JPH0619359A - Fixing device - Google Patents

Abstract

PURPOSE:To exchange only a felt pad without discarding a pad holding member which need not be exchanged by attaching an engaging member formed of a material having higher rigidity than the felt pad to the felt pad. CONSTITUTION:This device is provided with a felt 23 pressured to contact with a fixing roller and the felt holding member 29 being the engaging member consisting of plastic material having the higher rigidity than the felt in order to give the rigidity to the felt 23. The felt 23 and the member 29 are stuck with adhesive or a double coated tape. As for a contact surface between the felt 23 and the member 29, in such a case, the area of the contact surface of the member 29 is larger, and the felt 23 is stuck to the central part of the member 29. By inserting the member 29 in the groove part 22a of a holder 22 in a direction shown by an arrow from a shaft direction, the felt 23 is fixed in the holder 22. In the case of exchanging the felt 23, the felt 23 is allowed to slide in an opposite direction, so that it is easily detached.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device in an image forming apparatus.

[0002]

2. Description of the Related Art In a conventional image forming apparatus, in order to remove paper powder, toner, etc. adhering to the surface of a fixing roller due to use, a fixing felt is brought into pressure contact with a cleaning felt. Some are equipped with devices. In such an apparatus, the felt is held by a fixing pad holder made of a plastic material via a double-sided tape or the like in order to press the felt with uniform and proper pressure over the entire axial direction of the fixing roller holder. The pressing force is urged by a leaf spring or the like.

Further, the felt surface of the fixing pad is
As it is contaminated with paper dust and toner wiped off the surface of the fixing roller during use, hold the protruding grip part of the fixing pad holder at a certain time or when the cleaning performance deteriorates and the original performance is no longer exhibited. , The user of the image forming apparatus or a service person replaced it.

[0004]

However, according to the above-mentioned conventional example, when the felt surface of the fixing pad is soiled and the original cleaning performance is no longer exhibited, the holder and the felt are replaced by double-sided tape or the like. Since it was permanently bonded, the entire fixing pad was replaced with a new one, and the used one was discarded.

However, the holder of the fixing pad is made of a plastic material, and in the state of being used in the fixing device, the pressing force is only applied by a leaf spring or the like, and there is no rubbing against other parts, and the fixing pad is reused. Was possible.

In other words, even if the felt of the fixing pad becomes dirty and it is time to replace it, the holder itself can still be used, which is a great obstacle in terms of environmental protection and resource reuse.

An object of the present invention is to solve the above problems and to a fixing device which can use the fixing pad without waste.

[0008]

According to the present invention, the above problems are caused by a fixing roller for fixing an unfixed image on a recording material, and a surface of the fixing roller which is in contact with the fixing roller to clean the surface. In a fixing device having a felt pad and a pad holding member that holds the felt pad, an engaging member having higher rigidity than the felt pad is attached to the felt pad, and the engaging member is the pad. This is achieved by being detachably arranged on the holding member.

[0009]

According to the present invention, since the engaging member is attached to the felt pad and the engaging member is removably arranged on the pad holding member, for example, when the felt pad becomes dirty, The replacement work is completed by removing the felt pad from the pad holding member and attaching a new felt pad to the pad holding member. That is,
Only the felt pad can be replaced without discarding the pad holding member that does not need to be replaced.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment and a second embodiment of the present invention will be described with reference to the drawings.

<First Embodiment> First, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an explanatory diagram showing a schematic configuration of a laser beam printer according to a first embodiment of the present invention. Hereinafter, a schematic configuration of a laser beam printer to which the fixing device of the present invention is applied will be described with reference to FIG.

In FIG. 1, reference numeral 1 denotes a scanner unit, which is composed of a laser, a polygon mirror, a correction system lens and the like. The laser light modulated according to the image forming signal from the scanner unit 1 is scan-outputted, reflected by the folding mirror 2 and irradiated on the photosensitive drum 3 serving as an image carrier to form an electrostatic latent image. It has become.

A cartridge 4 constituting an image forming unit removably accommodated in the apparatus has a built-in primary charging device, a developing device, a cleaning device and the like (all not shown) in addition to the photosensitive drum 3. . The electrostatic latent image formed on the photosensitive drum 3 is developed by the developing device to form a toner image.

On the other hand, the sheet material 7, which is a recording material such as plain paper or plastic film, housed in the upper and lower two cassettes 5 and 6, respectively, is driven by driving the pickup roller 8 or the pickup roller 9. Alternatively, it is sent out from the cassette 6. In front of the cassettes 5 and 6, feed rollers 10 and 12 for conveying the picked-up sheet material 7 and retard rollers 11 and 13 for preventing double feeding of the sheets are respectively paired in the upper and lower directions in the same direction. The sheet material 7 is arranged between the roller pairs 10 and 11 or the roller pair 1.
It is conveyed between 2 and 13 in the direction of arrow α1 in the figure, and is fed to the registration roller 14.

Next, the sheet material 7 is conveyed by the registration roller 14 to the transfer charger 15 in synchronism with the front end of the toner image formed on the photosensitive drum 3, and the toner image is transferred to the direction of arrow α2 in the figure. The transferred image is conveyed and is permanently fixed by the fixing device 16.

After that, the sheet 7 is shown by arrows α3, α4, α in the figure.
Roller pairs 19a, 19b, 20a, 20b that are transported in the order of 5 and are transported to the sheet material transport apparatus A and rotate in the forward and reverse directions.
Thus, the switch back is performed, and the sheet material 7 is conveyed in the direction of the arrow α6 in the figure with the back surface thereof facing upward, and is again fed to the registration roller 14.

