JPH0238249A - Paper feeding mechanism - Google Patents

Abstract

PURPOSE:To permit the stable toner image transcription by properly maintaining the contact state between a paper and a photosensitive body by supporting a feed-in pin tractor onto a frame in free shift in the paper feed-in direction by urging said feed-in pin tractor in the reverse direction to the paper feed-in direction by a spring mechanism. CONSTITUTION:When a paper 4 is to be set onto a device, a feed-in pin tractor 1 is shifted in the paper traveling direction by an eccentric cam 20, and a spring mechanism 19 is released, and the paper 4 is set in the slack state. When paper is sent to copy the toner image on a photosensitive body onto the paper, the eccentric cam 20 is separated from a slide plate 18, and the feed-in pin tractor 1 is urged in the reverse direction to the paper feed-in direction by the spring mechanism 19, and the paper is applied with a tension. Therefore, the photosensitive body and the paper are attached by a proper contact pressure, and the stable toner image transcription is permitted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a paper feeding mechanism, and more particularly to a paper feeding mechanism for transferring a toner image on a photoreceptor to paper as a recording medium in an electrophotographic printing mechanism. .

[Prior Art] This type of paper feeding mechanism includes a frame, a guide plate for guiding the paper, and a pin tractor supported by the frame, and transports the paper along the guide plate to form an image on the photosensitive drum. is transferred onto paper using a transfer device.

In the past, all pin tractors were fixed to a frame, and there was no means to keep the tension of the paper, which is the recording medium, constant.

[Problems to be Solved by the Invention] In the conventional paper feeding mechanism described above, the pin tractor is fixed to the frame and the length of the paper path after the transfer cylinder is constant. If the paper expands or contracts, the paper may sag, resulting in poor transfer, or the tension may be too great, tearing the paper's feed holes and causing a jam. There was a drawback.

[Means for Solving the Problems] The present invention has been made to solve the above problems, and as a means for solving the problems, the paper feeding mechanism of the present invention includes a frame,
It includes a guide plate for guiding paper, a paper feeding pin tractor and a paper feeding pin tractor supported by an L frame, and a driving device for these feeding pin tractor and feeding pin tractor. The feeding pin tractor is supported by a frame so as to be movable in the paper conveyance direction, and is biased by a spring mechanism in the opposite direction to the paper feeding direction, and is capable of releasing the spring force to apply tension to the paper. It is configured so that it can be granted.

[Example] Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a side view showing a paper feeding mechanism according to an embodiment of the present invention.

This paper feeding mechanism consists of a frame 10 and a guide plate 1.
1, a feed pin tractor 1 and a feed pin tractor 2 for paper 4 supported by a frame 10, and a drive device 21 for these feed pin tractor 1 and feed pin tractor 2.

The toner image formed on the photosensitive drum is transferred by the electrostatic force of a transfer device 3 onto paper (recording medium) 4 with perforations, which is fed by a feed pin tractor 1, and sent out by a feed pin tractor 2. . At this time, the paper 4 is brought into close contact with the photosensitive drum 7 between the paper guides 5 and 6 due to tension.

A drive shaft 8 and a guide shaft 9 of the delivery pin tractor 2 are fixed to a frame 10, and are driven by a gear 12 from a motor (not shown) as a drive device which is also fixed to the frame.

Drive of the feeding pin tractor 1 is provided by a gear 13, an intermediate gear 14, and a gear 15. Here, the rotation shaft of the intermediate gear 14 is fixed to the link plate 16, and the link plate 16 is rotatable around M8. Furthermore, the gear 15 is movable parallel to the paper running surface while being engaged with the intermediate gear 14 by the link plate 17 and the slide plate 18, and while the paper is running, the tension force of the spring of the spring mechanism 19 keeps the paper 4 at a certain level. Give tension.

When setting the paper 4 in the apparatus, the eccentric cam 20 moves the pin tractor 1 in the paper running direction to release the spring mechanism 19 so that the paper 4 can be set in a slack state.

During operation, by separating the eccentric cam 20 from the slide plate 18, the position of the pin tractor 1 is moved to a position where the tension between the spring mechanism 19 and the paper 4 is balanced.

[Effects of the Invention] As explained above, the paper feeding mechanism of the present invention includes a frame, a guide plate for guiding the paper, a pin tractor for feeding the paper, and a pin tractor for feeding the paper supported by the frame. and a driving device for the feeding pin tractor and the feeding pin tractor, wherein the feeding pin tractor is supported by a frame so as to be movable in the paper conveying direction, and is movable in the paper feeding direction. It is biased by a spring mechanism and the spring force can be released, applying tension to the paper = J function, so by keeping the tension of the paper constant, the contact state between the photoreceptor and the paper is moderate. This has the effect of maintaining stable toner image transfer.

Moreover, by releasing the spring mechanism when attaching and detaching the paper, the tension of the paper is eliminated and the paper can be easily attached and detached.

[Brief explanation of the drawing]

FIG. 1 is a side view showing a paper feeding mechanism according to an embodiment of the present invention. 1: Feeding pin tractor 2: Feeding pin tractor 10: Frame 11 Guide plate 16
．． 17: Link plate 18 Ni-ride plate

Claims (1)

[Claims] a frame, a guide plate for guiding paper, a paper feeding pin tractor and a paper feeding pin tractor supported by the frame, and a drive device for these feeding pin tractor and feeding pin tractor; The feed pin tractor is supported by a frame so as to be movable in the paper conveyance direction, is biased by a spring mechanism in the opposite direction to the paper feed direction, and is capable of releasing the spring force, and is configured to A paper feeding mechanism characterized by being capable of applying tension.