JPH0125954Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a transfer type electrostatic recording device such as an electrophotographic copying machine, and particularly relates to an improvement in the transfer/separation section.

As is well known, a transfer type electrostatic recording device that performs transfer and separation using an electrode device has conventionally been constructed as shown in the first diagram. That is, facing an image carrier, for example, a photosensitive drum 1, which is rotationally driven in the direction of arrow A, a paper feed path 3 consisting of guide plates 2A and 2B is formed, and recording paper is passed through the paper feed path 3. X is supplied to the circumferential surface 1a of the photoreceptor drum 1. At a position adjacent to the paper feed path 3 in the rotational direction of the photoreceptor drum 1, there is a transfer electrode 4 for transferring the toner image on the circumferential surface 1a of the photoreceptor drum 1 onto the recording paper A separating electrode 5 is arranged which separates the recording paper X from the photosensitive drum 1 by attracting the recording paper X. Therefore, the tip 2a of the guide plate 2B and the circumferential surface 1 of the photoreceptor drum 1
As shown in the figure, the recording paper X fed from the gap between the recording paper 1, the rear end of the recording paper X becomes as shown in FIG. 1a. That is, when the trailing edge of the recording paper X comes off the guide 2a, transfer misalignment and white spots occur. Furthermore, in the conventional structure as described above, the distance between the tip 2a of the guide plate 2B and the circumferential surface 1a of the photoreceptor drum 1 is generally strictly set to 1.5 to 2.5 mm, and recording Although the paper X is brought into close contact with the circumferential surface 1a of the photoreceptor drum 1, the guide plate 2B of the conventional recording paper
are integrally constructed, so that when the adjustment method shown in FIG. It becomes impossible to adjust the interval on the extension line.

The purpose of the present invention is to obtain a recording paper guide device that does not cause the transfer failure as described above, and the purpose of this invention is to supply the recording paper to the circumferential surface of the image carrier drum through the paper feed path, and In an electrostatic recording device that transfers a toner image and separates a recording paper using a transfer electrode and a separation electrode facing a surface, a support shaft located facing the paper feed path is provided with a rotatable support shaft that contacts the recording paper. A plurality of rollers are supported, a plurality of guide members are positioned between these rollers, and the recording paper is guided by an extension of the guide member extending parallel to the circumferential surface of the image carrier drum up to the vicinity of the transfer electrode. This is what we propose.

Embodiments of the present invention will now be described in detail with reference to FIGS. 2 to 4.

FIG. 2 is a sectional view corresponding to FIG. 1 of an electrostatic recording device incorporating the recording paper guide device according to the present invention.
Structural parts that are the same as those in the figures are given the same reference numerals. The recording paper guide device 10 has a mounting plate 13 that is fixed to a pair of mounting portions 11a and 11b provided on the transport unit 11 with mounting screws 12. The conveyance unit 11 is rotatable around the support shaft 11C, and when the recording paper X becomes jammed, it can be moved away from the circumferential surface 1a of the photosensitive drum 1, making it easy to remove the jammed paper. It is configured as follows. This mounting plate 13 can be positioned in the mounting portions 11a and 11b by means of elongated holes 14 shown in the third and fourth figures, and a support shaft 15 parallel to the photoreceptor drum 1 is attached to the upper end of the mounting plate 13. A plurality of rollers 16 that contact the surface of the recording paper X are rotatably supported on the support shaft 15 . Therefore, as shown in an enlarged view in FIG.
4 connects the circumferential surface 1a of the photoreceptor drum 1 and the roller 1.
Generally, the distance L between the circumferential surface 16a of
The distance can be adjusted within the range of 1.5 to 2.5 mm, and by setting this distance, the recording paper X fed from the paper feed path 3 can be brought into close contact with the circumferential surface 1a of the photosensitive drum 1.

According to the present invention, at the tip of the mounting plate 13,
A plurality of guide members 17 interposed between the rollers 16 are attached to the openings 13a, 13b, and 13c of the attachment plate 13. These guide members 17 are made of a synthetic resin material and have a hole through which the support shaft 15 is inserted, and are formed in a dogleg shape, and a slot 18 for receiving the mounting plate 13 is formed at the base 17a of the guide members 17. be done. Further, each guide member 17 has an extension part 17b that extends above the transfer electrode 4, and the upper surface 19 of the extension part 17b is arranged such that a constant distance is maintained between the upper surface 19 of the extension part 17b and the circumferential surface 1a of the photoreceptor drum 1. It is a curved surface parallel to the circumferential surface 1a.

Since the apparatus of the embodiment has the above-described structure, the recording paper X that is fed to the photosensitive drum 1 through the paper feed path 3 is transported by the plurality of lightly rotating rollers 16.
Since the recording paper is guided to the photoreceptor drum 1 by contact with the recording paper, even curled recording paper or recording paper with a folded leading edge will not cause a "jam". In particular, since the recording paper X is guided along the circumferential surface of the roller 16 with low resistance, it is guided much more smoothly than in the conventional case where it is deflected at the tip of a guide plate.
The frequency with which "jams" occur is extremely reduced.

Furthermore, in the recording paper guide device of the present invention, the extension portion 17b of the guide member 17 prevents the rear end of the recording paper X from floating away from the circumferential surface 1a of the photoreceptor drum 1. Since the trailing edge portion of the recording paper X is brought into close contact with the circumferential surface 1a of the photosensitive drum 1 as shown in the figure, transfer defects such as "transfer misalignment" and "white spots" can be prevented.

As a result, according to the present invention, it is possible to obtain a recording paper guiding device in which "jamming" occurs less frequently and transfer defects do not occur.

[Brief explanation of the drawing]

1 and 1a are sectional views of main parts of a conventional electrostatic recording device, FIG. 2 is a sectional view corresponding to FIG. 1 of an electrostatic recording device incorporating a recording paper guide device according to the present invention, and The figure is a sectional view taken along the - line in FIG. 2, and FIG. 4 is an enlarged sectional view of the main part of FIG. 2. X... Recording paper, 1... Photosensitive drum, 1a...
Circumferential surface (of photoreceptor drum), 3...Paper feed path, 4...
Transfer electrode, 5... Separation electrode, 13... Mounting plate, 1
5...Support shaft, 16...Roller, 17...Guiding member, 17b...(Guiding member) extension part.

Claims (1)

[Scope of utility model registration request] In an electrostatic recording device, a recording paper is supplied to the peripheral surface of an image carrier drum through a paper feeding path, and a toner image is transferred and the recording paper is separated by a transfer electrode and a separation electrode facing the same peripheral surface, A support shaft located facing the paper feed path supports a plurality of freely rotatable rollers that contact the recording paper, a plurality of guide members are positioned between these rollers, and the image carrier is moved close to the transfer electrode. A recording paper guide device for an electrostatic recording apparatus, characterized in that the recording paper is guided by an extension of the guide member extending parallel to the circumferential surface of the drum.