JPH0481866A - Automatic both-side copying device - Google Patents

Abstract

PURPOSE:To minimize the generation of the waiting time between 1st side copying and 2nd side copying and to improve productivity at the time of both-side copying by generating a detection output without waiting for the completion of stacking by as much as the number of copying set parts in an inversion transfer section. CONSTITUTION:The detection output by a means 63 for detecting a paper feed state is generated at the point of the time when the sending of the copying paper from a paper feed section 110 of a main body by as much as the number of copying set parts is detected. The detection output by a means for detecting a refeedable state is generated at the point of the time when the refeeding of at least one sheet of the copying paper stuck in the inversion transfer section 80 is possible. A timing control section 111 applies an instruction for starting the refeeding to the inversion transfer section 80 upon receipt of this detection output. The detection output is generated without waiting for the completion of stacking for the number of the copying set parts in the inversion transfer section 80 and, therefore, the generation of the waiting time between 1st side copying and 2nd side copying is minimized. Then, the waiting time from the end of 1st side copying to the start of 2nd side copying is shortened and the productivity at the time of both-side copying is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to improving the productivity of an automatic duplex copying apparatus that reads both sides of a document and copies both sides of copy paper.

(Background of the Invention) There is an automatic reversing document feeder (hereinafter referred to as RADF) as a device for copying both sides of a double-sided document by automatically inverting the document as soon as it is set. Using such a device, large quantities of copies can be easily made. Furthermore, since the copies are in the same order as the original, there is no need to rearrange them after copying.

Furthermore, by linking it with a sorter, collation and page sorting can be performed automatically, making it possible to accurately arrange a large number of copies.

In addition, the ADU is a device that can automatically copy both sides of copy paper (hereinafter referred to as copy paper) with the touch of a button.
There is. By using this function, information from two pages of a document can be combined on one sheet, making it possible to save on copy paper costs and at the same time making filing easier. It can also be used in a variety of ways, such as organizing materials into a booklet format for easy viewing.

By the way, when double-sided copying is performed using a conventional automatic double-sided copying device, it is important to note that the final number of copy sheets (copy sheets on which only one side has been copied) of the set number of copies for first side copying has completed stacking in the ADU. After this was detected, paper refeeding from the ADU was started.

(Problem to be solved by the invention) Such an operation will be explained with reference to FIG.

When the copy button of the copier is pressed (Fig. 6(a)),
Copy paper for copying the first side is fed (FIG. 6(b)). In this operation explanation, it is assumed that a certain number of bones are to be copied (hereinafter, this set number of copies will be referred to as the set number of copies). Here, when the first sheet of copy paper reaches the photoreceptor, copying of the first side is started and is performed for the set number of copies (FIG. 6(C)).

The copy paper on which the first side has been copied in this way is
are stacked in U (FIG. 6(d)).

When stacking in the ADU is completed, paper alignment is performed in the ADU (FIG. 6(e)). After completing this paper alignment, A
Paper is re-fed from the DU (FIG. 6(f)), and the second side is copied (FIG. 6(g)).

According to the above time chart, there is a period during which the photoreceptor is on standby (not operating) from the completion of copying on the first side to the start of copying on the second side. Because of this waiting period for the photoreceptor, it has been difficult to improve productivity during double-sided copying.

Note that the ratio of standby time to copy time varies depending on the set number of copies, but in any case, it hinders the improvement of productivity.

The present invention has been made to solve the above problems, and its purpose is to improve productivity during double-sided copying by shortening the time from the end of copying the first side to the start of copying the second side. The object of the present invention is to realize an automatic double-sided copying apparatus that can perform the following functions.

(Means for Solving the Problems) The present invention, which solves the above-mentioned problems, reverses the copy paper on which the first side has been copied by a reversing transfer unit, and transfers the second side of the copy paper sent out from the reversing transfer unit to In an automatic duplex copying device that performs copying, the main body paper feed unit and the registration roller are connected to each other on the paper path in order to detect that copy paper for copying the first side has been fed from the main body paper feed unit for the set number of copies. The apparatus is characterized by comprising: a paper feeding state detecting means disposed between the paper feeding state detecting means and a timing control section receiving the detection output of the paper feeding state detecting means and giving an instruction to the reversing transfer section to start paper feeding again. .

