JPH04308775A - Paper feed method in printer - Google Patents

Abstract

PURPOSE:To save a trouble for removing continuous paper from a feed path at every printing mode change-over by a method wherein when a continuous printing mode is changed over to a cut sheet printing mode, continuous paper is fed back to a predetermined position to be retracted for forming a cut sheet feed path. CONSTITUTION:A common feed path for feeding a cut sheet 2 and continuous paper 8 is provided. One of said paper is selectively fed into the feed path. When the continuous paper 8 fed into said feed path is retracted at a predetermined position in a printer in which while paper subjected to an image forming is discharged from the feed path, the other paper is retracted at the predetermined position, the continuous paper 8 is cut after an image is formed thereon, and the leading end of the continuous paper 8 remaining in the feed path is returned to the predetermined position on the upstream side of an image forming position P in the feed path so as not to interfere with the feed of the cut sheet 2.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper conveyance method in an electrophotographic printer, and more particularly to a paper conveyance method in a printer capable of printing both continuous paper and cut paper by switching the print mode.

0002

[Prior Art] Conventionally, in an electrophotographic printer using a laser beam or the like, both continuous paper and cut paper are set in one printer, and these can be printed by switching the print mode. There is. This type of printer generally has separate paper feed sections for continuous paper and cut paper, but uses a common transport path for transferring images scanned by a laser beam and fixing the transferred toner. There are many ways to do this. Therefore, in these printers, the operator selects either continuous paper or cut paper printing mode during printing, and only the selected paper is thereby fed into the common conveyance path.

0003

[Problem to be Solved by the Invention] However, in the conventionally known printers of the above type, the operator has to replace the tray in the paper feed section and reset the paper every time the print mode is changed. In addition to forcing the operator to perform complicated operations, rapid mode switching was not possible. In other words, when switching the print mode from cut paper to continuous paper, remove the paper feed tray for cut paper, reinstall the paper feed tray for continuous paper, and then transfer the leading edge of the continuous paper to a conveyor such as a tractor. It is necessary to feed the continuous paper to the specified position on the transport path after setting it, and conversely, when switching the print mode from continuous paper to cut paper, it is necessary to This is because it is necessary to pull out and remove the continuous paper that is being transported while being connected by perforations from the transport path, and then reset the paper feed tray for the cut paper.

SUMMARY OF THE INVENTION Therefore, the problem to be solved by the present invention is to solve the problems of an electrophotographic printer capable of printing both continuous paper and cut paper, and to solve the troublesome work of the operator associated with switching the print mode. The purpose is to shorten the overall printing time by quickly performing the steps.

[0005]

[Means for Solving the Problems] In order to solve the above-mentioned technical problem, the present invention has a common conveyance path for conveying cut paper and continuous paper, and within this conveyance path, neither of the above-mentioned sheets of paper can be conveyed. In a printer in which one of the sheets is selectively conveyed, an image is formed on the paper, and then the paper is ejected from the conveyance path, while the other sheet is left waiting at a predetermined position, the paper is fed into the conveyance path. When waiting continuous paper at a predetermined position, cut the continuous paper after forming an image, and move the continuous paper remaining in the transport path to a predetermined position on the upstream side of the transport path where it will not interfere with the transport of the cut paper. This method uses a printer's paper conveyance method that allows paper to be returned to the original position.

[0006]

[Operation] According to the above-mentioned means, when the printing mode is switched from continuous paper to cut paper, the continuous paper is cut and then automatically returns to the conveyance path and waits at a predetermined position where it does not interfere with cut paper conveyance. , because it performs a so-called paper parking operation, it is possible to eliminate the troublesome manual work required in the past.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a printer for implementing the paper conveyance method according to the present invention. This printer is an electrophotographic printer that uses LEDs, laser beams, etc. as an exposure means, and has paper feed sections A1 and A2 for feeding cut paper and continuous paper separately, and each paper feed section. A paper feeding section B that transports the sheets from A1 and A2 at a constant speed, a printing section C that performs transfer and fixing on the paper transported from the paper feeding section B into a common transport path, and a printed paper. It basically consists of a paper discharge section D for discharging paper.

