JPH06314006A - Copying device - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain multiple copies that are larger than the transfer paper size without complicating the equipment, it is possible to make multiple copies with accurate image edge correspondence using ordinary cutting paper. A copying machine capable of performing the above is provided. [Structure] When the first transfer sheet P ₁ is conveyed by a pair of conveyance rollers 13 and a pair of registration rollers 14 and the leading edge is detected by the detection element S ₂ , the pair of registration rollers 14 is stopped and the repelling roller 15 is added. After abutting against the pressure roller, the rear end of the transfer paper P ₁ is grasped and repelled upward, and then the pair of registration rollers 14 starts to rotate in synchronization with the movement of the toner image on the photosensitive drum and the transfer paper P ₁ The first transfer sheet P ₁ and the subsequent transfer sheet P ₁ are transferred by rotating the pair of transfer rollers 13 with the trailing edge of the transfer sheet P ₁ and the leading edge of the subsequent transfer sheet P ₂ having a binding margin width d. The paper P ₂ is stacked and conveyed toward the transfer position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copying apparatus which reads an image of an original and makes a copy on a fed sheet-fed transfer paper by an electrostatic photography process, and in particular, an improvement of a conveyance mode for forming a large image. Pertain to.

[0002]

2. Description of the Related Art In many copying machines, transfer paper is fed from a plurality of paper feed cassettes containing several kinds of cutting papers corresponding to the size of a document to be read. However, there are cases where it is desired to copy a document larger than the size of the cutting paper stored in the paper feed cassette without reducing the size. In such a case, usually, the reading position of the original is changed, copying is performed twice, the image end portions of the two copies are cut, and the image positions are aligned and bonded. However, it is difficult to cut the image ends of the respective copies at the positions corresponding to each other and paste them in the correct image positions by such a method of making copies by pasting. Therefore, a copying apparatus has been proposed in which a wrapping paper is used as the transfer paper and the wrapping paper is cut at the end position of the formed image corresponding to the length of the document.

[0003]

However, the above conventional device requires a cutting device, which complicates the device and uses a wrapping paper as the transfer paper.
There was a drawback that it was not convenient in terms of purchasing paper. The present invention is intended to solve such a problem in the prior art, and when obtaining a copy larger than the transfer paper size without complicating the apparatus, a normal cutting paper is used to accurately correspond to the image edge. An object of the present invention is to provide a copying machine capable of making a plurality of copies.

[0004]

SUMMARY OF THE INVENTION The present invention is intended to solve the above problems in the prior art, and when a transfer image is larger than the size of the sheet transfer paper, a plurality of sheet transfer papers are partially It has a multi-feed sheet feeding means for feeding the sheet to the transfer position in a state of being overlapped. Preferably, the multi-feeding and feeding means conveys sheet-by-sheet transfer sheets carried in one by one, a conveying roller, a pressure roller integrally attached to a drive shaft of the conveying roller, and a contacting roller. By doing so, the trailing edge of the transfer sheet that grips the trailing edge of the transported sheet of transfer paper and releases the gripping action in the vicinity of the upper part of the peripheral curved surface, and the transfer roller located downstream of the transport roller When the leading edge of the sheet transfer paper reaches the delivery roller position, the rotation of the delivery roller is stopped and the delivery roller that sends the paper to the transfer position and the sheet transfer sheet that is loaded are transported by the transport roller. The trailing edge of the sheet of transfer paper is held by the trailing edge of the transfer paper, and the trailing edge of the transfer sheet is held by contacting the pressure roller with the trailing edge of the transfer roller. After releasing the gripping action near the upper part of the curved surface, the delivery roller is rotated at the delivery timing of the preceding sheet transfer sheet to the transfer position, and the trailing edge of the preceding sheet transfer sheet and the subsequent sheet transfer sheet The control means restarts the rotation of the transport roller at the timing when the leading ends partially overlap with each other, and separates the trailing end flip-up roller of the transfer paper from the pressure roller.

