JP2531630B2 - Electrophotographic copier - Google Patents

Description

The present invention relates to an electrophotographic copying machine having a double-sided copying function.

(Prior Art) Conventionally, an electrophotographic copying machine of this type has an automatic document feeder that automatically feeds a document onto the upper surface of a contact glass (document plate), and a double-sided document is copied on both sides of a copy sheet. It is provided with an intermediate tray for copying one side onto a plurality of copy sheets and temporarily storing the copy sheets. In such an electrophotographic copying machine, for example, when the allowable storage number of the intermediate tray is 50 sheets and eight (double-sided) originals are duplicated for eight copies, the automatic original feeding device drives the contact glass first to first The first original is sent out, the back side of the original is copied, and the copy sheets are sequentially accommodated in the intermediate tray. After that, the second and subsequent originals are copied by the same process, and the copy papers are sequentially stored in the intermediate tray. By this processing, the 8th copy of the back side of the 6th original is completed, and 48 copy sheets are stored in the intermediate tray.
After that, two copy sheets in which the back side of the 7th document is copied are stored. Here, 50 sheets of copy paper are stored in the intermediate tray, and since the number of stored sheets has reached the allowable number, 7 sheets of originals are set upside down in the automatic document feeder in order to copy the front side of the originals. After that, the front surface of the original is copied onto the front surface of the copy paper by the same processing as when the back surface is copied.

However, as described above, after the copying of the back side of the 7th original is completed for 2 sheets, the copying is started for the front side, so that the number of uncopied sheets of the 7th original remains six. Therefore, the user must set the seventh original document and the eighth original document, which has not been copied yet, in the automatic document feeder in order to perform the remaining six copies. Therefore, there is a high possibility that the user forgets to set the seventh original, which has not finished copying the desired number of sheets, in the automatic original feeder again and makes an erroneous copy. Also, it is very troublesome because the user side must check during the copying process whether each original has been copied by the desired number of copies.

(Object of the Invention) The present invention solves the above-mentioned technical problems, and when a user uses the automatic document feeder and performs double-sided copying of an original, there are few erroneous copies, and double-sided copying is possible with a simple operation. It is an object of the present invention to provide an electrophotographic copying machine capable of performing.

(Structure of the Invention) According to the present invention, a document feeding unit that sequentially feeds a plurality of documents to a document table, a copying unit that performs a one-sided copying operation on the sequentially-fed documents for each input number of copies, and one side of the document. In an electrophotographic copying machine for copying both sides of the document, the maximum number of copyable documents is determined on the basis of the input number of copies and the allowable number of sheets to be stored in the storing means. Calculation means for calculating,
An original feeding control means is provided to control so that the next original is not fed from the original feeding means when the copying of the maximum number of copyable originals calculated by the calculating means is completed.

With this configuration, the copy sheets in which one side of the original has been copied by the number of input copies are sequentially accommodated in the accommodating means, and when the maximum number of copyable originals has been copied, the next original is not delivered from the original feeding means. Therefore, it can be easily detected that at least the original sent out from the original feeding means is copied by the number of input copies, and the original remaining in the original feeding means is not copied.

(Embodiment) FIG. 1 is an overall configuration diagram of an electrophotographic copying machine according to an embodiment of the present invention.

In FIG. 1, a contact glass 2 which is a document table on which a document is placed is provided on an upper part of a housing 1 of an electrophotographic copying machine, and an automatic document feeder as a document feeding means is provided on the contact glass 2. 3 is provided. The automatic document feeder 3 includes a document feed cassette 3a.
A paper feed roller 3b for feeding the original set in the original feed cassette 3a, conveying rollers 3c, 3d for conveying the original to the upper surface of the contact glass 2, conveying rollers 3e, 3f and a guide plate 3g. 3h, a conveyor belt 3i for placing an original on the upper surface of the contact glass 2, an original container 3j for accommodating the copied original on the upper surface of the contact glass 2, and a conveyor belt 3i
The discharge rollers 3k, 3l and 3m, 3n for discharging the document conveyed by the guide plate 3p to the document storing section 3j.
And Further, in the housing 1, an original irradiation lamp 4, a reflection plate 5, mirrors 6a, 6b, 6c, 6d, and a lens assembly 7 are provided, and these constitute an optical system.
Around the photosensitive drum 8 which receives the light from this optical system, the main charging device 9, the developing device 10,
A transfer device 11, a separation device 12 and the like are provided.