[0008] The paper feeding section includes a cut paper feeding section A1 and a continuous paper feeding section A2 arranged in the vertical direction. and,
In the cut paper feeding section A1, the cut paper 2 stored in the tray 1 is fed out one by one by a pair of separation rollers 3b that rotate in opposite directions by a feed roller 3a, and the cut paper 2 that is fed out by the separation roller 3b is The leading edge of the cut paper 2 is brought into contact with the bonding roller surface of the pair of registration rollers 4 in the paper feed section B, and in this state, the cut paper 2 is once curved by the registration guide section 5, thereby aligning the leading edge of the cut paper 2 straight. Make corrections. After correction, the registration rollers 4 are rotated to feed out the cut paper 2, and the edge detection sensor 55 installed near the rear of the registration rollers 4
After detecting the leading edge of the cut paper 2, the cut paper 2 is transported into the transport path by the transport roller 6 installed behind it. On the other hand, the paper feed hopper 7 of the continuous paper feed section A2
Continuous paper 8 folded at perforations is stored in the hopper 7. After this continuous paper 8 is detected as passing at that position by an end sensor 9 set near the top of the paper feed hopper 7, it is transferred to the tractor. 10 into the transport path. A rotary encoder 11 that detects the amount of rotational movement of the tractor 10 and a counter 12 that cumulatively counts the number of pulses are attached to the tractor 10, and the amount of paper feed of the continuous paper 8 by the tractor 10 is integrated. Note that these have a function of integrating the paper feed amount in the negative direction not only when the tractor 10 rotates in the forward direction but also when the tractor 10 rotates in the reverse direction.

The printing section C consists of a step of transferring an image onto paper and a fixing step of fixing the image. In the transfer process, the photosensitive drum 13, which rotates at the same speed as the conveyance speed of the paper, is first uniformly charged by the charging unit 14, and then charged by the LED.
An exposure section 15 consisting of an LED array arranged in a line exposes image data from a host computer, and a developing section 16 forms a toner image. A transfer section 17 is arranged near the lower end of the photosensitive drum 13 corresponding to the image transfer position P, and the photosensitive drum 1 is charged by the transfer section 17.
The toner image formed on the photosensitive drum 13 is transferred at an image transfer position P to the paper that is conveyed in a state that is stuck to the photosensitive drum 13. A guide for guiding the paper to the image transfer position P is provided by a guide section 18 disposed close to the photosensitive drum 13 at a position immediately before the paper. The paper onto which the image has been transferred is conveyed on a conveyor belt 19 set on a horizontal plane that is approximately the same as the image transfer position P.
At the rear upper part of 9 is a flash fixing device 2 that uses radiant heat.
0 is placed. This flash fixing device 20 includes preheating halogen lamps 21 arranged in the paper width direction.
and a xenon lamp 22 for fixing are arranged adjacent to each other in a reflective case, and the toner is emitted based on the paper feeding timing of each of cut paper and continuous paper, and radiant heat melts the toner and fixes it on the paper. . Further, the conveyor belt 19 is provided with a large number of small holes (not shown) over the entire surface, and a suction device 23 provided on the back side of the conveyor belt 19 conveys the paper while sucking it onto the belt. ing. In addition, around the photosensitive drum 13, there is a static eliminator 24 that applies an alternating voltage to remove static electricity from the charged paper in order to separate the paper from the photosensitive drum 13 after transfer, and a static eliminator 24 that removes static electricity from the charged paper in order to separate the paper from the photosensitive drum 13 after transfer. a peeling claw 25 that prevents
A cleaner unit 26 is provided for scraping off the adhered toner.