(Function) In the automatic double-sided copying apparatus of the present invention, the paper feeding state detection means generates a detection output when it is detected that the copy paper from the main body paper feeding section has been fed by the set number of copies. In response to this detection output, the timing control section gives an instruction to the reversal transfer section to start paper refeeding.

Here, since the detection output is generated without waiting for the stacking of the set number of copies to be completed in the reverse transfer unit, the first side copy and the second
The waiting time between copying and copying can be minimized.

(Example) Examples of the present invention will be described in detail below with reference to the drawings.

First, the general operation of the electrophotographic copying apparatus to which the present invention is applied will be explained with reference to FIG.

In Figure 2, the automatic double-sided document feeder (hereinafter referred to as RAD)
A document 1 placed on a 10 (referred to as F) is moved onto a platen glass 2 by RADFlo at the start of copying. The original 1 placed on the platen glass 2 is exposed by the scanning exposure optical system 20, and a latent image corresponding to the original 1 is formed on the surface of the photoreceptor 30. This latent image is formed into a toner image on the surface of the photoreceptor 30 by the photoreceptor image forming section 3 . The toner image is transferred to copy paper 41 supplied from a paper feed section 40, which will be described later, and the transferred toner image is heated and fixed by a fixing device 50. The copy paper on which the first side has been copied in this manner is transferred to the reverse transfer section by the paper ejection switching section 70.
(hereinafter referred to as ADU) 80. And this A
The second side of the copy sheet is reversed in the DU 80 and transferred to the photoreceptor 30 again (formation of a toner image).

After this toner image is fixed, the paper is discharged to the outside of the machine by the paper discharge switching section 70.

Next, FIG. 1 shows the electrical configuration of the device of this embodiment.

Figure 2 above and Figure 3 showing the flow of operation of the device of this embodiment.
The operating state of this embodiment will be explained step by step along the copy paper feeding process with reference to FIGS.

First, settings such as the number of copies, copy paper size, variable magnification and final ejection position are made from an operation setting section (not shown) (step 2).

When an original is set in RADF1,0 and the copy button is pressed, copying starts.

As described above, the copy paper 41 is supplied to the photoreceptor 30 from the copy paper feed section 40 (step (2)).

The copy paper feed section 40 is provided with three paper feed cassettes 42a to 42c that accommodate, for example, three types of copy paper 41a to 41c of different sizes.

Copy sheets 41a to 41c are stored in paper feed cassettes 42a to 42c.
From the feed rollers 43a to 43c and the feed healds 44a to 4
4c. Delivery rollers 43a to 43
Delivery belts 44a to 44c are stretched on c.
These delivery belts 44a to 44c serve as copy sheets 41a to 41c.
By rotating the delivery rollers 43a to 43c clockwise (FIG. 2) while in contact with the uppermost layer of copy paper 41,
A to 41C are sent out one by one to the left in FIG.

Copy paper 41a sent out by sending belts 44a to 44c
-41c are paper feed rollers 61 and registration rollers 62
and is transported to position P2 (FIG. 2). From position P2, the toner image is sent out by registration rollers 62 in synchronization with the rotation of photoreceptor 30, and the toner image is transferred from the surface of photoreceptor 30 (first side copying; step (2)).

In the case of one-sided copying, the image is then heated and fixed in the fixing device 50,
Copying is completed when the paper is ejected from the paper ejection switching section 70 to the outside of the machine.

In the case of double-sided copying, the copy sheets stacked in the ADU 80 are re-fed (step 2) as described below.