In order to convey a copy sheet to the transfer device 11 on the downstream side of the developing device 10 in the rotation direction of the photosensitive drum 8 and on the upstream side of the transfer device 11, relatively near the periphery of the photosensitive drum 8. Transport rollers 13a, 13b are provided. Transport rollers 15a, 15b are provided on the upstream side of the transport rollers 13a, 13b via a guide plate 14. Furthermore, this transport roller 1
On the upstream side of 5a, 15b, there is set a copy paper cassette 18 to which copy paper is fed by a paper feed roller 17 via a guide plate 16.

A conveying belt 19 is provided on the downstream side of the separating device 12 in the copy conveying direction, and further, a fixing device 20 having a heat roller 20a is provided.
Is provided via a guide plate 19 '. This fixing device 20
Branch rollers 23a, 23b, 23c for selecting the direction of the tray 21 and the direction of the temporary tray 22 for temporarily storing one copy sheet and conveying the copy sheet are provided downstream of the guide plate 20 '. There is. A branch plate 24 is provided between the branch rollers 23a, 23b, 23c and the paper discharge rollers 24a, 24b. The pinch roller 25 is driven by the solenoid SOL1 and driven by the paper discharge roller 24a,
The copy sheet is sent to the temporary tray 22 or the copy sheet is discharged from the temporary tray 22. The solenoid SOL2 provided on the branch plate 24 sets the branch plate 25 toward the tray 21 or the temporary tray 22.

Conveying rollers 26a and 26b are arranged downstream of the branching rollers 23b and 23c via a guide plate 27, and the conveying rollers 26a and 26b are further arranged.
Transport rollers 29a and 29b are provided downstream of a and 26b via a guide plate 28.
Is provided. Further, conveyance rollers 31a, 31b are provided downstream of the conveyance rollers 29a, 29b via a guide plate 30. The guide plates 28 and 30 are provided with solenoids SOL3 and SOL4, which are appropriately controlled according to the size of the copy paper.

The intermediate tray 32 as the accommodating means includes the transport rollers 31a, 31
It is arranged below b and accommodates a copy sheet on which one side of the original is copied. The intermediate tray 32 is provided with a width regulating plate 32a for regulating the width of the copy paper and a leading edge regulating plate 32b for regulating the leading end of the copy paper, and between the intermediate tray 32 and the conveying rollers 31a, 31b. A guide plate 33 is provided.
The conveyor belt 34 is arranged at one end of the intermediate tray 32, and is for delivering the copy paper temporarily stored in the intermediate tray 32 toward the guide plate 35. Conveying rollers 36a and 36b are arranged on the downstream side of the guide plate 35, and the conveying rollers 36a and 36b convey the copy paper through the guide plate 16 in the conveying roller 15a and 15b directions.

Next, a description will be given of a conveyance path of a copy sheet during double-sided copy processing of a document in the electrophotographic copying machine having such a configuration.

When a document is placed on the upper surface of the contact glass 2 by driving the automatic document feeder and a predetermined copying process for copying the back side of the document is performed, one copy sheet fed from the paper feed cassette 18 is guided. Plate 16, transport rollers 15a, 15b,
It is sent to the transfer device 11 and the separation device 12 via the guide plate 14, the conveyance rollers 13a and 13b, and the guide plate 13 ', and transferred and separated. Transferred and separated copy paper is conveyed belt 19, guide plate
19 ', fixing device 20, guide plate 20', branch rollers 23a, 23b,
Branch plate (at this time, set in the direction indicated by the broken line)
24, the sheet enters the temporary tray 22 via a space between the paper discharge roller 24a and the pinch roller 25. After that, the paper discharge roller 24a rotates in the reverse direction, the copy paper is discharged from the temporary tray 22, and the branch plate 24, the branch rollers 23b and 23c, the guide plate 27, the transport rollers 26a and 26b, and the guide plate.
28, conveying rollers 29a, 29b, guide plate 30, conveying rollers 31a, 31
It is accommodated in the intermediate tray 32 via b and the guide plate 33.

With such a path, a plurality of copy sheets can be transferred to the intermediate tray 32.
When the number of copy sheets reaches a predetermined number, the front side of the original is copied next, so that the copied original on the back side is turned upside down and set in the original feeding cassette 3a of the automatic document feeder 3. To do. The document set in this manner is driven by the automatic document feeder 3 to contact glass 2
When the original is placed on the upper surface and the surface copying process is started, the original stored in the intermediate tray 32 is conveyed through a path described below.

