JPH02150880A - Transfer paper separation device in fixing device - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to a transfer paper separation device in a fixing device.

The fixing device as described above is installed in copying machines and the like, and the one shown in FIG. 5, for example, is conventionally known. 1
5 is a heating roller with a built-in heater 3, and 2 is a pressure roller.
Both rollers 1.2 are arranged so as to sandwich the paper passing path of the transfer paper P carrying an unfixed toner image and press against each other. Reference numeral 5 denotes a separation claw arranged in contact with the surface of the heating roller 1 to prevent the transfer paper P passed between the rollers 1 and 2 and fixed from curling and wrapping around the heating roller 1. It has become. Reference numerals 7 and 8 denote a thermistor and a temperature fuse arranged around the heating roller 1, and the temperature is controlled by these. 9 is silicone coated felt.

Problems to be Solved by the Invention By the way, in the conventional fixing device, since the separating claw 5 is in contact with the surface of the heating roller 1,
When the heating roller 1 is made of a silicone-based rubber material, the surface is easily scratched and there is a problem in the durability of the heating roller 1.

Therefore, the present invention solves the above-mentioned conventional problems and provides a method for separating transfer paper in a fixing device that can easily and effectively separate the transfer paper without worrying about scratching the surface of the heating roller. The purpose is to provide equipment.

Means for determining the problem In order to achieve the above-mentioned object, the present invention provides a separate member (separation claw 5) between the heating roller 11 and the heating roller 11 with a small gap therebetween as shown in FIGS. It is characterized by a separation roller 25 or 25'' rotating in the same direction as the rotation direction.

■ As mentioned above, the separating roller 25 or 25' is connected to the heating roller 1.
1, the surface of the heating roller 11 is not scratched by the separation roller 25 or 25'. Further, the transfer paper P that is about to be wrapped around the heating roller 11 is separated by a separation roller 25 or 25' that rotates in the same direction as the heating roller, and the wrapping is prevented.

This example depends on the type of transfer paper P, i.e. oHP
This allows you to select either the first or second fixing section that is suitable for the fixing temperature of special paper that is difficult to absorb developer, such as film, second original drawing paper, or art paper, or plain paper. By selecting this option, it is possible to obtain good images without image deletion even on special paper.

In FIG. 1, 11 is a heating roller (RTV roller) with a built-in heater 13, 12 is a pressure roller, and both rollers 1
1 and 12 are arranged in pressure contact.

A plurality of suppression rollers 15 are arranged on the surface of the heating roller 11 on the opposite side to the pressure roller 12. On this occasion,
The suppression roller 15 is an emery roller with a sharp uneven surface and protrusions of 50 to 500 μm, and the heating roller 11
This is because they are arranged with a gap of 0.2 to 0.5 mrQ.

Even if toner adheres to the tip of the protrusion, it is cleaned by the cleaning roller 43.

The heating roller 11 is capable of forward and reverse rotation, and when driven in the normal direction, the first fixing section formed by the heating roller 11 and the pressure roller 12 fixes the plain paper, and when driven in the reverse direction, the heating roller 11 and the pressure roller 15 fix the paper. The second fixing unit that forms the special paper is fixed.

17 is a silicone oil application roller (material: surface silicone rubber) that serves both to clean the heating roller 11 and apply silicone oil, and is disposed in contact with the surface of the heating roller 11; 18 is in contact with the surface of the silicone oil application roller 17; A silicone oil application roller (material: surface coated with Teflon) arranged as a silicone oil coating roller uniformly and automatically replenishes the silicone oil 22 in the silicone oil reservoir 21 which has been deposited by the felt 20 from the roller 18 through the roller 17, and It is adapted to be applied to the surface of the heating roller 11. 23 is a scraper blade attached to the felt 20 in contact with the lower peripheral surface of the roller 18;
Foreign matter such as toner and paper dust offset on the surface of 8 is scraped off and collected.

As shown in FIGS. 2 and 3, 25 is a separation roller as a separation member having stepped collars 26 at both ends (only one end is shown in the drawing), and its both end shafts 25a are connected to both end shafts of the roller 17. It is supported by a long hole 31 of a bearing case 30 that is fitted through the shaft hole 28 . A spring 32 is disposed in the bearing case 30 to urge the shaft portions 25a at both ends of the separation roller 25 toward the shaft portions at both ends of the roller 17, and the force of the spring 32 causes the separation roller 25 to move against the stepped collar 26. A small gap G is formed with the surface of the roller 17 in a portion 27 other than the stepped collar 26 (inner portion where sheet passing is effective) that is in contact with the surfaces of both ends of the roller 17. Further, the bearing case 30 is brought into contact with the surfaces of both ends of the heating roller 11 by the force of the leaf spring 33 (FIG. 1), and at this time, the bearing case 30 is brought into contact with the surfaces of both ends of the heating roller
A small gap G2 is provided between the stepped collar 26 of the separation roller 25 and the portion 27 of the separation roller 25, respectively.
G3 is now formed.