Then, after the registration roller 14 transfers the toner image to the transfer charger 15 in synchronism with the front end of the toner image formed on the photosensitive drum 3, the toner image is transferred again and is permanently fixed by the fixing device 16. , Arrow in the figure α7, α
The sheets are sequentially conveyed in eight directions and discharged. In the figure, 1
Numerals 7 and 18 are flappers for switching the conveying direction of the sheet material 7.

The above-mentioned apparatus is accommodated almost entirely in a lower outer cover 31 and an upper outer cover 32. The upper and lower outer covers 31, 32 can be opened and closed with a fulcrum 34 as a center and a conveyance roller for the sheet material 7 as a boundary. Has become. However, the fixing device 16 is detachably attached to a machine frame (not shown) on the lower exterior cover 31 side.

FIG. 2 is an enlarged sectional view of the fixing device 16 to which the present invention is applied. The fixing roller 24 and the pressure roller 25, which have a heat source (not shown) inside, are pressed against each other and supported so as to be rotationally driven in the direction of the arrow in the figure. Pressure springs 2 arranged at intervals in the longitudinal direction of the fixing roller 24.
6 is fixed to the back side of the fixing device lid 27 by means such as heat staking, and by closing the fixing device lid 27 pivotally supported at a fulcrum 30 on the fixing sheet metal 33 which is the upper cover of the fixing device 16, A cleaning member having the same length as the fixing roller 24 at its tip, for example, the felt 23 which is a felt pad.
The fixing pad 28 provided with is pressed against the fixing roller 24 with an appropriate pressure. As a result, the paper dust and the toner attached to the surface of the fixing roller 24 are removed from the surface of the fixing roller 24.

To attach and detach the fixing pad 28, the fixing device cover 27 is rotated counterclockwise around the fulcrum 30 as shown in FIG. 3, the pressure spring 26 is loosened first, and then the fixing pad 28 is fixed to the fixing sheet metal. It can be pulled up from the groove 33a provided in the 33. Thus, when the fixing pad 28 is replaced and the fixing device lid 27 is closed again, it becomes immovable with respect to the fixing sheet metal 33 by the locking means (not shown).

FIG. 4 is a drawing which best represents the present invention, and the present invention will be described in detail with reference to FIG.

In FIG. 4, reference numeral 22 denotes a holder which is a pad holding member and is made of a plastic material. Two rib-shaped handles 21 are integrally attached to the upper part. Further, on the lower side of the holder 22, there are provided U-shaped grooves 22a as shown in the figure on both sides, which have the same sectional shape over the entire axial direction.

On the other hand, 23 is a felt which comes into pressure contact with the fixing roller, and 29 is a felt holding member which is an engaging member made of a plastic material having a rigidity higher than that of the felt in order to give the felt rigidity. The felt 23 and the felt holding member 29 are attached by an adhesive or a double-sided tape.

Here, as shown in FIG. 4, the area of the contact surface between the felt 23 and the felt holding member 29 is wider in the felt holding member, and the felt 23 is attached to the center of the felt holding member 29.

Then, the felt holding member 29 is inserted into the groove 22a of the holder 22 in the direction of the arrow from the axial direction, whereby the felt is fixed to the holder 22.

When the felt is to be replaced due to dirt on the felt due to use in the fixing device, it can be easily removed by sliding the felt in the opposite direction. By replacing the felt and the felt holding member with a new one, the holder 22 can be used without being discarded.

<Second Embodiment> Next, a second embodiment of the present invention will be described with reference to FIG. The same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the first embodiment described above, the holder 22 of the fixing pad is provided with the groove 22a, and the felt holding member 29 is slid in the axial direction to be inserted. However, in the present embodiment, the holder 22 of the holder 22 is provided. By mounting the felt holding member 29 having the claw-shaped snap fit 22b on the side surface and the felt 23 attached with a double-sided tape or the like in the direction of the arrow (upward) in the figure, the snap fit 22b elastically bends and the felt 23 is holder 2
It is attached to 2.

After the felt 23 is attached, the snap fit 22b returns to its original shape and prevents the felt holding member 29 from coming off.

Further, when the felt 23 is replaced, the snap fit 22b can be replaced by bending the snap fit 22b with a tool or the like and removing the felt holding member 29 between them.

Here, the fixing by the snap fit is
Compared to the first embodiment, the felt 22 can be attached to the holder 22 by simply pushing in the felt holding member, which facilitates the attachment.

[0032]

As described above, according to the present invention,
Since the engaging member made of a material having a higher rigidity than that of the felt pad is attached to the felt pad, the rigidity of the felt pad is increased, and the felt pad is easily attached to and detached from the pad holding member. When the felt pad is replaced, the engaging member is detachably disposed on the pad holding member and the pad holding member is detachably held on the fixing device. It can be removed from the fixing device and replaced, and the pad holding member can be reused. Further, since the pad holding member can be reused, it can contribute to environmental protection and resource reuse.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a schematic configuration of a fixing device of the apparatus shown in FIG.

FIG. 3 is a view for explaining how to remove the pad holding member in the apparatus shown in FIG.

FIG. 4 is a perspective view of a felt pad and a pad holding member of the apparatus shown in FIG.

FIG. 5 is a perspective view of a felt pad and a pad holding member according to a second embodiment of the present invention.

[Explanation of symbols]

 7 sheet material (recording material) 22 holder (pad holding member) 23 felt (felt pad) 24 fixing roller 29 felt support member (engaging member)

Claims (2)

[Claims] 1. A fixing roller for fixing an unfixed image on a recording material, a felt pad for contacting a surface of the fixing roller to clean the surface, and a pad holding member for holding the felt pad. In the fixing device having the above-mentioned, the felt pad is provided with an engaging member having a rigidity higher than that of the felt pad, and the engaging member is detachably arranged on the pad holding member. Fixing device. 2. The fixing device according to claim 1, wherein the pad holding member is detachably attached to the fixing device.