JPH03256977A - Copying device - Google Patents

Abstract

PURPOSE:To use one intermediate tray alone by installing a feeding means for feeding copying paper stacked on the intermediate tray to the side of an image surface by means of but-friction feeding, and another means for transporting the copying paper so as to make the opposite side of the image surface, at time of duplex copying, and/or the same image surface, at time of compound copying, pass through an image forming part, respectively. CONSTITUTION:Copying paper C is stacked on an intermediate tray 23 after turning its image surface upside down, and this stacked copying paper C is fed piece by piece in order from the lowermost paper after turning each surface downward by a feed belt 24 and a separate roller 25 or the like. In brief, it is subjected to friction feeding in a part of the image surface side. Then, it proceeds upward by way of an interval between feed rollers 27 and 29 as being held between a feed roller pair 26 and these feed rollers 27, 28. At the time of compound copying, a selector claw 38 is selected to a full-line position, so it is guided by the claw 38, proceeding upward and fed to a fixing unit 17 by way of a transferring part. At time of duplex copying, the claw 38 is selected to a virtual line position, whereby it passes through an interval between two rollers 34 and 35, then it is nipped between these rollers 34 and 36, passing through a roller pair 37, thus is reversed inside and outside.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a copying apparatus that can perform both double-sided copying and composite copying.

[Prior Art and Problems to be Solved by the Invention] Copying apparatuses capable of double-sided copying, in which copy images are formed on both sides of copy paper, or composite copying, in which copy images are superimposed on the same side of copy paper, have conventionally been available. It is well known. A conventional copying apparatus of this type has an intermediate tray on which copy sheets are stacked, and the copy sheets on this tray are sequentially re-fed by a feeding means. There are two types of intermediate paper stacking: copy sheets are stacked with the copy image side facing up, and copy sheets are stacked with the copy image side facing down. Usually, when in double-sided copy mode, the copy paper is stacked with the copy image side facing up. When in composite copy mode, the copied images are normally stacked with the copy facing down.

Copy sheets stacked in this manner are sequentially re-fed by the feeding means, but when the feeding means is configured to feed the copy sheets on the intermediate tray starting from the topmost sheet, the feeding means always feeds the topmost sheet first. If the configuration is such that copy sheets are fed from the lowest sheet, the copy sheets are always fed sequentially from the lowest sheet.

However, this configuration has the following drawbacks.

The intermediate paper feeding device illustrated in FIG.
It has a feeding means consisting of a paper feed roller 150 that presses against the uppermost sheet C1 of the copy sheets C stacked above, and a friction pad 151, and by rotating the paper feed roller 150 in a clockwise direction, copying is performed. Paper C is re-fed one by one starting from the topmost paper C1.

At this time, if the copy sheets C are stacked on the intermediate tray 123 with the side on which the copy image T is formed facing downward,
When refeeding the top paper C1, this is the next second copy paper C.
2, the paper feed roller 150 presses the topmost paper C1 downward. The surface is strongly rubbed. Therefore, as shown in FIG. 15, the toner that has slightly peeled off from the image on the first copy paper C1 is rubbed against the roller corresponding portion 152 of the second copy paper C2, and the toner is rubbed here. dirt occurs.

Conversely, as shown in FIG. 16, the copy paper C is stacked on the intermediate tray 123 with the side on which the copy image T is formed facing upward, and the uppermost paper C1 is stacked by the rotation of the paper feed roller 150.
If the second copy paper C2 is fed from the roller corresponding part 1
Although the image formed on the second copy paper C1 slides onto the first copy paper C1, the image formed on the roller corresponding portion 152 of the second copy paper C2 does not rub against the same spot on the uppermost paper C1.
Since the topmost paper C1 is rubbed along its entire length from the leading edge to the rear end, even if some of the toner on the second copy paper peels off and adheres to the topmost paper C1, it will not stick to the surface of the copy paper C1. Dispersed, the stain is inconspicuous and does not become a discernible stain.

For the same reason as mentioned above, when copy sheets are stacked in the intermediate tray with the image side facing up and are re-fed starting from the lowest sheet, toner stains may appear on the copy sheets as shown in Figure 14. Also, when copy sheets stacked with the copy image facing down are fed again from the lowest sheet, substantially no toner stain occurs as in FIG. 16.

As mentioned above, depending on the orientation of the image surface of the copy paper and whether the upper or lower copy paper is re-fed, the copy paper may or may not be smeared, so it is necessary to prevent toner smudges from occurring. However, if the copy paper is always re-fed using the method shown in FIG. 16, for example, toner staining can be prevented.