Immediately behind the conveyor belt 19, a scuff roller 27 rotated by the same drive motor as the conveyor belt 19 is disposed, and the scuff roller 27 pinches the paper that has undergone the fixing process from both sides and delivers it to the paper discharge section D. Send it in. The scuff roller 27 and the conveyor belt 19 are set at a rotation speed slightly faster than the rotation speed of the tractor 10 in the continuous paper printing mode, and rotate with some slippage against the continuous paper, so that during transfer and fixing, Appropriate tension is applied to the paper. Note that on the downstream side of the scuff roller 27, a paper passage detector 28 and a cutting device 29 are provided adjacent to each other.

The paper discharging section D has a first paper discharging gate 30 at its entrance that switches between cut paper and continuous paper, and a so-called face-up state in which the cut paper is discharged with the printed surface facing upward, and a state in which the printed surface faces downward. A second paper discharge gate 31 is provided on the upstream side and a downstream side of the conveyance path, and the first paper discharge gate 30 can be switched in conjunction with switching the print mode, and Second paper discharge gate 31
is switched in conjunction with the operation of the cut paper discharge tray 32. Note that even when printing continuous paper, by switching the first paper ejection gate 30 to the cut paper side and switching the second paper ejection gate 31 to the face-up side, continuous paper can be printed using the cut paper ejection port. It is possible to discharge straight paper, which is effective when transferring continuous paper to the next process for processing. At the continuous paper delivery section, the continuous paper is sequentially folded and stacked from the perforation in the paper delivery hopper 33. To ensure smooth folding, a flat belt 34 with claws at predetermined intervals and a chain belt are used. 35. By ejecting the continuous paper between the two, the claws of the flat belt 34 and the chain belt 35 make it easy to bend the mountain folds and valley folds of the perforation alternately, and stack the paper in the proper position. go. This paper discharge hopper 33 has a structure that moves up and down depending on the amount of accumulated paper discharge, so by setting the paper discharge hopper 33 at a position where the flat belt 34 and chain belt 35 act effectively, Paper ejection troubles can be effectively prevented.

FIG. 2 shows a separating device for the guide section 18, transfer section 17, and conveyance belt 19 in the printing section C of the printer. The guide portion 18 is connected to the photosensitive drum 1
A pair of upper and lower guide plates 18a, 18b arranged close to 3.
In particular, the rear end bent portion 3 of the upper guide plate 18a
6 and a rear end curved portion 37 of the lower guide plate 18b to guide the paper to an appropriate image transfer position P. The guide section 18 and the transfer section 17 are fixed to a support member 42 that is rotatably supported by a shaft 41 on a printing section main body 40, and the support member 42 has a guide hole in which an eccentric roller 43 is inserted. 44 is opened, and one end of an operating rod 45 extending downward is pivotally supported near the opening. In addition to the support member 42, the printing unit main body 40 supports a conveyor belt 19 and a connecting rod 46 for interlocking the conveyor belt 19 and the support member 42 so as to be rotatable about shafts 47 and 48, respectively. The other end of the actuating rod 45 is supported at the rotating end of the connecting rod 46, and an actuating arm 49 spanned between the connecting rod 46 and the conveyor belt 19 is supported at approximately the middle portion thereof.
One end is pivoted. The actuating arm 49 has a hook 50 on its upper part, and is normally engaged with a pin 52 planted in the frame of the conveyor belt 19 by a spring 51 stretched between it and the connecting rod 46 . Note that a guide roller 54 that moves along a guide groove 53 provided in the frame of the conveyor belt 19 is rotatably attached to the operating arm 49.

