JPS59143853A - Duplex copier - Google Patents

Abstract

PURPOSE:To prevent paper jam, misalignment of pictures on the front and back of paper, etc. by providing side plates reciprocating left and right on both sides of a paper resupplying stacker for accumulating temporarily blanks having a picture formed on a first surface to arrange properly the accumulated blanks. CONSTITUTION:In a paper resupplying stacker of a duplex copier, the left and right side plates 31a, 31b are provided integrally with racks 32a, 32b respectively meshing with gears 33a, 33b. The respective gears 33a, 33b are rotatably driven by power transmitting gears 35a, 35b through spring clutches 34a, 34b which are engageably stopped selectively by a ratch plate 36 swung by or against the force of a spring 39 under the control of a solenoid 37. Thus, one gear 32a or 32b is rotated to reciprocate the side plates 31a, 31b away from or close to each other to arrange blanks properly widthwise.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a duplex copying machine that obtains a copy having images on both sides of a sheet of paper, and more specifically, it relates to a duplex copying machine that obtains a copy having images on both sides of a sheet of paper, and more specifically, The present invention relates to a double-sided copying machine having an improved paper aligning mechanism in a paper refeed stacker section for temporarily accumulating paper.

[Prior art]

In a so-called double-sided copying machine that records copied images on both sides of a sheet of paper, the paper is fed from the first paper feed section, and after the image is transferred and fixed on the first side, the paper is fed again. After once being accumulated in the paper stacker section, the sheets are sent out one by one and the entire image is transferred and fixed on the second side to obtain the desired screen copy.

FIG. 1 is a schematic diagram of a paper feeding path in a double-sided copying machine as described above. Reference numeral 1 denotes a first paper feed section, and paper is normally loaded into a cassette or the like. The paper is fed by the paper feed roller 2 from the first boat feeding section, is sent to the upper transfer section whose position is regulated by the registration roller 3, contacts the photosensitive drum 4, transfers the image, and is transferred to the fixing roller 6 by the conveyance heald 5. be introduced and established.

The part (R) indicated by the chain line in the figure is a paper reversing path switching section, where the paper sent from the fixing section is switched and packed, and transferred to the paper re-feeding stacker 9 by the conveyance rollers 7 and the conveyance belt 8 as an image. Stacked face up. When the transfer of the original to be recorded on the first side of the paper is completed and the copying of the original to be recorded on the second side of the paper is started, the stacked papers are transferred to the re-feed stacker 9 by the re-feed roller IOK. The sheets are fed out one by one and transported to the position of the registration rollers 3 by the conveying roller 11, where transfer and fixing are performed in the same manner as in the case of the first side. After fixing, the paper path was switched to paper ejection (R)
and is discharged outside the machine (/C) by the discharge roller 12.

In the above-mentioned paper feeding system, the paper loaded into the first paper feeding section is well aligned in advance and stored in a cassette, etc., but the paper that has been conveyed the entire long path is stored in the re-feeding stacker section. Since the sheets are fed in one by one, it is difficult to stack them in the correct position. Misaligned stacking of paper in the paper refeed stacker (for example, misalignment of the image formed on the second side of the paper) may cause discrepancies between the front and back images, or in extreme cases may cause malfunctions due to paper jams. This was a major problem in the production of a double-sided electrostatic copying machine.

Conventionally, as a means for positioning the paper after image formation on the first side is completed, a position regulation plate is placed on one side of the conveyance path to the paper refeed stacker after fixing, and the side edge of the paper being moved is placed on the regulation plate. Previously, a one-sided reference method was used in which a paper conveying means that works in an oblique direction to press the paper was installed to align one side of the paper.However, in copying machines that use paper of various sizes, one-sided paper alignment is used. K had various difficulties. US Patent 4.
No. 334,759 improves on this point by detecting the size of the paper using a sensor and automatically moving the above-mentioned position regulating plate, so that even if the paper size changes, the center position is kept constant and the paper is aligned. However, this method of regulating the paper position during conveyance cannot prevent the paper from being misaligned due to floating when it is ejected to the paper refeed stacker, and it is not always possible to prevent the paper from being stacked correctly. There were some drawbacks that made it impossible.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a double-sided copying machine that prevents paper jams, front and back image misalignment, etc., by accurately stacking sheets at predetermined positions in a paper refeed stacker section.

[Structure of the invention]

The above object has been achieved by a double-sided electrostatic copying machine which has side plates on both sides of the stacker that move back and forth from side to side.

Preferably, the center position of the reciprocating movement of the side plate can be changed according to the width of the paper being used.

The mechanism for reciprocating the side plate may be any small device that can be incorporated into the copying machine, such as a mechanism that utilizes forward and reverse rotation of a DC motor, a mechanism that uses a combination of a DC motor and an electromagnetic clutch, etc. Alternatively, a clutch may be attached to each of the side plates, and the two gears that mesh with the rack and each connected to the drive gear via a spring clutch are alternately engaged with the two spring clutches. Most preferred is the use of a mechanism consisting of a latch plate and means for controlling the latch plate. Also, the reciprocating movement of the side plate is m.
It is also possible to install various sensors etc. to regulate the temperature.

The effects of the present invention will be explained below with reference to Examples.

