JPS60126676A - Transfer paper separating device - Google Patents

Abstract

PURPOSE:To separate stably a transfer paper, and to simplify a constitution by providing a separation auxiliary roller having a member whose diameter is larger than that of the separation auxiliary roller, on a position where the transfer paper is separated from a photosensitive body by stiffness of the transfer paper and electrostatic charge of itself. CONSTITUTION:The tip of a transfer paper 2 goes straight on by stiffness of paper as shown by a broken line, and in a curved part of a photosensitive body driven roller 1b, the transfer paper 2 is separated naturally from a photosensitive body 1 for an instant. A separation auxiliary roller 10 is provided on this place, therefore, the tip of the transfer paper 2 contacts to the separation auxiliary roller 10, and it is attracted electrostatically to the separation auxiliary roller 10 by a charge charged electrostatically to the transfer paper 2 by means of a transfer. Also, when the photosensitive body 1 and the transfer paper 2 advance at the same speed, the tip of the transfer paper 2 reaches a fixing guide 13 and the separation is executed exactly. Accordingly, the transfer paper can be separated from the photosensitive body without using a separating charger, a separating belt and a separating pawl, the separation is stabilized, and the constitution is simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a device for separating a photoreceptor and a transfer paper in an electrophotographic copying apparatus.

Structures of conventional examples and their problems Conventional transfer paper separation devices include one based on electrical processing using a separation charger, one based on mechanical processing using a separation belt, and one based on electrical processing using the above-mentioned separation charger and separation claw. Some use mechanical processing in combination.

In general, an electrophotographic copying device charges a photoreceptor formed in the shape of a drum or belt with a charging charger and then exposes it to i.
to form an electrostatic latent image. Develop this with toner,
With the transfer paper in contact with the developing surface, a transfer charger applies corona discharge to the transfer paper with a polarity opposite to the charge held by the toner, thereby transferring the developed toner image on the photoreceptor to the transfer paper. Next, when the transfer paper on which the toner image has been transferred is separated from the surface of the photoreceptor, the fc of the transfer paper is
Since there is an extra charge of opposite polarity to the toner due to corona discharge, the transfer paper is attracted to the photoreceptor by this electrostatic attraction. This makes it difficult to separate the transfer paper from the photoreceptor. A separation charger is installed separately from the transfer charger as one of the devices to easily separate this.This removes the excess charge applied during transfer, and the rigidity and weight of the transfer paper allows it to be naturally separated from the photoreceptor. A so-called electrostatic separation device that is electrically processed to do so is used.

As described above, the electrostatic separation device must include a separation charger in addition to the transfer charger.

Furthermore, since the separation charger uses alternating current (AC) corona discharge, it is necessary to provide an AC high voltage power source.

On the other hand, a separation belt device that processes the separation method mechanically has a transfer guide 6 as shown in FIGS. 1 and 2.
The transfer paper 2 guided by the photoreceptor drum 1 is
The toner image formed on the surface of the photosensitive drum 1 is transferred by the transfer charger 5 to the image forming means.

At this time, one end A of the transfer paper 2 is held between the separation belt 3 and the separation roller 4, and the end of the transfer paper 2 away from the image area is moved along the end of the transfer material conveyance path of the photoreceptor drum 1. It advances without contacting the photoreceptor drum 1.

On the other hand, the portion of the image area near the center other than the above-mentioned end portion is in contact with the photoreceptor drum 1, and the toner image is transferred by the transfer charger 5, progressing at the same speed as the photoreceptor drum 1, and the transfer and separation are completed. It is done. As is clear from the above, the transfer end portion held by the separation belt exists separately from the image portion. Therefore, the image is deleted from the edges of the copied image (the part held by the separation belt), and there is a drawback that the entire image cannot be copied.

There is also another separation device that uses a separation charger and separation claws together.

As shown in Figure 3, this device uses a transfer mechanism to
A toner image formed on the surface of the photoreceptor drum 1 by an image forming means is transferred to the transfer paper 2 kited to the photoreceptor drum 1 by a transfer charger 5, and then separated by a separation charger 7. However, the force that separates the transfer paper 2 from the photoreceptor drum 1 is likely to deteriorate depending on ambient environmental conditions such as humidity, so the transfer paper 2 may not be separated sufficiently from the photoreceptor drum 1 or may not be separated at all. . At these times, the transfer paper 2 is separated from the photosensitive drum 1 by the separating claw 8 in the direction of the arrow as shown by the dashed line. However, in this case, there is a drawback that the unfixed toner image held on the surface of the transfer paper 2 is rubbed when it comes into contact with the separation claw 8, and a mark is formed on the toner image. Furthermore, since the separating claw constantly contacts and rubs the photoreceptor, there are problems such as scratches on the surface of the photoreceptor.

OBJECTS OF THE INVENTION An object of the present invention is to provide a transfer paper separation device that separates transfer paper from a photoreceptor without using a separation charger, a separation belt, or a separation claw.