However, if the refeeding method is standardized as shown in FIG. 16, there will be no problem in double-sided copying, but this will not be possible in composite copying.

This is because, when refeeding, the copy paper is fed so that the back side of the copy paper corresponds to the image forming section.

Conventionally, for example, as shown in Figure 16, there is an intermediate tray that feeds the stacked copy sheets with the image side facing up, starting from the topmost sheet, and a tray that feeds the stacked copy sheets with the image side facing down. An intermediate tray was provided that fed paper from the lowest position, and copy paper was re-fed from the former intermediate tray in the case of double-sided copying and from the latter intermediate tray in the case of composite copying. In this way, double-sided copying and composite copying are possible, and there is no risk of staining the copy paper.

However, according to this configuration, it is necessary to provide two intermediate trays, which increases the size of the apparatus and increases the cost.

The object of the present invention is to
Another object of the present invention is to provide a copying apparatus that can perform both double-sided copying and composite copying without causing local toner stains.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a copying apparatus according to the present invention, which includes an intermediate tray for stacking copy sheets after passing through an image forming section, and a stack of copy sheets stacked on the intermediate tray. A feeding means that sequentially feeds the sheets one by one by rubbing, and a feeding means that feeds the same image surface one by one by rubbing, and in the case of double-sided copying, the surface opposite to the image surface passes through the image forming section, and in the case of composite copying, the same image surface passes through the image forming section. The apparatus is characterized by comprising means for transporting the copy paper fed from the feeding means so as to pass through the image forming section.

Further, in order to achieve the above object, the present invention provides a copying apparatus according to the present invention, which includes: an intermediate tray for stacking copy sheets after passing through an image forming section with the image side facing downward; and copy sheets stacked on the intermediate tray. a feeding device that sequentially feeds sheets of paper one by one starting from the lowest sheet; and a copy paper reversing device that inverts the copy paper fed by the feeding device, front and back, and directs it toward the image forming section; The present invention is characterized by comprising a copy paper advancing direction switching means for guiding the copy paper to the copy paper reversing means for double-sided copying and directly to the image forming section for composite copying.

Furthermore, in order to achieve the above object, the present invention provides a copying apparatus according to the present invention including a first copy paper reversing means for reversing the copy paper after passing through an image forming section, and a first copy paper reversing means. an intermediate tray that stacks the copy sheets that have passed through the intermediate tray with the image side facing downward; a feeding means that sequentially feeds the copy sheets stacked on the intermediate tray one sheet at a time starting from the lowest sheet; and the feeding means. a second copy paper reversing means for reversing the front and back of the copy paper fed by and directing it toward the image forming section; and in the case of double-sided copying, the surface opposite to the image surface passes through the image forming section; When performing composite copying, the copy paper is guided to the image forming section via the second copy paper reversing means, or the copy paper reversing means is guided so that the same image surface passes through the image forming section. It is characterized by comprising a means for switching the traveling direction of the copy paper to directly guide the copy paper to the image forming section without passing through the copy paper.

Further, in order to achieve the above object, the present invention provides a copying apparatus according to the present invention, which includes: an intermediate tray for stacking copy sheets after passing through an image forming section with the image side facing upward; and a copy sheet stacked on the intermediate tray. a feeding device that sequentially feeds sheets of paper one by one starting from the topmost sheet; and a copy paper reversing device that turns the copy paper fed by the feeding device upside down and directs it toward the image forming section; The copy paper is moved to the second side so that the side opposite to the image side passes through the image forming section in the case of double-sided copying, and so that the same image side passes through the image forming section in the case of composite copying. It is characterized by comprising a copy paper traveling direction switching means for guiding the copy paper to the image forming section via the copy paper reversing means or directly to the image forming section without passing through the copy paper reversing means.

Furthermore, in order to achieve the above object, the present invention provides a copying apparatus according to the present invention including a first copy paper reversing means for reversing the copy paper after passing through an image forming section; an intermediate tray that stacks the copy sheets that have passed through with the image side facing upward; a feeding device that sequentially feeds the copy sheets stacked on the intermediate tray one sheet at a time starting from the topmost sheet; a second copy paper reversing means for reversing the fed copy paper front and back and directing it toward the image forming section; and a second copy paper reversing means for reversing the front and back of the fed copy paper and directing it toward the image forming section; In the case of composite copying, the copy paper is guided to the image forming section through the second copy paper reversing means so that the same image surface passes through the image forming section, without passing through the copy paper reversing means. It is characterized by comprising a means for switching the traveling direction of the copy paper to directly guide the copy paper to the image forming section.

