JPH0996980A - Fixing device - Google Patents

Abstract

(57) Abstract: When a recording material is jammed in a fixing device having a fixing and pressure roller, it is possible to prevent paper discharge means arranged downstream of these rollers from being contaminated by unfixed toner. To do. A fixing roller 1 heated by a heating source
A pressure roller 2 pressed against the fixing roller, a manual rotation member 9 for manually rotating at least one of the fixing roller and the pressure roller, and a downstream side of the fixing roller and the pressure roller. In the fixing device having the paper discharge guide means 17, the paper discharge guide means 17 is rotated counterclockwise from the illustrated state to release the engagement with the grip 24, and the manual rotation member is rotated to rotate the roller. Jam processing is performed.

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 such as a copying machine or a printer.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine or a printer, a fixing roller is heated by a heating source such as a heater in order to make an unfixed toner image formed on a recording material a permanent image. There is used a fixing device that presses and conveys the recording material in a nip portion formed between the pressure roller and the pressure roller that is pressed against and rotates.

In such a fixing device, while the recording material is passing between the rollers, there are cases where the recording material cannot be normally conveyed due to a trouble such as kinking or skewing of the recording material. Must be stopped and the recording material caught between the rollers must be removed by hand.

However, when a considerably large pressure is applied from the pressure roller, the recording material cannot be easily taken out even if it is pulled, so a means for manually rotating the roller is provided.

FIGS. 8 and 9 show an example of a fixing device having such a jam processing mechanism. In the figure, 41 is a fixing roller,
Reference numeral 42 denotes a pressure roller, the fixing roller 41 is driven by a driving means (not shown) through gears 43, 44 and 45 in the direction of arrow J, and the pressure roller 42 is gears 43, 44, 46 and 4.
A recording material is nipped and conveyed while being rotated by receiving a driving force in the direction of arrow K via 7. Reference numeral 48 is a jam clearance lever. By lowering this lever 48 in the direction of arrow L,
The fixing roller 41 is rotated via the gears 49 and 45 to eject the recording material.

A one-way clutch 50 is press-fitted into the gear 49 as shown in FIG. 8. The fixing roller 41 is rotated when the lever is lowered in the arrow L direction, and the one-way clutch 50 idles when the spring 51 returns. , Roller 41
Is designed not to rotate.

[0007]

However, in the above-mentioned conventional example, when the guide member for discharging the paper is located on the downstream side of the roller, the recording material whose fixing is incomplete does not guide the guide member during the jam processing. There is a drawback that it stains and the stain is transferred to the next recording material.

Further, although there is no problem in taking out the recording material stopped during the conveyance, when the recording material is wound around the roller, the one-way clutch prevents the roller from being rotated in the reverse direction so that the recording material can be taken out. Can not.

Further, even when the reverse rotation of the roller is possible, there is a drawback that the cleaning web for cleaning the fixing roller is slackened by the reverse rotation of the roller.

A first aspect of the present invention has an object to solve the above-mentioned problems and to provide a fixing device in which a guide member for ejecting a sheet during jam processing is not contaminated.

Further, according to the second invention of the present application, even when the recording material is wound around the roller, the recording material can be taken out by a simple operation, and at that time, the cleaning web is prevented from slackening. The purpose is to provide.

[0012]

According to a first aspect of the present invention, the above object is to provide a fixing roller heated by a heating source, a pressure roller in pressure contact with the fixing roller, a fixing roller and a pressure roller. In a fixing device having a means for manually rotating at least one of the above, it is achieved by providing a configuration in which the means for manually rotating the roller cannot be operated unless the paper discharge portion on the roller downstream side is moved. It is possible to prevent the discharge guide part from being soiled when the recording material is rotated to take out the recording material.