The separating mechanism having such a configuration is intended to minimize the influence of transfer and fixing on paper at times other than printing, and is activated each time printing is completed for cut paper and continuous paper. It operates during auto-setting when paper is first set in a predetermined position, during paper parking when switching the print mode from continuous paper to cut paper, and during cutting operation. In this operation, the eccentric roller 43 rotates under a drive not shown, pushes the guide hole 44 downward, rotates the support member 42 clockwise, and separates the guide section 18 and transfer section 17 from the photosensitive drum 13. At the same time, the operating rod 45 is also pushed down to rotate the connecting rod 46 counterclockwise about the shaft 48. With this movement, the actuating arm 49 is pushed down, and while the pin 52 remains engaged, the conveyor belt 19 is pulled down and separated from the normal conveyance position, thereby completing a series of operations. If a problem such as a paper jam occurs, the conveyor belt 19 can be moved to one point by disengaging the hook 50 of the operating arm 49 from the pin 52 and moving the guide roller 54 along the guide groove 53 of the frame. As shown by the chain line, it is possible to create a large separation.

Next, a method of conveying and printing cut sheets and continuous sheets using the printer configured as described above will be described. First, in cut paper printing mode, the photosensitive drum 13
The pair of conveyor rollers 6 rotated by the same drive motor and the conveyor belt 19 are controlled to have the same rotational speed. Then, the registration rollers 4 correct the registration of the cut sheets 2 fed one by one into the conveyance path from the paper feed tray 1 at a constant speed, and a leading edge detection sensor 5 installed near the rear of the registration rollers 4
LE onto the photosensitive drum 13 by the tip passage signal from 5.
Image writing is started from the exposure section 15, which is composed of a D array. The conveyance of the cut paper 2 is transferred from the registration roller 4 to the conveyance roller 6, and the cut paper 2 is transferred into the guide section 18 at a constant speed.
send in. After the leading end of the cut paper 2 hits the lower guide plate 18b, the cut paper 2 moves along the guide portion 18, and is moved to the rear end bent portion 36 of the upper guide plate 18a or the rear end curved portion 37 of the lower guide plate 18b. The photosensitive drum 13 is forcibly guided to the image transfer position P of the photosensitive drum 13, and the toner image formed on the photosensitive drum 13 is transferred by charging at the transfer section 17. Immediately after the transfer, the charge is removed by the charge removal unit 24, and furthermore, the tip of the peeling claw 25 contacts the photosensitive drum 13 for a predetermined period of time, thereby preventing the toner from being caught in the photosensitive drum 13. The cut paper 2 that has come off the conveyance roller 6 is conveyed on the conveyance belt 19 at the same speed as described above by the suction force from below, and is sent to the paper discharge section D after passing through a fixing process.

On the other hand, when printing continuous paper, a continuous paper selection signal is input to the printer together with image information from the host computer, and the printer enters continuous paper printing mode. Then, the paper feeding speed of the tractor 10 is controlled to be the same speed as the rotational speed of the photosensitive drum 13, and the speeds of the conveyor belt 19 and the scuff roller 27 are controlled to be slightly faster than these speeds. In case of continuous paper printing mode, continuous paper 8
If it is already set in a position where it can be printed, printing will start as is, but if it is not set, the perforation of the continuous paper 8 will be automatically fed to the predetermined position by the auto-setting operation, and printing will then start. will be started. In this auto-setting operation, the continuous paper 8 is fed into the conveying path by the paper feeding action of the tractor 10 while the down position of the separation mechanism is maintained. Then, the leading edge of the continuous paper 8 is detected by a leading edge detection sensor 56 provided near the tractor 10, and the amount of subsequent movement is integrated by a rotary encoder 11 and a counter 12 connected to the tractor 10. The leading end of the continuous paper 8 is connected to the upper guide plate 18a of the guide section 18.
The direction of movement is regulated by hitting the drum, and being caught in the photosensitive drum 13 is prevented. Further, as shown in FIG. 2, when the leading end of the continuous paper 8 passes the photosensitive drum 13, the peeling claw 25 comes into contact with the photosensitive drum 13, thereby preventing entrainment. When the continuous paper 8 is further fed and the leading end is detected by the passage detector 28 immediately after passing through the conveyor belt 19 and being nipped by the scuff rollers 27, the amount of continuous paper 8 fed by the tractor 10 is determined based on the detection signal. The tractor 10 is stopped when the perforation of the continuous paper 8 aligns with the image transfer position P. In addition, when aligning the perforations during the auto-set operation, as shown in Fig. 3, because the separating mechanism is in the down operation, the continuous paper 8 is pulled slightly compared to the normal position 8a during printing. It is in the auto-set position 8b of the state. Therefore, during auto-set operation, the image transfer position P is set by shifting the perforation backward by Δl with respect to the normal image transfer position P1, taking into account the correction value.
2, and the perforation of the continuous paper is controlled so as to coincide with the regular image transfer position P1 when the separation mechanism is moved up during printing. In this way,
When the image information from the host computer is written to the photosensitive drum 13 after a series of auto-setting is completed,
The conveyance of the continuous paper 8 by the tractor 10 is started using the image writing start signal as a timing signal, and the separating mechanism is operated up to transfer the image at the image transfer position P. Note that the auto-setting operation is performed when the continuous paper 8 is in so-called paper parking or when the continuous paper 8 is not set on the tractor 10 due to paper out or paper replacement. As mentioned above, in printers of the type in which a continuous paper mode identification signal is input to the printer together with image information from the host computer, autoset operation and printing are performed automatically when paper is parked, but when the paper runs out, Sometimes an error signal is generated, so the operator first fits the paper feed holes provided continuously along both sides of the continuous paper 8 into the paper feed pawls of the tractor 10, and then moves the leading end of the continuous paper 8 to any position on the tractor 10. When set to the position, the subsequent series of operations will be performed automatically in the same way as described above. On the other hand, in the case of a printer that receives only an image information signal from the host computer and has a paper selection switch on the printer side, the above-mentioned autoset operation and printing are automatically performed by input from the printer by the operator.

