JPS58105268A - Transfer device of electrophotographic copying machine - Google Patents

Abstract

PURPOSE:To prevent deterioration of a sensitized material of the surface of a photoreceptor, and deformation and quality change of an intermediate transfer body, by making the intermediate transfer body press-contact to the photoreceptor only in case of transfer, and separating it from the photoreceptor in other case. CONSTITUTION:Supporting shafts 8a, 9a of a conductive roll 8 and a pressure roll 9 are provided so as to freely move up and down, along lontiduinal holes 12, 13 of a substrate 11, and to a roll 14 axially supported by the supporting shaft 9a, a rocking lever 15 energized upward by a spring 16 is made to press- contact, and a cam 17 is made to press-contact to the lever 15. When transfer is not executed, for instance, a holding time of a copier, etc., the cam 17 is rotated, the lever 15 is rocked downward, and the rolls 8, 9 are separated from a photoreceptor 1. In case of transfer, the cam 17 is rotated, and is made to press-contact to the photoreceptor 1. Therefore, even if this device is used for many hours, it is possible to prevent deterioration of a sensitized material of the photoreceptor 1, and deformation and quality change of the roll 8.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transfer device for transferring a toner image on a photoreceptor to a transfer material such as paper in an electrophotographic copying machine.

Conventional seed transfer devices are those in which the paper is brought into close contact with the surface of the photoreceptor and a corotron discharges from the back side to transfer the paper, or the paper is transferred by pressing the paper against the surface of the photoreceptor using a roller to which a bias voltage is applied. There are known products that are pressurized to give the same effect.

However, in both transfer devices, paper is transferred to the surface of the photoreceptor.
! Since the structure allows the paper to be touched, it is necessary to remove the paper from the surface of the photoreceptor, which damages the photoreceptor surface when the paper is removed (9), and damages the photoreceptor surface when a paper jam occurs due to a mistake in paper removal, etc. Contains defects with.

Therefore, by making it possible to transfer the toner image on the photoreceptor without bringing the transfer material into contact with the photoreceptor surface, the photoreceptor surface was prevented from being damaged when the transfer material was peeled off or when the transfer material was peeled off incorrectly, resulting in paper jams. 2. Description of the Related Art There is known a transfer device for an electrophotographic copying machine, specifically, a transfer device that uses an intermediate transfer member to transfer a toner image on the surface of a five-photosensitive member to the intermediate transfer member, and then retransfers the toner image onto a sheet of paper.

However, in this transfer fI position, the intermediate transfer member and the photoreceptor are in constant pressure contact, so if the intermediate transfer member is contaminated with toner or the pressure applied to the nip area with the photoreceptor), the photoreceptor may This may result in deterioration or peeling of the sensitive material on the surface of the body, or deformation or alteration of the three intermediate rollers.

The present invention has been made in view of the above circumstances, and its purpose is to press the intermediate transfer member against the photoreceptor only when transferring the toner image on the surface of the photoreceptor to the intermediate transfer member; Transfer using an electrophotographic copying machine where the intermediate transfer body is sometimes separated from the photoreceptor! The purpose is to provide an I-position.

The present invention will be described in detail below with reference to the drawings.

A charging device 2, an exposure device 3, a developing device 4, a transfer device 5, a static eliminator 6, a cleaning device 7, etc. are sequentially arranged around the photoreceptor 10.

The transfer device 5 presses a conductive roll 8, which serves as an intermediate transfer member, and a pressure roll 9, and a voltage 1 having a polarity opposite to that of the toner image is applied to the conductive roll 8, and the pressure roll 9 receives the voltage. A high voltage v2 is applied to v1, hl, etc.

Then, the paper 10 is inserted into the nip between the conductive roll 8 and the pressure roll 9.

The conductive roll ε and the pressure roll 9 maintain a pressure contact state a and have a transfer position b (solid line position in FIG. 1) where the conductive roll 6 is in pressure contact with the photoreceptor surface 1- and a non-transfer position (FIG. 1 imaginary line position).

