JPH02244178A - Fixing device - Google Patents

Abstract

PURPOSE:To allow the easy and sure exchange of a cleaning pad by pressing the cleaning pad to a fixing roller by the closing action of an opening/closing door and moving a process cartridge to a working space side for exchange and releasing the pressing force of the cleaning pad on the fixing roller by the opening action thereof. CONSTITUTION:The cleaning pad 50 is held pressed to the fixing roller 40 when the opening/closing door is closed and, therefore, the cleaning of the fixing roller 40 is sufficiently executed. The cleaning pad 50 is attachably and detachably exposed to the fixing roller 40 and is mounted to a fixing device body 44; in addition, the cleaning pad 50 moves together with the opening/closing door toward the working space side for exchanging the process cartridge when the opening/closing door is opened. The pressing force of the cleaning pad 50 onto the fixing roller 40 is thereby released. The sure exchange of the cleaning pad 50 is executed in this way and since the exchange operation of the cleaning pad 50 is directly executed from the working space side for exchanging the process cartridge, the exchange operation is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a fixing device for an image forming apparatus using an electrophotographic method.

(Prior art) When a developed image (toner image) formed on a photosensitive drum, which is an image carrier, is transferred onto a transfer paper, a fixing device fixes the toner image on the transfer paper by heating, etc. It is meant to be left as a permanent image.

The fixing device generally has a pair of fixing rollers, and the toner image on the transfer paper is heated and pressurized between the fixing rollers to fix the toner image on the transfer paper. Since one side (for example, the side of the heating roller equipped with a heater) always comes into contact with the toner on the transfer paper, there is a risk that toner will adhere to this heating roller. If toner adheres to the heating roller, the transfer paper may wrap around the heating roller, or the transfer paper may be smeared with toner, and if the surface temperature of the heating roller is detected using a thermistor, etc. There was an inconvenience that the temperature would go crazy. Therefore, it is necessary to clean such a heating roller every time a fixing operation is performed, and for this purpose, the heating roller is slidably pressed against the roller, and as the roller rotates, the heating roller comes into sliding contact with the surface to perform cleaning. A cleaning pad is pressed, and the outer surface of the heating roller is cleaned by the cleaning pad every time a fixing operation is performed.

As a laser beam printer equipped with the fixing device as described above, a configuration as shown in FIG. 6 can be considered. To explain this figure, reference numeral 110 denotes a process cartridge that is detachably attached to the apparatus main body 100 and that integrally supports an image carrier and at least one process means. The photosensitive drum 11 is
When a predetermined developed image (toner image) is formed on the optical scanning system 112 and the developing device 113 on the photosensitive drum 11. The image is transferred onto the transfer paper P supplied to the fixing device 1 via the conveyor belt 115.
Sent to 20. The toner image carried on the transfer paper P is attached to a pair of fixing rollers 121 and 12 in a fixing device 120.
2, it is heated, pressurized, etc., and fixed onto the transfer paper P.

Thereafter, the transfer paper P is stacked on the paper discharge tray 116.

One fixing roller 121 of the fixing device 120. That is, the cleaning pad 1 is placed on the side that comes into contact with the toner image on the transfer paper P.
23 are arranged, and the cleaning pad 123 can be opened and closed.
It is housed in the fixing device main body 124 via the i 124 a and can be opened and closed! The fixing roller 121 is pressed against the fixing roller 121 by the engaging portion 101 of the apparatus main body 100 via a pressure member (spring member) 125 attached to the inside of the n l 24 a.

On the other hand, the transfer charger 114, the conveyor belt 115, the fixing device 120, etc. are attached to the front door 1ooa side of the apparatus main body 100, and the front door is used for replacing the process cartridge 110 and handling jams, as shown in FIG. For use, support shaft 11
7 can be opened and closed forward, so by opening the front door 100a, the fixing device can be installed! ! 120 rotates together with the rotation, and the position of the cleaning pad 123 also moves upward from the horizontal position, and the pressure on the fixing roller 121 from the engaging portion 101 of the apparatus main body 100 via the pressing member 125 is released.

