JPS6237784B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a double-sided copying machine.

In conventional copying, it was common to make copies on one side of a single sheet, but in recent years, the need for double-sided copying machines has increased due to the storage capacity and weight of copies, copying costs, and resource conservation. The sex is great.

Generally, a double-sided copying machine places a document on a document loading table and exposes it to form a toner image on the first side of the transfer paper. A double-sided copy is obtained by turning over the original or, in the case of a single-sided original, placing another original on the original stacking table and exposing it to light to form a toner image on the second side of the transfer paper.

By the way, the types of manuscripts include book-like manuscripts with manuscript images formed on the front and back sides, double-sided manuscripts in the form of individual sheets, and single-sided manuscripts in the form of sheets with images formed only on one side. There are different copying methods depending on each manuscript.

Furthermore, in recent years there has been a strong demand for so-called high-performance copying, which allows a large number of copies to be made in a short period of time. Among the various types of originals mentioned above, it is possible to improve the copying speed of sheet originals, unlike book originals. That is, while book originals must be placed manually on the document tray, sheet documents can be stacked and automatically fed one by one to the document tray or exposure position. can.

A so-called document conveying device that conveys the stacked documents from a paper feeding position to an exposure position and further from an exposure position to a paper ejection position is already known and greatly contributes to improving copying speed.

However, although the above-mentioned document conveyance device is highly effective when obtaining single-sided copies from a large number of single-sided originals, various problems arise when attempting to use it for double-sided copying. For example, to obtain a double-sided copy from a double-sided original, two copying operations are performed, but the order of the sheet originals changes when copying to the first side and when copying to the second side. Post-processing is troublesome, as it is necessary to rearrange originals and copies in order. Particularly in the case of so-called "page" originals in which the original sheets on both sides have an order, it is a big disadvantage from the viewpoint of high-speed copying that the order of copies or originals differs before and after copying.

SUMMARY OF THE INVENTION An object of the present invention is to provide a double-sided copying machine equipped with a sheet document processing device that does not change the order of documents before and after copying and greatly improves the operability of sheet document processing in the double-sided copying machine. .

The present invention will be explained below with reference to illustrated embodiments.

First, in FIG. 1, an example of a double-sided copying machine will be briefly described. Reference numeral 1 indicates a photosensitive drum that rotates in the direction of the arrow. A charging device 2, a developing device 3, a transfer device 4, a separating device 5, a static eliminating charger 6, a cleaning device 7, and a static eliminating lamp 8 are arranged around the photosensitive drum 1, respectively. A document mounting table 9 made of a transparent glass plate is fixedly installed on the upper part of the copying machine main body.

A slit exposure optical system 10 is disposed between the document mounting table 9 and the photosensitive drum 1.
The original on the original placing table 9 is exposed and scanned. The slit exposure optical system 10 is provided directly below the original table 9, and an illumination lamp 11 that reciprocates in parallel with the document table 9 at the same speed as the photosensitive drum 1.
It consists of a lens 12 that reciprocates in the same direction at one-half the speed of the illumination lamp 11, and two fixed reflecting mirrors 13 and 14.

A sheet document processing device 15 is disposed above the document table 9 . This processing device 15
a removable first stacking table 16 on which sheet originals S are stacked with the side to be copied facing downward;
A paper feed roller 17 serves as a document sending means for sending out the originals S on the first stack table 16 one by one toward the original placing table 9, and a paper feeding roller 17 serves as a document sending means for sending out the originals S on the first stack table 16 one by one toward the document placing table 9. A conveyance belt 18 serves as a document conveyance means for conveying the document to a predetermined exposure position, and also conveys the document after exposure to a paper discharge position with the exposed side facing upward. It also includes a detachable second stack table 19 on which exposed original documents S are loaded. Note that reference numerals 20 and 21 respectively indicate guide members for the transported document.

The present invention relates to the document processing apparatus 15, and its most significant feature is that the first and second stack tables 16 and 19 are constructed to be interchangeable. The operation of the device 15 will be explained in detail later.

On the other hand, the transfer paper conveyance device includes a paper feed cassette 22,
It consists of registration rollers 23, a conveyance path switching device 24, an intermediate cassette 25, and a paper discharge tray 26. The intermediate cassette means is the intermediate cassette 25.
and a feeding roller disposed above these. This feeding roller feeds the transfer paper stacked in the intermediate cassette 25 toward the registration roller 23 during image transfer to the second side of the transfer paper, which will be described later.

A fixing device 27 consisting of a pair of rollers is disposed between the switching device 24 and the transfer position A.

The operation of the double-sided copying machine configured as described above will be explained by taking as an example a case where a double-sided copy is obtained from a double-sided sheet original.