Downstream of the fixing device 50, there is an ejector that has a function of switching between a paper ejection path 76 that allows the fusing copy paper 4 to advance straight and eject it outside the machine, and an introduction path 77 that transports it to the guide plate 71 for double-sided copying. A paper switching section 70 is also provided. Paper ejection switching section 7
0 is the guide plate 71° and the upstream roller 72. Downstream roller 73
．． It is comprised of a movable branch body 75° having an inverted triangular cross section that swings about a shaft 74, an electromagnetic solenoid (not shown), and the like. A movable branch body 75 having an inverted triangular cross section has a paper discharge path 76 along the upper surface of the movable branch body 75, an introduction path 77 communicating with the guide plate 7 along the lower right side surface, and a guide plate 7 along the lower left side surface. ] and a reverse sheet discharge path 78 communicating with the downstream roller 73 are formed.

The movable branch body 75 is driven by a drive device (not shown) such as an electromagnetic solenoid, so that the right tip moves up and down, and the introduction path 7
7 and close the paper ejection path 76, or conversely, open the paper introduction path 77.
It can be switched by closing the paper discharging path 76 and opening the paper ejection path 76.

The copy paper 41 sent downward (FIG. 2) through the paper ejection switching section 70 is sent into the ADU 80 (stored in the ADU; step 2).

The copy paper 41 conveyed to the reversing conveyance section 80 is transferred to the stacker 8
It is reversed and released towards 3. At this time, the trailing edge of the ejected copy paper is detected by a stack sensor 84 composed of a photosensor or the like.

The ejected copy paper 41 slides on the surface of the stacker 83 and comes into contact with the abutting surface and stops. Subsequent copy sheets 41 that are subsequently sent in are also stacked one after another on the stacker 83.
By coming into contact with the abutment surface, the leading edge of the copy paper 41 is aligned.

In this state, when the ADU control unit 114 generates a paper refeeding start signal, the ADU drive unit 123 drives and rotates the roller 85, and the double-feed prevention roller 86 rotates counterclockwise. As a result, the plurality of copy sheets 41 stacked in the stacker 83 are sent out one by one from the bottom layer.

The copy paper 41 is then conveyed by the pressure rotation between the paper feed roller 87 and the paper feed roller 87', and the passage of the leading edge of the copy paper 41 is detected by an ADU passage sensor 88 composed of a photosensor. The copy paper 41 is subsequently conveyed and fed into the registration rollers 62 (step 2).

Thereafter, the second side (back side) of the copy paper 41 is copied on the photoreceptor 30 (step ■), and the fixing unit 5
After being fixed at 0, the sheet passes through the reverse sheet discharge processing section 76 of the sheet discharge switching section 70 and is discharged to the outside of the machine.

In this way, copying of the back side of the first copy paper 41 by paper refeeding is completed, and then a paper refeeding start signal is input.
The next copy sheet 41 waiting on the stacker 83
paper refeeding will start. After that, the above-mentioned paper refeeding operation,
The back side copying operation is performed continuously for the set number of copies N copies.

In addition, when the stack sensor 84 detects the passage of N sheets, the ADU
If the passage sensor 88 has not counted N sheets, a jam may have occurred, and therefore, jam processing (step 2) is performed.

If there is a document in the ADF 80, the above-described operations are repeated (steps ① to ①).

Here, the features of this embodiment will be explained with reference to FIG. 3.

The stack sensor 84 detects that the first document is stacked (first ready condition; FIG. 3(f)), and the paper feed unit 4
Paper passing sensors 63a to 63d (hereinafter referred to as
When the sheet passing sensor 63 (simply referred to as the sheet passing sensor 63) detects the passing of paper every minute (second ready condition: FIG. 3(C)), the timing control unit 111 instructs the ADU 80 to refeed the paper. (Figure 3 (g)).

With this configuration, the timing of refeeding paper from the ADU 80 is earlier than before, so there is no waiting time between copying the first side and copying the second side, as shown in FIG. 3(i). .

In this case, it is also possible to control the timing based only on the detection output from the paper passing sensor 63.

Furthermore, in the case of FIG. 3, the number of copies set is large to some extent, and stack detection precedes the completion of first side paper feeding. Furthermore, when the set number of copies is small, as shown in FIG. 4, the completion of paper feeding on the first side precedes stack detection. In any case, since the copying of the second side is instructed to start at the timing when the same condition becomes ready, it becomes possible to minimize unnecessary waiting time. As a result, productivity during double-sided copying can be improved.

