JPH0695548A - Fixation device of image forming device - Google Patents

Abstract

(57) [Abstract] [Purpose] The gap between the fixing rotator and the peeling guide can be easily obtained with a simple and low-cost structure, and the occurrence of scratches due to interference can be reliably prevented, so that the fixed image Improve quality. [Structure] A fixing guide 5 for separating the transfer material 18 from the fixing rotator 3 is provided with a fixing rotator cleaning means of a felt 25 or a blade, and these cleaning means are brought into contact with the fixing rotator 3 to thereby fix the fixing rotator 3 By forming a gap between the peeling guide 5 and the peeling guide 5 to prevent the fixing rotating body 3 from being damaged, deterioration of the fixed image can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device of an image forming apparatus which is used in a copying machine, an electrophotographic printer or the like and fixes an unfixed toner image on a transfer material.

[0002]

2. Description of the Related Art In recent years, copying machines applying electrophotographic technology,
In a fixing device such as a printer, a transfer member holding an unfixed toner image is nipped and conveyed by a fixing rotor that is heated by radiant heat such as a halogen lamp and a pressure rotor that presses at a constant pressure relative to the fixing rotor. Therefore, a fixing device of an image forming apparatus has been actively used, in which a toner image is fixed and a transfer material wound around a fixing rotating body is made peelable by a peeling guide.

By using the peeling guide, not only the peeling claw becomes unnecessary and cost efficiency and working efficiency are improved, but also the peeling guide is held in the image area in a non-contact manner to damage the surface of the fixing rotating member. Can be prevented and the problem of deterioration of the fixed image can be solved. The conventional image forming apparatus will be described below.

FIG. 3 is a sectional view of an image forming apparatus incorporating a conventional fixing device. In FIG. 3, an image carrier 7 having an inorganic or organic photoconductive layer provided on a conductive drum substrate.
Is rotatably supported by a support shaft 8 and is given a uniform negative charge on the surface by corona discharge generated by the charger 9. Then, a desired electrostatic latent image is formed on the image carrier 7 by the light emitted from the LED print head 10. Reference numeral 11 denotes a process cartridge, which is detachably attachable to the image carrier 7 and the process cartridge 11 and which accommodates a heat-meltable toner 12 which can be attached / detached, a supply roller 14 for supplying and stirring toner, and an agitator 15 and a developing device. It is composed of a roller 16.

The toner 12 supplied from the toner cartridge 13 is thinned on the surface of the developing roller 16, and the electrostatic latent image on the image carrier 7 is developed by the toner 12. On the other hand, the transfer material 18 supplied from the paper feed tray 17 is transferred by the half-moon shaped paper feed roller 19 via the conveyance path 20.
The toner image on the image carrier 7 is transferred to the contact point between the image carrier 7 and the image carrier 7 and transferred onto the transfer material.

The transfer material 18 on which the toner image is transferred has a fixing rotator 3 having a halogen lamp 2 as an internal heat source, and a pressing rotator 4 which is installed opposite to the fixing rotator 3 and forms a contact area by a certain pressing force. The unfixed toner image is fixed by passing through the fixing device 1 including a separation guide 5 for separating and guiding the transfer material 18 from the fixing rotating body 3 and a guide 6 for guiding the transfer material 18 in the contact area region. Then the ejection roller 22
Is discharged to the paper discharge tray 23.

FIG. 4 is an enlarged sectional view of the fixing device 1 shown in FIG. 3, in which both ends of the peeling guide 5 are provided with abutting portions 24 covered with a fluororesin having good slidability. Since it is configured to come into contact with the fixing rotator 3 outside the maximum image area, the peeling guide 5 is held with a minute gap with the fixing rotator 3 within the maximum image area. As a result, it is possible to obtain the gap amount relatively easily and with high accuracy, and even if the fixing rotary member 3 is scratched, the fixed image is hardly adversely affected.

[0008]

However, in the above-mentioned conventional structure, it is necessary that the abutting portion of the peeling guide is made of an expensive material such as fluororesin having high heat resistance and sliding property. If it is made into an integral structure including parts, it will be quite expensive.

Further, even when the peeling guide and the abutting portion are constituted by different members, not only the cost is increased due to an increase in the number of parts etc., but the peeling guide is relatively long in the longitudinal direction of the rotating body. Since it is a long resin molded product, it is difficult to completely suppress warpage of the finished product due to the residual stress during injection molding, even when using a low warp type heat-resistant reinforced resin containing a filler such as glass. A desired minute gap cannot be obtained in the area.

When this is remarkable, there is a problem that the surface of the fixing rotator is damaged due to the interference between the fixing rotator and the peeling guide and the fixed image is deteriorated, and the function required for the peeling guide is sufficiently satisfied. I can't do it.

