JPH0453658Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a peeling device for an image forming apparatus which is particularly suitable for use in a fixing device of an electrophotographic copying machine.

"Prior Art" Generally, the toner image transferred from a photoreceptor to copy paper or a sheet (hereinafter referred to as copy paper, etc.) is in an unstable state and can be removed even by touching it with the hand, so it must be stabilized by some method. The toner must be fixed on the copy paper, etc. in a safe condition. Usually, toner uses resin as its main component, and therefore, heat, pressure, etc. are used to fix the toners, and the toner and the copy paper, etc., for fixation.

Electronic copying machines that use a heat roller fixing system apply heat energy to the toner and copy paper through thermal conduction, and the copy paper holding the toner image passes between the fixing roller and the pressure roller. As a result, heat is directly transmitted from the surface of the fixing roller, and fixing is performed by the pressure of the pressure roller.

However, when such a heating type fixing roller is used, since the toner is melted, the copy paper or the like tends to adhere to the circumferential surface of the fixing roller due to its tackiness. Therefore, various means have been taken to separate the leading edge of copying paper, etc., in order to prevent such problems and send out the leading edge of copying paper, etc. in the correct ejection direction.

``Problems to be solved by the invention'' For example, in the past, a peeling device was configured to separate the leading edge of copy paper, etc. by bringing the tip edge of a thin plate-shaped peeling member into contact with the circumferential surface of a fixing roller. Proposed. However, in such a structure, there is a risk that the surface of the fixing roller may be damaged by the leading edge portion of the peeling member.

Therefore, in order to solve this problem, the leading edge of the thin plate-like peeling member is separated from the circumferential surface of the fixing roller, and at the same time, the leading edge of the peeling member is made to face the circumferential surface of the fixing roller with a predetermined distance. ,
So-called non-contact type devices have been proposed that are configured to separate the leading edge of copy paper, etc. However, in such a structure, since the width of the peeling member is narrow, the peeling force is concentrated on the paper itself, resulting in the formation of streaks on the paper (particularly OHP).

On the other hand, as a non-contact type, there are known peeling devices disclosed in, for example, Japanese Patent Application Laid-Open Nos. 53-70827, 1981-81241, and 1987-14245. In a peeling device with this structure,
The peeling member is formed of a single plate, and its width is approximately equal to the length direction of the fixing roller, so that concentration of peeling force on the copy paper or the like can be avoided. However, since the conventional peeling member described above is made of a single plate, it is difficult to produce straightness, and it is difficult to maintain a certain distance between the tip edge of the peeling member and the circumferential surface of the fixing roller. It was extremely difficult. Furthermore, although the peeling device with this structure is a non-contact type, the non-contact part is between the image area part of the fixing roller and the peeling member, and the non-contact part is between the part of the fixing roller in the non-image area and the peeling member. It is in contact with the other members. Therefore, damage to the fixing roller and removal of mold release agents such as silicone oil may occur, and in the latter case,
The scraped release agent enters the non-contact portion of the peeling member, spills from between the peeling member and the fixing roller, and adheres to copy paper, etc., resulting in image damage.

SUMMARY OF THE INVENTION An object of the present invention has been made in view of the above-mentioned drawbacks, and is to provide a completely non-contact type peeling device for an image forming apparatus in which the distance between the fixing roller and the peeling member can be set optimally.

"Means for Solving the Problems" A peeling device for an image forming apparatus according to the present invention includes a suspension body supported by both side plates of the device body, and a suspension body that is supported by the suspension body and is divided into a plurality of plate-like members. In order to achieve the above-mentioned object, the fixing roller is provided with a peeling member which is formed and has a predetermined gap between the leading edge portion of each of these divided members and the circumferential surface of the fixing roller. It is something.

"Example" Hereinafter, details of the present invention will be explained using examples shown in the drawings.

FIG. 1 is a schematic configuration diagram of a fixing device equipped with a peeling device for a copying machine according to the present invention, and FIG. 2 is a plan view of the fixing device. The fixing roller 1 has a heating element 2 therein, and a shaft 3 is connected to a side plate 4 of the main body of the copying machine.
5 via bearings 6 and 7 so as to be rotatable. The pressure roller 8 is arranged so as to be in pressure contact with the fixing roller 1, and is made of a material having appropriate elasticity to improve fixing performance. Although not shown in the drawings, the shaft of the pressure roller 8 is also rotatably supported by the side plates 4 and 5 of the copying machine body via bearings, similar to the shaft 3 of the fixing roller 1. When the fixing roller 1 and the pressure roller 8 pinch and press the copy paper 9 holding the toner image and convey it, the heat from the heating element 2 is directly transmitted from the surface of the fixing roller 1 to the copy paper 9. The structure is such that the toner image is fixed on the copy paper 9 by this action.