As shown in Figure 2, each roll has a spindle of 8°9.
The rollers 14 m and 9m are movable up and down along the vertical holes 12 and 13 of the substrate 11, and are provided on the support shaft 9 of the press roll 9.
The swinging lever (15) is in contact with the swinging lever 15, and the cough swinging lever 15 is
6, the cam 17 is in contact with the cam 17, and the cam 1) is rotated in forward and reverse directions by a solenoid (not shown) or the like.

Then, rotate the cam 17 to adjust the height @ 17a to the swinging lever 15.
Km, the swinging lever 15 swings downward against the spring 16, and each roll 8.9 becomes a non-rolling zero position device due to its own weight.
Rotate cam 17' to lower @ 17b t-swing lever 15
When it comes into contact with the
5. The cam 17 is moved to the transfer position via the roller 14, and when there is no need to transfer a toner image, such as when the copying machine is on standby, in an interim image area, or during an empty scan, the high s1 flap 1 is moved to the swing lever by a solenoid. When the toner image is transferred, the KFi low s1 foot is rotated to the position where it contacts the swing lever 15.

The rotation of the cam 17 is controlled by operating seven solenoid pipes in response to timing signals from the copying cycle.

Thus, an electrostatically charged image is formed on the surface 1 m of the photoreceptor, which is charged according to the original image, and toner charged to θ is adhered and developed by the developing device 4, toner gI! A mouth is formed.

At this time, each Ktj roll 8.9 is maintained at a non-transfer position.

Then, when the toner opening moves to a position facing the conductive roll 8 (toe 9, when transferring), each roll 8, 9 becomes the transfer position, and the conductive roll 8 comes into pressure contact with the surface of the photoreceptor 1 m, The toner image on the photoreceptor surface 11 is adhered and transferred to the conductive roll 8 and then transferred to the paper 10 again.

When the transfer is completed, each roll 8.9Fi is moved to the non-transfer position again.

In this way, since the conductive roll 8 is separated from the photoconductor surface 1m except when transferring, even if it is used for a long time, the photosensitive material on the photoconductor surface 1m will deteriorate, peel, or deform the conductive roll 8. There is no change in voltage, etc., and the surface of the photoreceptor!
Unnecessary toner on the conductive roll 8 does not adhere to and stain the conductive roll 8.

Note that the mechanism for vertically moving each roll 8.9 is the third one.
As shown in the figure, the support shafts 8m and 9m of each roll 8.9 are connected to the first. supported on the second swing lever 20.2+; The second swinging levers 20 and 21 are each urged upward by a spring 22 and brought into contact with the cams 23, and each cam 23 is rotated forward and backward by a solenoid or the like to move between a transfer position and a non-transfer position. It may also have a structure that moves up and down.

FIG. 4 shows an embodiment in which the photoreceptor is in the form of a belt.

The present invention is as described above, and after the toner image on the photoreceptor surface 11 is transferred to the intermediate transfer member 8, it can be transferred to paper again, and the intermediate transfer member S is transferred to the photoreceptor surface 11 except when transferring.
This can prevent deterioration and peeling of the photosensitive material on the surface of the photoreceptor 11, deformation and deterioration of the intermediate transfer member 8, and staining of the intermediate transfer member 6 due to long-term use.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is an overall explanatory diagram, FIG. 2 is an explanatory diagram of the main part, and FIG. 3 is an explanatory diagram of the main part. Fig. 84 is an explanatory diagram of another embodiment of the section. 1 is a photoreceptor, Is is a photoreceptor surface, 8 is an intermediate transfer member, 10
is paper. Applicant Fuji Xerox Co., Ltd. Agent Patent Attorney Masaaki Yonehara Patent Attorney Tadashi Soeki

Claims (1)

[Claims] In a transfer device that transfers one toner image on the surface of the photoreceptor 10 to the intermediate transfer member 6 and then transfers it again to the paper 14 after completion, the intermediate transfer member 8 is pressed against the photoreceptor surface 11 only at the time of rolling,
At other times, the sensory body surface is separated from the surface of the sensory body by one set.1--Characteristics of the electrophotographic copying machine 5iit.