JP2002244475A - Fixing device and image forming device equipped therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of parts required for a mechanism making a peeling member retreat from/abut on a fixing roller and to make measures for thermal protection in the case of opening the opening/closing unit of an image forming device more complete. SOLUTION: This fixing device 150 has fixing roller pair consisting of a heat roller 151 and a pressure roller 152, a peeling member 154 for peeling paper from the roller 152, and a guiding member 155 to which the member 154 is attached. The member 155 is provided so as to be movable with respect to a supporting plate 165, and the member 154 is made to abut on or retreat from the roller 152 by the movement of the member 155 in a direction shown by an arrow X.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device provided in an image forming apparatus such as a copying machine or a facsimile machine and an image forming apparatus provided with the fixing device, and more particularly, to peeling off a sheet adhered to a fixing roller. For contacting or retracting a peeling member for fixing to a fixing roller.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus such as a copying machine or a facsimile machine has a fixing roller pair including a heat roller and a pressure roller, and a fixing roller for fixing a toner image transferred to a sheet. A fixing member provided with a separating member for separating the sheet, the image forming apparatus having a configuration in which the sheet is vertically conveyed from the sheet feeding mechanism to the developing device and the fixing device. Are arranged horizontally. In such a fixing device, in order to avoid interference between the fixing roller and the peeling member when the opening / closing unit of the image forming apparatus is opened for paper jam processing or the like, the peeling member retracts from the fixing roller when the unit is opened, When the unit is closed, the peeling member contacts the fixing roller. For example, a peeling member is rotatably attached to a part (operation plate) of the opening / closing unit, and the portion to which the peeling member is attached slides in conjunction with the opening / closing operation of the unit, so that the guide member is used for paper conveyance. There is an apparatus configured to rotate upward by contacting a guide member and to retract the leading end of the peeling member from the surface of the fixing roller (for example, JP-A-2000-264).
No. 520).

[0003]

However, in such an apparatus as described above, in order to make the opening / closing operation of the unit and the turning operation of the peeling member interlock, the operation plate on which the peeling member is attached is slid with respect to the opening / closing unit. Since the mechanism must be movable, a large number of parts are required for the mechanism, and the number of assembly steps for the mechanism has increased. As a matter of course, since there are a plurality of members, there are many variations in the positions of the claw tip and the guide. Further, in the fixing device, since the iron plate or the like must be used for the portion of the opening / closing unit to which the peeling member is attached for maintaining strength, heat from the fixing roller is easily transmitted through the peeling member. It is desirable to take thorough thermal protection measures in consideration of the above.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and the number of components required for a mechanism for retracting and contacting a peeling member from a fixing roller is reduced.
It is another object of the present invention to provide a fixing device and a fixing device capable of taking sufficient thermal protection measures when an opening / closing unit of the image forming device is opened, and an image forming device provided with the fixing device.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a fixing roller pair including a heat roller and a pressure roller, and a peeling method for peeling a sheet from the roller by contacting at least one of the rollers. A fixing member provided in the image forming apparatus for fixing unfixed toner on the surface of the sheet to the sheet, wherein a guide member for guiding a conveying direction of the sheet passing between the fixing roller pair includes an image forming member. The guide member is integrally movably attached to the openable unit of the apparatus, and the peeling member abuts or retracts from the roller by moving the guide member in conjunction with the opening and closing operation of the unit. Is what it is.

[0006] For example, the peeling member is rotatably supported by the unit, and one end of the peeling member is a claw that abuts on the roller. Is fixed to the unit by an elastic member, the guide member has a locking portion that locks to the peeling member, and the locking portion locks to the peeling member by movement of the guide member, and The peeling member may be configured to rotate in a direction in which the claw portion is retracted from the roller by pressing.

Further, the guide member is elastically biased so as to move in a direction in which the peeling member is retracted from the roller, and when the unit is opened, the locking portion is released by the biasing force. When the unit is moved in the direction in which the unit is closed and the unit is closed, movement by the urging force is suppressed, and the locking unit is configured to be in a state where it is not locked to the peeling member. Good.

In these configurations, the interlocking between the unit opening and closing operation of the image forming apparatus and the moving operation of the guide member, and the interlocking between the moving operation of the guide member and the rotating operation of the peeling member are realized with a simple structure. Therefore, the number of components required for a mechanism for abutting and retracting the peeling member from the fixing roller is reduced, and the number of assembling steps is reduced.

Further, a part of the guide member may be interposed between the opening / closing unit of the image forming apparatus and the peeling member.

According to this configuration, since the gap between the opening and closing unit and the peeling member is blocked by the guide member, it is difficult for heat from the fixing roller to be transmitted to the opening and closing unit.