〔Example〕

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

FIG. 1 shows a schematic configuration diagram of a copying apparatus according to an embodiment corresponding to the first invention and the second invention. and an automatic document feeder 2 are attached.

The automatic document feeder 2 is disposed at the upper part of the main body 1 of the copying apparatus, and a document tray is set on the paper feed tray 5 and the paper feed belt 6 on the right side thereof. By the operation of the belt 6, the lowest document is fed toward the right in the figure and is conveyed as shown by arrow A around a rotating roller ruff that rotates clockwise. on glass 8,
It is fed by a conveyor belt 9 placed opposite to this and electrostatically charged at a predetermined position. At this time, the image surface of the document is directed toward the contact glass 8.

On the other hand, a photosensitive drum 10 that is rotationally driven in a counterclockwise direction is supported in the main body 1 of the copying apparatus. An imaging optical system 14 including a light source 13 is powered.

The document stopped on the contact glass 8 is illuminated by a light source 13 that scans in the direction of the arrow, and the reflected light reaches the surface of the photosensitive drum 10, which is charged by the charger 11, via the optical system 14. by drum 1
A latent image corresponding to the original image is formed on the original image.

This latent image is made visible by toner when passing through the developing device 12, and this visible image is selectively transferred from the first or second paper feed device 15.16 to the transfer portion of the photoreceptor drum 10, that is, the image The image is transferred onto one side (first side) of the copy paper C fed to the forming section, and this transferred copy image is fixed by the fixing device 17. The remaining toner on the drum 10 is cleaned by a cleaning device 18.

The document that has been illuminated by the light source 13 is transferred to the conveyor belt 9
is sent to the left by the reactivation of the paper, is conveyed around the turn roller 19, and is returned to the paper feed tray S (arrow B).
The originals are stacked with the image side facing up, starting from above the other originals loaded here.

A switching claw 21 is provided on the right side of the fixing device 17 in the figure, and this is used in the case of single-sided copying, after completing the single-sided copying, and in the case of double-sided 1 composite copying, which will be described later. After the copy paper is finished, the position is switched to the solid line position at an appropriate time so that the copy paper is guided toward the copy paper final processing device 4. Note that in a copying machine that is not equipped with the copy paper final processing device 4, the paper output tray (
(not shown) guides the copy paper.

On the other hand, in the case of double-sided, composite copying, after the first copying is completed, the switching claw 21 is switched to the position shown by the broken line. This switched claw 21 allows the first
The copy paper on which the side has been copied is conveyed through the reversing conveyance path 22 and discharged in the direction of arrow E.

An intermediate tray 23 is provided in the discharge direction, and the copy sheets discharged as described above are stacked here with the image side facing downward. As shown in FIG. 2, feeding means consisting of a feeding belt 24, a separation roller 25, etc. is provided adjacent to the intermediate tray 23.

By this means, the copy sheets C stacked on the intermediate tray 23 are fed one by one in page order starting from the lowest sheet with the image side facing downward. That is, by the rotation of the feed belt 24, the copy sheets stacked on the intermediate tray 23 are
It is fed by friction on the image side.

Note that inside the feeding belt 24, air suction is performed in the direction shown by the arrow in FIG.
rotates in the opposite direction to the direction in which the copy paper is fed, and separates the copy paper one by one. At this time, air may be blown from the leading edge of the copy paper to make the entire paper float.

The copy paper fed from the feeding means configured as described above passes through the pair of conveying rollers 26, and is further held between the conveying rollers 27, 28.
Proceed upwards through 29 spaces.

As shown in FIG. 3, above the feeding means, there is a stopper member 31, a pair of guide plates 32, 33, a copy paper trailing edge roller 34, and conveyance rollers 35, 36 in contact with this. A paper reversing means 3° is provided.

Further, near the downstream side of the conveyance rollers 27 and 29 in the direction of conveyance of the copy paper, there is provided means for switching the direction of copy paper movement, which is comprised of a switching claw 38 .

In FIGS. 1 and 3, the switching claw 38 is switched to the solid line position for composite copying.

The copy paper that comes out from between the transport rollers 27 and 29 is guided by the switching claw 38 located at the solid line position, advances upward, passes through the transfer section mentioned earlier, passes through the fixing device 17, and then
The copy paper is sent toward the final processing device 4. At this time, the copy paper, of course, passes through the transfer section with the image side facing upward, and at this time, the images are superimposed and transferred onto the same side.

On the other hand, during double-sided copying, the switching claw 38 is switched to the imaginary line position by a driving means such as a solenoid (not shown), and the copy paper is moved to the copy paper trailing edge roller 34. and the conveying roller 35, and stops with its tip Ca touching the stopper member 31.