That is, the copy paper stored in the intermediate tray 32 is transported in the direction of the guide plate 35 by the drive of the transport belt 34, and the transport rollers 36a and 36b, the guide plate 16, the transport rollers 15a and 15b, the guide plate 14,
The transfer device 11 passes through the conveying rollers 13a and 13b and the guide plate 13 '.
It enters the separating device 12, and is transferred and separated. After that, the copy paper is conveyed by the conveyor belt 19, the guide plate 19 ', the fixing device 20, the guide plate 2
0 ', the branch rollers 23a, 23b, the branch plate (in this case, the direction shown by the solid line) 24, and the sheet discharge rollers 24a, 24b are discharged to the tray 21.

The copy paper, which has been copied on both sides of the original through such a path, is discharged to the tray 21.

FIG. 2 is a block diagram of a control device for explaining the characteristic operation of the electrophotographic copying machine according to the embodiment of the present invention. In FIG. 2, the processing circuit 40 is a calculating means for calculating the maximum number of copyable originals based on the number of copies input from the operation unit 41 and the allowable number of sheets accommodated in the intermediate tray 32, and the calculated maximum copyable originals. When the copying is completed, it has a function as a document sending control means for controlling so as not to send the next document to the automatic document feeder 3. The sensor 42 detects a copy sheet that enters the intermediate tray 32, and the detection switch SW1 detects a document set in the document feeding cassette 3a of the automatic document feeder 3. Solenoid SOL1 drives pinch roller 25 and solenoid SOL2
Is for driving the branch plate 24. When the copy sheet is stored in the intermediate tray 32 after one-sided copying, the processing circuit 40 turns on the solenoid SOL2 to set the branch plate 24 to the state shown by the phantom line, and the pinch roller 25 (at this time, the solenoid SOL1 is turned off). ) And the discharge roller 24a, and when the trailing ends of the copy sheets are separated from the branch rollers 23a and 23b, the solenoid SOL1 is turned on to bring the pinch roller 25 into contact with the discharge roller 24a. (Following) The traveling direction of the copy paper is reversed so that the copy paper is introduced between the branch roller 23b and the branch roller 23c. After that, the processing circuit 40 appropriately controls the solenoids SOL3 and SOL4 according to the copy paper size to introduce the copy paper to the intermediate tray 32.

Further, the processing circuit 40 operates the output circuit 44 to drive the DC motor for driving the optical system, the photosensitive drum 8, and other motors for driving the rollers and the like.

FIG. 3 is a flow chart for explaining the characteristic operation of the control device. Referring to FIG. 3, the permissible number of sheets accommodated in the intermediate tray 32 is set to 50, and 8 sheets of 8 originals are copied on both sides. An example will be described in the case of performing.

In step S ₁ , the user sets eight originals in the original feed cassette 3a of the automatic original feeder 3, and then the operation unit 41
Then, the copy number input key is input to the processing circuit 40, and then the copy key of the operation unit 41 is turned on.
As a result, the automatic document feeder 3 is driven and the document is placed on the upper surface of the contact glass 2. In step S _2, copied at a time 8 parts of a document, to the copy paper calculates how can be accommodated in the intermediate tray 32 to the number of sheets up, performs a calculation of 50 (allowable accommodation number) ÷ 8 (number of copies) A value obtained by rounding down the decimal point, that is, the processing circuit 40 stores in the memory 43 the maximum number A (= 6) of copyable documents for one double-sided copy. The number of accommodated copies is calculated from the maximum copyable number A of originals and the number of copies. In this case, the number of accommodated copies is
It will be 48 sheets.

Then, start the back surface of the copying operation of the document, also, the maximum copiable document page number A which is stored in the memory 43 is decremented (Step S _3), the back surface of the copying operation of the document at step S ₄ is performed . In step S _5, for determining whether the copied the next document exceeds the allowable capacity allowed in the intermediate tray 32, the maximum copying possible number of documents A determines whether it is "0". In the case of this example, the number of copyable documents A (= 6) is exceeded for the seventh document, so the process proceeds to step S ₆ . Further, in the case of this example, the processing circuit is also used to detect whether or not all 8 copies of the 6th original among the 8 originals have been copied and 48 copy sheets have been accommodated in the intermediate tray 32. 40
Step S ₆ when the maximum copiable document page number A is determined whether or not "0", a copy enable the number of documents A is "0"
Moved to, and then proceeds to step S ₇ not "0".