According to another aspect of the present invention, there is provided a fixing roller pair comprising a heat roller and a pressure roller, and a peeling member which comes into contact with at least one of the rollers and peels off the paper from the roller. In an image forming apparatus provided with a fixing device for fixing toner to a sheet, a guide member for guiding a conveying direction of the sheet that has passed between the fixing roller pair is positioned relative to an openable and closable unit of the image forming apparatus. And the guide member moves in conjunction with the opening and closing operation of the unit so that the peeling member abuts or retreats from the roller.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a fixing device and an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing a schematic configuration of an image forming apparatus (copier) according to the present invention. As shown in FIG. 1, in the copying machine 1, a charging unit 10
2, the photosensitive drum 103 rotating in the direction A in the figure is uniformly charged, and the photosensitive drum 103 is irradiated with a laser beam from a laser scanning unit (LSU) 105 based on the original image read by the original reading unit 104. An electrostatic latent image is formed on the electrostatic latent image, and toner is attached to the electrostatic latent image by the developing unit 106 to form a toner image. The supply of the toner to the developing unit 106 is performed from a toner supply container 107.

The paper is conveyed vertically from the paper feed mechanism 200 via the paper conveyance path 204 toward the photoconductor drum 103 on which the toner image is formed as described above, and is transferred by the transfer roller 108. The toner image on the surface is transferred to the paper. Then, the sheet on which the toner image has been transferred is separated from the photosensitive drum 103 and is conveyed to a fixing device 150 including a pair of fixing rollers, where the toner image is fixed.
The fixing roller pairs are arranged side by side in the horizontal direction.
Then, the sheet after the toner image is fixed is discharged to the discharge unit 111 by the discharge roller pair 110 as it is (or after being inverted and double-sided copied by a switchback unit (not shown)).

A cleaning unit 112 removes residual toner and the like on the photosensitive drum 103. The paper feeding mechanism 200 is detachably attached to the copying machine main body 101 and has a paper feeding cassette 20 for storing paper.
1 and 202 and a stack bypass (bypass tray) 203 provided thereabove, and these are connected to the developing unit 106 and the fixing device 150 by a paper transport path 204. Further, the main body 1 of the image forming apparatus 1
01 is a transport path 20 for enabling paper jam processing and the like.
4 to open and close.

Next, the fixing device 150 will be described with reference to FIGS. FIG. 2 is a sectional view showing a schematic configuration of the fixing device, and FIG. 3 is a perspective view showing a guide member forming a part of the fixing device.

The fixing device 150 has a fixing roller pair including a heat roller 151 having a built-in heater and a pressure roller 152 pressed against the heat roller 151. The heat roller 151 is used to prevent the sheet from winding. Has a peeling member 15
3, a pressure roller 152 is provided with a peeling member 154, respectively. The heat roller 151 and the pressure roller 152
As described above, they are arranged side by side in the horizontal direction.
In the direction indicated by the arrow. Also,
Above the heat roller 151 and the pressure roller 152, a guide member 15 for guiding the conveyance of the sheet passing through the pair of fixing rollers is provided.
The guide member 155 is formed of a synthetic resin or the like having a low heat transfer property.

The fixing unit 150 has the developing unit 10
6 (from the lower side of the pair of fixing rollers in FIG. 2), the paper in the toner unfixed state is conveyed.
51 and between the pressure roller 152 and the toner
The toner is melted and the toner is fixed on the paper.
When the sheet adheres to the heat roller 151 and the pressure roller 152, the sheet is separated from the heat roller 151 and the pressure roller 152 by the separation members 153 and 154. The paper that has passed between the heat roller 151 and the pressure roller 152 is guided in the transport direction toward the discharge roller pair 110 (in FIG. 2, above the fixing roller pair) by the transport surface 155 a of the guide member 155.

The structure of each part of the fixing device 150 will be described in detail. The peeling member 153 on the side of the heat roller 151 has a substantially L-shaped side surface so that a rotating force is generated about the rotation support shaft 162 by a tension spring 161. It comes into contact with the surface.

The peeling member 154 on the side of the pressure roller 152 has a substantially L-shaped side surface, and is disposed inside the guide member 155. The peeling member 154 is held rotatably while its rotation support shaft 165 is in sliding contact with the rib 155e of the guide member 155, and is slidably held along the rib 155e. Further, the peeling member 154 is configured to generate a rotating force about the rotation support shaft 165 by the tension spring 166, so that the tip portion (claw portion) 154 a contacts the surface of the pressure roller 152. The tension spring 166 is fixed to the support plate 163 through the opening of the guide member 155. With such a configuration, the peeling member 154 can freely move out of the guide member 155 by rotating. When the leading end 154a of the peeling member 154 is pushed upward by the conveyed paper, the peeling member 154 is displaced upward, and the leading end 154a of the peeling member 154 does not bite into the pressure roller 152. , And acts to peel off the paper stuck to the pressure roller 152.