During this time, the rear end cb of the copy paper passes through the nip between the rollers 34 and 35, and comes into contact with the circumferential surface of the former roller 34, with the leading end Ca touching the stopper member 31, and remains in this position. As the roller 34 rotates in the direction of the arrow, the rear end cb is brought to the surface of the roller 34 and pulled upward, and eventually the rear end cb is caught in the nip between the rollers 34 and 36. You will be able to do it.

Next, the copy paper is conveyed upward, this time with the trailing edge cb as the leading edge, and passes through a pair of conveyance rollers 37. In this way, the copy paper C is turned upside down, and the image is transferred to the back side (second side).

In other words, double-sided copying is performed.

The copy paper on which double-sided copying has been performed in this manner passes through the fixing device 17, and then, at the copy paper final processing device 4, the double-sided copy paper is subjected to, for example, a stapling process. Of course, such stapling processing is also performed in the composite copy mode.

In this way, in the case of double-sided copying, - copy paper reversing means 30
Now, the copy paper is turned over and is transported so that the surface opposite to the image surface faces the photoreceptor drum 10 and passes through the transfer section. Also, in the case of composite copying, the copy paper is not reversed, but directly.

It is sent to the transcription section. In other words, the same image surface passes through the transfer section while facing the photoreceptor drum.
The copy paper is transported.

In either mode, copy paper is stored in the same intermediate tray 2.
3, and in either case, the copy paper is fed with the image side facing downward by downward feeding, so
Local toner stains (FIG. 15) can be made less likely to occur. Moreover, since there is no need to provide two intermediate trays, the device can be made smaller, which greatly contributes to cost reduction.

In FIG. 3, if the stopper member 31 is made of a sponge-like material, for example, the restoring force after the leading edge Ca of the copy paper hits the stopper member 31 will cause the rear end cb of the copy paper to be It can be strongly applied to the peripheral surface of the end-carrying roller 34, making it easy to carry it out. By making the copy paper trailing edge roller 34 similarly a sponge body, or by making its surface into a letter or the like,
The trailing edge cb can be more easily gripped by the surface of the copy paper trailing edge bringing roller 34.

Two opening grooves 31a are cut laterally in the stopper member 31, and the parallel portions of both guide plates 32, 33 are fitted into these portions. By driving the drive belt 40 forward and backward by the motor 39, the stopper member 31 connected to the belt 40 is guided by the guide rail 41 and driven to be displaced in the horizontal direction. In this type of copying apparatus, copy sheets of different sizes are used, and the stopper member 31 moves according to the size of the copy sheets.

Incidentally, if copies are made one by one in page order and the copies are fed one by one from the intermediate tray 23 in page order, a bundle of copy paper is obtained one by one, and this is subjected to, for example, stapling processing by the copy paper final processing device 4. This also applies to each of the embodiments described below.

FIG. 4 shows a schematic configuration diagram of a copying apparatus according to an embodiment corresponding to the first invention and the third invention.

This copying apparatus main body includes an imaging optical system 42 including a light source 13.
is provided. The document (not shown) on the contact glass 8 is illuminated by the light source 13, and the reflected light passes through the optical system 42 and reaches the surface of the photoreceptor belt 43, which has been charged in advance by the charger 11. A latent image corresponding to the original image is formed on the photoreceptor belt.

When this latent image passes through the developing device W44, it is made visible by toner, and this visible image is
．． 47 onto one side of a copy sheet fed to the transfer section of the photoreceptor belt 43, that is, the image forming section, and this transferred copy image is fixed by the fixing device 48.

On the other hand, residual toner on the photoreceptor belt 43 is cleaned and removed by a cleaning device 49.

The copy paper that has passed through the fixing device 48 is sent toward a first copy paper reversing means 51 shown in FIG. This copy paper reversing means 51 is a vertical version of the one shown in FIG. 3, and has exactly the same structure as this, so the same reference numerals are used for convenience.

In FIGS. 4 and 5, in the case of only one-sided copying, or when one composite copying or double-sided copying is completed, the switching pawl 38 is switched to the solid line position, and the copy paper that has been fixed is moved to the position shown in the solid line. The paper is guided by the claws 38, passes through the transport roller pair 37, and is discharged onto the tray 53.

