JPH0343184B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a double-sided recording device for an electrophotographic copying machine, which is capable of copying on both sides of recording paper, and has an improved paper stacking device.

[Conventional technology]

Recording devices that can copy both the front and back sides of a manuscript or two pages of a document onto the front and back sides of a single sheet of recording paper are becoming increasingly necessary due to the recent increase in the amount of office work and demands for resource and labor savings. The functionality is increasing, and the development of functions that can meet various demands is progressing.

Regarding this double-sided recording device, Japanese Patent Application Laid-Open No. 52-137341
Publication No. 54-43742, and Special Publication No. 1987-43742.
- Although proposals have been made in Publication No. 41107, etc.,
All of them have the disadvantage that they have a complicated structure, are prone to failure during the paper conveyance process, and are also large in size.

In addition, the positions of the originals copied on the front and back sides of the recording paper are often uneven, causing inconvenience in binding, and many practical problems have been recognized.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a double-sided recording device having a paper stacking device that prevents accidents during conveyance of recording paper with an extremely simple configuration and makes it possible to copy accurately at a predetermined position on the back side of recording paper. That is.

[Structure of the invention]

The present invention has been made to achieve the above-mentioned object.
After the recording paper recorded on one side by the image forming means is stacked in a recording paper stacking device provided in the main body of the apparatus, the recording paper is fed by the refeeding means, and the recording paper is recorded on the other side by the image forming means. In the double-sided recording device, the recording paper stacking member is provided to be inclined in a direction perpendicular to the advancing direction of the recording paper, and a front end portion of the recording paper stacked on the receiving member; a front end stopper and a side guide member for regulating one side surface; a means for restoring the inclination of the receiving member in a direction perpendicular to the moving direction of the recording paper after the stacking of recording papers is completed; means for rotating the paper in a horizontal direction to press the uppermost paper on the receiving member against the refeeding means; The present invention provides a double-sided recording device equipped with a recording paper stacking device having a pressing member provided nearby. That is, the present invention is a double-sided recording apparatus having a paper stacking device configured to press the front end of the stacked recording papers with an elastic member or a pressing member such as an elastic means to prevent them from rising.

〔Example〕

FIG. 1 is a configuration diagram showing a conveying path of recording paper in a copying machine equipped with a double-sided recording device of the present invention. FIGS. 2a and 2b are detailed views of the recording paper stacking device according to the present invention, and FIGS. 3 and 4 are views of the main parts thereof.

In FIG. 1, an original 2 placed on a platen glass of a copying machine main body 1 is image-exposed onto a photoreceptor drum 4 by moving optical systems 3 and 3a. At the periphery of the photosensitive drum 4, various processing devices such as charging and developing devices are arranged as known image forming means.

The uppermost recording paper is fed one by one from the recording paper cassette 5 by a paper feeding section 6 consisting of a paper feeding roller, a separation belt, and a sorting roller, and after being temporarily stopped by a registration roller 6a, it is transferred to the photosensitive film. After matching the timing with the leading edge of the image on the body drum 4, feeding is performed again.

The toner image on the photoreceptor drum 4 is transferred to the fed recording paper at the transfer pole 7, and the toner image is transferred to the fixing section 8.
After completing the copying process, the paper is discharged to the outside of the machine by a paper discharge roller 9.

Reference numerals 12 and 13 are paper transport rollers that constitute a part of the double-sided recording device 11 in the main body 1 of the copying machine, but in the case of normal copying of only one side of the recording paper, the paper transport rollers 12 and 13 are Since both rotate in the forward feed direction, the recording paper discharged outside the machine can be conveyed to, for example, a known sorter 10.

On the other hand, when performing double-sided copying, when the operation of the main body 1 of the copying machine is switched to the double-sided copy mode, the paper conveyance roller 13 is reversed, but its conveyance force is less than the conveyance force of the paper conveyance roller 12. Since it is weak, the recording paper slips on the surface of the paper transport roller 13 and is fed sequentially. However, when the trailing edge of the recording paper leaves the paper transport roller 12, the recording paper P completely loses its transport force in the paper ejection direction, and at the same time, the paper P is transported by the paper transport roller 13 in the opposite direction to normal paper ejection. Receive power. Therefore, the trailing edge of the recording paper is guided downward by the rotating paper conveyance roller 12 and the guide plate, and is therefore conveyed downward by the backup roller 14, with its transfer surface facing upward. , and are stored in a tray 15 for double-sided copying, which is the main part of the paper stacking device of the present invention, and are stacked one after another.

