JPS60125872A - Transfer paper separating device - Google Patents

Abstract

PURPOSE:To eliminate the need for a separation charger, separation pawl, etc., and take an entire-surface copy through simple constitution by bringing the front end of transfer paper into contact with the projection plate of a separation auxiliary roller where the transfer paper leaves a photosensitive body, and separating the transfer paper from the photosensitive body by the rotation of the roller. CONSTITUTION:The fed transfer paper 2 contacts the projection plate 10a of the separation auxiliary roller 10 where its front end leaves the photosensitive body by its stiffness at the curved part of the driven roller 1b of the photosensitive body, and is attracted to the projection plate 10a by charge charged electrostatically. The paper presses the projection plate 10a against the force of a spring 21 to rotate the roller 10 and separate the transfer paper 2 completely, and the roller 10 returns by the energizing force of the spring 21 after the paper passes. Therefore, the need for a separation charger, separation pawl, etc., is eliminated, so an entire-surface copy of an image is taken; and the projection plate 10a returns to its original position after the transfer paper passes, so continuous separation is performed stably through the simple constitution.

Description

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

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

Generally, an electrophotographic copying apparatus forms an electrostatic latent image by charging a photoreceptor formed in the shape of a drum or belt with a charging charger and exposing it to light. 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, because the transfer paper has an extra charge of the opposite polarity to the toner due to the corona discharge of the transfer stop, The transfer paper is attracted to the photoreceptor by this electrostatic attraction. This makes it difficult to separate the transfer paper from the photoreceptor. As one of the devices to easily separate this, a separation charger is provided separately from the transfer charger, and this removes the excess charge applied during transfer.
A so-called electrostatic separation device is used, which is electrically treated so that the transfer paper naturally separates from the photoreceptor due to its rigidity and weight.

As described above, in the electrostatic separation device, separate chargers must be provided for the transfer charger and 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, in a separation belt device that processes separation mechanically, as shown in FIGS. 1 and 2, a transfer paper 2 guided to a photoreceptor tram 1 by a transfer guide 6 is exposed to light by an image forming means. The toner image formed on the surface of the body drum 1 is transferred by a transfer charger 5. At this time, one end A on one side of the transfer paper 2 is held between the separation belt 3 and the separation roller 4 -9, and is removed from the image area of the transfer paper 2 along the end of the transfer material conveyance path of the photoreceptor drum 1. is&:
A: Proceeds without contacting the photoreceptor tram 1 6
On the other hand, the portion of the image area near the center other than the above-mentioned end portions is in contact with the photoreceptor drum 1, and the toner image is transferred by the transfer charger 6, progressing at the same speed as the photoreceptor drum 1, and transfer and separation occur. will be carried out.

As is clear from the above, the end portion of the transfer paper held by the separation belt exists separately from the image area.

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. Actually, there is another separation device that uses a separation charger and separation claw together. As shown in FIG. 3, the transfer paper 2 guided by the photoreceptor drum A 1 transfers the toner image formed on the surface of the photoreceptor drum 1 by the image forming means to the transfer charger 5 by the transfer guide 6 as shown in FIG. and then separated by a separation charger 7. However, since the force that separates the transfer paper 2 from the photoreceptor drum 1 easily changes depending on the ambient environmental conditions such as humidity, it may be difficult to separate the transfer paper 2 from the photoreceptor drum 1 when it is not separated enough or when the separation is difficult. There are times when it is not done. At these times, the transfer paper 2 is separated from the photoreceptor 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 uses a protruding plate at a position where the transfer paper is separated from the photoconductor due to the charging of the transfer paper itself after transfer and the rigidity of the transfer paper at the photoconductor 1-circle portion. / A separation auxiliary roller is arranged, and after the leading edge of the transfer paper after transfer comes into contact with the protruding plate, the separation auxiliary roller is rotated by the general feeding force of the transfer paper to separate the transfer paper from the photoreceptor. It is something.

In addition, after the transfer paper has passed, the protruding plate of the separation auxiliary roller is configured to return to its original position, which enables stable transfer paper separation, simplifies the multi-unit configuration, and improves image quality. It is possible to copy the entire area.

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 4, 1b op
A belt-shaped photoreceptor (hereinafter referred to as photoreceptor) using c (organic photoconductor), 1a is a 120 mm φ photoreceptor 1 driving drum, 1b is a 30 nm, φ photoreceptor driven roller, 2 is a transfer paper, 6 is a transfer guide, 9 is a charging and transfer charger, 10 is a separation auxiliary roller including a projection plate 10a, 11
1 is a fixing guide, 12 is a cassette containing the transfer paper 2, 13 is a feed roller, 14 is a pair of transport rollers, 1
6 is a developing device, 16 is an exposure device including an optical fiber lens 16a and a lamp 16b, 1 is a cleaning device, 18 is a photoreceptor static elimination lamp, 19 is a fixing device, and 20 is a paper discharge tray.