The double-sided sheet originals S arranged in page order are placed on the first stack stand 1 with the first page facing down.
Load onto 6. Suppose there are two sheet manuscripts S ₁ and S ₂
is loaded on the stack table 16, the document S ₁
The first page of S2 is in contact with the stack table 16, and the fourth page of _S2 is in contact with the stack table 16.
The page is at the top and facing upward.

Now, when the print button (not shown) is pressed,
The document S ₂ is sent out by the paper feed roller 17, conveyed by the conveyor belt 18 to a predetermined exposure position on the document table 9, and then stopped. At this time, the document _S2 is stopped with the third page facing down.

The arrival of the original S ₂ at the exposure position is detected directly or indirectly by an appropriate means, and the slit exposure optical system 10 is moved by this signal to expose and scan the third page of the original S ₂ . An electrostatic latent image corresponding to the image is formed on the photosensitive drum 1.

The electrostatic latent image on the photosensitive drum 1 is visualized by the developing device 3. On the other hand, the transfer paper O ₁ sent out from the paper feed cassette 22 is sent toward the photosensitive drum 1 by the registration roller 23 in synchronization with the electrostatic latent image, and forms a visible image in the transfer section A. transcribed.

The first visible image corresponds to the image on the third page of manuscript _S2 .
After the visible image is fixed on the transfer paper _O1 by the fixing device 27, it is guided by the switching device 24 located at the solid line position and placed onto the intermediate cassette 25 with the first side facing upward. (See symbol O ₁ A in Figure 2).

On the other hand, the exposed original S ₂ is transferred to the conveyor belt 1.
8, the document is conveyed from the document placing table 9 to the second stacking table 19, and is ejected and placed thereon. At this time, the document S ₂ is placed with the exposed side, that is, the third page facing upward (see reference numeral S ₂ A in FIG. 2).

When ejection of the exposed original S ₂ starts,
The next document S ₁ is sent out by the paper feed roller 17, and the same operation as described above causes the photosensitive drum 1 to
An image corresponding to the page is formed. Transfer paper O ₂ is fed from the paper feed cassette 22 in response to the exposure of the original S ₁ , an image corresponding to the first page of the original S ₁ is formed on its first side, and the first side is turned upward. The paper is then stacked on the transfer paper O ₁ A of the intermediate cassette 25 (see reference numeral O ₂ A in FIG. 2). Further, the exposed original S ₁ is stacked on the original S ₂ A on the second stack table 19 by the conveyor belt 18 with the exposed side, that is, the first page facing upward, in the same manner as described above. (See symbol S ₁ A in FIG. 2).

When it is detected that all the documents on the first stack table 16 have been fed out, the conveyance path switching device 24 is switched from the solid line position to the broken line position, and the transfer paper feeding position is changed from the paper feed cassette 22 to the intermediate cassette. 25.

Further, the empty first stack table 16 is removed from the apparatus, and the second stack table 19 loaded with the exposed documents S ₁ A and S ₂ A is set at the paper feeding position, and the The first stacking table 16 is set behind the second stacking table 19, that is, at the sheet feeding position. The first and second stack tables may be replaced by replacing the entire stack table, or by replacing only the member on which documents are directly stacked in the stack table.

The originals on the stack stand placed in the paper feed position are originals S ₁ A with the exposed first page facing upwards,
The original S ₂ A with the exposed third page facing upward is stacked at the bottom. In addition, the intermediate cassette 25
In this case, a transfer paper O ₂ A with an image corresponding to the first page of the above original S ₁ formed on the first side is placed with the same side facing upward and on top, corresponding to the third page of the above original S ₂ . Transfer paper O ₁ A with an image formed on its first surface is stacked at the bottom.

Then, when a print button (not shown) is pressed, the document S ₁ A placed in the paper feed position is transferred to the paper feed roller 17.
After being conveyed to a predetermined exposure position by the conveyor belt 18, the sheet is stopped with the second page facing down. The image corresponding to the second page of the document S ₁ A is formed on the photosensitive drum 1 in the same manner as described above.

On the other hand, the transfer paper O ₂ A on the intermediate cassette 25 has been sent out to the registration roller 23 in advance.
In synchronization with the rotation of the photosensitive drum 1, the second
It is fed by the same roller so that its surface is brought into contact with the photoreceptor drum 1. The transfer paper O ₂ A, on which the image of the first page has been transferred to the second side, passes through the fixing device 27, is guided to the switching device 24 which has been switched to the position shown by the broken line, and onto the paper output tray 26, where it is transferred to the duplex copy O ₂ B. The document is ejected and placed with the first side corresponding to the first page of the document facing downward, that is, the second side on which images are formed in series faces upward. In FIG. 2, the transfer paper comes into contact with the photosensitive drum during transfer to the second surface, but the arrows in the figure are shown separated for convenience.