The guide member 155 is slidably attached to the support plate 163. The side of the guide member 155 is attached to the support plate 163 via a pressing spring 167. 151. The guide member 155 has an upper surface 1
55b is configured to be interposed between the peeling member 154 and the support plate 163, and a pin 168 is provided on the upper surface 155b. The pin 168 is connected to the support plate 16.
3, the operation is regulated such that the guide member 155 can move only in the direction of the arrow X in FIG.

The heat roller 151 of the guide member 155
A protrusion 155c is provided on the side of the side. When the opening / closing unit (support plate 163) of the image forming apparatus is closed, the protrusion 155c is
When the peeling members 153 and 154 are set in 2, they come into contact with the guide member 170 on the heat roller 151 side. The protruding portion 155c is provided with a pressing spring 167 so that the support plate 163 and the guide member 155 are at a predetermined position with a predetermined distance therebetween when the opening / closing unit is closed.
And thereby stabilize the positions of both members.

Further, inside the guide member 155, there are provided a locking portion 155d which can be locked to the peeling member 154, and a rib 155e which comes into sliding contact with the rotation support shaft 165 of the peeling member 154. In a state where the protrusion 155c is in contact with the guide member 170 and the guide member 155 is pushed into the support plate 163 side, the peeling member 154 is in a state where the rotation support shaft 165 is in contact with the rib 155e, and the tension spring 166 is provided.
Is set so as to come into contact with the pressure roller 152 with the turning force of When the contact between the projection 155c and the guide member 170 is released and the guide member 155 moves toward the heat roller 151 by the urging force of the pressing spring 167, the peeling member 1
The rotation support shaft 165 of 54 is engaged with a bearing portion 164 extending downward from the support plate 163, and the locking portion 155d presses the peeling member 154 to rotate upward.

Also, as shown in FIG.
Reference numeral 5 denotes an elongated shape along the rotation axis direction of the pressure roller 152. In the present embodiment, four peeling members 154 are arranged in the longitudinal direction. Each of the four peeling members 154 is displaced in conjunction with the movement of the guide member 155 with the same configuration as described above. Further, the protrusion 1 of the guide member 155
55c are formed at both ends in the longitudinal direction of the guide member 155 so that the paper can be smoothly transported by the heat roller 151 and the pressure roller 152.

Next, the peeling member 154 and the guide member 155 when the opening / closing unit of the image forming apparatus 1 is opened.
Will be described. FIG. 4 is a diagram showing the open / close state of the opening / closing unit of the image forming apparatus 1, and FIG. 5 is a diagram showing the operation of the guide member and the peeling member when the opening / closing unit is opened.

As shown in FIG. 4, the main body of the image forming apparatus
A part thereof is the transport path 204 as the opening / closing unit 101a.
It is configured to open and close along. The opening and closing unit 101a is opened and closed by rotating about a rotation support shaft 180, so that the fixing roller pair and the transport path 204 are exposed. In the opening and closing unit 101a,
The support plate 163, the guide member 155, and the peeling member 15
The supporting plate 163, the guide member 155, and the peeling member 154 are detached from the fixing roller pair with the opening / closing operation of the opening / closing unit 101a.

The guide member 155 and the peeling member 154
When the opening / closing unit 101a shown by a solid line in FIG. 4 is closed, it is set to be located above the pressure roller 152. Then, the protrusion 155c of the guide member 155 comes into contact with the guide member 170 on the heat roller 151 side, and the pressing spring 1
The urging force by the 67 is suppressed, and the guide member 155 is pushed into the support plate 163 side. In this state, as shown in FIG. 2, the tip 154a of the peeling member 154 is rotated by the rotating force of the tension spring
Is set in contact with

In order to open the opening / closing unit 101a as shown by a two-dot chain line in FIG. 4, the opening / closing unit 101a is moved in the direction of the arrow in FIG.
When the contact between the protrusion 155c and the guide member 170 is released, the guide member 155
7 moves in the direction of the arrow shown in FIG. The movement of the guide member 155 causes the rotation support shaft 165 of the peeling member 154 to engage with the bearing portion 164, and
5d presses the peeling member 154, and the peeling member 154 rotates upward, and the front end portion 154a is retracted from the pressure roller 152.