Further, according to the second invention of the present application,
A means for manually rotating at least one of the fixing roller and the pressure roller connects the rotation of the rotation member and the rotation member to the rotation of at least one of the fixing and pressure roller and the rotation of the rotation member. A means for switching the presence / absence of power transmission depending on the moving direction, a means for cutting the transmission of the rotation of the rotating member to the gear train, and a means for preventing the feeding operation of the cleaning web for cleaning the fixing roller. In the case where the recording material is wound around the roller, the above-described object is achieved by having a structure in which the feeding operation of the web is blocked when the rotation of the rotation member is not transmitted to the gear train. However, by rotating the rotation of the rotating member to the gear train, it is possible to reverse the rotation of the roller, so that the recording material can be taken out, and the slack of the cleaning web can be prevented during the reverse rotation of the roller.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) The present embodiment will be described below with reference to the drawings.

FIG. 1 is a diagram showing a fixing device according to the present embodiment, FIG. 2 is a top view thereof, FIG. 3 is a diagram showing a state during jam processing in the fixing device of FIG. 1, and FIG. FIG.

In the figure, reference numeral 1 denotes a fixing roller having a heater as a heating source therein, and the fixing roller 1 includes a pressure roller 2
Is rotatably pressed. The unfixed image is fixed by conveying the recording material having the unfixed image while nipping it while heating the nip portion formed between the fixing roller 1 and the pressure roller 2.

Both ends of the fixing roller 1 are rotatably supported by the side plate 3 via bearings and the like, and a gear 4 is fixed to one end of the fixing roller 1 so as to rotate integrally with the roller. The pressure roller 2 is supported by a pressure arm (not shown),
The gear 5 is fixed.

Further, gears 6 and 7 are arranged on the side plate 3 so as to mesh with each other, and the gear 6 meshes with the gear 4 and the gear 7 meshes with the gear 5. The gear 6 also meshes with a gear 8 that transmits rotation from a drive means (not shown).

Reference numeral 9 denotes a jam clearance lever, which is a rotating member, is fitted in a sleeve 10 having a plurality of claw portions 10a in the circumferential direction, and is biased in one direction by a spring 11. A plurality of groove portions 9a are formed in the inner diameter of the jam processing lever 9 in the circumferential direction, and the claw portions 10a of the sleeve 10 are inserted into the groove portions 9a, so that the sleeve 10 is integrated with the rotation of the jam processing lever 9. Rotate.

The sleeve 10 is attached so as to rotate integrally with the sleeve 12, and the sleeve 12 is attached to the side plate 3.
A gear 15 that is rotatably fitted to a shaft 13 attached to, and a part of which is fitted with a one-way clutch 14 as a means for switching the presence / absence of power transmission depending on the turning direction of the jam clearance lever 9 is fitted. Has been done.

This one-way clutch 14 is locked when the sleeve 12 rotates in the direction of arrow A, and the gear 15
Is press-fitted in such a direction as to rotate. Further, the jam clearance lever 9 is urged to rotate in the direction of arrow B by the spring 16 and comes into contact with the bent portion 3a of the side plate 3 to restrict the rotation.

Reference numeral 17 designates a side plate of the paper discharge portion through which the recording material fixed by the fixing roller and the pressure roller passes, and a part of the side plate is rotatably attached to a shaft 18 attached to the side plate 3. .

The paper discharge section includes a paper discharge roller 19, a paper discharge roller 20,
It is composed of a paper ejection upper guide 21 and a paper ejection lower guide 22, and the paper ejection roller 19 is rotatably supported by the side plate 17 via a bearing or the like and rotated by a drive gear (not shown). The paper discharge roller 20 is rotatably held by a holder 23 such as a leaf spring, abuts on the paper discharge roller 19, and rotates together with the paper discharge roller 19.

Reference numeral 24 denotes a handle which is put on the side plate 17 with a finger when opening and closing the paper discharge section. There is a cutout portion 24a in a part of the handle 24, and there is a positional relationship in which a part of the jam clearance lever 9 is inserted into the cutout portion 24a when the paper discharge section is closed. Regulated.

Reference numeral 25 is a cleaning web for removing dirt such as toner and paper dust on the surface of the fixing roller 1, which is wound around a shaft 27 rotatably supported by a side plate 26 and is attached to a shaft 28. Rolled up. The web roller 29 presses against the fixing roller 1, and the winding drive means (not shown) rotates the shaft 28 at regular intervals to wind the shaft 28. In addition, the disk-shaped member 30 having irregularities on the outer periphery,
It is attached so as to rotate integrally with the shaft 27.