After the second page has been exposed, the document S ₁ A is transferred by the conveyor belt 18 to the stack stand placed at the paper ejection position, with the second page that has just been exposed facing upwards, and the first page facing downwards. (See symbol S ₁ B in Figure 2).

Simultaneously with the start of ejection of the original document S ₁ A, the original document S ₂ A with the third page facing up is conveyed onto the document tray 9 with the fourth page facing down, and is stopped at a predetermined exposure position. . When the photosensitive drum 1 on which the image corresponding to the fourth page has been formed reaches the transfer position, the transfer paper
O ₁ A is fed with the second side facing the same drum, and an image for the fourth page is formed on the same side. The transfer paper O ₁ A to which the image corresponding to the fourth page has been transferred is transferred to the fixing device 2
7 and then to the paper ejection tray 26, where the third page faces down and the fourth page faces upward, and is discharged and stacked onto the double-sided copy O ₂ B as a double-sided copy O ₁ B. Therefore, the double-sided copies on the paper ejection tray 26 are ejected and stacked with the pages arranged in the same order.

Further, the original S ₂ A whose fourth page has been exposed is transferred by the conveyor belt 18 to the already ejected original S ₁ on the stack table which is placed at the ejecting position with the fourth page facing upward. B is discharged and loaded onto B (symbols in Figure 2)
(see _S2B ). Therefore, the fully exposed originals S ₁ B and S 2 B stacked on the stack table at the paper ejection position are the same as the originals S ₁ and S ₂ B stacked on the first stack table 16 at the time of the first exposure start. The order is exactly the same as that of page ₂ .

As explained above, the double-sided copying apparatus of the present invention is characterized in that the stack tables provided at the paper feed position and the paper discharge position are respectively replaceable, and the document conveying means is provided for conveying and discharging the document with the exposed side facing upward. According to the machine, since the order of originals does not change before exposure and after duplex copying is completed, there is no need to rearrange the order of originals after copying, and an efficient double-sided copying machine can be provided. .

In addition, in the double-sided copying machine shown in Fig. 1,
Of course, one-sided copying is possible, and if the sheet document processing device 15 is evacuated from the document table 9,
Copying of book manuscripts is also possible.

Furthermore, there are various types of exposure optical systems, such as those that expose a sheet document while moving it, and those that expose the entire surface of a sheet document while it is stopped, and the present invention can be applied to either type.

An example in which an exposure optical system of the former type is used in a copying machine of the present invention will be explained with reference to FIG. In the figure, various copying units other than the exposure optical system are omitted. At the top of the copying machine, a first contact glass 30 made of a transparent glass plate for exposing sheet originals and a second contact glass 31 for exclusively placing book originals etc. that cannot be transported by the original transporting device described later are provided. ing.

A slit exposure optical system 32 is disposed below the contact glass. This optical system 32
consists of movable mirrors 33 and 34, fixed imaging lenses 35 and mirrors 36 and 37, and an illumination lamp 38 that moves together with the movable mirror 33.

In the case of exposing a book original, the optical system 32 moves forward from the starting position indicated by the broken line to the right in the figure and then returns to the original position, and in the case of a sheet original, the optical system 32 moves back to the original position. , is fixed at the solid line position for exposure.

A sheet document processing device 38 is provided above the first contact glass 30 . The same device 38
It consists of a paper feed roller 39, a first stack stand 40, a conveyor belt 41, and a second stack 42 which can be replaced with the first stack stand 40.

When double-sided copying is performed, the originals are stacked on the first stack table 40 with the first page facing down, as described above. And paper feed roller 3
The document sent out at step 9 is transferred to the first conveyor belt 41, which rotates in the direction of the arrow at the same speed as the photoreceptor drum 1.
While being conveyed over the contact glass 30, the first page is exposed by a fixed slit exposure optical system 32. The exposed document is discharged onto the second stack table 42 with the exposed side facing upward. In the same manner, when the first side of all originals has been copied, the first stack table 40 and the second stack table 42 loaded with single-sided exposed originals are exchanged, and the same operation as described above is performed. If you do this, you will get a double-sided copy.

In the apparatus shown in FIG. 3 as well, the order of the originals does not change before exposure and after both sides are exposed.

In the embodiments shown in FIGS. 1 and 3, the documents to be loaded on the stack stand placed at the paper feed position are placed face down in page order, but they may also be placed face up in page order. . This example will be explained in FIG. In this example, the same components and functions as those shown in FIG. 1, such as the optical system and the paper feed cassette, are designated by the same reference numerals, and detailed explanations thereof will be omitted to avoid duplication.

A sheet document processing device 43 is arranged above the document table 9 . This device 43 includes a first stack table 44 disposed at a paper feed position, a paper feed roller 45 serving as a document feed means for feeding out the sheet documents stacked on the stack table one by one, and a paper feed roller 45 that serves as document feed means for feeding out the sheet documents stacked on the stack table one by one. It consists of a conveyance belt 46 serving as a document conveyance means for conveying the exposed document to a predetermined exposure position on the placing table 9 and discharging the exposed document, and a second stack table 47 arranged at the sheet discharge position. The first and second stack stands 44, 47 are interchangeable.

