding LED are switched.

Then, the cassette selection key 18h on the operation panel 18 is used to select the cassette for storing the paper P suitable for the original size. In the case of this embodiment, any one of the main body cassette 14a, the LCC 14c, and the internal cassettes 62a, 62b, 62c of the PFP 60 is selected.

Here, the O from the ADF processor 122
When receiving the RG-RDY signal, the operation panel 1
When the print key 18a on the No. 8 is turned on, the copy operation in the single / double-sided copy mode is started. When the print key 18a is turned on, the main processor 1
21 outputs the ORG-IN signal to the ADF processor 122.

Upon receipt of the ORG-IN signal, the ADF 12 starts the automatic feeding of the document D to the exposure position on the document mounting table 10 based on the above-described operation during single-sided document transportation. That is, the ADF processor 1
22 the feed motor 12 ₁ is turned on by the pickup roller 12b and the separation roller 12c is driven. Then, the lower one of the documents D on the paper feed tray 12a is taken out and sent to the exposure position.

At this time, the size of the taken-out document D is detected by the registration sensor 12g and the size sensor 12h during the transportation thereof. Here, the length of the document D in the conveying direction is counted by the number of pulses generated from the first pulse generator 142 until the leading edge of the document D turns on the registration sensor 12g and the trailing edge of the document D comes off. It is detected by doing. Further, the length in the direction orthogonal to the transport direction (width of the document D) is detected by checking ON / OFF of the size sensor 12h when the document D passes. Then, the size of the document D is determined based on these two detection results, and SIZE0 to SI
ZE3 is transmitted to the main processor 121.
The detected document size signals SIZE0 to SIZE3
Is output to the main processor 121 each time.

When the document size signals SIZE0 to SIZE3 from the ADF processor 122 are accepted, the main processor 121 agrees with the paper size selected at the time of the first mode setting and the size of the first document D detected. It is judged whether or not there is something.

If it is determined that they do not match,
A message such as "Please use a cassette of the correct size" is displayed on the LCD 18e of the operation panel 18.

After that, when the print key 18a is turned on, the above-mentioned copy operation is executed as it is, that is, on the paper P taken out from the cassette selected in the first mode setting and fed from there. To be done. Also,
When a certain period of time has passed without the print key 18a being turned on, the initial state, for example, cancellation of the single / double-sided copy mode is performed.

On the other hand, when it is judged that the sheet size selected at the time of the first mode setting and the detected size of the first document D match, the sheet is taken out from the cassette and fed from there. The above-described copy operation using the first document D is performed on the first surface of the sheet P to be printed. The paper P on which the image of the first original D is formed on the first surface is sent into the ADD 70 without being discharged onto the discharge tray 16a. Then, after being stacked here, the front side and the back side are reversed, and are again fed to the transfer area in the PPC 2 in accordance with the reading operation of the next original D.

Here, it is determined that the paper size matches the size of the detected first original D, and the copy operation of the first original D on the first side of the paper P is performed. After that, the copy operation is performed according to the following conditions.

That is, for the second and subsequent sheets of the document D, it is determined in the same manner as described above whether the paper size selected at the time of the first mode setting and the detected size of the document D match. .. Further, it is checked whether or not the mode is returned from the single-sided copy mode.

In this case, if the sizes match and it is not a return from the single-sided copy mode, the above ADD
The above-described copying operation using the original D is performed on the second surface of the paper P that is fed from 70 and on which the original image is already formed on the first surface. The paper P on which the images of the original document D are formed on the first surface and the second surface is discharged and stocked on the discharge tray 16a without being guided into the ADD 70.

However, in the case of returning from the single-sided copy mode, if the paper P on which the original image is already formed on the first side is
On the second surface, the images of the original document D and the subsequent images are formed.

If the sizes do not match,
A cassette that matches the detected document size is selected, and the above-described copy operation using the document D is performed on the first surface of the paper P that is fed from the cassette. And this first
The paper P on which the image of the document D is formed is discharged onto the discharge tray 16a and stocked without being guided into the ADD 70.

In this way, when the paper size and the document size do not match, the single-sided / double-sided copy mode is once canceled, and the single-sided copy mode, that is, the proper cassette is reselected and the normal copy operation is performed. Done. And
When the one-sided copy is completed, the original cassette selected at the time of the first mode setting is selected again, and the one-sided / two-sided copy mode is restored again.

If the paper size and the original size do not match and there is no cassette that matches the detected original size, the first paper P fed from the cassette selected at the time of the first mode setting is set. After the one-sided copy is similarly performed on the side, the single / double-sided copy mode is restored again. The above operation is repeated until all the documents D set in the paper feed tray 12a of the ADF 12 are exhausted.