Reference numeral 31 is an arm for restricting the rotation of the shaft 27. The arm 31 is rotatably fitted to a shaft 32 erected on the side plate 26 and is urged to rotate by a spring 33.
1a is in contact with a portion 24b of the handle 24 and is restricted in rotation when the sheet discharge section is closed.

Next, the operation during the jam processing will be described.

When a jam occurs in the device, it is detected and the device automatically stops. When the recording material is stopped while being sandwiched by the rollers, the jam clearance lever 9 is operated to take it out. First, the paper discharge portion is tilted outward (FIG. 3). Then, the handle 24 that regulates the movement of the jam clearance lever 9 is separated from the lever 9 and the lever 9 can be operated. Then, move the jam clearance lever 9 to the arrow C
When pushed down in the direction, the sleeves 10 and 12 rotate, and the one-way clutch 14 is in the locking direction, so the gear 15 also rotates in the direction of arrow A. Gear 4 is rotated accordingly,
The fixing roller 1 rotates in the direction of arrow D. At the same time, the gear 5 is also rotated via the gears 6 and 7, and the pressure roller 2 rotates in the direction of arrow E. Then, the recording material sandwiched by the rotation of both rollers is discharged for a certain length.

Further, the jam processing lever 9 is restricted from rotating by the bent portion 3b of the side plate 3, and is returned to its original position by the spring 16 when the hand is loosened. At this time, the sleeves 10 and 12 rotate in the direction of arrow B, but the gear 15 does not rotate because the one-way clutch 14 is in the idling direction, and both rollers remain stopped.

In this way, the recording material is completely discharged by repeating the pushing-down operation of the lever 9. The ejected recording material is ejected from the ejecting roller 19, the ejecting roller 20, and the ejecting vertical guide 2 because the ejecting unit is tilted.
No touching 1, 22. Next is a case where the recording material is wound around the roller. In this case, the recording material cannot be taken out by the above operation, and the rear end of the recording material is pulled out by hand. First, similarly to the above operation, the paper discharge unit is tilted outward. Next, the jam handling lever 9 is slid in the arrow F direction. The lever 9 is a bent portion 3 of the side plate 3.
It catches on the stepped portion 3c of a and stops in the state of FIG. 4,
At this time, the groove 9a of the lever 9 and the claw 10 of the sleeve 10
The engagement of a is disengaged, and the lever 9 and the sleeve 10 are in a rotatable fitting state.

In this state, the wound recording material is pulled, and when the trailing end of the wound recording material is pulled, both rollers 1 and 2 rotate in the direction opposite to the normal rotation. Gear 4 rotates in the direction of arrow G, and gear 15 accordingly moves in the direction of arrow H.
Rotate in the direction. Since the one-way clutch 14 is in the lock direction, the sleeves 12 and 10 also rotate in the direction of arrow H, but since the claw 10a of the sleeve 10 and the groove 9a of the lever 9 are not engaged, the rotation is not disturbed. .

On the other hand, when the paper discharge section is tilted outward, the arm 3
Since the handle 24 that was in contact with 1 is released, the arm 31
Is pulled by the spring 33 to rotate in the direction of arrow I, and the arm 3
One end 31b of No. 1 enters into the concave portion on the outer circumference of the disk-shaped member 30. As a result, the rotation of the shaft 27 around which the cleaning web 25 is wound is restricted, and the cleaning web 25 is prevented from sagging when the fixing roller 1 is reversed.

Next, the normal operation of the fixing device will be described.

During normal operation, the fixing roller 1 is moved in the direction of arrow D from the driving means (not shown) through the gears 8, 6, 4 and the pressure roller 2 is moved in the direction of arrow D through the gears 6 and 7, 5. The recording material is conveyed by rotating in the E direction. At this time, gear 4
The gear 15 meshed with each other rotates in the direction of arrow A, but the one-way clutch 14 rotates in the idling direction. Therefore, the sleeves 12 and 10 do not rotate, and the lever 9 does not move regardless of the position.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIGS. 5, 6 and 7. The same parts as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In FIGS. 5, 6 and 7, reference numeral 34 is a slide lever, which is slidably supported by shafts 35 and 36 provided on the bent portion 3b of the side plate 3. A disk-shaped member 37 having holes at equal intervals in the circumferential direction is attached to the shaft 27 so as to rotate integrally.