With the above configuration, the opening / closing unit 101a
When the user opens the guide member 155, the release member 154 moves.
Is retracted from the pressure roller 152, and when the opening / closing unit 101a is closed, the guide member 155 moves and the peeling member 154 comes into contact with the pressure roller 152.

The present invention is not limited to the configuration of the above embodiment, and various modifications are possible. For example, in the above embodiment, the peeling member 154 on the side of the pressure roller 152 is retracted and abuts from the pressure roller 152 as the guide member 155 moves. The peeling member 153 may be retracted and abutted from the heat roller 151 as the guide member moves.

[0030]

As described above, according to the present invention, the interlocking between the unit opening and closing operation of the image forming apparatus and the moving operation of the guide member, and the interlocking between the moving operation of the guide member and the rotating operation of the peeling member are simplified. Therefore, the number of components required for a mechanism for abutting and retracting the peeling member from the fixing roller is reduced, and the number of assembling steps is reduced. Further, since the configuration is simplified, the operation of the opening / closing unit of the image forming apparatus and the contact / retreat operation of the peeling member can be linked with high accuracy.

If a part of the guide member is interposed between the opening / closing unit and the peeling member, the space between the opening / closing unit and the peeling member is blocked by the guide member, and the heat from the fixing roller is transmitted to the opening / closing unit. It becomes difficult. Therefore, measures for protecting the user from heat when the unit is opened for paper jam handling or the like are further improved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a schematic configuration of a copying machine according to the present invention.

FIG. 2 is a cross-sectional view illustrating a schematic configuration of a fixing device according to the present invention.

FIG. 3 is a perspective view showing a guide member forming a part of the fixing device according to the present invention.

FIG. 4 is a diagram illustrating an open / close state of an open / close unit of the image forming apparatus.

FIG. 5 is a diagram illustrating the operation of a guide member and a peeling member when the opening / closing unit is opened.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image forming apparatus 101a Opening / closing unit 150 Fixing device 151 Heat roller 152 Pressure roller 154 Peeling member 154a Tip part 155 Guide member 155c Projection part 155d Lock part 163 Support plate 164 Bearing part 166 Tension spring 167 Press spring

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) G03G 21/16 G03G 15/00 554 F-term (reference) 2H033 AA16 AA36 BA06 BA10 BA16 BA20 BA21 BA22 BB01 BB28 2H071 AA13 AA20 BA03 BA14 BA15 DA12 DA23 2H072 JA02 JA04 3F053 AA19 AA22 LA02 LA05 LB03 3F101 FB08 FB11 FE17 LA02 LA05 LB03

Claims (5)

[Claims] A fixing roller pair comprising a heat roller and a pressure roller, and a peeling member which comes into contact with at least one of the rollers and peels the paper from the roller, wherein unfixed toner on the paper surface is transferred to the paper. In a fixing device provided in an image forming apparatus for fixing, a guide member for guiding a conveying direction of a sheet passing between the fixing roller pair is integrally movable with respect to an openable and closable unit of the image forming apparatus. The fixing device is mounted, wherein the guide member moves in conjunction with the opening / closing operation of the unit so that the peeling member comes into contact with or retracts from the roller. 2. The exfoliating member is rotatably supported by the unit, and one end of the exfoliating member is a claw that abuts on the roller. The other end is used to abut the claw on the roller. Is fixed to the unit by an elastic member, the guide member has a locking portion for locking to the peeling member, and the locking portion is locked to the peeling member by movement of the guide member, and the peeling member is The fixing device according to claim 1, wherein the pressing unit is configured to rotate the peeling member in a direction in which the claw portion is retracted from the roller. 3. The guide member is resiliently urged to move in a direction in which the peeling member is retracted from the roller, and when the unit is opened, the locking portion is released by the urging force. It is configured to move in a direction in which it is locked to a member, and when the unit is closed, movement by the urging force is suppressed, so that the locking portion does not lock to the peeling member. The fixing device according to claim 2, wherein 4. The fixing device according to claim 3, wherein a part of the guide member is interposed between the unit and the peeling member. 5. A fixing roller pair comprising a heat roller and a pressure roller, and a peeling member which comes into contact with at least one of the rollers and peels off the paper from the roller, wherein unfixed toner on the surface of the paper is transferred to the paper. An image forming apparatus having a fixing device for fixing, wherein a guide member for guiding a conveying direction of a sheet passing between the fixing roller pair is movable relatively to an openable and closable unit of the image forming apparatus. An image forming apparatus, wherein the peeling member is attached to or retracted from the roller when the guide member moves in conjunction with the opening and closing operation of the unit.