JP3199479B2 - Image forming apparatus having double-sided unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus having a double-sided unit for recording (transferring) an image on both sides of a recording sheet, and more particularly to an image forming apparatus having a double-sided unit.

[0002]

2. Description of the Related Art In order to transfer a toner image to the other side of a recording sheet having a toner image transferred to one side thereof, that is, to transfer an image to both sides of a recording sheet, an image forming apparatus having a double-sided unit is known. Are known.

[0003] This is a double-sided conveyance path for guiding recording paper by a branch claw provided between a fixing device and a double-sided unit paper discharge section, a double-sided tray for temporarily storing recording paper conveyed by the double-sided conveyance path, and It comprises a mechanism for aligning the recording paper on the double-sided tray, feeding the recording paper again to the transfer section, and the like.

[0004] By the way, in many cases, the rear end of the double-sided tray is curved upwards in consideration of downsizing of the double-sided unit and matching with other option devices.

[0005]

As described above, when the rear end of the double-sided unit is curved upward and upward, the recording paper discharged into the double-sided tray is switched back (the sheet is inverted and discharged to the rear end side). when the recording sheet can be moved to the paper Sutotsu path of the tip) is, falls to paper Sutotsu path by the weight of the recording paper, can not gather in roller closer to Jiyogafuensu of conveyance before the reference, the horizontal Sutotsuku becomes poor This causes a problem of lowering the transport quality of the double-sided unit, which is a problem.

The present invention solves the above-mentioned drawbacks of the conventional device,
An object of the present invention is to provide an image forming apparatus having a double-sided unit capable of improving the storage quality of the recording paper in the double-sided tray and thereby improving the transport quality of the double-sided unit.

[0007]

An object of the present invention is to provide a recording sheet having a toner image transferred on one side thereof from a double-sided unit conveyance path.
Drop onto a double-sided tray with its rear end curved upward with the non-recording surface facing up, switch back to a predetermined position at the leading edge, temporarily store in the double-sided tray, and feed again to the transfer section of the photoconductor. in the image forming apparatus having a duplex Yunitsuto that, as a recording paper which has fallen into the duplex tray from falling shifted forward Rutotomoni provided Mylar sheet for pressing the recording sheet from above to the duplex tray upward,
The tip of the mylar sheet always contacts the double-sided tray
It has a wedge-shaped structure and has fallen on the double-sided tray
When the recording paper is at the tip of the mylar sheet and the double-sided tray
This is achieved by a first means adapted to be inserted into a wedge-shaped structure consisting of:

[0008]

[0009] The above objects are achieved by a first means, it is achieved by the second means in which a plurality placed on the recording sheet in the conveyance span the Mylar sheet.

[0010]

In the first means, recording paper is stored in a double-sided tray.
By releasing the recording paper on the top of the mylar sheet
And is automatically inserted into the wedge-shaped structure of the double-sided tray to record
Because the paper is held down, the recording paper falls due to its own weight.
Prevents the recording paper from being stored in the double-sided tray.
Can be expensive.

[0011]

In the second means, by installing a plurality of mylar sheets in the recording paper transport span, it is possible to make the recording paper storage in the double-sided tray highly reliable.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram of a copying machine according to an embodiment.

In FIG. 1, a copier main body 1 is removably loaded with a paper feed cassette 2. The recording paper P fed in the direction of arrow A by the paper feed roller 3 is conveyed to the photosensitive drum 5 of the image carrier at a timing by the registration roller pair 4. The photosensitive drum 5 is driven to rotate clockwise. At this time, the surface of the photosensitive drum 5 is charged by a charging charger 6, and is exposed to exposure light L from an optical device 7, so that an electrostatic latent image is formed on the photosensitive drum 5. Is formed. This latent image is visualized by toner when passing through the developing device 8, and this visible image is transferred by the transfer charger 9 to the recording paper P conveyed to the photosensitive drum 5. Also, the photosensitive drum 5
Is forcibly separated by a pick-off belt, a turn belt, and a separator roller, and sent to the downstream side. The transferred visible image on the recording paper P is fixed by the fixing device 10. Then, the recording paper P that has left the fixing device 10 is discharged to a paper discharge tray 11 in the direction of arrow B. On the other hand, the photosensitive drum 5 after the transfer of the visible image removes and collects residual toner by a cleaning device 12 having a cleaning blade and a cleaning roller.

Further, when the duplex mode for transferring to both sides of the recording paper is selected, the branch claw 14 in the duplex unit 13 is operated, and the recording paper P passes through the transport unit 15 of the duplex unit 13 and is placed on the duplex tray 16. It is discharged in the direction of arrow C, and is backed and aligned by the approach roller 17 and stored in the direction of arrow D on the double-sided tray 16. Then, the recording paper P stored on the double-sided tray 16 is fed in the direction of arrow E, and the same operation as above is performed after the registration roller pair 4.