Reference numeral 38 denotes an arm for restricting the rotation of the shaft 27, which is rotatably supported by a shaft 39 and urged clockwise by a spring 40.

The jam processing operation when the recording material is wound around the roller in such an apparatus will be described.

As in the first embodiment, when the jam jam handling lever 9 is moved in the direction of arrow F in order to enable the reverse rotation of the roller, a part 9b of the lever 9 contacts the end 34a of the slide lever 34. The slide lever 34 also slides in the direction of arrow F. Along with that, slide lever 3
The other end 34b of the arm 4 abuts on the end 38a of the arm 38, and the arm 38 rotates counterclockwise.
Enters into the hole of the disk-shaped member 37 (Fig. 7).

As a result, the rotation of the shaft 27 is restricted so that the cleaning web 25 does not slacken even when the fixing roller rotates in the reverse direction when the recording material is taken out.

[0041]

As described above, the first aspect of the present invention
According to the invention, the jam-discharging operation cannot be performed unless the paper-discharging portion of the fixing device is moved from the paper-passing portion, whereby the paper-discharging portion can be prevented from being contaminated during the jam-discharging operation.

Further, according to the second aspect of the invention, means for preventing the rotation of the rotating member for jam clearance from being transmitted to the gear train for rotating the roller is provided, and when the transmission is cut off,
With the configuration in which the feeding of the cleaning web is also blocked, the recording material wound around the roller can be easily taken out, and at that time, the cleaning web can be prevented from slackening.

[Brief description of drawings]

FIG. 1 is a diagram showing a fixing device according to a first embodiment of the present invention.

FIG. 2 is a top view of the fixing device according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a state of the fixing device according to the first embodiment of the present invention during a jam process.

FIG. 4 is a top view of the fixing device according to the first embodiment of the present invention when jammed.

FIG. 5 is a diagram showing a fixing device according to a second embodiment of the present invention.

FIG. 6 is a top view of the fixing device according to the second embodiment of the present invention.

FIG. 7 is a diagram showing a state during jam processing in the fixing device according to the second embodiment of the present invention.

FIG. 8 is a top view showing a conventional fixing device.

FIG. 9 is a front view showing a conventional fixing device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fixing roller 2 ... Pressure roller 9 ... Jam handling lever 10 ... Sleeve 12 ... Sleeve 14 ... One-way clutch 19 ... Discharging roller 20 ... Discharging roller 21 ... Discharging upper guide 22 ... Discharging lower guide 24 ... Handle 25 ... Cleaning web 30 ... Disc-shaped member 31 ... Arm 34 ... Slide lever 37 ... Disc-shaped member 38 ... Arm

Claims (4)

[Claims] A fixing roller heated by a heating source;
A pressure roller that is in pressure contact with the fixing roller, a manual rotation member that manually rotates at least one of the fixing roller and the pressure roller, and a discharge guide unit that is disposed downstream of the fixing roller and the pressure roller. In the fixing device having the above, the paper discharge guide means is movably provided in the main body of the device, and the manual rotation member can be operated by moving the paper discharge guide portion. 2. A fixing roller heated by a heating source,
In a fixing device having a pressure roller that is brought into pressure contact with a fixing roller and a manual rotation member for manually rotating at least one of the fixing roller and the pressure roller, the rotation of the manual rotation member is applied to the fixing roller and the pressing roller. A gear train that transmits to at least one of the pressure rollers, a first switching unit that switches presence / absence of power transmission depending on a rotating direction of the manual rotation member, and a first switching unit that switches presence / absence of power transmission by movement of the manual rotation member. 2. A fixing device comprising: a second switching unit; and a movement restricting unit that restricts the movement of the cleaning member of the fixing roller. 3. The fixing device according to claim 2, wherein the rotation member can be moved by operating a movement restricting means of the cleaning member of the fixing roller. 4. The fixing device according to claim 2, wherein movement of the cleaning member of the fixing roller is restricted in association with movement of the rotating member.