A peeling member 1 is located near the circumferential surface of the fixing roller 1.
0 is placed. This peeling member 10 is composed of three plate-shaped divided members 11 to 13 extending a predetermined amount in the axial direction of the fixing roller 1, and an appropriate interval α is set between these divided members 11 to 13. It is provided. Note that from the viewpoint of dispersing the peeling force, it is better that the width of the dividing members 11 to 13 is large and the distance α between the dividing members 11 to 13 is narrow. Divided members 11 to 1 of peeling member 10
3 is rotatably supported by a suspension body 14 via a shaft 15, and has a distal edge portion 11.
a to 13a are set to maintain a constant distance β from the circumferential surface of the fixing roller 1.

A pair of adjustment screws 16 and 17 are screwed and held in the suspension body 14, and the lower ends thereof are in contact with shoulders 11b to 13b located on both sides of the upper surfaces of the divided members 11 to 13, as shown in FIG. It has a structure.
In addition, in FIG. 1, the shoulder portion 11 of the divided member 11
Although only the configuration in which the lower ends of the adjusting screws 16 and 17 are in contact with b is illustrated, other divided members 1
The lower end portions of the adjustment screws 16 and 17 are also in contact with the shoulder portions 12b and 13b (13b is not shown) of the screws 2 and 13. The divided members 11 to 13 rotatably supported on the shaft 15 are provided with adjustment screws 16 and 17.
The distance β between the distal end edges 11a to 13a of the divided members 11 to 13 and the circumferential surface of the fixing roller 1 can be adjusted by tightening or loosening the adjustment screws 16 and 17. This is done by doing things like That is, if you want to set the distance β even narrower than the state shown in the figure, tighten the adjustment screw 16 located on the outside by a predetermined amount by moving it downward, and at the same time move the adjustment screw 17 located inside it upward. If loosened by a predetermined amount, the divided members 11 to 13 will rotate in the direction of arrow A in FIG.
The dimensions of can be set narrower. on the other hand,
If it is desired to set the distance β even wider, the operation described above may be reversed. In addition, to adjust the distance β, for example, use the thickness gauge with the dividing members 11 to 1.
3 and the fixing roller 1
This is done while it is sandwiched between the peripheral surface of the

Corner portion 1 of each divided member 11 to 13 of peeling member 10
When 1C, 12C, and 13C are formed into approximately right angles,
At the time of peeling, the toner surface touches these corners 11C, 12C,
13C may cause rubbing, resulting in dull streaks. Therefore, in this embodiment, these corner portions 11C, 12
C and 13C are formed into circular arc shapes with a predetermined curvature.

The suspension body 14 has both ends attached to the side plates 4 and 5 of the copying machine main body.
It has a structure in which it is hooked and supported on a shaft 18 fixed to. Note that the suspension body 14 may be structured to be easily fixed to the side plates 4 and 5 via magnets or the like.

With the structure of this embodiment, the peeling member 10 is disposed in a completely non-contact state with respect to the fixing roller 1, so it may damage the fixing roller 1 or scratch the release agent on the surface of the fixing roller 1. We are now able to reliably resolve problems such as falling off. Also,
Since the peeling member 10 is a plate-like member, the peeling force can be dispersed, and streaks that occur on the copy paper 9 due to concentration of the peeling force can be prevented. Furthermore, since the peeling member 10 has a divided structure consisting of three plate-shaped divided members 11 to 13, it is easier to achieve straightness in manufacturing compared to the conventional structure consisting of a single plate. The distance β formed between the peeling member 10 and the fixing roller 1 can also be maintained at a substantially constant dimension over the entire area. especially,
When the peeling member 10 has a split structure,
This is particularly convenient when the fixing roller 1 is a so-called tapered roller having different diameters along the axial direction as shown in FIG. That is, with a peeling member made of a single plate, it is extremely difficult to maintain a constant distance between the tapered fixing roller 1 and the peeling member in terms of manufacturing. However, if the peeling member 10 has a divided structure, each divided member 11 to 1
By making the rotation angles of 3 different, it is possible to adjust the distance between the tapered fixing roller 1 and the leading edge portions 11a to 13a of the dividing members 11 to 13 so that the distance is β at both sides and the center. can. Therefore, the releasability of such a tapered fixing roller 1 can be improved.

