JPH02304473A - Transferring device of electrophotographic device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a transfer device for an electrophotographic apparatus.

BACKGROUND OF THE INVENTION First, a conventional example of a transfer device that forms an electrostatic latent image on a photoreceptor, develops the electrostatic latent image, and transfers the developed image to paper is shown in FIGS. 6 and 7. , transfer charger 50
has a wire (not shown) housed in a metal case 51 and a grid 53 facing the wire. The dielectric belt 1 has a dielectric layer on the front surface and a conductive layer on the back surface.

Then, by charging the dielectric belt l that conveys the paper 4 with a transfer charger 50, the developed image developed on the photoreceptor (not shown) is transferred to the paper 4.

Problems that the invention aims to solve The dielectric belt 1 ages over time.

Both side edges between the drive rollers 2 and 3 are warped in the outer circumferential direction. That is, both side edges of the dielectric belt l are close to or in contact with the grid 53 of the transfer charger 50, as shown in FIG. Therefore, the electric charge applied to the grid 53 is discharged to the dielectric belt 1, causing deterioration of the dielectric belt 1, and there is a risk that the circuit may malfunction due to the discharge.

Means for Solving the Problems After forming an electrostatic latent image on a photoreceptor, this electrostatic latent image is developed, and the developed image on the photoreceptor is transferred by a transfer charger to a paper conveyed by a dielectric belt. In the electrophotographic apparatus, an insulating portion extending from both side edges of the sheet to both outsides of the dielectric belt is disposed on a surface of the transfer charger on the dielectric belt side.

Even if both side edges of the working dielectric belt warp in the outer circumferential direction, they come close to or come into contact with the insulating portion, so that discharge from the transfer charger to the dielectric belt can be prevented.

Embodiment A first embodiment of the present invention will be described with reference to FIGS. 1 to 3. The same parts as the conventional example explained in FIG. 6 and FIG.
. Reference numeral 5 denotes a transfer charger, and as shown in FIG. 3, this transfer charger 5 is composed of a frame 6, a wire 7, and a grid 8, each made of stainless steel. Wire holders 9 made of synthetic resin are attached to both ends of the channel-shaped frame 6.
10 is fixedly provided, and the force wire holder 9 is integrally formed with a pin 12 that holds the other end of the spring 11, one end of which is fixed to the end of the wire 7. A high voltage terminal 13 to which the end of the wire 7 is fixed is held. These wire holders9. The open surface of the to is closed by a synthetic resin holder lid 14 which is an insulating part. That is, a plurality of tongue pieces 15 are formed on these holder lids 14, and these tongue pieces 15 are elastically engaged with locking portions 16 formed on the wire holders 9 and 10. Furthermore, locking holes 17 are formed on both sides near both ends of the grid 80, and a grid terminal 19 and a projecting piece 18 that engages with the locking hole 17 are bent in the frame 6.

As shown in FIGS. 1 and 2, the width of the dielectric belt l is α, the width of the paper 4 is Ql, the total length of the grid 8 and the interval between the inner edges of the holder lid 14 are α1, and the width of the holder lid 14 is α1. Assuming that the distance between the outer edges is Q, these dimensions are determined as follows.

Q, (Q, , (12(α.

In such a configuration, for example, the high voltage terminal 13G,
When a voltage of 6KV is applied to the grid terminal 19, corona discharge occurs due to the potential difference, and the paper 4
The dielectric belt l that conveys the is charged. This results in
The developed image developed on the photoreceptor is transferred to paper 4.

At this time, even if both edges of the dielectric belt 1 warp in the outer circumferential direction between the drive rollers 2 and 3, the insulating holder lid
4, the charges applied to the frame 6 and the grid 8 through the grid terminal 19 will not be discharged to the dielectric belt l. This prevents the circuit of the electrophotographic apparatus from malfunctioning and prevents the dielectric belt 1 from deteriorating.

Next, a second embodiment of the present invention will be described based on FIGS. 4 and 5. In this example, grid 8 and frame 6
An insulating sheet 20 made of mylar or the like is pasted to both ends of the insulating section.

In this case as well, the width of the dielectric belt 1 is 0 and the width of the paper 4 is
The width of the insulating sheet 2o is Ql, the distance between the inner edges of the insulating sheet 2o is L,
Assuming that the distance between the outer edges of the insulating sheet 20 is Q, these dimensions are determined as follows.

Q, <Q, <Q<Q.

Therefore, when both side edges of the dielectric belt l are warped in the outer circumferential direction, they come into contact with the insulating sheet 2o. As a result, the same effects as in the embodiment described above can be obtained.

Effects of the Invention Since the present invention is constructed as described above, even if both edges of the dielectric belt curve in the direction of the outer circumference, they contact the insulating portion of the transfer charger, so that the electric charge applied to the grid is not transferred to the dielectric belt. can be prevented from discharging, therefore
This has the effect of preventing malfunction of the circuit of an electrophotographic apparatus and deterioration of the dielectric belt due to discharge.

[Brief explanation of the drawing]

1 to 3 show a first embodiment of the present invention; FIG. 1 is a perspective view, FIG. 2 is a front view, FIG. 3 is an exploded perspective view of the transfer charger, and FIG. 4 is a perspective view of the transfer charger. and FIG. 5 show a second embodiment of the present invention, FIG. 4 is a perspective view, FIG. 5 is a front view, FIGS. 6 and 7 show a conventional example, and FIG. is a perspective view, and FIG. 7 is a front view.

Claims (1)

[Scope of Claims] 1. After forming an electrostatic latent image on a photoreceptor, this electrostatic latent image is developed, and the developed image on the photoreceptor is transferred onto a sheet of paper conveyed by a dielectric belt using a charger. An electrophotographic apparatus for transferring, characterized in that an insulating section extending from both side edges of the sheet to both outsides of the dielectric belt is disposed on a surface of the transfer charger on the side of the dielectric belt. transcription device. 2. A transfer device for an electrophotographic apparatus, characterized in that an insulating sheet is attached as an insulating portion to the surface of the transfer charger on the dielectric belt side.