The details of the structure of the tray 15 are explained in the second section.
This will be explained with reference to Figure a.

The recording paper P conveyed downward by the back-up roller 14 passes through a pair of pressing and feeding rollers 21 provided on the tray 15, and then passes through the guide plate 2.
6, and is conveyed to the right while being held by a conveyor belt 23 that is hooked around the drive shaft 22 and driven shafts 22a and 22b, and a pressure roller 25 that is pressed against the conveyor belt 23 by an elastic means (not shown). Ru. The guide plate 26 and the pressure roller 25 are respectively attached or rotatably supported on the upper part of the parallel four-bar link 24 which can be raised and lowered using fixed points 24c and 24d as fulcrums. Note that when the recording paper P is short, the parallel four-bar links 24a and 24b, which are constructed in the same manner as the parallel four-bar link 24, also stand up, and the pressure roller 2 is pressed by their respective elastic means (not shown).
5a and 25b are brought into pressure contact with each other via the conveyor belt 23 at the positions of the driven shafts 22a and 22b, and the guide plate 2 is provided on the parallel four-bar links 24a and 24b.
6a and 26b, the recording paper P can be conveyed to near the right end of the tray 15. Further, since the recording paper receiving member 27 is inclined by approximately 10 degrees with respect to the conveying direction of the recording paper P, the recording paper receiving member 27 is tilted at an angle of approximately 10 degrees with respect to the conveying direction of the recording paper P.
slides on the receiving member 27 of the recording paper P and further moves in the transport direction, and is stopped by a front abutting plate 28 fixedly provided near the end of the receiving member 27. The recording paper P that is subsequently conveyed also comes into contact with the front abutting plate 28 and stops in the same manner.
As shown in the figure, the end faces of the recording sheets P are aligned and aligned and stacked.

Furthermore, the alignment of the recording sheets P is performed more reliably by the blower 29 installed to blow air in the conveyance direction of the recording sheets P.

Further, the receiving member 27 for the recording paper P according to the present invention is configured such that when the recording paper P is stacked, the end surface 2 of the receiving member 27 is
7c follows the cam 30a fixed to the shaft 30 by the tension spring 27b, and is inclined about 5 degrees to the right as shown in FIG. The recording paper P whose leading edge is aligned with the plate 28 further has its side surface aligned with the receiving member 27.
The recording paper P is aligned with the guide portion 31a of the right guide support plate 31 disposed above, and as a result, the two perpendicular sides of the recording paper P are properly aligned at the predetermined position, and therefore, for back side copying. It is then possible to make the original surface correspond exactly to the surface that has already been copied.

On the other hand, in this embodiment, since conveyance and image formation are performed with the center of the recording paper P as a reference, the receiving member 2
The right side guide part 31c and the left side guide part 32c arranged on the guide plates 31 and 32 are connected to the pins 31b on the rack plates 31a and 32a attached to the guide plates 31 and 32, respectively, as shown in the plan view of FIG. ,32
b is a long hole 27d provided in the receiving member 27, respectively.
Since it is fitted into the recording paper, it is configured to be able to move parallel to the center line C of the recording paper. Therefore, by controlling a motor (not shown) that rotates a gear G based on a signal from a sensor that detects the size of the recording paper P, the racks R1 and R2 of the rack plates 31a and 32a are moved by a predetermined amount. The guide support plate 3 is adjusted to fit the size of the recording paper P.
It is possible to set the interval between the guide portions 31c and 32c of each of the guide portions 1 and 32. In this case, the right guide support plate 31 serves as a reference for alignment as described above, so it is correctly placed at a distance of 1/2 of the prescribed dimension of the recording paper P with respect to the center line C, while the left guide support plate 31 In consideration of the variation in the dimensions of the recording paper P, the recording paper P is placed at a position slightly outward from the recording paper P.

Further, the guide portion 32 of the left guide support plate 32
c is provided with sloped portions 32d and 32e on the side and top surfaces, respectively, in order to easily receive the recording paper P carried in. Furthermore, the guide portion 32c
Alternatively, a plurality of elastic members (not shown) may be interposed to press the stacked recording sheets against the right guide support plate 31 to further promote alignment. However, the pressing force exerted by the elastic member should be strong enough not to interfere with the conveyance of the recording paper P.

When the recording sheets P are aligned with the receiving member 27 according to the present invention and stacking is completed, the shaft 30 rotates 180 degrees clockwise in response to a feeding start signal and stops, resulting in the state shown in FIG. 2b. That is, in FIG. 3, the receiving member 27, which was tilted about 5 degrees to the right with the shaft 27a as a fulcrum, has its right end pressed against and supported by the cam 30 by the tension spring 27b.
By rotating the shaft 30, which is integral with a, by 1/2 rotation in the clockwise direction, the position is shifted from the inclined position shown by the solid line to the horizontal position shown by the broken line. With a slight delay in this operation, the cutout plate 3, which is also integral with the shaft 30,
3 by turning 1/2 clockwise, the notch plate 33
The bell crank 35, whose rotation in the clockwise direction was restricted by the bell crank 35, is rotated around the shaft 34 by the action of the tension spring 35b as its end 35a is released by the notch 33a of the notch plate 33. It rotates clockwise as follows. Therefore, the pressing roller 36a provided on the pressing plate 36 integral with the bell crank 35 on the extension of the shaft 34 common to the bell crank 35 serves as a receiving member for the front end of the recording paper whose one end is supported by the receiving member 27. The plate 37 is pushed up counterclockwise, and the recording paper P on the intermediate plate 37 is pressed against the paper feed roller 38. Note that the middle plate 37 is connected to the guide plate 31, as shown in FIG.
The guide plates 31 and 32 are dimensioned so that they do not interfere with each other even when the guide plates 32 are closest to the center line C of the recording paper P.

In this way, the recording paper P on the receiving member 27 is ready to be fed again for backside copying.
Note that if the rotation shaft of the eccentric cam 30a is provided separately from the shaft 30 and is connected to the shaft 30 so as to rotate at an increased speed, the recording paper P is The operation from the tilted state to the horizontal state is repeated repeatedly, and the above-described alignment of the recording paper P to the predetermined position is performed more reliably.

Then, the intermediate plate 3 is pressed by the paper feed roller 38.
The recording paper P on 7 is attached to the shaft 38a in the paper feed section 16.
Feeding is started by counterclockwise rotation of the paper feed roller 38, which is integrated with the paper feed roller 38.
and a belt drive roller 39 integrated by a shaft 38a.
By the counterclockwise rotation of a belt 41 that is hooked on a driven roller 40 provided independently from the belt 41, and by the double-feed prevention member, that is, the sorting roller 42, which is in contact with the belt 41 and is also driven and rotated in the counterclockwise direction. Only one of the top recording sheets continues to be fed.

On the other hand, the front abutment plate 28 has a height that is as close as possible to the paper feed section 16 in terms of alignment of the recording papers P, and always keeps the accumulation of the recording papers P below that height. It is desirable to keep it. However, due to the configuration of the paper feed section 16 and the transport of the recording paper P, its height must be restricted, so it is difficult for the recording paper P to be accumulated to the full height of the abutting plate 28. many. In such a state, the recording paper P may come off the front abutment plate 28 due to slight curling or lifting, disturb its alignment, and disturb the image forming position, and in severe cases, it may become impossible to convey.

In the present invention, in order to maintain the alignment of the recording paper P in such a state, the recording paper P is placed near the abutment plate 28.
A pressing member 43 for preventing lifting is provided at the center of the plate. The holding member 4 according to the present invention
3 is constituted by an elastic member or the like having appropriate strength so as not to impede the accumulation or conveyance of the recording paper P. Therefore, in this embodiment, when the recording sheets are stacked on the intermediate plate 37, the rubber plate-shaped pressing member 43 uses its elasticity to hold the recording sheets P.
Press down lightly to prevent it from lifting and ensure proper alignment. Further, when the middle plate 37 is pushed up in the counterclockwise direction and the recording paper P on the middle plate 37 comes into contact with the paper feed roller 38 and is conveyed, the pressing member 43 is deformed by its elasticity. Recording paper P
This does not impede the contact and conveyance between the paper feed roller 38 and the paper feed roller 38.