The operation of the transfer paper separating device head of this embodiment constructed as described above will be described below.

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 14.

Next, the transfer paper 2 is guided to the photoreceptor 1 and is brought into close contact with the photoreceptor 1 electrostatically, and the l/toner image formed on the photoreceptor 1 is transferred by a charging and transfer charger 9.

On the other hand, the lower part of the photoreceptor driven roller 1b has a thickness of 0.2
Mm, height 2 stories, width 270 Deaf shape with attached protruding plate 102L made of aluminum, diameter 10M, width 270
An aluminum rod of MTo is arranged as a separation auxiliary roller 10. 1. To the separation auxiliary roller 10.
A coil spring 21 is provided so as to rotate with a tension of 59, and the tip of the protruding plate 10a, 7jAj, is at an angle of 3f from the center line of the photoreceptor driven roller 1a.
Photoreceptor 1 and protruding plate 10? The gap between the tip of L'/jfj is 0
．． It's supposed to be 58. When the transfer paper 2 transferred in this state advances and goes straight to the photoconductor driven roller 1b, the leading edge of the transfer paper 2 is separated from the photoconductor 1 for an instant due to the rigidity of the IT transfer paper 2. At this time, the leading edge of the transfer paper 2 comes into contact with the protruding plate 102L of the separation auxiliary roller 10 disposed on the photoreceptor driven roller 1b, and is electrostatically attracted to the transfer paper 2 by the electric charge generated by the transfer. As shown in FIG. 6, when the transfer paper 2 further advances at the same speed as the photoreceptor 1, the conveying force of the transfer paper 2 causes a coil spring 2 of 5 g to
The transfer paper 2 is pushed onto the photoreceptor 1 while rotating the separation auxiliary roller 10 by pushing the protruding plate 10a with a force stronger than the tension of 1.
The toner is completely separated from the toner, reaches the fixing guide 11, and is sent to a fixing device (not shown). When the transfer paper 2 further advances and passes the separation auxiliary roller 10, the tension of the coil spring 21 causes the projection plate 10a to rotate toward the photoconductor driven roller 1b and return to its original position, in order to separate the next transfer paper 2. It is something that is prepared. In the above embodiment, the material used for the protruding plate and the separation auxiliary roller was aluminum, but the protruding plate is not limited to aluminum, and has the function of electrostatically adsorbing the transfer paper using an electric charge. Anything is fine as long as it has the following. For example, stainless steel can be used.

Effects of the Invention As is clear from the invention described above, the present invention is a device for separating transfer paper from a photoreceptor, which separates the transfer paper from the photoreceptor by the charging of the transfer paper itself after transfer and the rigidity of the transfer paper at the photoreceptor roll portion. A separation auxiliary roller having a protruding plate is arranged at the detachment position, and after the leading edge of the transfer paper after the transfer comes into contact with the protruding plate, the separation auxiliary roller is rotated by the conveying force of the transfer paper to remove the transfer paper from the photoreceptor. Since it is configured to be separated, there is no need for a conventional separation charger and AC power supply, and there is no need to worry about the separation bell 1 or separation claw, so it is possible to copy the entire image, and the separation No more problems with claw marks. Furthermore, after the transfer paper has passed, the protruding plate of the separation auxiliary roller is configured to return to its original position, thereby providing continuity.

[Brief explanation of the drawing]

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.
This figure is a side view of another conventional device, FIG. 4 is a schematic diagram of an example of a copying machine to which an embodiment of the present invention is applied, and FIGS. 6 and 6 are side views of an embodiment of the present invention. 1... Belt-shaped photoreceptor, 1b - Photoreceptor driven roller, 10 - Separation auxiliary roller, 10a... Projection plate, 21
··· Spring. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 3 A Figure 4

Claims (1)

[Claims] (1) A separation auxiliary roller with a protruding plate is arranged at a position where the transfer paper separates from the photoreceptor due to the charging of the transfer paper itself after transfer and the rigidity of the transfer paper at the photoreceptor roll part, and the transfer paper after transfer is A transfer paper separation device characterized in that, after the tip of the transfer paper comes into contact with the projection plate, the separation auxiliary roller is rotated by the conveying force of the transfer paper to separate the transfer paper from the photoreceptor. (≧ The transfer paper separation device according to claim O), characterized in that the separation auxiliary roller has a function of returning to its original position after the transfer paper has passed.