On the other hand, when performing synthetic resin or double-sided copying, the switching pawl 38 is switched to the imaginary line position by a driving means such as a solenoid (not shown), and the copy paper is moved at the trailing edge of the copy paper. Entrainment roller 34 and conveyance roller 35
It passes through the gap and stops with its tip Ca in contact with the stopper member 31. During this time, the rear end cb of the copy paper passes through the nip between the rollers 34 and 35, and comes into contact with the circumferential surface of the former roller 34, with the leading end Ca touching the stopper member 31, and remains in this position. As the roller 34 rotates in the direction of the arrow, the rear end cb is brought to the surface of the roller 34 and brought to the right, and eventually the rear end cb is held in the nip between the rollers 34 and 36. Becomes involved.

Next, the copy paper is conveyed upward, this time with the trailing edge cb as the leading edge, and passes through a pair of conveyance rollers 37. The copy sheets are then guided by the switching claw 81 to the intermediate tray 23, where they are stacked with the image side facing downward. Note that the functional description of the stopper member 31 and the like in FIG. 5 is exactly the same as that of the previous embodiment, and therefore will be omitted here for convenience.

The copy sheets stacked on the intermediate tray 23 are fed page by page, starting from the lowest sheet, by a feeding means including a feeding belt 24, a separating roller 25, etc. shown in FIG.

The copy paper fed in this manner passes through a pair of transport rollers 54, and in the case of double-sided copying, is sent toward a second copy paper reversing means 52 shown in FIG. Conveying roller pair 54
A copy paper advancing direction switching means comprising a switching claw 55 is provided below.

During double-sided copying, the switching claw 55 is switched to the imaginary line position, and the copy paper is guided by the switching claw 55, passes between both rollers 34 and 36, and then is reversed and transferred to both rollers. It is sent from between the rollers 34 and 35 in the direction of the solid arrow. Then, through the copy paper conveyance path 56 shown in FIG.
Another visible image on the photoreceptor belt 43 is transferred to the back side, and then the sheet passes through the fixing device 48 and is discharged to the tray 53 as double-sided copy paper.

On the other hand, in the case of composite copying, the switching claw 55 in FIG. 6 is switched to the solid line position, and the copy paper fed from the intermediate tray 23 in FIG. The paper is sent directly in the direction of the dashed arrow without passing through the means 52, and then passes through the copy paper transport path 56 in FIG.
A visible image is transferred onto the same surface, and the paper is discharged to a tray 53 as composite copy paper via a fixing device 48.

In this example as well, since the copy paper is fed out downward in the intermediate tray 23 with the image surface facing downward, it is possible to prevent local toner stains from occurring.

This example differs from the embodiment shown in FIG. 1 in that the copy paper reversing means is provided at two locations, and the following embodiment is similarly provided with copy paper reversing means at two locations. It is something.

FIG. 7 shows a schematic configuration diagram of a copying apparatus according to an embodiment corresponding to the first invention and the third invention.

In this figure, for both composite copying and double-sided copying,
All the copy sheets whose first side has been copied pass through the first copy sheet reversing means 51 (FIG. 5) and are stacked on the intermediate tray 23 with the image side facing downward. .

In the case of single-sided copying, composite copying, or double-sided copying, the copy paper is directly discharged onto the tray 53.

The copy sheets stacked on the intermediate tray 23 are sent out from the intermediate tray 23 from the lowest sheet by a feeding means consisting of a feeding belt 24 and a separation roller 25, and the subsequent destination is the second copy sheet reversal. It is selected whether or not to pass through the section of means 52'.

FIG. 8 shows the configuration of the second copy paper reversing means 52', in which a switching claw 58 is provided below a pair of transport rollers 57 for continuously transporting the copy paper fed from the intermediate tray 23.
Copy paper advancing direction switching means is provided.

In the case of composite copying, the switching claw 58 is switched to the solid line position, and in this state, the copy paper C continues to advance downward. Then, the copy paper continues to advance while slightly pushing the extremely thin elastic plate 58A provided on the switching claw 58 to the left, and when the trailing edge of the copy paper leaves the elastic plate 58A, the lower part of the switching claw 58 The rotation of the pair of conveying rollers 59 provided at 59 is stopped. In this state, the copy paper enters the reversing path 60 leaving the upper rear end portion intact.

Thereafter, the pair of conveyor rollers 59 is reversed, and the copy paper is now conveyed toward the pair of conveyor rollers 61 with its trailing edge leading.

In FIG. 7, the copy paper passes through a pair of transport rollers 61 with the image side facing downward, passes through a copy paper transport path 56, and reaches a transfer section, where a visible image is formed on the same surface. is transcribed.

Thereafter, the copy paper passes through the fixing device 48 and is discharged onto the tray 53 as composite copy paper.