Structure of the Invention The transfer paper separation device of the present invention includes a member having a diameter larger than the diameter of the separation auxiliary roller at a position where the transfer paper is separated from the photoconductor force due to the charge of the transfer paper itself and the rigidity of the transfer paper at the photoconductor roll portion. Placing auxiliary separation rollers provided at both ends, pressing the auxiliary separation rollers against the photoreceptor roll,
The transfer paper is rotated with the drive of the photoreceptor, and after the leading edge of the transfer paper after transfer comes into contact with the separation auxiliary roller, the transfer paper is separated from the photoreceptor. This allows for stable transfer paper separation. This simplifies the configuration of the copying machine and makes it possible to copy the entire image.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 4 shows a schematic diagram of an example of a copying machine to which the transfer paper separating device of the present invention is applied. In Figure 5, 1 is OP
A belt-shaped photoreceptor (hereinafter referred to as
1a is a 120mmφ photoconductor driving drum, 1b is a 30mmφ photoconductor driven roller, 2 is a transfer paper, 6 is a transfer guide, 9 is a charging and transfer charger (
(hereinafter referred to as charger), 10 has a diameter of 10 mm
, a separation auxiliary roller with natural rubber members 10 c each having a width of 3B and a diameter of 11.4 m attached to both ends of an aluminum rod with a diameter of 270 + n + n, 10 a is a shaft on which the separation auxiliary roller 10 can rotate. be.

11 is an L-shaped metal fitting integrated with the shaft 10a of the separation auxiliary roller, 11a is a shaft that allows the L-shaped metal fitting 11 to rotate fully, 12 is a pipe, 13 is a fixing guide, and 14 is a transfer paper 2.
15 is a delivery roller, 1
6 is a pair of transport rollers, 17 is a developing device, 18 is an exposure device of an optical fiber lens 18a and a lamp 18b, 19
20 is a photoconductor cleaning device, 20 is a photoconductor static elimination lamp 521 is a fixing device, and 22 is a paper discharge tray.

The operation of the transfer paper separation device of this embodiment constructed as described above will now be described.

The transfer paper 2 indicated by a broken line in FIG. 5 is sent to the transfer guide 6 by a pair of transport rollers 16.

Next, the transfer paper 2 is guided to the photoreceptor 1 and comes into close contact with it electrostatically, and the toner image formed on the photoreceptor 1 is transferred by the charger 9.

On the other hand, the separation auxiliary roller 1o is a photoconductor driven roller 1b.
The separation auxiliary roller 10 is arranged at an angle of 32° from the center perpendicular to the direction in which the transfer paper 2 travels, and the separation auxiliary roller 10 is attached to the photoreceptor 10 by an L-shaped fitting 11 and a spring 12, as shown in FIG.
Pressed against the surface.

At this time, the natural rubber members 10c at both ends of the separation auxiliary roller 100 are in contact with the photoreceptor 1, and there is a gap of 0.7 inch in the middle between them, equal to the thickness of the natural rubber member 10C. When the photoreceptor runs in this state, the separation auxiliary roller 10 always rotates with a gap of 0.7M maintained.

The leading edge of the transfer paper 2 indicated by a broken line in FIG. 5 moves straight due to the rigidity of the paper, and the transfer paper 2 is automatically separated from the photoreceptor for an instant at the curved portion of the photoreceptor driven roller 1b. Since the separation auxiliary roller 10 is arranged at this location, the leading edge of the transfer paper 2 comes into contact with the separation auxiliary roller 10, and is electrostatically attracted to the separation auxiliary roller 10 due to the electric charge charged on the transfer paper 2 during transfer. do. Furthermore, photoreceptor 1
When the transfer paper 2 advances at the same speed, the leading edge of the transfer paper 2 reaches the fixing kite 13, thereby ensuring separation.

In the above embodiment, an aluminum rod was used as the separation auxiliary roller, but the material is not limited to aluminum, and any material may be used as long as it has the function of electrostatically adhering to the transfer paper due to its electric charge. For example, stainless steel, brass, etc. can be used, and a cylindrical shape can also be used.

Effects of the Invention As is clear from the invention described above, the present invention is a device for separating a transfer paper from a photoreceptor. A separation auxiliary roller having members having a diameter larger than the diameter of the separation auxiliary roller at both ends is arranged at a position where the separation auxiliary roller is detached, and the separation auxiliary roller is pressed against the photoreceptor roll portion and rotated together with the drive of the photoreceptor; The structure is such that the transfer paper is separated from the photoreceptor after the leading edge of the transfer paper comes into contact with the separation auxiliary roller, so there is no need for a conventional separation charger, AC power supply, etc.
Furthermore, since no belt or separation claw is required, it is possible to copy the entire image, there is no problem of separation claw marks, stable transfer paper separation is possible, and the copying machine configuration is simplified.

[Brief explanation of drawings]

Figure 1 is a perspective view of the conventional device, Figure 2 is its side view, and Figure 3 is a perspective view of the conventional device.
4 is a schematic diagram of an example of a copying machine to which an embodiment of the present invention is applied; FIG. 5 is a side view of essential parts of an embodiment of the present invention; FIG. 6 is a side view of another conventional device; FIG. 2 is a perspective view of the embodiment of the present invention. 1. Belt-shaped photoreceptor, 1b Photoreceptor driven roller, 1o Separation auxiliary roller, 10a Separation auxiliary roller shaft, 10C Natural rubber member, 1
1... L-shaped fitting, 11a... Shaft of L-shaped fitting,
12. Spring. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure I Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] Separation auxiliary roller metal arrangement in which members with a diameter larger than the diameter of the separation auxiliary roller are provided at both ends at the position where the transfer paper separates from the photoconductor due to the charge of the transfer paper itself after transfer and the rigidity of the transfer paper at the photoconductor roll part. Then, the separation auxiliary roller is pressed against the photoreceptor roll part and rotated as the photoreceptor is driven, and after the leading edge of the transfer paper after transfer comes into contact with the separation auxiliary roller, the transfer paper is separated from the photoreceptor. A transfer paper separating device characterized by being configured as follows.