The cleaning pad 123 can be easily replaced with a new one. Generally, the cleaning pad 123 of the fixing device 120 is also replaced at the same time as the front door 1ooa is opened and the process cartridge 110 is replaced.

As shown in FIG. 8, the cleaning bunt 123 is inserted from the side into the fixing device main body 124, and has a pressure member 126. There is also a type in which it is pressed toward the fixing roller 121 via...

(Problem to be Solved by the Invention) However, in the above conventional example, the cleaning pad 12
When replacing the process cartridge 110, the cleaning pad 123 is stored in the opening/closing door 124a of the fixing device main body 124 or inserted into the fixing device main body 124 and is not visible from the outside. There was an inconvenience that it was easy to forget to replace the cleaning pad 123. Also, when replacing the cleaning pad 123, open and close Jl 124a each time, or open and close the cleaning pad 123 from inside the fixing device main body 124.
There is also an inconvenience that it takes time and effort to replace the cleaning pad 123.

Furthermore, since it is necessary to attach the opening/closing door 124a for the cleaning pad 123 to the fixing device main body 124, the number of parts of the fixing device layer increases accordingly, which also causes an increase in the cost of the entire device.

The present invention has been made in view of the above problems, and its purpose is to ensure that the cleaning pad can be replaced easily and reliably when replacing the process cartridge, and to eliminate the need for extra members when installing the cleaning pad. It also provides a fixing device that is easy to install.

(Means for Solving the Problems) In order to achieve the above object, the present invention is installed on the opening/closing door side of an apparatus main body that is opened and closed for replacing a process cartridge having an image bearing member, etc., and is used for cleaning a fixing roller. In a constant S device in which a pad is pressed against a fixing roller via a pressure member, the cleaning pad is removably exposed to the fixing roller and attached to the main body of the fixing device, and the cleaning pad is pressed against the fixing roller by the closing operation of the opening/closing door. At the same time, the process cartridge is moved toward the replacement work space by the opening operation of the opening/closing door.
Further, it is characterized in that the pressing force of the cleaning pad against the fixing roller is released.

(Function) When the opening/closing door is closed, the cleaning pad is pressed against the fixing roller, so the fixing roller is sufficiently cleaned by the cleaning pad. The cleaning pad is detachably exposed to the fixing roller and attached to the main body of the fixing device, and when the opening/closing door is opened, the cleaning pad or the opening/closing door moves toward the work space for replacing the process cartridge. As a result, the pressing force of the cleaning pad against the fixing roller is released, so that the cleaning pad can be easily and reliably replaced.

(Example) An example of the present invention will be described below with reference to the accompanying drawings, taking a laser beam printer as an example.

First, the overall structure of a laser beam printer will be described with reference to FIG. 1. In FIG. 1, lO is a photosensitive drum which is an image carrier, and around the photosensitive drum lO is a primary charger 11.
Developing device 12, cleaning device 13. A pre-exposure lamp 14 and the like are provided, and these process devices are integrally housed in a cartridge container 15a as a process cartridge 15 in consideration of ease of maintenance. It is removably placed inside. - The optical scanning system 16 in the apparatus main body l is applied to the photosensitive drum lO uniformly charged by the wide charger 11.
When only image light is exposed via laser light, an electrostatic latent image is formed on the photosensitive tram 10, and the electrostatic latent image is visualized by the developer 12 and converted into a toner image.

On the other hand, a cassette 17 for storing the transfer paper P is disposed at the upper part of the apparatus main body l, and a device that hangs from the right end of the cassette 17 in FIG. A conveyance processing path M for the transfer paper P is formed on the front side of the main body l. During the conveyance processing path M, a paper feed roller 18. Feeding roller 19, registration roller 20. Transfer charger 21, minute 11'
It device 22, conveyor support l-23, fixed S device 24° paper ejection roller 25. A paper discharge tray 26 is provided, and the transfer paper P taken out from the cassette 17 by the paper feed roller 18 is
is sent to the registration roller 20 via the feeding roller 19, and is sent to the photosensitive tram IO in the process cartridge 15 with the timing adjusted by the registration roller 20. When the toner image on the photosensitive tram 10 is transferred to the transfer paper P that has reached the photosensitive tram 10 via the transfer charger 21, the transfer paper P is separated from the photosensitive tram 10 by the separation charger 22. The image is sent to the fixing device 24 via the conveyor belt 23. And the fixing device! When the toner image carried on the transfer paper P by 124 is heated, pressurized, etc. and melted and solidified into the transfer paper ph, the transfer paper P is loaded onto the paper discharge tray 26 via the paper discharge roller 25. be done. still,
After the transfer, the photosensitive tram 10 is cleaned of residual toner by a cleaning device 13, and the pre-exposure lamp 14
Static electricity is removed by

In addition, the front part of the apparatus main body l, that is, the front door la, is moved forward and backward around the support shaft 27, with the transport processing path M of the transfer paper P as the boundary, for maintenance such as replacing the process cartridge 15, and for clearing jams. It is designed to open and close.

The front door la has a registration roller 20. transcription,
Separation charger 21.22. Conveyor belt 23. Fixing device 24
．． Since a discharge roller 25 and the like are attached, as shown in FIG. 2, when the front door 1a is opened, these devices also rotate forward together with the front door la.

Next, the fixing device 24 according to the first embodiment will be explained with reference to FIGS. 1 and 2.

As shown in figure t141, the fixing device 24 includes a pair of fixing rollers 40.41 on the upper side and a separating claw 42.4 on the lower side.
The separation claw 42, 42 and the carry-out roller 43 are integrally assembled into a mounting member 45. The mounting member 45 is rotatably mounted to the fixing device main body 44 via a support shaft 46, and the spring member 4
Since the separating claws 42 and 42 are elastically biased toward the fixing rollers 40 and 41 via the fixing rollers 7, the leading ends of the separating claws 42 and 42 are slidably pressed against the fixing rollers 40 and 41.

The fixing rollers 40 and 41 rotate while being in pressure contact with each other. Of the fixing rollers 40 and 41, the side that contacts the toner image on the transfer paper P, that is, the fixing roller 40 on the left side in FIG. It has become a heated roller. The surface temperature of the heating roller 40 is detected by a thermistor 48, and the heater is controlled by a controller (not shown) to control the surface temperature within a predetermined range. Furthermore, the separation claws 42 and 42 are connected to the fixing roller 40.
, 41 is transferred to this fixing roller 40, 4.
The transfer roller 43 is for discharging the transfer paper P on which the fixing operation has been completed from the fixing device 24 and conveying it toward the paper discharging roller 25. be.

Furthermore, since there is a possibility that the toner on the transfer paper P may adhere to the heating roller 40, it is necessary to clean the surface thereof every time a fixing operation is performed.
0, a cleaning pad 50 is slidably pressed. The cleaning pad 50 is attached to the fixing device main body 44 by being inserted horizontally toward the heating roller 40 through a mounting hole 49 provided in the side wall of the fixing device main body 44 .

Its inner end surface is curved along the curved surface of the heating roller 40, and its head 50a protrudes outward from the fixing device main body 44, so that the cleaning pad 50 can be easily attached to the fixing device main body 44 from the outside. is starting to come. Further, the cleaning pad 50 has its head 50
Since the pressure receiving part 50b provided on the a side is pressed toward the heating roller 40 side by the leaf spring 28 attached to the lower part of the apparatus main body l, the inner end of the cleaning bud 50 is pressed against the heating roller 40 as the heating roller 40 rotates. The heating roller 40 is in sliding contact with the surface thereof, so that the heating roller 40 can be sufficiently cleaned.

When the transfer paper P carrying the toner image is conveyed into the fixing device 24, the transfer paper P is conveyed while being held between the fixing rollers 40 and 41, and the toner image is transferred to the heating roller 40.
is heated and melted and fixed onto the transfer paper P. Then, the transfer paper P on which the toner image has been fixed is separated from the fixing roller 40.41 by the separation claw 42.42, and the transfer paper P is separated from the fixing roller 40.41 by the separation claw 42.
The paper is sent to the paper discharge roller 25 via the paper. After the fixing operation has been completed, the heating roller 40 is cleaned of toner adhering to its surface by the cleaning pad 50, and is put on standby for a new fixing operation.

By the way, does the cleaning pad 50 need to be replaced with a new one after repeated cleaning work to some extent?
This is done at the same time as the process cartridge 15 is replaced on the boat. That is, as shown in FIG. 2, when the front door la of the main body l of the apparatus is opened by rotating approximately 90 degrees clockwise, the fixing device 24 is also rotated approximately 90 degrees together with the front door 1a, and the cleaning pad 50 and the plate are opened. Separated from spring 28.

The pressure of the cleaning pad 50 on the heating roller 40 is released, and the cleaning pad 50 is removed from the fixing device 2.
4, the fixing device main body 44 is free of obstacles around it.
Since the cleaning pad 50 is positioned above the cleaning pad 50, the cleaning pad 50 can be easily replaced with a new one.

That is, when the front door la is opened to open the inside of the apparatus and the process cartridge 15 is moved in the direction shown by the arrow in FIG. Since the cleaning pad 50 can be seen in a clean position, you can avoid forgetting to replace the cleaning pad 50, and the cleaning pad 50 can be replaced only once in the process cartridge 15 where there are no obstructions around the cleaning pad 50.
This is easy because it can be performed directly from the outside to the fixing device main body 44 from the replacement work space side. Further, since an extra member for suppressing the cleaning bud 50 is not required, it becomes easier to manufacture the fixing device 24, and the cost can be reduced accordingly. When the process cartridge 15 and cleaning pad 50 have been replaced and the front door la is completely closed, the cleaning pad 50
is pressed against the heating roller 40 by the leaf spring 28, and cleaning operation can be performed.

If a jam occurs in the fixing device 24, as shown in the prior art in FIG. It is sufficient to open the inside of the device and clear the jam. In this case, the unloading roller 43 in the mounting member 45 and the guide plate 29 of the transfer paper P
If there is a risk of interference between the guide plate 29 and the guide plate 29, a notch may be provided in the guide plate 29.

Next, a fixing device 30 according to a second embodiment of the present invention will be explained with reference to FIG.

Note that the parts having the same functions as the parts according to the first embodiment are given the same reference numerals as the parts according to the first embodiment, and the explanation thereof will be omitted.

In this embodiment, instead of pressing the cleaning pad 50 against the heating roller 40 via the plate spring 28 attached to the main body l of the apparatus as in the R1 embodiment, the cleaning pad 50 is pressed against the heating roller 40 by the fixing apparatus main body 40.
The head Bo of the cleaning pad 60 protrudes outward from the
One end of a coil spring 61 is fixed to a, and the other end is engaged with a protrusion 2 in the main body l of the apparatus, so that the coil spring 61 presses the cleaning pad 60 against the heating roller 40.

Even with the configuration as described above, the same effect as in the first embodiment can be obtained, and the coil spring 61 acts as a knob for holding the cleaning pad 60, making it easy to replace the cleaning pad 60. In addition, in this example,
Compared to the first embodiment, the number of parts is further reduced because the plate springs 28 and the like are not required in the main body of the apparatus.

Next, a fixing device 31 according to a third embodiment of the present invention will be explained with reference to FIGS. 4 and 5.

In this embodiment as well, parts having the same functions as those in the first embodiment are given the same reference numerals as those in the first embodiment, and the explanation thereof will be omitted.

The cleaning pad 50 according to the first embodiment is
When the front door la is closed, the heating roller 4 is moved by the leaf spring 28.
In the state where the head 50a is pressed to 0, the head 50a may point slightly below the horizontal, and in this case, if some kind of impact is applied to the main body l, the leaf spring 28 and the pressure receiving part of the cleaning pad 50 There is a possibility that the cleaning pad 50 may be disengaged from the fixing device body 50b and the cleaning pad 50 may be pulled out from the fixing device body 44 and fall below the device body 1.

In order to prevent the above-described problems, the cleaning pad 70 according to the present embodiment has a head 70 of the cleaning pad 70.
Concave portions 70b, 70 are provided in the middle portions of both sides of a so as to face each other.
curved clip portions 70c, 70c having an elastic force outward of the recesses 70b, 70b;
The clip portions 70c, 70 are formed in a cantilever shape.
The cleaning pad 70 can be attached to the fixing device main body 44 by engaging the cleaning pad 70 with the mounting hole 49 of the fixing device main body 44 in a pressed state.

That is, in order to attach the cleaning pad 70 to the fixing device main body 44, as shown in FIG.
The cleaning powder 70 is inserted into the mounting hole 4 of the fixing device main body 44 while pressing the cleaning powder 70c toward the concave portions 70b and 70b to bend the cleaning powder 70.
After inserting it into the clip part 7 and positioning it in the fixed position,
As long as the pressure of 0c and 70c is released, the clip portions 70c and 70c are pressed and engaged in the mounting hole 49, and the cleaning pad 70 does not easily fall out of the fixing device main body 44. Therefore, even when the front door la is opened and the process cartridge 15 is replaced, the cleaning pad 70 can be easily replaced in the same manner as the cleaning pad 50 of the first embodiment by pressing the clip portions 70c, 70c with your hands. , it is possible to obtain the same effects as in the first embodiment, and there is no fear of the cleaning pad 70 falling off compared to the first embodiment.

In this embodiment, the cleaning pad 70 is pressed against the heating roller 40 via the plate spring 28 on the side of the main body l of the apparatus, but it goes without saying that a coil spring 61 may be used as in the second embodiment. .

(Effects of the Invention) As is clear from the above description, according to the present invention, the cleaning pad is removably attached to the fixing roller, and when the opening/closing door is opened, the cleaning pad or the opening/closing door is used to replace the process cartridge. As the cleaning pad moves toward the work space side, the pressing force of the cleaning pad against the fixing roller is released, so that when replacing the process cartridge, the cleaning pad can be reliably replaced without forgetting to do so. Furthermore, since the cleaning pad can be replaced directly from the process cartridge replacement work space outside the main body of the fixing device, the replacement work is also facilitated.

[Brief explanation of drawings]

FIG. 1 is a side sectional view of a laser beam printer having a fixing device according to the first embodiment, and FIG. 2 is a state diagram around the fixing device when the front door of the laser beam printer is opened.
Figure 3 shows fixation according to the second embodiment! A cross-sectional view of the main parts of a laser beam printer with a li-position! Figure R4 is a sectional view of the main parts of a laser beam printer having a fixing device according to the third embodiment, Figure 5 is an enlarged view of the cleaning pad attached to the same fixing device, and Figure 6 is a fixing device according to the prior art. FIG. 7 is a side cross-sectional view of a laser beam printer having the device, and FIG. FIG. 8 is an enlarged view of the cleaning pad and its surroundings of a fixing device according to another prior art. l... Apparatus main body, la... Front door, 10... Photosensitive tram (image carrier), 15... Process cartridge. 24.30.31... Fixing device, 28... Plate blade (
Pressure member), 61... Coil spring (pressure member)
, 40... Fixing roller, 44... Fixing device main body, 5
0.60.70...Cleaning pad.

Claims (1)

[Claims] In a fixing device that is attached to the opening/closing door side of an apparatus main body that is opened and closed for replacing a process cartridge having an image bearing member, etc., and in which a cleaning pad of the fixing roller is pressed against the fixing roller via a pressure member, The cleaning pad is removably exposed to the fixing roller and attached to the fixing device main body, and the cleaning pad is pressed against the fixing roller by the closing operation of the opening/closing door, and a work space for replacing the process cartridge is created by opening the opening/closing door. A fixing device characterized by moving the cleaning pad toward the side and releasing the pressing force of the cleaning pad against the fixing roller.