Even if the above problem is solved, if friction occurs at the abutting portions provided at both ends of the peeling guide, a minute gap between the fixing rotating member and the peeling guide is not maintained, and the peeling guide and the fixing guide are fixed. This causes interference with the rotating body, and eventually the surface of the fixing rotating body is scratched in the image region, causing a problem such as deterioration of the fixed image.

The present invention solves the above-mentioned problems, and by eliminating the direct contact between the fixing rotator and the peeling guide with a simple and low-cost structure and preventing the occurrence of scratches on the surface of the fixing rotator, An object of the present invention is to provide a fixing device for an image forming apparatus that is high in quality and reliable.

[0013]

In order to achieve this object, in the fixing device of the image forming apparatus of the present invention, the peeling guide is provided with a cleaning means for the fixing rotary member, and the cleaning means rotates the fixing rotation within the maximum image area. By making contact with the body, a gap is formed between the peeling guide and the fixing rotator to prevent contact.

[0014]

According to the present invention, it is possible to prevent damage due to contact between the peeling guide and the fixing rotary member without being affected by the warp or positioning accuracy of the peeling guide.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2 showing the sectional views of the respective embodiments of the present invention, the same parts as those of the conventional example are designated by the same reference numerals and the description thereof will be omitted.

As shown in the sectional view of the first embodiment of FIG. 1, the peeling guide 5 of the fixing device 1 is provided with a felt 25 in which a proper amount of silicone oil having a cleaning function is impregnated, and the felt 25 is fixed to the fixing rotating body 3 of the peeling guide 5. The structure is provided on the surface on the side that is close to. The peeling guide 5 receives a force by the spring 26 so as to come into contact with the fixing rotary member 3 about the rotation support shaft 27, and is arranged so as to press the felt 25 in parallel with the generatrix direction of the fixing rotary member 3. As a result, the felt 25 is interposed between the peeling guide 5 and the fixing rotator 3, so that the fixing rotator 3 and the peeling guide 5 are held with a gap,
Not only the damage caused by these interferences can be prevented, but also the toner 25 remaining on the fixing rotary member 3 is cleaned by arranging the felt 25 in the longitudinal direction so as to be in contact with at least the maximum image area. It is also possible to maintain a desired high quality fixed image. Further, by providing the peeling guide 5 with a cleaning function, the degree of freedom in arranging the components of the fixing device 1 is increased, and it is effective for downsizing.

Next, as shown in the cross-sectional view of the second embodiment of FIG. 2, a blade 28 made of an elastic material such as silicone rubber is provided in place of the felt 25 as in the first embodiment. By doing so, a similar effect can be obtained.

As described above, according to the first and second embodiments, the peeling guide 5 is provided with the felt 25 or the blade 28 as the cleaning means, and the felt 25 or the blade 28 is brought into contact with the fixing rotary member 3. This prevents the peeling guide 5 from damaging the fixing rotator 3.

[0020]

As described above, in the fixing device of the image forming apparatus of the present invention, the peeling guide is provided with a cleaning function for the fixing rotary member, and the fixing device is rotated by the cleaning means coming into contact with the fixing rotary member. With the structure in which contact with the body is prevented, deterioration of the fixed image can be prevented in advance.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a fixing device showing a first embodiment of the present invention.

FIG. 2 is a sectional view of a fixing device showing a second embodiment of the present invention.

FIG. 3 is a cross-sectional view of an image forming apparatus including a conventional fixing device.

FIG. 4 is an enlarged cross-sectional view of the fixing device of FIG.

[Explanation of symbols]

1 ... Fixing device, 3 ... Fixing rotator, 4 ... Pressing rotator,
5 ... Peeling guide, 6 ... Guide, 12 ... Heat-melting toner, 18 ... Transfer material, 25 ... Felt, 26 ... Spring,
27 ... Rotary support shaft, 28 ... Blade.

Claims (5)

[Claims] 1. A fixing rotator having a heat source inside for fixing an unfixed toner image on a transfer material, and a pressure rotator that conveys the transfer material by a holding force of the fixing rotator.
In a fixing device of an image forming apparatus, which has a peeling guide which is disposed in the vicinity of the fixing rotating body and separates a transfer material from the fixing rotating body, the peeling guide has a cleaning means for the fixing rotating body, and the cleaning means. The fixing device of the image forming apparatus is characterized in that a gap is formed between the peeling guide and the fixing rotator by contacting the fixing rotator with each other to prevent the contact. 2. The fixing device for an image forming apparatus according to claim 1, wherein the cleaning unit is made of felt impregnated with silicone oil. 3. The fixing device of the image forming apparatus according to claim 1, wherein the cleaning unit is composed of a blade made of an elastic material such as silicone rubber. 4. The fixing device for an image forming apparatus according to claim 1, wherein the cleaning means is in contact with the fixing rotating member in parallel with a generatrix direction of the fixing rotating member. 5. The fixing device for an image forming apparatus according to claim 1, wherein the cleaning means is in contact with the fixing rotating body at least in the maximum image area.