JPH0261658A - Both-surface recorder - Google Patents

Abstract

PURPOSE:To improve both-surface printing speed by inverting and guiding recording paper fed out by means of a conveyance roll in a twisted state, then correcting the recording paper in a conveying direction of a conveyance path again and feeding it out. CONSTITUTION:The recording paper 2a is fed out obliquely right forward with respect to the conveying direction of the conveyance path 5 and then guided along a bent guide 81c in a half circular arc shape, so that it is inverted up surface down in the twisted state to become recording paper 2b. As for the recording paper 2b, the surface A faces and contacts with an upper plate 81b to be an upper surface and the surface B is a lower surface. By making the paper pass between conveyance rolls 83 and 83 obliquely disposed on the upper plate 81b near an exit 8b side, the recording paper 2b is corrected again to be in the conveying direction of the conveyance path 5 and fed forward. Then, the recording paper is fed out from the exit 8b as recording paper 2c in a state where the surface B faces and contacts with a lower plate 81a with its own weight. Thus, both-surface printing sped can be increased since the convey ance of the recording paper is not stopped from an entrance 8a to the exit 8b.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a double-sided recording device that prints on both sides of a sheet of recording paper.

[Prior Art] Some conventional technologies perform so-called double-sided copying, in which images are formed on both sides of a sheet of copy paper. In this case, the copy paper is sent to the copy processing section, and after copying on one side, the paper is turned over and sent to the copy processing section again.

One of the copy paper feeding devices for this purpose includes a copy paper storage section that stacks and stores new copy paper that has not yet been copied, and a copy paper storage section that feeds the copy paper from the copy paper storage section one sheet at a time to a copy processing section. a first feeding device that feeds the paper, and an intermediate tray that takes in the copy paper fed to the copy processing section and has a copy image formed on one side of the copy paper from one side with the front and back reversed, and stores it. and a second feeding device that feeds the copy sheets stored in the intermediate tray one by one from the one side of the intermediate tray to the copy processing section. In this device, when the copy paper that has entered the intermediate tray is sent to the copy processing section again, it is pulled out in the opposite direction from the direction in which it entered the intermediate tray, that is, it is switched back, so it is removed from the copy paper storage section. When the paper is sent to the copy processing section, the top and bottom of the page, that is, the top and bottom, are reversed.
It is not possible to obtain a double-sided copy with the front and back sides aligned.

To improve this problem, for example,
Japanese Patent No. 44656 discloses a device in which the intermediate tray in the above-mentioned copy paper feeding device is configured to rotate substantially in 180-degree increments with the surface of the copy paper stored in the tray as the rotation surface. It is shown.

[Problem to be Solved] In the former prior art described above, since the recording paper that has been reversed by the reversing device is once taken into the intermediate tray and then fed again, it takes time to convey the recording paper. Furthermore, in the latter conventional technique in which the intermediate tray is divided and rotated, the copy paper feeding path becomes complicated, which is likely to cause paper jams and the like. In addition, a space is required to accommodate a device that divides and rotates the intermediate tray, which hinders miniaturization, and increases costs because the number of parts is large and the configuration is complex. Both methods have a problem in that the double-sided printing speed decreases.

Therefore, a first object of the present invention is to improve the double-sided printing speed without stopping the conveyance of the recording paper even during the reversal of the front and back sides.

A second objective is to make the front and back sides aligned, reduce the number of parts, reduce manufacturing costs, and achieve thinner and smaller sizes.

[Means for Solving the Problems] In order to achieve the above object, the double-sided recording device of the present invention uses a loop-shaped recording paper that has been printed on one side at the print formation position and conveys it again to the print formation position. It includes a conveyance path and a recording paper reversing device provided in the middle of this conveyance path. The recording paper reversing device includes a transport roller that sends out the recording paper fed from the transport path diagonally forward with respect to the transport direction, and a curved guide that twists and guides the recording paper sent out by the transport roller in a reverse direction.
It has a conveyance roller that corrects the recording paper that has passed through the curved guide again in the conveyance direction of the conveyance path and sends it out to the conveyance path.

[Function] In the recording paper reversing device with such a configuration, the recording paper is twisted and reversed without stopping the conveyance of the recording paper, so that the printing speed is not decreased and the printing paper is not turned upside down, so the recording paper can be smoothly reversed. It is then transported upside down.

[Example] Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 is a schematic diagram of a double-sided recording apparatus according to the present invention. The print forming position 1 is provided with a photosensitive drum 11 and a transfer means opening. The photosensitive drum 11 and the transfer means record data stored in a data buffer (not shown) onto recording paper according to an address signal sent from a central processing unit (not shown). 11 and the transfer means 12.
The upper toner image is transferred.

Unprinted recording papers 2 are stocked in a stacked state in a recording paper tray 3, and the uppermost recording paper is sent out one by one by a paper feed roller 4. The fed recording paper 2 passes through a portion of a loop-shaped conveyance path 5 including conveyance rollers 51 . . . and is conveyed to the print forming position 1 . A shutter (not shown) is provided in front of the print forming position 1.
The leading edge of the recording paper 2 is detected, the photoconductor drum 11 rotates according to this detection signal, the recording paper 2 is sent to the print forming position 1, and the developing image on the photoconductor drum 11 is transferred onto the recording paper 2 by the transfer means 12. transcribed. A fixing device 6 is provided at a position outside the print forming position 1. The fixing device 6 fixes the toner image transferred to the recording paper 2 by heat fixing, pressure fixing, or the like.

After leaving the fixing device 6, the recording paper with prints formed on one side A is conveyed according to the attitude of the feed switching lever 7.

