JPS5842076A - Transfer device - Google Patents

Abstract

PURPOSE:To prevent scattering of a developer to hold a good charging state, by charging the surface of a transfer material with a prescribed polarity before the transfer material is led to the surface of a photosensitive drum and providing a guide means which leads the transfer material. CONSTITUTION:Before transfer on a photosensitive drum 1, the electric charge having a polarity opposite to that of a developer is given to a transfer material by a corona discharger 3. A conductive roller 6 is so grounded that it functions as the counter electrode of a corona discharger 3, and the rear face of the transfer material is charged with the same polarity as the corona discharge polarity, which is given to the front face, by an insulating layer 5 on the outside circumference of the roller 6. A conductive rubber roller 7 functions to neutralize the opposite-polarity charge which is induced on the surface of the insulating layer 5 by friction. A feed roller 8 and a leading guide 9 are insulated from peripheral parts so as to prevent the escape of the charge given to the transfer material. Thus, the developer on the photosensitive drum is transferred well to the transfer material.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transfer device, and specifically relates to a transfer device that does not deteriorate the surface of a Fi image carrier (and is not easily contaminated by floating developer generated in the transfer section).

Conventionally, developed images formed on an image bearing member such as a photoreceptor based on an electrophotographic method or the like are transferred onto a transfer material by a transfer device. This transfer device applies a corona discharge of opposite polarity to the reverse side dye development when the transfer material is loaded onto the image carrier island. The corona transfer method 1 or transfer roller method is common, in which a conductive roller is pressed from the back side of the transfer material and a voltage of opposite polarity to that of the developing roller is applied to perform transfer.

However, in either case, since the image bearing member is disposed close to or in contact with the transfer position, it is inevitably affected by the scattering of developer that occurs during transfer, which causes contamination of the apparatus.

In the case of the corona transfer method, developer adheres to the discharge wire of the transfer corona discharger, causing problems in copying efficiency. In addition, in the 1-transfer-roll-2 system, the developer that adhered to the surface of the controlling roller adhered to the back surface of the transfer material, resulting in the inconvenience that the back surface of the transfer material was stained.

Further, in the case of the corona transfer method, there is a problem in that the pressure of the corona discharge acting on the surface of the image carrier causes deterioration of the surface of the image carrier such as the photoreceptor. Furthermore, in the transfer roller method, wear and tear on the image 414 carrier due to mechanical contact with the roller is unavoidable.

The present invention has been made in view of the above points.

The apparatus of the present invention is an apparatus for transferring the developed images on an image carrier onto a transfer material, and includes a charging means for charging the transfer material to a predetermined polarity before Igk the transfer material to the surface of the image carrier. Features. Furthermore, the present invention is characterized by having a guide means which is held insulatively and guides the transfer material to the image carrier transfer position.

Hereinafter, details of the present invention will be explained using specific examples with reference to the drawings.

FIG. 1 is a side view illustrating a specific example transfer device based on the present invention.

Reference numeral 1 denotes a photosensitive drum, which is rotated in the direction of the arrow by a drive source (not shown). A latent image forming means and a developing means (not shown) are arranged in the circuit of the drum 1 to form developed images on the photosensitive drum.

2 is a transfer material feeding roller, 3 is a corona group/electric device that applies a charge of opposite polarity to the developer onto the transfer material prior to transfer, and 4 is an opposing roller.

An insulating layer 5 with four opposing rollers is provided on a conductive core row 26, and the conductive core roller 6 is grounded so as to function as a counter pole of the corona discharger.

Further, five insulating layers on the conductive core row 26 are provided for contact and friction with the transfer material.

The material of this insulating layer is selected from a charging series that is charged to the same polarity as the corona discharge polarity that provides the back side of the FiX transfer material to the front side.

7a% conductive rubber roller ÷ opposing - 1 24 It functions to neutralize the opposite polarity charges induced by friction on the insulating layer on the surface.

Eight companies use a pair of feeding rollers to feed the pre-charged transfer material to the transfer position.

A guide 9 guides the transfer material to the image carrier transfer position.

Both the feed row 28 and the guide guide 9Fi are maintained insulated from the surroundings so that the charges applied to the transfer material do not escape.

In particular, the material of the guide is important for contact friction with the transfer material,
A material that induces charges of the same polarity as the corona discharge is suitable. . , For example, use plain paper as the transfer material and print a positive (+
) When a charge is applied, it is best to use a Teflon-based material.

Further, when a metal is used as the guide plate, voltages of the same polarity may be applied.

Furthermore, the guide plate may be sandwiched between insulating layers.

FIG. 2 shows a modification of the device according to the present invention, in which a corona discharger 10 to which the same polarity voltage is applied is also arranged on the side facing one corona discharger 6 instead of the above-mentioned opposing rollers. This forces the front and back surfaces of the transfer material to be corona-charged to the same polarity at the same time.

FIG. 6 is a side view of a further modified device based on the present invention.

In the apparatus shown in FIG. 6, a pair of voltage application electrodes 11 are arranged in place of the corona discharger. Demon mask low 2121, 121. , is hung up on. Each roller 121° 121 is a grounded metal roller. This insulating belt is in close contact with the transfer material, and also achieves the effect of preventing charges of opposite polarity from being placed on the transfer material side.

14h, to neutralize the opposite polarity charges induced on the surface of the insulating belt by a conductive rubber roller.
Since the transfer material is configured to be charged in advance before being led to the transfer position, the transfer material charging means is not affected by any adverse effects caused by floating developer that occurs at the transfer position, and a good charging state can always be maintained.

Moreover, since the transfer is sufficiently performed by the visible charge of the transfer material itself, there is no risk that the surface of the image carrier will be exposed to unnecessary high pressure or mechanical contact. Therefore, wear and deterioration of the surface of the image carrier is significantly reduced.

[Brief explanation of the drawing]

Figure 1 is a side view of a specific example transfer device based on the present invention, Figure 2 is a side view of a specific example transfer device based on the present invention (1111I @ figure of a modified example device,
FIG. 3 is a sectional view of a further variant of the device according to the invention. In the figure, 1: photosensitive drum (image carrier), 2: transfer material feeding roller, 3: corona discharger (charging means), 4: opposing roller, 5: insulating layer, 6: conductive core roller, 7; Conductive rubber roller, 8; feeding roller, 9; guiding guide.

Claims (1)

[Scope of Claims] (1) Charging means for charging the transfer material to a predetermined polarity before applying the transfer material to the surface of the image transfer material for transferring the developed images on the image carrier onto the transfer material; 1. A transfer device comprising: a guide means which is held insulatively and guides a transfer material to an image carrier transfer position. (2. In the invention set forth in claim 1, the transfer device is characterized in that the charging means has a corona discharger to which a voltage of the required polarity is applied. In the invention described in item 1, the transfer device is characterized in that the charging means has a plate to which a polarity voltage is applied.