As described above, the mode setting is canceled only when a document of a different size is detected, and after that, the mode is automatically set again so that double-sided copying can be continued.

That is, the original size is checked in the single / double-sided copy mode, and when a different size original is detected, only one side is copied. This prevents an improper copy, for example, formation of an A4 original image on the back side of an A3 original image, or conversely, formation of half an A3 original image on the back side of an A4 original image. Is possible. Further, after the one-sided copy, the mode is automatically returned to the one-sided / two-sided copy mode, so that the two-sided copy in the correct order can be obtained by extracting the copy of the one-sided copied different type original. Therefore,
Even if you mix different-sized originals that you do not intend to copy in a single-sided original of the same size,
It is possible to efficiently make a double-sided copy. The present invention is not limited to the above embodiment,
Needless to say, various modifications can be made without departing from the spirit of the invention.

[0117]

As described above in detail, according to the present invention, even when originals of different sizes are mixed in originals of the same size when a double-sided copy is obtained from a single-sided original, It is possible to provide an image forming apparatus capable of preventing an improper copy from being output.

[Brief description of drawings]

FIG. 1 is an external view of a copying apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram of a copying apparatus.

FIG. 3 is a diagram similarly showing an example of an operation panel.

FIG. 4 is a schematic configuration diagram of an ADF.

FIG. 5 is a perspective view showing an example of arrangement of electric components in the ADF.

FIG. 6 is a block diagram showing the main part of the control system.

FIG. 7 is a flow chart similarly illustrating the first half of the operation in the simplex / duplex copy mode.

FIG. 8 is a flow chart similarly shown for explaining the latter half of the operation in the simplex / duplex copy mode.

[Explanation of symbols]

2 ... Copier body (PPC), 2a ... Power switch, 10
... manuscript table, 12 ... automatic document feeder (ADF), 1
2a ... Paper feed tray, 12b ... Pickup roller, 12
c ... Separation roller, 12e ... Aligning roller pair, 12
f ... empty sensor, 12g ... resist sensor, 12
h ... Size sensor, 12k ... Conveyor belt, 12o ... Paper ejection tray, 12p ... Paper ejection roller, 12q ... Ejection sensor, 1
2r ... flapper, 12s ... ADF open sensor, 12
x ... Shutter solenoid, 12y ... Flapper solenoid, 12z ... Electromagnetic clutch, 12 ₁ ... Paper feed motor, 12
₂ ... Transport motor, 14a ... Main body cassette, 14c ... Large capacity cassette (LCC), 18 ... Operation panel, 18a ... Print key, 18g ... Mode key, 18h ... Cassette selection key, 22 ... Exposure lamp, 36 ... Imaging lens , 40 ...
Photoreceptor, 42 ... Charging device, 44 ... Developing device, 46 ... Transfer device, 58 ... Fixing device, 60 ... Multi-stage paper feeding device (PF)
P), 62a, 62b, 62c ... Internal cassette, 70 ...
Automatic double sided device (ADD), 71 ... Sorting gate, 72
... Paper discharge roller, 80 ... Relay unit, 121 ... Main processor, 122 ... ADF processor, 142 ... First pulse generator, 143 ... Second pulse generator, D ... Original, P
… Copy paper.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location G03G 15/00 107 8530-2H

Claims (3)

[Claims] 1. An image forming apparatus having a function of forming images of one-sided originals, which are sequentially placed at exposure positions of an original placing table, on both sides of an image forming medium, and detecting the size of the one-sided original. An image forming apparatus comprising: a means and a canceling means for canceling the setting of the function when a document of a different size is detected by the detecting means. 2. A placing means for picking up a large number of single-sided originals in order and placing them on an exposure position of an original placing table, a detecting means for detecting a size of an original placed by the placing means, and this detecting means. When a document of a predetermined size is detected by the means, first image forming means for sequentially forming a document image of the document on both sides of the image forming medium; and when the detecting means detects a document of a different size, An image forming apparatus comprising: a second image forming unit that forms an original image of the original on only one side of an image forming medium. 3. A placing means for picking up a large number of single-sided originals in order and placing them on the exposure position of an original placing table, a detecting means for detecting the size of the original placed on the placing means, and this detecting means. An image forming means for sequentially forming an original image of the original on both sides of the image forming medium when the means detects a document of a predetermined size; An image forming apparatus comprising: a prohibition unit that prohibits formation of a document image on any surface of a forming medium.