Following the paper feed roller 38, one sheet of recording paper P is separated.
The feeding section for conveying the paper is made up of the belt drive roller 39, driven roller 40, and sorting roller 42, and since these are arranged on a single substrate, high precision is maintained and a stable sorting function is achieved. can get.

The recording paper P, which has thus passed through the paper feed section 16, reaches the intermediate conveyance roller 17 along the guide plate 44.

In FIG. 1, the recording paper P that has reached the intermediate conveyance roller 17 enters the paper feed section of the copying machine main body 1, and is temporarily stopped by the registration roller 6a, as in the case of the first transfer described above, and then After matching the timing with the leading edge of the image on the photosensitive drum 4, feeding is performed again and a new image is transferred. In this case, since the recording paper P enters the transfer pole 7 of the photosensitive drum 4 after being reversed, images can be recorded on both the front and back sides of the recording paper P.

Further, the intermediate conveyance roller 17 carries the optional recording paper cassette 5b,
Since it also serves to receive the recording paper P from 5c, it is configured so that it can handle recording paper conveyance from both sides.

Furthermore, since the recording paper is strongly pinched between the belt 41 and the separating roller 42, the leading edge of the recording paper P passes through the intermediate conveyance roller 17, reaches the registration roller 6a, stops temporarily, and then starts feeding again. In this case, if the trailing edge of the recording paper P is caught between the belt 41 and the sorting roller 42, it is expected that the recording paper P cannot be conveyed. Therefore, it is desirable that the distance between the sorting roller 42 and the registration roller 6a be slightly longer than the maximum recording paper P.

〔Effect of the invention〕

According to the present invention, when the recording paper that has been copied on the front side is reversed and the image is transferred again to the back side, the front edge of the recording paper is prevented from lifting up in the recording device, and the high-precision image is automatically transferred. Since vertical and horizontal position alignment is performed reliably and accurately, it is possible to correctly record the document surface in the specified position of the recording paper on both the front and back sides, making it a very useful paper stack for recording devices that improves office efficiency and saves resources. A device was proposed. In particular, according to the present invention, even the thinnest recording paper can be reliably fed because its leading edge contacts the paper feeding section accurately.

Although this embodiment has been described with reference to the center of the recording paper for conveyance and image formation, the present invention is not limited to this, and the present invention can also be used when one side of the recording paper is used as the reference. A similar effect can be obtained by slanting the side so that it is facing downward.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing a recording paper conveyance path of a double-sided recording apparatus of the present invention. FIGS. 2a and 2b are side sectional views showing respective states of the recording paper stacking apparatus according to the present invention at the time of stacking and at the end of stacking, respectively. 3 and 4 are views of the main parts of FIG. 2a. 11...Double-sided recording device, 15...Double-sided copy tray, 16...Paper feed section, 23...Transport belt,
24, 24a, 24b...parallel four-bar link, 2
5, 25a, 25b...Crimping roller, 27...Receiving member, 28...Front abutment plate, 29...Blower,
30a...Cam, 31...Right guide support plate, 3
2...Left side guide plate, 33...Notch plate, 33a...
... Notch, 35 ... Bell crank, 36a ... Pressure roller, 37 ... Middle plate, 38 ... Paper feed roller,
41... Belt, 42... Judging roller, 43...
...Press member.

Claims (1)

[Scope of Claims] 1. Recording paper fed from the recording paper feeding section and recorded on one side by the image forming means is stacked in a recording paper stacking device provided in the main body of the apparatus, and then re-fed. In the double-sided recording device configured to feed the recording paper by a means and record on the other side by the image forming means, a receiving member for accumulating recording paper provided inclined in a direction perpendicular to a traveling direction of the recording paper. a front end stopper and a side guide member for regulating the front end and one side surface of the recording sheets stacked on the receiving member; means for restoring the inclination of the receiving member in the direction in which the receiving member is in a horizontal state;
A recording paper stack comprising: means for pressing the uppermost paper on the receiving member against the refeeding means; and a pressing member provided near the refeeding means so as to be in elastic contact with the uppermost paper. Double-sided recording device equipped with a device.