[0005]

[Function] When the transferred image is larger than the size of the sheet transfer paper, the double feeding / feeding unit feeds the plurality of sheet transfer papers to the transfer position in a partially overlapped state to transfer the plurality of sheet transfer sheets. One image is divided and formed on paper. Further, in a preferable means, the control means conveys the sheet transfer paper to be carried in by a conveying roller, and when the front end of the sheet transfer paper reaches the delivery roller position, stops the rotation of the delivery roller and The trailing edge of the transfer sheet is held by the pressure roller and the trailing edge of the sheet of transfer paper that continues to be transported by the transport roller is gripped by the trailing roller of the transfer sheet.
After releasing the gripping action in the vicinity of the upper part of the circumferential curved surface of the transfer sheet rear end flip-up roller, rotate the delivery roller at the delivery timing of the preceding sheet transfer sheet to the transfer position, and The rotation of the transport roller is restarted at the timing when the edge partially overlaps with the leading edge of the subsequent sheet-shaped transfer sheet, and the trailing edge repelling roller of the transfer sheet is separated from the pressure roller.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic diagram showing a schematic configuration of an embodiment of the present invention. The copying apparatus according to this embodiment is configured as a manual-feeding type copying apparatus that manually feeds a document and a transfer sheet. First, when the transfer paper P of a predetermined size is inserted from the finger insertion port, the detection element S ₁ detects the front end of the transfer paper P and outputs a detection signal. Upon receiving the detection signal of the detection element S ₁ , the control device drives a main motor (not shown) to rotate the pair of transport rollers 13 and the pair of registration rollers 14 to transport the transfer paper P inserted from the finger insertion port to the downstream side. . When the leading edge of the transfer sheet P thus conveyed passes through the registration roller 14 pair and is detected by the detection element S ₂ , the registration roller 14 pair and the conveyance roller 13 pair stop rotating and stand by. Next, when the document M is inserted into the document insertion port of the document transport unit, the leading edge of the document M is inserted into the document transport roller 4, and the document M is reversely transported and sent to the exposure unit on the contact glass 3. The document M is discharged at a constant speed by the cooperative transport of the document transport roller 4 and the pair of document delivery rollers 5 located downstream thereof. After a lapse of a predetermined time from when the leading edge of the conveyed document M is detected by the sensing element S ₃ disposed on the upstream side of the exposure unit, the pair of registration rollers 14 starts to rotate and the leading edge is clamped by them. The transfer paper P is sent out toward the transfer position. A light source 2 for illuminating the back side of the document M being conveyed is provided on the back side of the contact glass 3.
The lower surface of the original M that has reached the exposure unit is illuminated by the light source 2. The reflected light of the document M is guided to the photosensitive drum 1 via the lens 6, and the document image is formed there. The photosensitive drum 1 is rotating in the direction of the arrow and is uniformly charged in advance by the charging charger 7, and the document M is placed there.
The area on the photosensitive drum 1 corresponding to the non-image portion of the document M is photo-electrified by the irradiation of the reflected light, and an electrostatic latent image corresponding to the document image is formed. This electrostatic latent image moves circularly as the photosensitive drum 1 rotates, and is eventually developed by the developing device 8 to become a toner image. In synchronism with the movement of the toner image on the photoconductor drum 1 to the transfer position, the transfer of the transfer paper P to the transfer position is performed. The transfer sheet P is electrostatically attracted to the photosensitive drum 1 before the transfer position and moves together with the photosensitive drum 1. The transfer charger 9 applies a discharge charge to the back surface of the transfer paper P, so that the toner image is transferred to the front surface of the transfer paper P. Next, the transfer paper P is separated from the photoconductor drum 1 by applying a discharge charge having a sign opposite to that of the charge supplied from the transfer charger 9 from the separation charger 10 to the back surface of the transfer paper P. The separated transfer paper P is conveyed to the fixing device 22, where it is heated and pressed, and the toner image is transferred to the transfer paper P.
Is fixed in. After that, the transfer paper P is discharged onto a paper discharge tray by a paper discharge roller (not shown). On the other hand, after the transfer paper P is separated, the photosensitive drum 1 is cleaned by the cleaning device 1.
The residual toner is scraped off by 1 and the residual charge is removed by the static elimination lamp 12.