Then, the double-sided originals are stacked in page order on the first stack table 44 with the first page facing upward, fed out by a paper feed roller 45, and then transported to an exposure position by a transport belt 46 and stopped there. Thereafter, the first page of the document is exposed, and then the document is discharged and placed on the second stack table 47 with the exposed first page facing down.

When one side has been copied, the first and second stack tables 44 and 47 are replaced and the other side is copied. The page order of the originals discharged and stacked on the stack table at the paper discharge position after both sides have been copied is the same as that of the originals stacked on the first stack table before the start of exposure.

In this example, in which the surface to be copied is placed facing upward, the transfer paper discharged after the transfer to the second surface is transferred from the guide 49, the reversing guide 50, and the pair of transport rollers 51, 52, 53. After reversing the paper using the reversing conveyance device 54,
, the order of the resulting double-sided copies will be exactly the same as the order of the originals.

As explained above, according to the double-sided copying machine of the present invention, there is no need to rearrange the order of the originals, and it is possible to make double-sided copies of page originals by simply replacing the first and second stack tables. Since the order of the originals does not change between the front and back, processing of the originals becomes extremely simple. Further, since the originals are moved together with the stack table, the order of the originals will not be messed up, and double-sided copies in the correct order can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view showing an embodiment of the present invention, FIG. 2 is a perspective view illustrating the movement of a document and the corresponding movement of transfer paper in the apparatus of the present invention, and FIGS. 3 and 4. 2A and 2B are front sectional views showing different embodiments of the present invention. S ₁ , S ₂ ... Sheet original, S ₁ A, S ₂ A ... Single-sided exposed original, S ₁ B, S ₂ B ... Double-sided exposed original,
16,44...first stack stand, 17,45...
...Paper feed roller, 18...Transport belt, 19,47...
...Second stack stand, 22...Paper feed cassette, 2
4...Conveyance path switching device, 25...Intermediate cassette,
26, 48... Paper discharge tray, 27... Fixing device.

Claims (1)

[Scope of Claims] 1. A first stacking table arranged at a paper feeding position and stacking sheet originals to be sent to an exposure position with the side to be copied facing downward; a sheet original on the first stacking table; A document feeding device that sends out the original sheets one by one from the top to the exposure position, a document conveying device that inverts the sheet document after exposure and conveys it to the paper ejection position with the exposed side facing upward, and a document ejecting device. a second stacking table disposed at a paper position and stacking the exposed originals transported by the original transporting means with the most recently exposed side facing upward; A sheet document processing device having a structure in which a second stack table can be exchanged, a paper feed cassette that stores transfer paper to be fed toward a transfer section, and a fixing device that fixes an image transferred to the transfer paper. , the transfer paper with the image fixed on the first side and reversed,
An intermediate cassette is placed with the image surface facing upward, and the transfer paper placed on this is fed one by one from the upper one to the transfer section in order to transfer the image to the second side. means, a paper discharge tray for loading the transfer paper after the image has been transferred and fixed to the second side, and a paper discharge tray for transporting the transfer paper after the image fixation towards the intermediate cassette means or towards the paper discharge tray. A double-sided copying machine characterized by comprising a conveyance path switching device that selects whether to send or not. 2. A first stack table which is placed at the paper feed position and stacks the sheet originals to be sent to the exposure position with the side to be copied facing upward; A document sending unit that sends out one sheet at a time; a sheet document sent out by the document sending device is reversed and transported to an exposure position with the side to be copied facing down, and the exposed sheet document is transported to a discharge position It consists of a document conveyance means, and a second stack table, which is disposed at the document discharge position, and on which the exposed documents conveyed by the document conveyance means are stacked with the most recently exposed side facing down. a sheet document processing device in which the first and second stack tables are interchangeable; a paper feed cassette containing transfer paper to be fed to a transfer section; and an image transferred to the transfer paper. A fixing device that fixes the
An intermediate cassette is placed with the image surface facing upward, and the transfer paper placed on this is fed one by one from the upper one to the transfer section in order to transfer the image to the second side. means, a paper discharge tray for loading the transfer paper after the image has been transferred and fixed to the second side, and a paper discharge tray for transporting the transfer paper after the image fixation towards the intermediate cassette means or towards the paper discharge tray. A conveyance path switching device is provided between the conveyance path switching device and the above-mentioned paper ejection tray, and the device reverses the ejected transfer paper so that the image surface formed immediately before is removed. A double-sided copying machine characterized by comprising a reversing conveyance device that conveys the paper downward to the discharge tray.