The surface of the portion 27 of the separation roller 25 is subjected to an uneven treatment 35 such as knurling to improve separation performance.

Reference numeral 36 denotes an emery roller for guiding the transfer paper, which is rotatably supported under the silicone oil reservoir 21, and rotates when the transfer paper P is conveyed in contact with the emery roller.

In FIG. 1, 38 is a fixing entrance switching guide plate, 39 is a temperature sensor, 40 is a conveyance guide plate, 41 is a box plate which also serves as a conveyance guide, 42 is a paper discharge roller, and 43 and 44 are cleaning rollers. Further, in FIG. 3, reference numeral 46 denotes a drive gear for the heating roller 11, which is meshed with a gear system of a forward/reverse switching drive device (not shown) via an intermediate gear. A one-sided clutch 47 is operated to stop the rotation of the roller 18 when the heating roller 11 rotates in reverse. .

FIG. 4 shows another embodiment of the separation roller,
The separating roller 25' of this embodiment has a stepped collar 26' and a portion 27' separated from each other, and the collar 26' is attached to both end shaft portions.
It is rotatably inserted into 5'a. When installed in the fixing device, the collar 26' contacts the surface of the heating roller 11 so that a small gap G is formed between the portion 27' and the surface of the heating roller 11, and does not contact the roller 17. It is designed not to. With this configuration, for example, when the heating roller 11 is driven in reverse, only the stepped collar 26 rotates in the opposite direction, and the above-mentioned portion of the separation roller 25'
7' rotates in the same direction as the heating roller 11 in both forward and reverse directions.

In the embodiment shown in FIGS. 1 to 3, when the transfer paper P is plain paper, the guide plate 38 is switched to the solid line position, and the plain paper is placed in the first position.
Normally rotating heating roller 11 and pressure roller 1 as a fixing section
After passing through the nip No. 2 and being fixed, the paper passes through the conveyance guide plate 40 and is discharged from the paper discharge roller 42 to the outside of the machine. At this time, the silicone oil application roller 17.18
rotates in the forward direction relative to the heating roller 11, and the felt 20
The attached oil is evenly applied to the heating roller 11. Further, the separation roller 25 is rotated in the same direction as the rotational direction of the heating roller 11 via a stepped collar 26 in contact with the roller 17, and the fixed plain paper that is about to be wound around the heating roller 11 is separated.

Foreign matter such as offset toner and paper powder adhering to the heating roller 11 during the coating is transferred to the roller 18 via the roller 17, and these foreign matter are collected by the scraper blade 23.

At this time, the surface of the portion 27 of the separation roller 25 is not contaminated with foreign matter due to the small gap G□.

On the other hand, when the transfer paper P is special paper, the guide plate 38 is switched to the chain line position, and the special paper is fixed by passing through the gap between the reversing heating roller 11 and the pressure roller 15 serving as the second fixing section. Thereafter, the paper is discharged from the machine via a box board 41 and a paper discharge roller 42. At this time, the silicone oil application roller 17 rotates in the opposite direction to that when applying plain paper, but the rotation of the roller 18 is stopped by the one-sided clutch 47, and the foreign matter accumulated at the tip of the scraper blade 23 is removed from the roller 17. In addition to preventing the transfer of silicone oil, the silicone oil application function is also cut off.

In the above, the fixing temperature of the heating roller 11 is 140~
The temperature is set at 150° C., and the temperature is kept constant by a temperature sensor 39.

The transfer paper separation device described above can be applied to, for example, either a wet type or a dry type fixing device of a copying machine.

Since this invention is as described above and performs non-contact separation using the separation roller placed with a small gap from the heating roller, there is no possibility of damage to the surface of the heating roller. This method is effective in protecting the heating roller, as it can completely eliminate the transfer paper, make it possible to easily and effectively separate the transfer paper, and dramatically improve the durability of the heating roller.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an embodiment of the present invention. Fig. 2 is a partial perspective view of the main part, Fig. 3 is a partial plan view of the main part, Fig. 4 is a partial perspective view of the main part showing another embodiment of the separation roller, and Fig. 5 shows a conventional example. It is a front view.

Claims (1)

[Claims] 1. A fixing device in which a separating member is placed facing the heating roller to prevent the transfer paper that is fixed by passing between the heating roller and the pressure roller from being wrapped around the heating roller. A transfer paper separating device in a fixing device, wherein the separating member is a separating roller that rotates in the same direction as the heating roller with a small gap therebetween.