On the other hand, in the case of double-sided copying, the switching claw 58 shown in FIG.
is switched to the imaginary line position, and the copy paper coming out of the conveyance roller pair 57 advances in the direction of the solid arrow, passes through the conveyance roller pair 61, and passes through the copy paper conveyance path 56 in FIG. , to the transcription section.

Here, the visible image on the photoreceptor belt 43 is transferred to the back side of the copy paper, and then the paper passes through the fixing device 48 and is discharged onto the tray 53 as double-sided copy paper.

The embodiment described above has two copy paper reversing means, and in the embodiment shown in FIG. 4, the copy paper on the intermediate tray 23 is fed by switching back, but in the embodiment with one , the copy paper is fed in the same direction as the direction in which the copy paper is discharged to the intermediate tray 23. Hereinafter, this will be referred to as ``forward transport''.

The switching claw 55 shown in FIG. 6 and the switching claw 58 shown in FIG. During copying, the copy paper is not guided to the image forming section via the second copy paper reversing means 52, 52' or passing through the copy paper reversing means so that the same image surface passes through the transfer section. This constitutes an example of a means for switching the traveling direction of a copy sheet for directly guiding the copy sheet to an image forming section.

FIG. 9 shows a schematic configuration diagram of a copying apparatus according to an embodiment corresponding to the first invention and the fourth invention.

In this figure, copy sheets that have been transferred from the fixing device 48 after copying the first side are stacked on the intermediate tray 63 with the image side facing upward. This stacking method is the same for both 5-component copying and double-sided copying. In the case of one-sided copying, the copy paper exiting the fixing device 48 is directly ejected to the tray 53.

FIG. 10 shows the details of the intermediate tray section, and the copy paper coming out of the pair of ejection conveyance rollers 64 hits the stopper member 65 made of a soft elastic material such as sponge, and then moves onto the intermediate tray 63. will be stacked.

The stopper member 65 is driven to be displaced in the direction of the arrow in the same manner as the stopper member 31 shown in FIG. Pickup roller 6 which is a feeding means
It is moved to a position where it touches 6.

Thereafter, the uppermost copy sheet is sent between the feed roller 67 and the separation roller 68 by the pickup roller 66 . When duplicate sheets of copy paper are fed, only the uppermost copy sheet is separated between both rollers 67 and 68 and sent toward a pair of transport rollers 69. Then, the copy paper passes through that area and heads toward a pair of transport rollers 54 shown in FIG.

The rollers 66, 67, and 68 constitute an example of a feeding means that sequentially feeds the copy sheets stacked on the intermediate tray one sheet at a time, starting from the topmost sheet.

The copy paper that has passed through the pair of transport rollers 54 passes through a copy paper reversing means 52 in the case of composite copying. Such copy paper reversing means 5
2 is constructed as shown in FIG. 6, and the copy paper enters the guide plates 32 and 33 with the image side facing downward.

In the 9th step, the copy paper that has entered both guide plates 32 and 33 is guided in the direction of the arrow with the image side facing downward, passes through the copy paper conveyance path 56, and is transferred for the second transfer on the same side. After this, the sheet passes through the fixing device 48 and is discharged onto the tray 53 as composite copy paper.

On the other hand, in the case of double-sided copying, the copy paper fed from the intermediate tray 63 does not pass through the copy paper reversing means 52, but directly passes through the copy paper transport path 56, reaches the transfer section, where the copy paper is The visible image on the photoreceptor belt 43 is transferred to the back surface.

Finally, the paper is discharged onto the tray 53 as double-sided copy paper.

FIG. 11 shows a schematic configuration diagram of a copying apparatus according to an embodiment corresponding to the first invention and the fourth invention. In the embodiment shown in FIG. 9, the copy paper feeding method from the intermediate tray 63 is a switchback type, but in this example.

This is a forward feeding method.

The copy sheets that have undergone the first transfer are stacked on the intermediate tray 73 with the image side facing upward. In the case of double-sided copying, the copy sheets are transferred from the intermediate tray 73 to the top layer by a pickup roller 66 serving as a feeding means. The copy paper fed from the paper is sent toward the copy paper reversing means 52'. The copy paper reversing means 52' is constructed as shown in FIG. 8, and enters the reversing path 60 in the case of double-sided copying. Thereafter, the copy paper is reversed and horizontally moved to the left through the pair of transport rollers 61 in FIG. Transfer is performed, and the paper is finally stored on the tray 53 as double-sided copy paper.

On the other hand, in the case of composite copying, the copy paper fed from the intermediate tray 73 does not pass through the copy paper reversing means 52', but directly passes through the copy paper transport path 56 and reaches the transfer section, where it is transferred onto the same surface. A second transfer is performed, and the paper is finally stored on the tray 53 as composite copy paper.