Note that the optimum condition in this case is that, under the above-mentioned timing instructions, A
Copy paper re-fed from DU80 is placed on registration roller 6.
By reaching 2, unnecessary waiting time is minimized.

Therefore, the time difference between these times should be set in the delay unit 120, taking into consideration the transport time required for paper passing from the paper passing sensor 63 to the registration rollers 62 and the transport time required for refeeding the paper from the ADU 80 to the registration rollers 62. This makes it possible to easily obtain optimal conditions.

Furthermore, it is also possible to use only the second ready condition described above as a criterion. In such a case, the paper cassette 42
By electrically adjusting the difference in paper passing time due to the difference in the positions of a to 42c using the delay means, it becomes possible to always obtain optimal conditions.

(Effects of the Invention) As described in detail above, in the present invention, the copy paper on which the first side has been copied is reversed by the reversing transfer unit, and the second side is copied onto the copy paper sent out from the reversing transfer unit. In an automatic duplex copying device that performs the a paper feeding state detecting means disposed; a paper refeeding possible state detecting means for detecting that it is possible to refeed at least one sheet of copy paper stacked in the reversing transfer section; and a paper feeding state detecting means. and a timing control section that receives the detection output from the paper refeeding state detecting means and gives an instruction to the reversal transfer section to start paper refeeding.

As a result, when it is detected that the set number of copies of copy paper has been fed from the paper feed section of the main body, a detection output is generated by the paper feed state detection means, and at least one of the copy sheets stacked in the reverse transfer section is fed. A detection output is generated by the paper refeeding state detecting means at the time when the sheet can be refeeded. In response to this detection output, the timing control section gives an instruction to the reversal transfer section to start paper refeeding.

Here, the detection horn is generated without waiting for the stacking of the set number of copies to be completed in the reversal transfer unit, so the waiting time between copying the first side and copying the second side can be minimized. .

Therefore, it is possible to realize an automatic double-sided copying apparatus that can shorten the time from the end of copying on the first side to the start of copying on the second side, and improve productivity during double-sided copying.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing the electrical configuration of an automatic double-sided copying apparatus according to an embodiment of the present invention, FIG. 2 is a configuration diagram illustrating the mechanical configuration of the apparatus of this embodiment, and FIG. FIG. 4 is a time chart for explaining the operating state of the example device. FIG. 5 is a time chart for explaining other operating states of the example device. FIG. 5 is an automatic double-sided copying machine of the example shown in FIG. A flowchart showing the operation of the apparatus, FIG. 6 is a time chart 1 for explaining the productivity of a conventional automatic double-sided copying apparatus. 1. Manuscript 2. Platen crow 10.
・・RADF 20・Optical system 30・・Photoconductor 4[-)・・Paper feed section 41, a~41C・
...Copy paper 42a to 42c, paper feed cassettes 438 to 43C, delivery rollers 44a to 44c, delivery belt 50, fixing section 61, paper feed roller 62, lens roller 63,
・Paper passing sensor 70...fJi paper switching section 80...A
DU 84 Stack sensor 88・ADD
Passing sensor ] 00... Control unit ] 10 - CPU 111... Timing control unit 1 ] 2... RADF control unit 113... Photoconductor control unit] 14... ADU control unit] 5... Registration roller Control unit 116... Paper feed roller control unit 120... Delay unit] 21... RADF drive unit 122... Photoreceptor drive unit 123... ADU drive unit] 24. Registration roller drive unit 125... Paper feed roller drive unit

Claims (1)

[Claims] The copy paper whose first side has been copied is transferred to the reversal transfer unit (80).
In an automatic double-sided copying device that copies the second side onto the copy paper sent out from the reversal transfer unit (80), the copy paper for copying the first side from the main paper feed unit (40) is copied. In order to detect that the set number of copies have been fed, the detection output of the paper feeding state detection means (63) and the paper feeding state detection means (63) arranged between the paper feeding section of the main body and the registration roller on the paper feeding path is detected. 1. An automatic double-sided copying apparatus comprising: a timing control section (111) for receiving and instructing a reversing transfer section (80) to start refeeding paper.