FIGS. 4 to 7 show a series of operations of the conveying system when the printing mode is switched from continuous paper to cut paper, and FIG. 8 shows a flowchart of the control. . FIG. 4 shows the state of the conveyance system when printing continuous paper (step 100), and when printing on continuous paper is finished from this state, the separating mechanism is activated as shown in FIG. Then, the guide section 18, transfer section 17, and conveyor belt 19 are lowered (step 101). Then, it is determined whether a cut paper selection signal has been input from the host computer or whether the operator has selected a cut paper selection switch or a mode changeover switch provided on the operation panel (step 102), and the print mode is If it is determined that the switch is to be performed, the next step 103
The continuous paper 8 is cut. Here, first, the tractor 10 rotates forward to feed the continuous paper, and the perforation that was at the image transfer position P reaches the cutting position. Next, both sides of the perforation are pressed down by the scuff rollers 27 and rubber pressing members 57, and the perforation is cut off by the cutting device 29, and the separated continuous paper 8 passes through the first paper discharge gate 30 and is delivered to the paper discharge hopper. It is discharged within 33 minutes. At the same time, the tractor 10 rotates in the opposite direction, and the continuous paper 8 remaining in the conveyance path is returned, as shown in FIG.
When the cut tip returns to the position corresponding to the tip detection sensor 56, the rotation of the tractor 10 is stopped, and the continuous paper 8 is made to wait at that position (step 104).
). Note that this standby position is not necessarily limited to the above-mentioned position as long as it does not interfere with the conveyance of the cut paper 2, and for example, the leading end of the continuous paper 8 may be located inside the guide section 18. Next, as shown in FIG. 7, the separating mechanism operates to separate the guide section 18, transfer section 17 and conveyor belt
9 returns to its original position (step 105), the first paper discharge gate 30 is switched (step 106), and printing of the cut paper 2 starts (step 107). Further, when it is determined in step 102 that the printing mode is not switched, the process moves to step 108, where it is determined whether or not the continuous paper 8 is to be kept waiting at the paper parking position.If it is determined that the continuous paper 8 is to be kept waiting at the paper parking position, the cutting After that (step 109), the printer is made to wait at the paper parking position (step 110), and, for example, the paper is replaced at this stage. Further, when it is determined not to wait, after cutting (step 111), the perforation is aligned to a predetermined position and reset (step 112). Note that in both steps 110 and 112, the separating mechanism is held in a down state.