In this embodiment, when the length of the formed image exceeds the length of the image that can be formed on the cut transfer paper, the divided copy is formed by continuously forming images on a plurality of transfer papers. The mode can be selected. FIG. 2 is a schematic diagram showing the state of transport of the transfer paper with the passage of time when the divided copy mode is selected. First, after pressing the division copy mode key of the operation unit, the original M and the first transfer paper P
After inserting ₁ into each finger insertion slot, press the print start key. As shown in (a), the leading edge of the original M caught in the original conveying roller 4 is the detecting element S ₃
Is detected, the pair of transport rollers 13 starts to rotate.
As described above, the transfer paper P ₁ is transported to the standby position by the transport roller 13 pair and the registration roller 14 pair. The leading end is pressed by the pair of registration rollers 14 and the latter half is conveyed by the pair of conveying rollers 13, so that the central portion of the first transfer sheet P ₁ is bent upward, and the first transfer sheet P ₁ gradually competes. Eventually, when the trailing edge of the transfer paper P ₁ reaches the nip portion of the pair of transport rollers 13, the repelling roller 15 comes into contact with a pressure roller (not shown) facing the roller. Here, the splashing roller contact mechanism will be described. FIG. 3 is a schematic diagram showing a splashing roller contact mechanism. The pair of transport rollers 13 is divided into two in the axial direction, the pressure roller is located between the two pairs of transport rollers 13, and the repelling roller 15 is located above the pressure roller. The support shaft of the flip-up roller 15 is rotatably supported at one end of each of the front and rear support arms 17, and the front and rear support arms 17 are rotatably supported by a support shaft 19 supported by the body frame. There is. The other end of the front and rear support arms 17 is locked at the other end of the coil spring 18 whose one end is supported by the main body frame, and applies a biasing force for rotating the support arm 17 in the clockwise direction in FIG. ing.
Further, an operating rod 20 of the solenoid 16 is connected to the central portion of the support arm 17, and when the solenoid 16 is energized, an urging force for rotating the support arm 17 in the counterclockwise direction is applied.
Since the solenoid 16 is not normally biased, the support arm 17 is rotated clockwise by the biasing force of the coil spring 18 and is locked by the locking portion, whereby the repelling roller 15 is applied. It is in a retracted position away from the pressure roller. By providing the repelling roller abutting mechanism, a thin transfer paper or a transfer paper which is easily deformed is squeezed between the repelling roller 15 and the pressure roller for a long time, and a fold is formed at the protrusion of the repelling roller 15. ,afterwards,
This prevents the transfer failure due to the fold portion not coming into close contact with the photoconductor drum 1 when it is sent to the transfer position.

As described above, the solenoid 16 is energized at the timing when the trailing edge of the first transfer sheet P ₁ reaches the pinching portion of the pair of transport rollers 13, thereby causing the support arm 1 to move.
7 rotates counterclockwise against the elastic force of the coil spring 18, and the repelling roller 15 contacts the pressure roller. The driving force of the pair of transport rollers 13 is transmitted to the lower transport roller 13, and the flip-up roller 15 is brought into contact with the pressure roller attached to the rotary shaft of the lower transport roller 13. Follow the pressure roller. On the circumferential surface of the flip-up roller 15, V-grooves 21 are formed at equal intervals along the circular curved surface and extending in the direction of the rotation axis and inclined in the counterclockwise circumferential direction in the figure. By contacting with the pressure roller and rotating together, as shown in FIG. 2B, the rear edge of the transfer paper P ₁ is fitted in the V groove 21 and lifted in the counterclockwise circumferential surface direction. When the rear edge of the transfer paper P ₁ is gripped by the V groove 21 and moved to the upper part of the flip-up roller 15, the transfer paper P ₁
The elasticity of the rear edge of the transfer sheet P ₁ causes the rear edge of the transfer sheet P _{1 to} rise above the flip-up roller 15 and then descend to rest on the flip-up roller 15 (FIG. 2). (See (c)). After a lapse of a predetermined time, the solenoid 16 is de-energized, the repelling roller 15 is separated from the pressure roller, and the rotation of the pair of transport rollers 13 is stopped. By the time the first transfer paper P ₁ is sent out to the transfer position, the second transfer paper P ₂ is conveyed by the transport roller 1.
When it is fed into the three pairs of pressure parts and the leading edge thereof is detected by the detection element S ₄ , the pair of conveyance rollers 13 stops rotating and makes the transfer sheet P ₂ stand by. As shown in (d), the first transfer paper P ₁ is sent out toward the transfer position by the pair of registration rollers 14 and the rear end thereof is conveyed by the transport roller 13.
Leaving the rear end and the second transfer sheet P ₂ the tip of the first transfer sheet P ₁ is, the transport roller 13 pair rotate at a timing overlap only binding margin width d of the transfer sheet P ₂ and the lower side from the Then, the pair of transport rollers 13 and the pair of registration rollers 14 integrally transport the transfer paper P ₁ and the transfer paper P ₂ in a partially overlapped state. The binding margin width d can be set by an operation input on an operation unit (not shown) on the upper portion of the copying apparatus. Based on the input binding margin width d setting information, the control device causes the transport roller 13 and the registration roller to be set. The rotation start timing of each of 14 is controlled. Further, when the front end of the second transfer paper P ₂ reaches the nip portion of the pair of registration rollers 14, the pair of transport rollers 13 is rotated at a high speed to fast-forward the latter half of the second transfer paper P _2. When the central portion of the transfer paper P ₂ is bent and the rear end reaches the nip portion of the pair of transport rollers 13, the solenoid 16 is urged to bring the repelling roller 15 into contact with the pressure roller. 2 by this
The rear end of the _second transfer sheet P ₂ is repelled above the upper transport roller 13 by the repelling roller 15 like the _first transfer sheet P ₁ . Further, when the trailing edge of the image to be formed exceeds the image forming range of the _second transfer paper P ₂ , 3
The second transfer paper P ₂ is the same as the _second transfer paper P ₂
The overlap width is conveyed in a state where the binding margin width d is maintained, and continuous conveyance is repeated in the same conveyance mode as the transfer paper P ₂ described above. When the trailing edge of the document M is detected by the detection element S ₃ , the feeding of the transfer sheet to be conveyed next is stopped and the copying operation in the split copy mode is completed.

By the way, in this embodiment, since the manual feeding method is adopted, the feeding timing of the second and subsequent transfer sheets may be delayed. In view of this, in this embodiment, when the transfer paper feed timing is delayed, the conveyance of the next transfer paper by the pair of registration rollers 14 is stopped to interrupt the copying operation, and the original M is discharged as it is. At that time, the length of the document M is measured by the detecting element S ₃ and
The copy completion position of the image is detected. Next, the original M is inserted into the manual insertion slot, the print start key is pressed to restart the copying operation, and the original M is moved by the original conveying roller 4.
After idling to the image copy completion position, the image reading operation of the document M and the image forming operation on the transfer paper are restarted. Further, when the transfer paper passes through the transfer / separation unit, discharge charges are imparted by the transfer charger 9 and the separation charger 10. The amount of charge at this time is the nature of the transfer paper, the paper thickness, the surrounding temperature and humidity, etc. The transfer efficiency and the separation efficiency also greatly change due to these factors. In the present embodiment, when the divided copy mode is selected, an overlapping portion occurs between the conveyed transfer sheet and the succeeding transfer sheet. Therefore, when the overlapping portion passes through the transfer / separation unit, the transfer charger 9 and The transfer efficiency and the separation efficiency are optimized by changing the current applied to the separation charger 10. Further, the fixing device 22 has a heater inside and is composed of a fixing roller whose surface is covered with a heat-resistant release material, and a pressure roller which is rotated with the fixing roller and whose surface is covered with heat-resistant rubber. However, when the thickness of the transfer paper passing therethrough changes, the heat capacity of the paper also changes, so that the fixability of the toner changes. In the case where the transfer papers are partially overlapped and fed as in this embodiment, the heat capacity of the overlapping portion is doubled. Therefore, if the toner is passed through the fixing device 22 as it is, the fixability of the toner deteriorates and the image bleeds on the copy. It happens. Therefore, in this embodiment, the fixing device 2 is used when the rear end of the conveyed transfer paper passes through the transfer / separation unit.
The transfer speed of the transfer paper by the fixing roller and the pressure roller of No. 2 is increased to make a gap between the preceding transfer paper and the subsequent transfer paper, and then the transfer speed of the transfer paper is returned to the steady speed. The fixing conveyance speed variable control is performed. The fixing conveyance speed variable control is performed by measuring the length of the transfer paper by the detection element S ₁ , passing the rear end of the transfer paper by the detection element S ₂ , and detecting arrival of the front end of the transfer paper by the detection element in the fixing device 22. ing.

[0010]

As described above, according to the first aspect of the present invention, when the transferred image is larger than the size of the sheet transfer paper, the double feeding / feeding means partially separates the plurality of sheet transfer paper. Since the paper is fed to the transfer position in the state of being overlapped with the paper, when cutting a copy larger than the size of the transfer paper without complicating the device, a normal cutting paper is used to make sure that the image edges correspond correctly. You can make a copy of. According to the second aspect of the invention, the sheet transfer paper to be carried is conveyed by the conveying roller, and when the front end of the sheet transfer paper reaches the delivery roller position, the rotation of the delivery roller is stopped and the transfer sheet is transferred. The trailing edge of the transfer sheet is held by the pressure roller and the trailing edge of the sheet of transfer paper that continues to be transported by the transport roller is gripped by the trailing roller of the transfer sheet.
After releasing the gripping action in the vicinity of the upper part of the circumferential curved surface of the transfer sheet rear end flip-up roller, rotate the delivery roller at the delivery timing of the preceding sheet transfer sheet to the transfer position, and Since the rotation of the transport roller is restarted at the timing when the edge and the leading edge of the succeeding sheet of transfer paper partially overlap, the rear end of the transfer paper and the rebound roller are separated from the pressure roller. With such a configuration, it is possible to obtain a plurality of copies on which divided images are formed in which the edges of the images correspond exactly. According to the invention of claim 3,
Since it is possible to set and input the amount of overlap where the trailing edge of the preceding sheet transfer paper and the leading edge of the following sheet transfer paper partially overlap, it is possible to bond multiple copies with divided images When making a copy of an image, the margin margin can be set in an appropriate range depending on the paper quality of the sheet transfer paper. According to the fourth aspect of the present invention, when the feeding timing of the succeeding sheet transfer sheet is delayed, the conveyance of the succeeding sheet transfer sheet by the conveying roller is interrupted, and the original document being read is idly fed as it is. When the document conveyed to the reading position is ejected again and is conveyed to the position where the previous reading operation is finished, the conveyance of the subsequent interrupted sheet transfer sheet to the transfer position is restarted. It is possible to prevent the copying in the middle of copying from being wasted due to a conveyance error of the sheet transfer paper. Claim 5
According to the described invention, the rear end of the transfer paper flip-up roller is rotatably supported around the rotary fulcrum, and acts on the supporting arm that rotatably supports the rear end of the transfer paper flip-up roller by elastic force. The elastic biasing means that biases the pressure roller in a direction away from it and the electromagnetic force exerted on the support arm to resist the biasing force of the elastic biasing means, causing the trailing edge repelling roller of the transfer paper to approach the pressure roller. Since the electromagnetic urging means for urging the transfer paper is provided, the mechanism for abutting and separating the trailing end repelling roller of the transfer paper to and from the pressure roller can have a simple structure. According to the sixth aspect of the present invention, when a plurality of sheet transfer papers are conveyed in a partially overlapped state and one image is divided and formed on the plurality of sheet transfer papers, the transfer means is used. Alternatively, since the high voltage current value applied to the separating means is changed, it is possible to prevent the transfer failure of the multi-feed portion of the plurality of sheet-transferred sheets to be conveyed. Claim 7
According to the invention described above, when a plurality of sheet transfer sheets are conveyed in a partially overlapped state and one image is divided into a plurality of sheet transfer sheets to be formed, the sheet passes through the fixing unit. At this time, the conveying speed of the sheet transfer paper is changed so that the plurality of sheet transfer papers are separated from each other, so that the fixing failure of the multi-fed portion of the conveyed sheet transfer papers can be prevented.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a schematic configuration of an embodiment of the present invention.

FIG. 2 is a schematic diagram showing the state of transfer paper conveyance over time when the split copy mode is selected.

FIG. 3 is a schematic diagram showing a splashing roller contact mechanism.

[Explanation of reference numerals] 1 photoconductor drum 3 contact glass 4 document transport roller 8 developing device 9 transfer charger 10 separation charger 13 transport roller 14 registration roller 15 rebound roller 16 solenoid 17 support arm 18 coil spring 21 V groove 22 fixing device

Claims (7)

[Claims] 1. A copying apparatus for reading an image of a document and copying it onto a fed sheet transfer paper by an electrostatic photography process, and a plurality of sheets are transferred when the transferred image is larger than the sheet transfer paper. A copying machine having a double feeding means for feeding the leaf transfer paper to a transfer position in a partially overlapped state. 2. The multi-feeding and feeding means includes a conveying roller for conveying the sheet-transferred sheets which are conveyed one by one, a pressure roller integrally attached to a drive shaft of the conveying roller, and the pressure roller. By contacting the transfer sheet rear end repelling roller that holds the rear end of the sheet transfer sheet being conveyed and releases the gripping operation in the vicinity of the upper part of the peripheral curved surface, and is located downstream of the conveyance roller. A delivery roller that sends the sheet transfer sheet to the transfer position and a sheet transfer sheet that is carried in are transported by the transport roller, and when the front end of the sheet transfer sheet reaches the delivery roller position, the rotation of the delivery roller is performed. Stop the transfer sheet, and bring the trailing edge flip-up roller of the transfer sheet into contact with the pressure roller to hold the rear end of the sheet of transfer sheet continuously conveyed by the transport roller. After releasing the gripping operation in the vicinity of the upper part of the peripheral curved surface of the transfer paper trailing edge repelling roller, the delivery roller is rotated at the delivery timing of the preceding sheet transfer sheet to the transfer position, and the preceding sheet is transferred. Control means for restarting the rotation of the transport roller at the timing when the trailing edge of the transfer sheet partially overlaps with the leading edge of the succeeding sheet transfer sheet and separates the trailing edge flip-up roller of the transfer sheet from the pressure roller. The copying apparatus according to claim 1, wherein the copying apparatus is composed of: 3. A setting input means for setting and inputting an overlapping amount by which the trailing edge of the preceding sheet transfer paper and the leading edge of the following sheet transfer paper partially overlap each other. Copying device. 4. The control means interrupts the conveyance of the succeeding sheet transfer paper by the conveying roller when the timing of carrying in the succeeding sheet transfer sheet is delayed, and the original document being read is idly fed and discharged. , Again, when the original document conveyed to the reading position is conveyed to the position where the previous reading operation is completed, the control to restart the conveyance of the interrupted subsequent sheet transfer sheet to the transfer position is performed. The copying apparatus according to claim 1, wherein: 5. A rotatably supported member around a rotation fulcrum,
A support arm that rotatably supports the trailing end repelling roller of the transfer sheet, and an elastic bias that acts on the supporting arm by an elastic force to bias the trailing end repelling roller of the transfer sheet in a direction of separating from the pressure roller. And an electromagnetic urging means that acts on the support arm and urges the transfer paper rear end flip-up roller toward the pressure roller by an electromagnetic force against the urging force of the elastic urging means. The copying apparatus according to claim 2, further comprising: 6. A transfer unit for transferring a toner image formed on a revolving photosensitive member onto a sheet transfer sheet, and a separation unit located downstream of the transfer unit for separating the sheet transfer sheet from the photoreceptor. And a control means, when the plurality of sheet transfer papers are conveyed in a partially overlapped state and one image is divided and formed on the plurality of sheet transfer papers, the transfer means or 3. The copying apparatus according to claim 2, wherein the copying apparatus is controlled so as to change the high voltage current value applied to the separating means. 7. A fixing means for heating and pressurizing the sheet transfer paper on which the toner image has been transferred by the transfer means to fix the toner to the sheet transfer paper, and the control means includes a plurality of sheet transfer papers. When the sheets are conveyed in the partially overlapped state and one image is divided into a plurality of sheet transfer sheets to be formed, the conveying speed of the sheet transfer sheets when passing through the fixing means is changed. 7. The copying apparatus according to claim 6, wherein the plurality of sheet transfer sheets are controlled so as to be separated from each other.