Reference numeral 31 denotes an ARDF (automatic circulating document feeder), 32 denotes a manual feed table, 33 denotes a large capacity paper feeder, 34 denotes a third paper feeder, 35 denotes a developing tank, and 36 denotes a table.

FIG. 2 is a structural diagram of a double-sided unit.

Although partially overlapping with the above description, the recording paper P transferred to both sides of the recording paper passes through the transport section 15 of the double-sided unit 13 by the operation of the branch claw 14 and is discharged by the discharge roller pair 18 to the double-sided tray 16. It is inverted upside down. The discharged recording paper P is switched back by the moving roller 17, and is moved to the paper stopper 20 while being moved by the jog fluence 19.
Sent to Then, the recording paper P with the non-image surface facing upward is timed by the pickup roller 21.
Again toward the transfer section.

The mylar sheet 22 is provided on the lower surface of the transport unit 15 so as to hang down on the upper surface of the double-sided tray 16.
One end of the mylar sheet 22 is attached.
Thus, the upper surface of the recording paper P discharged to the double-sided tray 16 is pressed. That is, mylar sheet 22
Is always in contact with the double-sided tray 16 to form a wedge-shaped structure.
The recording paper P falling onto the double-sided tray 16
A wedge composed of the leading end of the sheet 22 and the double-sided tray 16
To be inserted into the structure

As is clear from the drawing, the rear end of the double-sided tray 16 is curved upward, so that if no countermeasures are taken, the recording paper P will slip down to the front end when the recording paper P is switched back. As described above, the pulling operation by 17 cannot be performed, but the mylar sheet 22 can prevent the recording paper P from slipping off.

FIG. 3 is a plan view of a double-sided tray showing an example of attaching a mylar sheet, and FIG. 4 is a similar view showing another example.

In the example shown in FIG. 3, the front jog fuence 1 serving as a storage reference for the recording paper P discharged to the double-sided tray 16 is shown.
9a, the mylar sheet 22 is set at a position of 40 to 110 mm, and the width of the mylar sheet 22 is set to 20 to 4 mm.
By setting 0 mm, the recording paper P can be prevented from falling due to its own weight, so that the recording paper storage in the double-sided tray 16 can be made highly reliable. Reference numeral 19b denotes a rear joga fuence, 23a denotes a front side plate, and 23b denotes a rear side plate.

In the example shown in FIG. 4 , a plurality of mylar sheets 22 are provided in the recording paper transporting span on the double-sided tray 16 so that the recording paper P can be prevented from falling due to its own weight. is there.

[0025]

According to the first aspect of the present invention, a double-sided tray is provided.
By discharging the recording paper into the
Automatically inserts into the wedge-shaped structure of the error sheet and double-sided tray
In rare cases, I tried to hold down the recording paper,
The recording paper is prevented from dropping and is stored in the double-sided tray.
Performance can be made highly reliable.

[0026]

According to the second aspect of the present invention, by installing a plurality of mylar sheets in the recording paper transport span, it is possible to increase the reliability of recording paper storage in the double-sided tray.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a copying machine according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a double-sided unit.

FIG. 3 is a plan view of a double-sided tray showing an example of attachment of a mylar sheet.

FIG. 4 is a plan view of a double-sided tray showing another example of attachment of a mylar sheet.

[Explanation of symbols]

 Reference Signs List 13 double-sided unit 14 branching claw 15 transport unit (double-sided unit transport path) 16 double-sided tray 17 pulling roller 19 jigoji fuence 20 paper stopper 22 mylar sheet (pressing member) P recording paper

Claims (2)

(57) [Claims] 1. A recording sheet on which a toner image is transferred on one side,
From the double-sided unit transport path, drop it onto a double-sided tray with its rear end curved upward with the non-recording surface facing up, switch back to a predetermined position at the leading end, temporarily store in the double-sided tray, and transfer the photoconductor again. in the image forming apparatus having a duplex Yunitsuto for feeding toward section, the so recording paper which has fallen to the duplex tray from falling shifted forward, duplex tray upper mylar sheet <br/> for pressing the recording sheet from above to providing Rutotomoni, the Mylar sheet
The tip of the wedge-shaped structure always contacts the double-sided tray
Recording paper falling onto the double-sided tray
Wedge composed of the front end of the color sheet and the double-sided tray
An image forming apparatus having a double-sided unit, which is inserted into a structure . 2. The mylarcy according to claim 1, wherein
An image forming apparatus having a double-sided unit, wherein a plurality of sheets are provided in a recording paper transport span .