That is, when printing is performed on one side A and subsequently on the other side B, the lever 7 is positioned at the position shown by the solid line in FIG. is sent into a loop-shaped conveyance path 5, and then into a recording paper reversing device 8.

As shown in FIG. 2, the recording paper reversing device 8 is for conveying the recording paper 2 by inverting it in a twisted state. The cross section is approximately U due to the upper plate 81b that is parallel to each other at a predetermined interval and the curved guide 81c that connects the lower plate and the upper plate.
It is shaped like a letter. On the lower plate 81a, near the entrance 8a through which the recording paper 2 is fed from the conveyance path 5, a conveyance roller 82 is arranged in an inclined state so as to be able to feed out the recording paper 2 diagonally forward with respect to the conveyance direction of the conveyance path 5. It is set up. Curved guide 8
The shape of the recording paper 1c is set so as to guide the recording paper 2, which advances diagonally forward, by turning it upside down in a twisted state. The upper plate 81b has an inclined state near the outlet 8b from which the recording paper 2 is sent out again to the transport path 5, so that the recording paper 2, which is advancing diagonally forward, can be corrected and sent out again in the transport direction of the transport path 5. A conveyance roller 83 is disposed at the. 8
4 is an arm that supports the conveyance rollers 82 and 83;
Reference numeral 5 denotes a guide plate that guides the sides of the recording paper 2.

Next, the reversing operation of the recording paper will be explained.

The recording paper 2 sent out from the recording paper tray 3 has a print formed on one side A at the print formation position 1, and when this print is fixed by the fixing device 6, the travel switching lever 7
The object is transported according to its orientation.

That is, when printing is performed on one side A and subsequently on the other side B, the travel switching lever 7 is positioned at the position shown by the solid line in FIG.
The recording paper 2 is fed into a loop-shaped conveyance path 5, and then fed into a recording paper reversing device 8.

As shown in the second figure, when the recording paper 2a with printing on side A arrives at the entrance 8a of the recording paper reversing device 8, side A is located on the bottom surface, and side B on which printing will be performed is on the top surface. When the recording paper 2a enters the recording paper reversing device 8, a conveyance roller 82, which is disposed diagonally on the lower plate 81a near the entrance,
By passing between 82, the recording paper 2a is transferred to the conveyance path 5.
It is sent diagonally forward to the right with respect to the conveyance direction. Then, by being guided along the semicircular arc-shaped curved guide 81c, the recording paper 2b is turned over in a twisted state to become the recording paper 2b. The surface A of this recording paper 2b is in contact with the upper plate 81b, forming the upper surface, and the surface B is the lower surface. Here, the conveyance roller 8 is disposed diagonally on the upper plate 81b near the exit 8b side.
By passing between 3 and 83, the recording paper 2b that has been sent diagonally forward is again corrected in the transport direction in the transport path 5 and sent forward, and due to the weight of the recording paper, the surface B is brought into contact with the lower plate 81a. The recording paper 2c is in contact with the exit 8b.
sent from. From the inlet 8a to the outlet 8b, the recording paper is continuously twisted and sent out without being stopped.

The recording paper sent out from the outlet 8b is conveyed again through the conveyance path 5 to the print forming position 1 by the conveyance rollers 51 shown in the first diagram, and this time, printing is performed on the surface B. Then, the recording paper with prints on both sides of A and B fixed by the fixing device 6 is transferred to the paper output tray 10a or 10b according to the travel switching lever 7, which is switched to the chain line position, and the travel switching lever 9, which is switched to the solid line position. is discharged. Note that when the paper is ejected to the ejection tray 10a, it is ejected with the surface A facing down, and when it is ejected to the ejection tray 10b, it is ejected with the surface B facing down.

If printing is to be performed on only one side (side A), the recording paper that has been fixed on only side A by the fixing device 6 should be moved to the position shown by the chain line with the travel switching lever 7.
and is discharged to the paper discharge tray 10a or 10b according to the lever 9.

When the paper is ejected to the paper ejection tray 10a, the paper is ejected with the side A facing upward, and when it is ejected to the paper ejection tray 10b, the paper is ejected with the surface A facing down.

[Effects] As described above, according to the present invention, the recording paper is fed diagonally forward by the recording paper reversing device and is turned upside down in a twisted state without stopping during that time, so the double-sided printing speed is significantly increased. improve. Furthermore, since the top position of the front side is kept as it is and the paper moves forward, it is reversed and printed on the back side, so that the top and bottom of the front and back sides can be printed evenly.

In addition, the configuration is simple and the number of parts is small, so
It is possible to reduce manufacturing costs and achieve thinner and smaller size.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a schematic configuration diagram, and FIG. 2 is an enlarged perspective view of the main parts, both of which explain the reversing operation of the recording paper. 1. Print formation position, 2.2a, 2b, 2c... Recording paper, 5. - Conveyance path, 8. - Recording paper reversing device, 81C... Curved guide, 82.83... Conveyance roller, A. B: Side of recording paper. that's all

Claims (1)

[Scope of Claims] A loop-shaped conveyance path for conveying the recording paper printed on one side at the print formation position again to the print formation position, and a recording paper reversing device provided in the middle of the conveyance path. The recording paper reversing device includes a transport roller that sends out the recording paper sent from the transport path diagonally forward with respect to the transport direction, and a reversal guide of the recording paper sent out by the transport roller in a twisted state. A double-sided recording apparatus comprising: a curved guide; and a conveyance roller that corrects the recording paper that has passed through the curved guide again in the conveyance direction of the conveyance path and sends it out to the conveyance path.