〔Example〕

FIG. 2 is a plan view showing an example of the paper refeed stacker section according to the present invention.

The sheet of paper is sent in the direction of the white arrow by the conveyor belt 21, stops when it hits the wall 22 of the stacker section, and falls to the position indicated by the chain line in the figure. Since the paper is regulated, a large number of sheets can be easily arranged and stacked.

The center position of the reciprocating movement of the side plates may be set at a position slightly farther than the paper, and the drive may be controlled so that the width of the paper coincides with the width of the paper when the distance between the side plates becomes the narrowest.

FIG. 3 is a schematic diagram showing an example of the reciprocating mechanism for the side plate.

A rack 32 is provided on each of the side plates 31a and 31b.
& 32b are integrally provided, and the two racks mesh with gears 33a and 33b. Gear 3.3
a, 33b are spring clutches 34, respectively.
Power transmission gear 35 a through a + 34 b,
35b is FC connected, and is driven and rotated by power transmission gears 35a and 35b in the direction of the arrow in the figure, but freely rotates when the spring clutches 34a and 34b are disengaged. be able to. When the solenoid 37, which is an open launch plate and is a latch plate position regulating means, is activated and the lever engagement is pulled as shown in FIG. When the spring 39 stops,
The force causes the latch plate 36 to rotate, and the claw on the left side in the figure locks the spring clutch 34b. At this time, 34m will be released. The power transmission gears 35 a and 35 b are driven by a drive gear 40 connected to a motor 41 and continuously rotate in the direction of the arrow. When the upper solenoid 37 operates and the latch plate locks the spring clutch 34a, the gear 33a rotates in the direction of the arrow, and the rack 32a
, 32b to move the side plates 31a and 31b in the direction where they both exert a force of 4°. During this time gear 33b
spins idly according to the movement of the rack.

When the current is applied to the solenoid 37, the spring clutch 3
4b is locked, 34a is released, gear 33b rotates, gear 33a idles, and side plates 31a, 31
Also subtract b by 1'. It is possible to reciprocate the side plate in a predetermined width by cutting off and cutting off the current to the solenoid at appropriate intervals.

Also, if you continue in either state, you can freely expand or reduce the space between the side plates, so move the side plate to a position that matches the paper size you are using, and align the paper by moving it back and forth at that position. I can do it.

As mentioned above, the positional movement and reciprocating movement of the side plate can all be controlled by turning on and off the current to the solenoid, so if the necessary grograms for these are stored in a microcomputer and controlled, the position of the side plate can be adjusted according to the paper size. settings and paper alignment operations can be performed automatically.

The above paper refeed stacker is installed in a double-sided copying machine in order to align the paper in the front and rear directions, and its tip (right side in Figure 2)
It is preferable to mount it at an angle so that the angle is low.Also, as shown in Figure 5, it may be installed so that it can be tilted when stacking paper and rotated to an angle suitable for feeding paper when refeeding. good.

An example is shown in FIG.

FIG. 5A shows a state in which sheets are stacked, and the stacker is placed at an angle. The dotted line is the paper conveyance path.

The sheets conveyed by the conveyance rollers 51 and the conveyance belt 52 are fed into the stacker, are stopped by the front end blade assembly, and are stacked on the stacker bottom plate 54 with the front and back aligned. The left and right sides of the paper come to a horizontal position due to the reciprocating motion between the side roots, and are fed out one by one by the refeed roller. The stacker is gradually raised as the amount of accumulation decreases.

As a result of practical experiments, a double-sided copying machine equipped with the above-mentioned paper refeed stacker according to the present invention showed excellent performance in terms of matching of front and back image positions and fewer paper jams.

[Brief explanation of the drawing]

FIG. 1 is a paper conveyance route diagram of a double-sided electrostatic copying machine, FIG. 2 is a plan view of the paper refeeding stacker section according to the present invention, FIG. 3 is a dramatic view of the side plate drive mechanism of the paper refeeding stacker section, and FIG. FIG. 4 is an explanatory diagram showing the locked state of the spring clutch by the latch plate, and FIG. 5 is an explanatory diagram of an embodiment in which the paper refeed stacker is installed in a double-sided copying machine. 31 a, 31 b... side f32a, 32
b...Rack Showa, 33b...Gears 34a, 34b...Spring clutch 35
a, 35 b...Power transmission gear 36...
... Latch 37 ... Solenoid agent Rumi Kuwabara

Claims (3)

[Claims] (1) In a double-sided copying machine in which sheets of paper on which an image has been formed on the first side are once stacked in a re-feed stacker, and the sheets are fed one by one to form an image on the second side, the above-mentioned re-feed stacker is used. A double-sided copying machine characterized by having side plates on both sides that move back and forth from side to side to align the sheets stacked in the stacker. (2) The double-sided copying machine according to claim 1, wherein the center position of the reciprocating movement of the stacker side plate can be changed according to the width of the paper. (3) A rank in which the reciprocating movement of the stacker side plate is integrated with the core side plate, two gears meshing with the rank and each connected to a drive gear via a spring clutch, and the two spring clutches. 2. A double-sided copying machine according to claim 1, wherein said duplex copying machine is operated by means of a water latch plate that alternately locks the water latch plates, and a means for controlling the position of said latch plate.