In the case of single-sided copying, the copy paper is not fed into the intermediate tray 73 but is ejected to the tray 53 as it is.

The embodiments shown in FIG. 9 and FIG. 11 have one copy paper reversing means in common with a number of digits, and the feeding method in the intermediate tray is different. In both cases, the image surface is Since the method refeeds the copy paper facing upward by feeding it upward, it is possible to prevent local toner stains from occurring.

FIG. 12 shows a schematic configuration diagram of a copying apparatus according to an embodiment corresponding to the first invention and the fifth invention.

In both composite copying and double-sided copying, after the first transfer is completed, the copy paper passes through the fixing device 17 with the image side facing upward, and is sent toward the first copy paper reversing means 71. . That is, the paper enters the reversal conveyance path 72 by the action of the three rollers 80, which are known per se, where it is reversed and then advances downward.

The sheets are discharged in the direction of arrow f and stacked on the intermediate tray 83 with the image surface facing upward.

Thereafter, the copy sheets are fed from the intermediate tray 83 from the uppermost one by a feeding means comprising a pickup roller 66, and in the case of composite copying, are sent toward the second copy sheet reversing means 30. That is, it enters into both guide plates 32 and 33 shown in FIG. 3 with the image plane facing downward.

After this, the copy paper with the image side facing down is placed on both rollers 34.
．． 36 and proceeds toward the conveyance roller passage 37. Then, the copy paper passes through the pair of transport rollers 37 and reaches the photosensitive drum 10, where a second transfer is performed on the same image surface, and finally, the copy paper is transferred as composite copy paper. Either it is sent towards the paper final processing device 4 or it is directly discharged onto a tray, not shown.

On the other hand, in the case of single-sided copying, the copy paper fed from the intermediate tray 83 is guided by the switching claw 38, which is switched to the solid line position in FIG.

As it is, the copy paper advances upward without passing through the copy paper reversing means 30, and at the photosensitive drum 10 shown in FIG. As such, it is sent to the above-mentioned device 4 or directly discharged to a tray (not shown).

During single-sided copying, the copy paper is not fed into the intermediate tray 83, but is directly ejected to the device 4 or the tray.

FIG. 13 similarly shows an embodiment corresponding to the first invention and the fifth invention, and in the embodiment of FIG. 12, the copy paper feeding method in the intermediate tray is a forward feeding method. In contrast, this example uses a switchback feeding method.

In both cases of composite copying and double-sided copying, the copy paper that has undergone the first transfer enters the reversing conveyance path 72 in the first copy paper reversing means 71, after which it is reversed and transferred to the intermediate tray 6.
3 with the image side facing upward. After the stacked copy sheets are moved to the right in the figure by a stopper member 65, they are fed by a feeding means consisting of a pickup roller 66 and advance to a position where a pair of conveying rollers 57 are located.

In the case of double-sided copying, the copy paper passes through the pair of transport rollers 57 and enters the reversing path 60 in the second copy paper reversing means 52' with its end side held by the pair of transport rollers 59. In this state, as shown in FIG. 8, the copy paper is guided by the switching claw 58 which has been switched to the solid line position.
It is horizontally moved to the left in the figure with the image surface facing upward via the pair of conveying rollers 61 in FIG. Thereafter, the copy paper reaches the photoreceptor drum 10, where a visible image is transferred to the back side of the copy paper. Then, it passes through the fixing device l7 and finally becomes double-sided copy paper.

The copy paper is sent toward the final processing device 4 or discharged to a tray (not shown).

In the case of composite copying, the copy paper is transferred to the second copy paper reversing means 52.
' without passing through the roller pair 57, 61, a visible image is transferred from the photoreceptor 10 onto the same surface, and the sheet passes through the fixing device 17 and is discharged to the device 4 or a tray.

In the case of single-sided copying, the copy paper is not sent to the intermediate tray 63 but is ejected as is.

In this example, as in the example shown in Fig. 12, copy paper reversing means are provided at two locations, and in each case, the copy paper with one image side facing upward is fed out and re-fed. This method makes it difficult for local stains caused by toner to occur.

Note that if a configuration is adopted in which the copy sheets are stacked on the intermediate tray with the image side facing up, the structure can be particularly miniaturized and the degree of freedom in layout can be increased.