In the above-mentioned embodiment, the cutting device 29 is provided at the rear of the fixing process, and the perforation of the continuous paper is cut immediately after the fixing process is completed. There are fewer blank spaces on the paper than in the previous version, and paper waste can be reduced accordingly. That is, since the fixing process must be completed when continuous paper is cut, the shorter the distance from the cutting position to the fixing process, the more the margin can be reduced. Also, if continuous paper printing mode continues,
If the paper is cut before the transfer process, it must be auto-set each time, but in the above example, unless the paper is parked, it is already auto-set, which saves time spent on auto-setting. It becomes possible to do so. In the above embodiment, the cutting device 29 is provided to automatically cut the continuous paper, but the present invention can also be applied to a case where the continuous paper is cut manually by an operator. In addition, in the present invention, paper parking for continuous paper can be carried out either when the printing mode is switched from continuous paper to cut paper as in the above embodiment, or when paper jams etc. are caused in the continuous paper printing mode. This may occur when it is necessary to remove continuous paper from the conveyance path or when replacing paper.

[0018]

Effects of the Invention As explained above, according to the paper conveyance method for a printer according to the present invention, in an electrophotographic printer capable of printing both continuous paper and cut paper, the paper feed tray is There is no need to re-set the paper, and when changing the print mode from continuous paper to cut paper, the continuous paper automatically returns to the paper parking position and does not interfere with the conveyance of cut paper, making it easier for the operator to There is no need to remove continuous paper from the transport path,
This makes it possible to eliminate the operator's complicated work associated with switching print modes, and to shorten the overall printing time.

[Brief explanation of drawings]

FIG. 1 is an overall view showing an electrophotographic printer for implementing a paper conveyance method according to the present invention.

FIG. 2 is an explanatory diagram showing a separating mechanism for printing units in a printer.

FIG. 3 is an explanatory diagram showing a correction means for aligning perforations of continuous paper with image transfer positions during autosetting.

FIG. 4 is an explanatory diagram of a conveyance path when printing continuous paper.

FIG. 5 is an explanatory diagram of a conveyance path during cutting of continuous paper.

FIG. 6 is an explanatory diagram of a conveyance path during paper parking of continuous paper.

FIG. 7 is an explanatory diagram of a conveyance path when printing cut paper.

FIG. 8 is a flowchart when paper parking continuous paper.

[Explanation of symbols]

A1 Cut paper feed section A2 Continuous paper feed section B Paper feed section C Printing Department D　Paper discharge section P Image transfer position 2 Cut paper 6 Conveyance roller 8 Continuous paper 10 Tractor 13 Photosensitive drum (photosensitive member) 17 Transfer section 18 Guide part 19 Conveyor belt 20 Flash fuser

Claims (3)

[Claims] Claim 1: A common conveyance path for conveying cut paper and continuous paper; one of the above-mentioned sheets of paper is selected and conveyed within this conveyance path, and an image is formed on the paper; In this printer, the paper is ejected from the conveyance path, while the other paper is kept waiting at a predetermined position.
When the continuous paper fed in the above-mentioned transport path is placed on standby at a predetermined position, the continuous paper is cut after forming an image, and the continuous paper remaining in the transport path is cut into cut sheets on the upstream side of the transport path. A method for transporting paper in a printer, characterized in that the paper is returned to a predetermined position where it does not interfere with paper transport. 2. When returning the continuous paper remaining in the transport path to a predetermined position, a transfer section for transferring image information formed on the photoreceptor onto the paper is separated from the photoreceptor. 2. A method for conveying paper in a printer according to claim 1. 3. When the continuous paper remaining in the conveyance path is returned to a predetermined position, the conveyance means for the continuous paper from the transfer section to the fixing section is separated from the normal position during conveyance. A method for conveying paper in a printer according to claim 1.