In addition, in the embodiment described above, the peeling member 10
Although the structure is divided into three parts, it is not limited to this number. Moreover, the peeling member 10
The material is not specified (iron, aluminum, resin, etc. may be used), but it is better to use a material that has heat resistance. In particular, if the surface of the release member 10 is coated with a high release material such as Teflon (registered trademark),
Furthermore, the peeling performance can be further improved. Also,
Although the suspension body 14 has a structure in which both ends are supported by the shaft 18 fixed between the side plates 4 and 5 of the copying machine main body, the structure is not limited to this, and although not shown, the suspension body 14 is supported by the fixing device main body. The structure may be such that it is supported by a shaft fixed between the side plates. Further, in the above-described embodiments, a peeling device of a copying machine is used as a peeling device of an image forming apparatus, but the device of the present invention is not limited to this. It can also be applied to

In the above-described embodiment, a mechanism (such as ISIL) that prevents toner from adhering to the leading edge of the copy paper is provided in the process before the copy paper enters the fixing device, and a third
As shown in the figure, toner 1
A configuration that prevents 9 from adhering may also be considered. Here, ISIL is an abbreviation for Interside Image Lamp. An inside image lamp is an LED (light emitting diode) lamp used to erase black streaks on the edges of copies. With this configuration, since there is no toner 19 in a predetermined range 9b from the leading edge 9a of the copy paper 9, the melted toner 19 will not be adsorbed to the fixing roller 1, and therefore the toner from the fixing roller 1 will not be absorbed. The leading edge 9a of the paper can be peeled off stably. This can prevent problems such as folding of the leading edge 9a of the paper (for example, dog ears) and poor peeling. This configuration is particularly effective for the toner 19 that is strongly attracted to the fixing roller 1.

"Effects of the Invention" As explained above, according to the peeling device of the image forming apparatus according to the present invention, the peeling member is arranged in a completely non-contact state with respect to the circumferential surface of the fixing roller. It is now possible to reliably eliminate the conventional problems of damaging the fixing roller or scraping off the release agent on the surface of the fixing roller, resulting in damage to the image.

In addition, since the peeling member is formed in a plate shape, the peeling force can be dispersed, and it is possible to eliminate the streaks (image damage) that conventionally occur on copy paper or sheets due to concentration of peeling force. can. Furthermore, since the peeling member is not a single plate but has a divided structure, it is easier to achieve straightness in manufacturing, and therefore the peeling member is formed between the tip edge of the peeling member and the circumferential surface of the fixing roller. The gap can be maintained at a constant size over the entire area. In addition, if the peeling member has a split structure, even if the fixing roller is a so-called tapered roller, by appropriately changing the rotation angle of the split member, the distal edge of the peeling member and the fixing roller can be separated. It has the effect that the distance between the roller and the peripheral surface can be maintained at a constant dimension, and the peelability can be further improved.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a fixing device equipped with a peeling device of a copying machine according to the present invention, FIG. 2 is a plan view of the fixing device, and FIG. 3 is a schematic diagram of a fixing device equipped with a peeling device of a copying machine according to the present invention. FIG. 3 is a schematic configuration diagram of another embodiment of the fixing device. DESCRIPTION OF SYMBOLS 1... Fixing roller, 4, 5... Side plate, 8... Pressure roller, 9... Copy paper, etc., 10... Peeling member, 11-13... Dividing member, 11a, 13a...
...Top edge portion, 14...Suspension body, β...〓between.

Claims (1)

[Claims for Utility Model Registration] A fixing roller and a pressure roller in pressure contact with the fixing roller are provided, and a copy paper or sheet is held and conveyed by the fixing roller and the pressure roller to fix the toner image on the copy paper or sheet. An image forming apparatus equipped with a fixing device includes: a fixing roller tapered to have different external shapes; a suspension body supported by both side plates supporting the fixing roller at both ends; and a suspension body supported by the suspension body. A peeling member is provided, which is a plurality of divided plate-like members, and is arranged such that a predetermined distance is formed between the leading edge part of the plate-like member and the peripheral part of the fixing roller. A peeling device for an image forming apparatus, characterized in that: