JP2003167466A - Fixing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily exchange a web even when a fixing device is equipped with a one-way clutch for preventing the web from being sagged in a driving transmission path where the web is taken up. <P>SOLUTION: In this fixing device 400 attachably/detachably equipped with a cleaning unit 600 where the web 601 impregnated with a release agent is brought into contact with a heating roller 401 so as to clean the surface of the roller, the unit 600 is equipped with a feeding roller 610 around which an unused web is wound and a take-up roller 630 on which the used web is taken up. A take-up gear 631 for transmitting rotational force to the roller 630 is attached to the shaft 632 of the roller 630 to freely rotate by a specified angle with respect to the shaft 632. A transmission gear 641 for transmitting driving from a driving source is meshed with the gear 631, and the one-way clutch 643 capable of rotating only in one direction with respect to driving from the driving source is attached to the rotary shaft of a one-way gear 642 coaxial to the gear 641. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device used in an electrophotographic image forming apparatus such as a copying machine, a facsimile or a printer, and more particularly to a web device for cleaning a fixing roller. Cleaning device.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine, a sheet on which an unfixed toner image is formed is nipped and conveyed by a fixing roller pair consisting of a heating roller and a pressure roller, so that the toner image is formed on the sheet. There are very many products that use the so-called heat fixing method for melt fixing. It is widely known that a fixing device in this heating and fixing system is equipped with a web cleaning unit in which a web impregnated with oil is brought into contact with the surface of the heating roller to clean residual toner on the heating roller and prevent offset. Has been. The web cleaning unit is mainly configured by a web, a winding roller around which the web is wound, a winding roller that winds up the web wound around the winding roller, and the like. For example, in the case of a copying machine, the portion of the web that comes into contact with the surface of the heating roller becomes dirty each time a copy is piled up. , A new web is brought into contact with the surface of the heating roller.

When adopting such a web cleaning mechanism, it is necessary to make sure that the web itself does not sag in order to realize smooth cleaning. Therefore, conventionally, for example, as in Japanese Patent No. 2882842, gears are provided on the web feed-out shaft and the take-up shaft, and the gears are engaged with the brake mechanism to prevent unnecessary rotation of the shaft and prevent slack. is doing. Alternatively, it has been proposed to employ a ratchet mechanism on the winding shaft and a one-way clutch on the feed-out shaft to prevent the slack of the web (Japanese Patent Laid-Open No. 8-152801).

However, in this conventional technique, a plate-like brake member, which has a relatively weak spring property, is used by being meshed with a gear, so that a considerable amount of driving force is applied.
In addition, a contact sound between the gear and the brake is also generated. When using a one-way clutch, when the web cleaning mechanism is unitized, if this unit is connected to an external drive means by a gear, etc., the rotation of the gear itself is controlled by the action of this one-way clutch. Therefore, it becomes difficult to take out the gear from the meshed state.

[0005]

Therefore, there is a technique that can prevent the slack of the web even when the above-mentioned conventional technique is further improved and the web cleaning mechanism is unitized and a mechanism detachable from the fixing device is adopted. Is desired.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an image forming apparatus in which the amount of bending of a sheet by a registration roller is appropriate and a sheet jam or a sheet break does not occur. Is.

[0007]

In order to achieve the above object, the invention described in claim 1 cleans the heating roller surface by bringing a web impregnated with a release agent into contact with the heating roller. In a fixing device having a detachable web cleaning unit, the web cleaning unit includes a feed roller around which an unused web is wound and a take-up roller for winding a used web, and a shaft of the take-up roller is A winding gear for transmitting a rotational force to the winding roller is attached to the winding shaft so as to be rotatable at a predetermined angle, and a transmission gear for transmitting a drive from a drive source meshes with the winding gear. The fixing device is characterized in that a one-way clutch that is rotatable only in one direction from a drive source to a drive is attached to a rotation shaft of the transmission gear.

According to the first aspect of the present invention, since the winding gear is rotatable with respect to the winding shaft by a predetermined angle, when the one-way clutch is inserted in the drive connecting means of the winding mechanism. However, the take-up gear rotates when taken out, and the engagement with the drive gear can be easily released.

Further, the invention of claim 2 relates to the fixing device of claim 1, wherein the winding gear has a pair of substantially fan-shaped spaces facing each other with respect to the center of rotation.

According to the present invention, by forming a substantially fan-shaped space in the gear itself, it is possible to provide a structure in which the winding gear is rotatable by a predetermined angle without employing a complicated mechanism.

According to a third aspect of the present invention, in the fixing device according to the first aspect, the take-up roller shaft is engaged with the fan-shaped space of the take-up roller at its end and is driven by the shaft as the take-up gear rotates. Is characterized in that a pin member for transmitting is transmitted.

According to the third aspect of the present invention, the pin member attached to the winding shaft moves in the substantially fan-shaped space and engages with the side surface of the fan-shaped space to transmit the drive of the gear to the shaft. it can. Therefore, with a very simple mechanism, drive transmission to the shaft,
It is possible to secure a playable space for the gear that can rotate when the unit is taken out.

The features of the present invention will be described below with reference to the accompanying drawings.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below with reference to the drawings. 1 is a schematic sectional view of a copying machine as an example of an image forming apparatus to which the fixing device of the present invention is applied, and FIG. 2 is a schematic sectional view showing the fixing device.
FIG. 3 is a partial perspective view showing a driving force transmission mechanism for winding a web on the cleaning device.

First, referring to FIG. 1, the copying machine includes a paper feeding section 100 arranged at a lower portion of the copying machine main body 1 and sheets arranged laterally and above the paper feeding section 100. Transport unit 20
0, an image forming unit 300 arranged above the sheet conveying unit 200, a fixing device 400 arranged on the discharge side of the image forming unit 300, and these image forming units 300.
Also, the image reading unit 500 including an optical system member disposed above the fixing device 400 is provided.

The paper feed unit 100 includes four paper feed cassettes 11
From the paper feed cassette 111 selected from among the paper feed cassettes 111, the paper 115 is sent to the exit side (the right side in FIG. 1) of the paper feed cassette 111 by the rotation operation of the paper feed roller 112 having an arc outer peripheral portion, and By separating by the separating sections 116 provided on both upper ends in the width direction, the uppermost sheets 115 are surely fed one by one to the sheet conveying section 200. Further, these four paper feed cassettes 111 are
It is constructed so that it can be pulled out freely.

The sheet conveying section 200 conveys the sheet 115 fed from the sheet feeding section 100 toward the image forming section 300 by the conveying roller pair 202 and the registration roller pair 203, and further from the image forming section 300 to the fixing device. The discharge roller pair 2
The sheet is discharged onto the discharge tray 204 by 05. A discharge switch SW is provided on the upstream side of the pair of discharge rollers 205 in the transport direction and on the downstream side of the fixing device 400, which will be described later, in the transport direction. The discharge switch SW
Is for detecting a paper jam in the paper transport unit 200, and is also for counting the number of copies made by the copying machine main body 1. The discharge switch S
The counting of the number of copies by W will be described later.

The image forming section 300 forms a predetermined toner image on the sheet 115 by an electrophotographic process, and is rotatably supported by a photoconductive drum 301 having photoconductivity and the photoconductive drum 301. The charging unit 302 and the exposure unit 3 are provided around the periphery of 301 along the rotation direction thereof.
03, a developing unit 304, a transfer unit 305, a cleaner 306, and a charge eliminating unit 307.

The charging unit 302 includes a charging wire to which a high voltage is applied, and applies a predetermined potential to the surface of the photosensitive drum 301 by corona discharge from the charging wire. The exposure unit 303 irradiates the photosensitive drum 301 with laser light output from the laser light emitter based on the image data of the original read by the image reading unit 500, which will be described later, via the polygon mirror and the reflecting mirror. The potential of the surface of the photoconductor drum 301 is selectively attenuated to form an electrostatic latent image on the surface of the photoconductor drum 301. The developing unit 304 develops the electrostatic latent image with toner, and the photosensitive drum 30
The toner image is formed on the surface of No. 1. The transfer unit 305 transfers the toner image on the surface of the photosensitive drum 301 onto the paper 115. In this copying machine, the transfer unit 305 is composed of a transfer roller which is separated from the photosensitive drum 301 by a predetermined distance. The cleaner 306 is the photosensitive drum 301 after the transfer.
The toner remaining on the surface of is removed. The charge eliminating unit 307 removes residual charges on the surface of the photoconductor drum 301.

The fixing device 400 includes the image forming section 300.
Of the image forming unit 300.
The paper 115 on which the toner image is transferred is sandwiched by the heating roller 401 and the pressure roller 402 pressed against the heating roller 401 and heated to fix the toner image on the paper 115. The fixing device 400
Is provided with a web cleaning unit 600 for the purpose of cleaning the residual toner adhering to the surface of the heating roller 401 and preventing offset (not shown in FIG. 1).
The web cleaning unit 600 will be described later.

The image reading unit 500 includes the contact glass 5
Image information of the original is read by irradiating the original placed on 01 with light from an exposure lamp and guiding the reflected light to a photoelectric conversion unit such as a CCD line sensor via a reflecting mirror. . Note that the exposure lamp and the reflecting mirror form a scanning operation unit, and the scanning operation unit moves the moving region 508 in the left-right direction in FIG. 1 at a predetermined speed to place it on the contact glass 501. The entire surface of the document thus scanned can be scanned and the image on the entire surface of the document can be read.

Next, a specific structure of the web cleaning unit 600 will be described with reference to FIGS. The heating roller 401 has two heaters 410 and 411.
Is built in and rotates in the direction of arrow A. In addition, the surface of the heating roller 401 is impregnated with oil, the web 60.
Web cleaning unit 600 so that 1 contacts.
Are arranged on the opposite side of the pressure roller 402. The web 601 is a thin web-like sheet made of unsightly cloth, paper, cloth or the like, and the web 601 is preferably impregnated with silicone oil.

The web cleaning unit 600 includes a winding roller 610 around which the web 601 is wound, a winding roller 630 around which the web 601 is wound around the winding roller 610, a winding roller 610 and a winding roller 630. The web 601 spanned between the heating roller 401 and the pressing roller 620 is pressed against the surface of the heating roller 401 by the spring 605, and is a detachable unit with respect to the fixing device 400.

The winding roller 610, the pressing roller 620,
The take-up roller 630 is the web cleaning unit 600.
Is rotatably supported by a side plate or the like that constitutes the housing 607. The winding roller 610 and the winding roller 630 are composed of only a core metal such as aluminum, and the web 601 is wound around the core metal. The pressure roller 620 is made of, for example, silicon sponge. A winding gear portion 631 for transmitting drive to the winding roller 630 is provided at one end of the winding roller 630. The winding gear 631 is gear-connected to the drive gear 651 via the transmission gear 641. As shown in FIG. 3, this transmission gear has a structure in which gears are provided at both ends of a shaft 647, and one transmission gear 641 is a winding gear 63.
The other gear is a transmission gear 642 (hereinafter referred to as a one-way gear) having a one-way clutch 643 coaxially attached to the outer plate of the fixing device main body. Then, the drive gear 651 is attached to the one-way gear 642.
Are engaged with each other to allow rotation only in the rotation direction of the drive gear.

A ratchet gear portion 652 is formed on the drive gear 651 coaxially with the drive gear 651, and is intermittently driven by engagement with a hook 662 formed at a free end of a plunger 661 of a solenoid (drive source) 660. It has become so. Therefore, when the solenoid 660 operates and the plunger 661 moves in the arrow F direction, the drive gear 651 intermittently rotates in the arrow E direction and the one-way gear gear 642, the transmission gear 641, and the winding gear 631.
The take-up roller 630 rotates in the direction of arrow B via. As a result, the web 601 moves in the direction of arrow C. Thus, the cleaning performance is improved by making the moving direction of the web 601 (direction of arrow C) and the rotating direction of the heating roller 401 (direction of arrow A) opposite to each other.
Moreover, since the one-way clutch 643 is attached to the drive transmission mechanism, reverse rotation of the winding roller 630 is restricted, and the web is wound without sagging.

The copying machine main body 1 provided with the web cleaning unit 600 having the above-mentioned configuration is provided with the sheet number counter 800 for counting the number of sheets of the copied (image-formed) sheets 115. The number counter 80
0 is the paper 115 that has passed through the discharge switch SW described above.
It is designed to count by detecting. In response to the count counter 800 having reached a predetermined count value T2, the solenoid 660 is driven by a predetermined amount and the winding control means 710 for winding the web 601 by the winding roller 631 is activated. There is. In the present embodiment, the winding control means 710 is operated when T2 = 30 sheets, but the value of T2 can be appropriately selected. Further, the winding amount of the web 601 by the winding roller 630 per one time may be about several millimeters, but this winding amount can be appropriately selected.

Further, the copying machine main body 1 is provided with a maintenance display instruction means 810 for displaying on the display section 900 that maintenance is to be performed when the number counter 800 reaches a predetermined count value T1. . The maintenance display instructing means 810 uses the number counter 800
Is activated in response to reaching T1, but in this embodiment, T1 is set to 500000 sheets. The value of T1 may be set to the number of copies, which is the life of maintenance depending on the model, and this value can be appropriately selected.
The maintenance display instruction means 810 is activated, and the display unit 9
When a message indicating that maintenance is to be performed is displayed on 00, the user contacts the service person, and the service person appropriately replaces desired parts or the like and performs maintenance. When the maintenance is completed, the service person resets the number counter 800, and the number counter 800 counts the number of the copied sheets 115 again.

When the winding control means 710 operates and the web is wound by the winding roller 630, the web winding counter 72 for counting the number of times of winding.
0 counts. The web winding counter 720 is provided in the web cleaning unit 600, and is electrically connected to the solenoid 660 that is a drive source. That is, each time the solenoid 660 operates, the web winding counter 720 counts.

In the web cleaning unit 600, the web winding counter 720 has a predetermined count value T.
Web 601 is displayed on the display unit 900 in accordance with the number 3 being reached.
Web exchange display instructing means 73 for displaying a message to exchange
It also has 0. In this embodiment, T3 = 17,000
Is set to. That is, the winding control means 710 determines that the number of sheets 115 copied by the copying machine main body 1 is 30.
Since it operates once per sheet, the web exchange display instruction means 73
0 will operate at 30 × 17000 = 510000 sheets. This is done by the take-up roller 630 and the web 60
1 is almost wound up, and is set to the number of copies predicted that the web needs to be replaced. The T3 is set to a value that is predicted to require replacement of the web 601, and this value can be appropriately selected depending on the model.

Further, the copying machine main body 1 includes a take-up roller 63.
The winding of the web 601 by 0 is almost completed, and the web 601 to be wound is not on the winding roller 610,
When the number of copies predicted to hinder the web cleaning unit 600 when the web 601 is wound by the take-up roller 630 any further, the operation of the copying machine main body 1 is prohibited to prevent copying. This operation is also performed by the web winding counter 72.
It is performed based on the count value of 0. That is, the copying machine main body 1 also has a mechanical lock instructing means (not shown) for stopping the operation of the copying machine main body 1 when the web winding counter 720 reaches the predetermined count value T4. I have it. In this embodiment, T4 = 18000 is set. That is, the machine lock instruction means is the copying machine main body 1
The number of sheets copied by 30 × 18000 =
It will operate with 540000 sheets.

Next, with reference to FIG. 4, the operation of the cleaning device will be described with reference to a flow chart. First, when copying is performed by the copying machine main body 1 (S1), the paper 115 is detected by the discharge switch SW, and the count value of the number counter 800 is counted (S2). next,
It is determined whether or not the count value of the number counter 800 has reached a predetermined count value of 500000 (T1) (S3). If not reached (N is 500000
If it is smaller than that, the process proceeds to S4, and if it is reached (if N is larger than 500000), the process proceeds to S13. S4
Then, it is determined whether or not the count value of the number counter 800 is a multiple of 30 in order to wind the web 601 by a predetermined amount every 30 sheets of the paper 115 copied by the copying machine main body 1. If not a multiple of 30, return to S1,
If it is a multiple of 30, the winding control means 710 is operated (S5). By the operation of the winding control means 740, the solenoid 660 is driven (the plunger 661 moves in the direction of arrow F in FIG. 2), and the winding roller 630 moves the arrow ‘B’ in FIG. 2 via the drive gear 651 and the transmission gear 641. The web 601 is wound up by a predetermined amount in the direction, and the new web 601 comes into contact with the surface of the heating roller 401. After that, the plunger 661 moves in the direction opposite to the arrow F direction in FIG. 2 and returns to the original standby state. However, since the drive gear 651 includes the ratchet gear portion 652, the drive gear 651 does not rotate in the direction opposite to the arrow E direction in FIG. Further transmission gear 641
Since the one-way gear 642 is arranged coaxially with
Since the winding roller 631 also does not rotate in the direction opposite to the arrow B direction in FIG. 2, the winding roller 630 can stably wind the web 601.

When the winding control means 710 is operated, the count value of the web winding counter 720 is counted (S6). Next, it is determined whether the count value of the web winding counter 720 has reached a predetermined count value of 17000 (T3) (S7). If not reached (if M is less than 17,000), return to S1,
If it has reached (if M is greater than 17,000), the process proceeds to S8. In S8, the count value of the web winding counter 720 is a predetermined count value of 18000 (T
It is determined whether or not 4) has been reached. If not reached (if M is less than 18000), proceed to S9,
If reached (M is greater than 18000) S15
Go to.

In S9, that is, the web winding counter 72
When the count value of 0 is larger than 17,000 and smaller than 18,000, the web exchange display instruction means 730 is activated to display on the display unit 900 that the web 601 is to be exchanged. When such a display is displayed on the display unit 900, the user contacts the service person, and the service person replaces the web 601 with a new one (S10). Whether or not the web 601 has been exchanged, the process proceeds to S11.

On the other hand, in the case of NO in S3, that is, when the count value by the number counter 800 reaches the predetermined count value of 500000 (T1), the maintenance display instructing means is activated (S13), and the display section 900 is displayed. Is displayed on the screen. When such a display is displayed on the display unit 900, the user will contact the service person, and the service person will replace or maintain the parts (S14). Even if such a display is displayed on the display unit, if the user does not contact the service person and maintenance is not performed, the process proceeds to S4, and copying by the copying machine body 1 is continued. Becomes However, if the count value of the web take-up counter 720 exceeds 18000 in S8 (the number of sheets copied by the copying machine main body 1 becomes 180).
When 00 × 30 = 540000 sheets are exceeded), the mechanical lock instruction means for stopping the operation of the copying machine body 1 is activated (S
15), the copying machine body 1 is in a state in which it cannot be copied. After that, the process returns to S14.

In S14, when maintenance by the service person is performed (YES in S14), the process proceeds to S10. Here, the maintenance display instruction means 81
0 operates when the count value of the sheet number counter 800 is 500000 sheets, and the count value of the web winding counter 720 at this time is 16666 (500000/3).
0), but soon the predetermined count value T3 is reached, so the serviceman will also exchange the web 601. Therefore, regardless of whether or not the web 601 has been replaced in S10, the process proceeds to S11.

In S11, it is determined whether or not the number counter 800 has been reset. If it has not been reset (NO in S11), the process returns to S13, and the maintenance display instruction unit 810 is operated to display on the display unit 900 that maintenance is to be performed. If the number counter 800 is reset (YES in S11), the process proceeds to S12.

In S12, it is determined whether the web winding counter 720 has been reset. There is no problem if the web winding counter 720 is reset, but if the web winding counter 720 is forgotten to be reset (NO in S12), the process returns to S9 and the web exchange display instructing means 730 is operated. in this way,
Even if the web take-up counter 720 is forgotten to be reset, the web exchange display instruction means 730 is operated to display on the display unit 900 that the web 601 is to be exchanged. Therefore, the service person exchanges the web 601. If not, then the web 601 must be replaced. Also, when the web 601 is being exchanged, such a display appears even though the web 601 has been exchanged, so that something unusual is noticed. This display is displayed on the display unit 9
Since there is no choice but to reset the web take-up counter counter 720 to erase from 00, the service person must always reset the web take-up counter 720. As a result, the replacement of the web 601 is ensured, and immediately after the replacement of the web 601 (several tens or hundreds of copies), a display indicating that the web 601 will be replaced is displayed on the display unit 900. Instead, the copy can be performed properly.

Next, the replacement procedure of the web cleaning unit when the replacement indication of the web 601 is displayed,
The description will be made again with reference to FIG. As described above, the web cleaning unit 600 is unitized and can be replaced. This web cleaning unit 600
Is a transmission gear 641 attached to the fixing device 400 side.
It is possible to remove the winding gear 631 attached to the web cleaning unit 600 side by releasing the meshing of the winding gear 631.

However, the take-up roller 630 is operated by the one-way gear 642 provided in the drive transmission path,
Normally, rotation in the counterclockwise direction in FIG. 2 is restricted because slack of the web occurs. So in this example,
A mechanism is adopted that allows the winding shaft 632 to rotate counterclockwise around the winding gear 631 only when the web cleaning unit 600 is taken out. Specifically, as shown in FIG. 3, the winding gear 631
Has a hole 633 at its center that rotatably fits to the shaft 632 of the winding roller. And this hole 63
Two fan-shaped spaces 634 and 635 facing each other are formed facing each other. The take-up roller 630
A pin 670 is attached to the shaft 632, and the pin 670 can move in the fan-shaped spaces 634 and 635 as the shaft 632 rotates.

Now, when the drive gear 651 rotates and its rotational force is transmitted to the winding gear 630 via the one-way gear 642 and the transmission gear 641, the winding gear 630 rotates in the direction of the arrow in FIG. 670 is a fan-shaped space 634, 63
The rotation is transmitted to the take-up roller shaft 632 by coming into contact with the side walls 672 and 673 of No. 5. Thus, the fixing roller 40
The web 601 abutting on the first surface is wound up by the winding roller 630. At this time, the winding gear 631 meshes with the transmission gear 641 including the one-way gear 642,
It rotates only in the direction of the arrow in the figure, and rotation in the opposite direction is restricted by the one-way gear 642. As a result, the web does not sag.

Next, the removal of the cleaning device 600 having the take-up roller 630 whose rotation is restricted only in one direction by the one-way gear 642 from the fixing device will be described with reference to FIG. Cleaning device 6
As shown in FIG. 5a, the reference numeral 00 indicates a winding shaft with respect to a guide groove 700 formed in the front and rear side plates (the side plate 702 on the rear side in the drawing) of the fixing device 400 and oriented in an oblique direction. 632 is attached. This cleaning unit is fixed to the main body of the fixing device by means such as a screw in a horizontal state as shown in the figure. Now, let's assume that the cleaning unit is at the end of its useful life and needs to be replaced. First,
The screw fixed to the main body of the fixing device is removed, and as shown in FIG. 5b, the winding gear 631 is rotated clockwise in the drawing. At this time, the take-up gear 631 meshes with the transmission gear 641 that is coaxially fixed to the one-way gear 642, and does not rotate itself. However, since the fan-shaped spaces 634 and 635 are formed in the winding gear 631, the winding shaft 632 can also rotate in the clockwise direction as the unit 600 rotates. The triangle mark in the figure indicates the winding shaft 63.
A rotation state such as 2 is shown. In this way, when the cleaning unit 600 is completely rotated until the engagement between the winding gear 631 and the transmission gear 641 can be released, the winding shaft 632 is pulled out along the groove 700 formed in the side plate 702 to fix the unit 600. The device 400 can be pulled out in the arrow direction.

As described above, by using the fan-shaped spaces 634 and 635, the winding gear 631 meshed with the transmission gear 641 whose rotation is restricted by the one-way gear is rotated by an extremely simple mechanism without rotating the winding gear 631. The shaft 632 can be rotated to release the mesh between the winding gear 630 and the transmission gear 641. In this embodiment, the size of one fan-shaped space is 1 / the center of the winding gear 631.
Although the size is about four corners, it is sufficient if the pin 670 can rotate when the cleaning unit 600 is taken out, and it can be appropriately determined according to the device used.

In the above embodiment, the solenoid is used as the drive source, but the present invention is not limited to this, and any device such as a motor may be used as the drive source. Further, although the winding roller is rotated from the drive source through the gear, the winding roller may be directly rotated.

Further, in the flow chart of the above embodiment, if the count value of the web winding counter in S12 is not reset (NO in S12), the process returns to S9 to activate the web exchange display instruction means.
It is also possible to set the count value of the web winding counter to T3, which is a predetermined count value, and then return to S7, and then activate the web exchange display instruction means in S9. Further, although the above embodiment has been described with respect to the example of the copying machine, the present invention can be applied to general image forming apparatuses such as a facsimile and a printer.

[0045]

According to the present invention, the fact that maintenance is to be performed is displayed on the display unit, and after the maintenance and the replacement of the web have been performed by the service person, the count value of the number counter is reset, but the web If the count value of the winding counter is not reset, the web exchange display instructing means operates and a message that the web is exchanged is displayed on the display unit, so that the serviceman notices the abnormality. That is, even though the web has been exchanged, such a display is displayed on the display unit, so that the service person notices that the count value of the web winding counter is reset.

Furthermore, a message indicating that maintenance is to be performed is displayed on the display unit, and although the maintenance has been performed by the service person, if the Web has not been replaced, the display unit displays that the Web will be replaced. We will definitely exchange the web.

[0047]

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a copying machine to which a fixing device of the present invention is applied.

FIG. 2 is a schematic sectional view showing a fixing device.

FIG. 3 is a partial perspective view of the cleaning device.

FIG. 4 Flow chart

FIG. 5 is a schematic diagram for explaining the operation of the winding gear attached to the cleaning unit.

[Explanation of symbols]

1 Copier body 400 fixing device 401 heating roller 402 pressure roller 600 Web cleaning unit 601 web 610 winding roller 620 pressure roller 630 Take-up roller 631 winding gear 641 transmission gear 642 one-way gear 643 one-way clutch 651 drive gear 660 solenoid (drive source) 710 Winding control means 720 Web winding counter 730 Web exchange display instruction means 800 sheet counter 810 Maintenance display instruction means 900 display SW discharge switch

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Claims (3)

[Claims] 1. A fixing device having a detachable web cleaning unit for contacting a heating roller-impregnated web with a release agent to clean dirt on the surface of the heating roller, wherein the web cleaning unit is unused. A winding roller for winding the used web and a winding roller for winding the used web, and a winding gear for transmitting a rotational force to the winding roller is provided on a shaft of the winding roller with respect to the winding shaft. The winding gear is mounted rotatably by a predetermined angle, and a transmission gear for transmitting the drive from the drive source meshes with the winding gear, and the rotation shaft of the transmission gear is only in one direction from the drive source to the drive. A fixing device having a rotatable one-way clutch attached thereto. 2. The fixing device according to claim 1, wherein the winding gear has a pair of substantially fan-shaped spaces facing each other with respect to the center of rotation. 3. The winding roller shaft is provided at its end with a pin member for engaging the fan-shaped space of the winding roller and transmitting drive to the shaft as the winding gear rotates. The fixing device according to 1.