In step S _6, the processing circuit 40 judges whether or not there remains a document on document feed cassette 3a of the automatic document feeder 3, when the remaining (in this example remain two original) Step S automatic document feeder 3 moves to ₈ is discharged to the document housing portion 3j remaining document feed cassette 3a, when none remain because all of the document has been copied proceeds to step S _9. The end of back side copying in step S ₉ is the end of copying when all the desired number of originals have been copied, and the original 6
In some cases, the back side copying up to the first sheet has been completed for eight copies. In this example, in step ₉ , the back side copying up to the 6th original is completed, and the original is not sent from the automatic original feeder 3 thereafter. At this time, the intermediate tray 32
It will hold 48 copy sheets.

In step S _5, shifts the maximum copiable number of documents A is the step S ₇ not "0", it is determined whether there remains a document in the automatic document feeder 3, a back surface of the document when the remaining I have to make a copy, so step
Returning to S _3, whereas, the original desired number proceeds to step S ₉ when no remaining document (e.g. six original) backside copying 8
Part ends.

Next, in order to replicate 8 parts of the above document six surfaces, again set in the automatic document feeder 3 in the front and back opposite user that 6 sheets of originals proceeds to step S _10, a copy key of the operation unit 41 Turn on. After that, the process proceeds to step S _11, the six original subjected to substantially the same procedure as in Step S ₃ to S ₉ 8 parts of duplex copying, a series of double-sided copying process is completed.

Further, the two-sided copy of the remaining two originals is set on the automatic document feeder 3, and the two originals are set to 8 by the processing of FIG.
Copied on both sides.

According to the above embodiment, the allowable number of sheets to be stored in the intermediate tray 32 is
Since it is 50, when 8 copies of 8 originals are copied on both sides, when 8 copies of the backside of the 6th original are finished, the intermediate tray 32 is set.
It stores 48 sheets of copy paper, and then makes 8 copies of the original 6 sheets of the original and ejects 48 sheets of copy paper. Then, after that, the remaining two originals are subjected to double-sided copying by the same process as eight copies, and the 16 copy sheets are ejected.

Therefore, since the originals that have entered the copying process are always copied by the number of copies (the number of copies) set by the user, the uncopied originals remain in the original feeding cassette 3a of the automatic document feeder 3 and are thus copied. The original and the original not copied can be easily distinguished, and the double-sided copying process can be performed without erroneous copying.

Although the original is copied from the back side in the above embodiment, it may be copied from the front side.

(Effect of the Invention) As described above, according to the present invention, a calculating unit that calculates the maximum number of copyable originals based on the input number of copies and the allowable number of sheets to be stored in the storing unit, and the maximum copy calculated by this calculating unit When the copy of the number of possible originals is completed, the original sending stop means for controlling so that the next original is not sent out from the original feeding means is provided, so that at least the originals sent from the original feeding means are equal to the input number of copies. Since it is possible to easily detect that the original document that has been copied and remains on the original document feeding unit is not copied, it is less likely that the user will make an erroneous copy when performing double-sided copying of the original document using the original document feeder. Double-sided copying is possible with a simple operation.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an electrophotographic copying machine according to an embodiment of the present invention, FIG. 2 is a block diagram of a control device for explaining the features of the electrophotographic copying machine, and FIG. 3 is the control device. 5 is a flowchart for explaining the operation of FIG. 2 ... Contact glass (document table), 3 ... Automatic document feeder (document feeder), 32 ... Intermediate tray (accommodating means), 40 ... Processing circuit (including calculation means and document delivery control means).

Claims (1)

(57) [Claims] 1. A document feeding unit for sequentially feeding a plurality of documents to a document table, a copying unit for performing a one-sided copying operation on the sequentially-fed documents for each input copy number, and a copy in which one side of the document is copied. In an electrophotographic copying machine for copying both sides of the original document, including a storing means for storing a predetermined number of sheets, a calculating means for calculating the maximum number of copyable originals based on the input number of copies and the allowable storing number of the storing means. When,
An electrophotographic copying machine characterized by further comprising an original feeding control means for controlling not to feed the next original from the original feeding means when the copying of the maximum number of copyable originals calculated by the calculating means is completed.