【Effect of the invention〕

According to the configurations of claims 1 to 5 of the present invention, both double-sided copying and composite copying can be performed without causing local toner stains, and there is no need to provide multiple intermediate trays. , the size of the copying device can be reduced, which greatly contributes to reducing its cost.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a copying apparatus according to a first embodiment of the present invention;
FIG. 2 is a side view of the vicinity of the intermediate tray section, FIG. 3 is a side view of the vicinity of the copy paper reversing means, FIG. 4 is a schematic configuration diagram of the copying apparatus of the second embodiment, and FIG. 5 is the first copying machine. FIG. 6 is a diagram showing the configuration of the second copy paper reversing means, FIG. 7 is a schematic configuration diagram of the copying apparatus of the third embodiment, and FIG. 8 is the third embodiment. FIG. 9 is a schematic diagram of the copying apparatus of the fourth embodiment, FIG. 10 is a diagram of the intermediate tray section of the fourth embodiment, and FIG. 11 is a diagram showing the configuration of the second copy paper reversing means. FIG. 12 is a schematic diagram of the copying apparatus of the fifth embodiment, FIG. 13 is a schematic diagram of the copying machine of the sixth embodiment, and FIG.
14 is a side view showing an example of a conventional intermediate tray section, FIG. 15 is a plan view showing a state in which toner stains are attached to copy paper, and FIG. 16 is a schematic diagram of the copying apparatus of the embodiment. 1
FIG. 4 is a side view showing the same conventional intermediate tray section as in FIG. 4, and clarifying the state in which the copy paper is oriented in the opposite direction.

Claims (5)

[Claims] (1) an intermediate tray for stacking the copy sheets after passing through the image forming section; a feeding means for sequentially feeding the copy sheets stacked on the intermediate tray one sheet at a time by friction-feeding them to the image surface side; Feed from the feeding means so that the surface opposite to the image surface passes through the image forming section in the case of double-sided copying, and so that the same image surface passes through the image forming section in the case of composite copying. 1. A copying apparatus comprising means for transporting copied paper. (2) an intermediate tray that stacks the copy sheets after passing through the image forming section with the image side facing downward; and a feeding means that sequentially feeds the copy sheets stacked on the intermediate tray one sheet at a time starting from the lowest sheet. , a copy paper reversing means for reversing the copy paper fed by the feeding means and directing it to the image forming section; guiding the copy paper to the copy paper reversing means when double-sided copying is performed; 1. A copying apparatus comprising: a means for switching the traveling direction of copy paper for directly guiding the copy paper to the image forming section during composite copying. (3) A first copy paper reversing means for reversing the copy paper after it has passed through the image forming section, and an intermediate member for stacking the copy paper that has passed through the first copy paper reversing means with the image side facing downward. a tray, a feeding means for sequentially feeding the copy sheets stacked on the intermediate tray one sheet at a time starting from the lowest sheet; and a feeding means for feeding the copy sheets stacked on the intermediate tray one by one from the lowest sheet, and turning the copy sheets fed by the feeding means upside down so as to convey the above-mentioned image. a second copy sheet reversing means for directing the copy sheet toward the forming section; when double-sided copying, the same image surface passes through the image forming section; during composite copying, the same image surface passes through the image forming section; switching the copy paper advancing direction for guiding the copy paper to the image forming section via the second copy paper reversing means or directly to the image forming section without passing through the copy paper reversing means; A copying apparatus comprising: means. (4) an intermediate tray for stacking the copy sheets after passing through the image forming section with the image side facing upward; and a feeding means for sequentially feeding the copy sheets stacked on the intermediate tray one sheet at a time starting from the topmost sheet. , a copy paper reversing means for reversing the copy paper fed by the feeding means and directing it to the image forming section; and in the case of double-sided copying, the surface opposite to the image surface is the image forming section; guiding the copy paper to the image forming unit via the second copy paper reversing means so that the same image surface passes through the image forming unit during composite copying;
or a copying paper advancing direction switching means for guiding the copy paper directly to the image forming section without passing through the copy paper reversing means. (5) A first copy paper reversing means for reversing the copy paper after passing through the image forming section; and an intermediate tray for stacking the copy paper that has passed through the first copy paper reversing means with the image side facing upward. a feeding device that sequentially feeds the copy sheets stacked on the intermediate tray one by one starting from the topmost sheet; and a feeding device that turns the copy sheets fed by the feeding device upside down and supplies them to the image forming section. a second copy paper reversing means for directing the copy paper, and in double-sided copying, the opposite side to the image plane passes through the image forming unit, and in composite copying, the same image plane passes through the image forming unit. a copy paper advancing direction switching means for guiding the copy paper to the image forming section via the second copy paper reversing means or directly to the image forming section without passing through the copy paper reversing means; A copying apparatus comprising: