JPH06301310A - Electrophotographic device - Google Patents

Abstract

(57) [Summary] [Object] To provide an electrophotographic apparatus in which the cleaning roller is driven to rotate by the rotation of the fixing roller when the apparatus starts to be used, and the cleaning function can be surely exhibited. The cleaning roller 15 is movably supported between a contact position where it contacts the surface of the fixing roller 13 and a separation position where it separates from the surface of the fixing roller 13. Further, the cleaning roller 15 is pressed against the bearing 16 at the other end of a spring 18 of which one end is fixed in position, and the spring 18 applies a pressing force to the cleaning roller 15 in a direction to always contact the surface of the fixing roller 13. It is energized. Fixing roller 13 and cleaning roller 1
A removable spacer 19 is inserted between the bearing 5 and the bearing 16 and is removed before the start of use.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus such as a copying machine, a printer, a facsimile or the like, which is provided with a fixing device having a cleaning roller which comes into contact with the surface of a fixing roller and rotates.

[0002]

2. Description of the Related Art Conventionally, in an electrophotographic apparatus provided with a fixing device for fixing a toner image onto a transfer material by the action of heat of a fixing roller, dirt such as transferred toner adhered to the surface of the fixing roller is cleaned by using a cleaning roller. Cleaning has already been suggested. For example, in JP-A-64-90478, a cleaning roller made of a material that easily absorbs softened toner is pressure-bonded to a heat roller, and the cleaning roller is rotated by being driven by the rotation of the heat roller, so that the toner removing function is excellent. It is described that a different cleaning roller can be obtained. Such a cleaning roller generally has a structure in which a heat-resistant felt is wound on a core metal and impregnated with silicone oil, and is in pressure contact with the fixing roller when the electrophotographic apparatus is manufactured.

[0003]

In the above-mentioned conventional electrophotographic apparatus, since the same portion of the cleaning roller 4 is pressed against the fixing roller 1 until the use of the apparatus is started, the contact portion is deformed. I may end up doing it.
Then, it may happen that the contact portion is not restored to the original shape while being deformed. If such deformation occurs, even if the fixing roller is rotated after the use of the apparatus is started, the cleaning roller does not rotate and the function of the cleaning roller is significantly deteriorated in such a state. Occurred.

The present invention solves the above-mentioned conventional problems,
It is an object of the present invention to provide an electrophotographic apparatus in which a cleaning roller is rotated by the rotation of a fixing roller when the use of the apparatus is started and a cleaning function can be surely exhibited.

[0005]

In order to achieve this object, the present invention provides an electrophotographic apparatus having a fixing device having a cleaning roller which contacts the surface of the fixing roller and rotates, wherein the cleaning roller is the fixing roller. A pressing unit that is movably supported between a contact position that contacts the surface and a spaced position that separates from the fixing roller surface, and that applies a pressing force to the cleaning roller in a direction that always contacts the cleaning roller surface. And a detachable space member for holding the cleaning roller at the separated position against the action of the pressing means.

Further, in order to achieve the above object, the present invention is movably supported between a contact position where the cleaning roller contacts the fixing roller surface and a spaced position where the cleaning roller separates from the fixing roller surface. A pressing unit that constantly applies a pressing force to the cleaning roller in a direction in which the cleaning roller is in contact with the surface of the fixing roller; a space member that holds the cleaning roller in the separated position against the action of the pressing unit; The space member is removed from the position for holding the cleaning roller at the separated position by being rotationally driven by being drive-coupled with the drive transmitting unit provided inside, and the space member is driven with the drive transmitting unit by the rotational drive. It is characterized in that a detaching means for releasing the connection is provided.

[0007]

According to the structure of the present invention, since the contact between the cleaning roller and the fixing roller can be held in the separated position by the detachable space member, the space member can be attached until the use of the apparatus is started. By this, the deformation due to the contact between the cleaning roller and the fixing roller can be prevented, and the cleaning function of the cleaning roller can be surely exhibited by removing the space member at the start of use.

According to the second aspect of the present invention, the contact between the cleaning roller and the fixing roller is separated by the space member, and the space member is automatically removed by the rotational driving of the apparatus. It is possible to prevent the deformation of the abutment with and to make the cleaning roller function reliably, and also to prevent forgetting to remove the space member at the start of use.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a laser printer showing an embodiment of the electrophotographic apparatus according to the present invention. In FIG. 1, reference numeral 1
Is an optical writing device that projects a laser beam 5 based on an image signal, and 2 is an image forming unit. The image forming unit 2 includes a photoconductor belt 3 and a charging charger 4 that charges the photoconductor belt 3.
A developing device 6 for developing an electrostatic latent image formed by the projection of the laser beam 5 by the post-charging optical writing device 1, and a developing device 6 for recording paper fed from the paper feeding device 7 by a registration roller 8 at a timing. Transfer charger 9 for transferring the toner image of the toner and a fixing device 10 for fixing the recording paper after the transfer
And a cleaning device 11 for cleaning the photoconductor belt 3 after transfer. The recording paper image-formed by the image forming unit 2 is discharged to the paper discharge unit 12.

The fixing device 10 includes a fixing roller 13 and
The fixing roller 13 is pressed against the fixing roller 13, and the cleaning roller 15 is pressed against the fixing roller 13. The cleaning roller 15 is driven to rotate by the rotation of the fixing roller 13 and cleans dirt such as toner adhering to the surface of the fixing roller 13.

In the laser printer, the period from the manufacture to the start of use is not uniform and may take a long time. If this period becomes long, the same portion of the cleaning roller 15 is pressed against the fixing roller 13 in the fixing device 10 having the above-described configuration, and therefore the contact portion may be deformed and may not be restored to the original shape. That was explained earlier. In order to solve such a problem, the present invention takes the following measures.

FIG. 2 is an explanatory diagram of the fixing device showing a state before the use of the laser printer is started. In FIG. 2, reference numeral 16 is a bearing of the cleaning roller 15, and the bearing 16 is an elongated hole 1 formed in a side plate (not shown).
It is fitted so as to slide along 7 (indicated by a chain double-dashed line). The elongated hole 17 is formed so as to extend in the direction in which the cleaning roller 15 comes in contact with and separates from the fixing roller 13, so that the cleaning roller 15 comes into contact with the surface of the fixing roller 13 and the fixing position. The roller 13 is supported so as to be movable between the roller 13 and a separated position away from the surface of the roller 13.

Further, the cleaning roller 15 is pressed against the bearing 16 by the other end of a spring 18 as a pressing means whose one end is fixed in position, and the fixing roller 13 is constantly fixed to the cleaning roller 15 by this spring 18.
The pressing force is applied in the direction of coming into contact with the surface of the. In the case of a newly manufactured laser printer, a spacer 19 as a space member is removably inserted between the fixing roller 13 and the bearing 16 of the cleaning roller 15, whereby the cleaning roller 15 is at the separated position. Held in.

The insertion position of the spacer 19 is arbitrary as long as the cleaning roller 15 can be held at the separated position. That is, the spacer 19 may be inserted between the bearing 16 and a fixing portion such as a side plate (not shown), or may be directly inserted between the cleaning roller 15 and the fixing roller 13.

In the thus constructed laser printer, the cleaning roller 15 is held at the separated position by the spacer 19 until the use is started, so that the same portion of the cleaning roller 15 may be pressed against the fixing roller 13 for a long period of time. The cleaning roller 15 is prevented from being deformed. Then, if the spacer 19 is removed in the direction of the arrow just before using the laser printer, the cleaning roller 15 is moved to the contact position by the action of the spring 18 and along the elongated hole 17, as shown in FIG. It is pressed against the roller 13.

Thus, by moving the cleaning roller 15 to the contact position, the cleaning roller 15 is rotated along with the rotation of the fixing roller 13 and a cleaning function can be exerted.

FIG. 4 is an explanatory view of the fixing device showing a state before the use of the laser printer showing another embodiment of the present invention is started. In FIG. 4, the cleaning roller 1
5, the bearing 16 is fitted so that the bearing 16 is slid along the long hole 17, and there are a contact position where the bearing 16 contacts the surface of the fixing roller 13 and a separation position where the bearing 16 separates from the surface of the fixing roller 13. It is supported so as to be movable between them, and is further urged by a pressing force by a spring 18. A cam 20 as a space member is rotatably supported on the shaft 15a of the cleaning roller 15, and a gear portion 21 is formed on a part of the peripheral surface of the cam 20.

Further, reference numeral 22 is one of gears as drive transmission means rotated by a drive source (not shown) of the laser printer, and the gear portion 21 can mesh with the gear 22. At this meshing position, the cam 20 is arranged such that the fixing roller 13 and the shaft 15a of the cleaning roller 15 have a substantially maximum eccentric amount, and the opposite end of the gear portion 21 is pressed against the fixing roller 13. With this configuration, the cleaning roller 15 is held at the separated position when the gear portion 21 and the gear 22 of the cam 20 mesh with each other.

Since it is only necessary for the cam 20 to hold the cleaning roller 15 at the separated position, the opposite end of the cam 20 may be brought into pressure contact with an appropriate fixed part when the gear part 21 and the gear 22 mesh with each other. .

In the laser printer thus constructed, the cleaning roller 15 is held at the separated position by holding the cam at the position where the gear portion 21 and the gear 22 mesh with each other when manufactured. Therefore, the same portion of the cleaning roller 15 is not pressed against the fixing roller 13 for a long period of time, and the deformation of the cleaning roller 15 is prevented.
When you start using the laser printer, the gear 2
2 rotates, and the cam 20 meshing with the gear 2 also rotates about the shaft 15a of the cleaning roller 15 as shown in FIG. Due to the rotation of the cam 20, the cam 20 is separated from the fixing roller 13 and the cleaning roller 1
5 is moved to the contact position along the long hole 17 by the action of the spring 18, and is pressed against the fixing roller 13. Further, at this time, when the cam 20 rotates by a certain angle, the gear portion 21 and the gear 22 are disengaged from each other, and the state is maintained thereafter. Therefore, there is no possibility that the cam 20 that has finished its function will hinder the operation of the printer.

The gear portion 21 meshing with the gear 22 is removed from the position where the cleaning roller 15 of this embodiment is held at the separated position, and the gear 22 is rotated by driving the gear portion 21.
It constitutes a detaching means for releasing the drive connection with.

Thus, by moving the cleaning roller 15 to the contact position, the cleaning roller 15 can be rotated along with the rotation of the fixing roller 13 to exert the cleaning function.
Moreover, when the use of the laser printer is started, the cleaning roller 15 can be automatically moved to the contact position, so that it is possible to prevent the spacer from being forgotten and misused when the use is started.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and various modifications can be made. In the embodiment shown in FIG. 4, a cam having a gear portion that meshes with a gear is used as the space member, but the cam member is not limited to the cam. For example, a plate member or a rod-shaped member that is easily bent at an appropriate position is rotatably supported by the shaft 15a of the cleaning roller 15, and the plate member or the rod-shaped member is inserted between the fixing roller side and the gear to rotate the gear. By doing so, the cleaning roller 15 may be moved to the contact position by bending the plate member or the rod-shaped member.

[0024]

According to the present invention, since the contact between the cleaning roller and the fixing roller can be separated by the detachable space member, if the space member is attached until the use of the apparatus is started, It is possible to prevent deformation due to contact with the fixing roller. Further, if the space member is removed at the start of use, the cleaning roller will not be deformed, so that the cleaning roller can be surely functioned.

Further, according to the present invention, the contact between the cleaning roller and the fixing roller is separated by the space member, and the space member is automatically removed by the rotational driving of the apparatus. The contact roller can be prevented from being deformed and the cleaning roller can be surely functioned. Besides, Since the space member is automatically removed by the drive at the start of use, it is possible to prevent the user from forgetting to remove the space member and using it.

[Brief description of drawings]

FIG. 1 is a laser printer showing an embodiment of an electrophotographic apparatus according to the present invention.

FIG. 2 is an explanatory diagram of a fixing device showing a state before the use of the laser printer is started.

FIG. 3 is an explanatory diagram of the fixing device showing a state after the start of use in FIG.

FIG. 4 is an explanatory diagram of a fixing device showing a state before the start of use of a laser printer according to another embodiment of the present invention.

FIG. 5 is an explanatory diagram of the fixing device showing a state after the start of use in FIG.

[Explanation of symbols]

 10 Fixing Device 13 Fixing Roller 15 Cleaning Roller 17 Long Hole 18 Spring 19 Spacer 20 Cam 21 Gear Part 22 Gear

Claims (2)

[Claims] 1. An electrophotographic apparatus including a fixing device having a cleaning roller that comes into contact with the surface of a fixing roller and rotates, wherein the cleaning roller comes into contact with the surface of the fixing roller and is separated from the surface of the fixing roller. A pressing unit that is movably supported between the cleaning roller and a pressing unit that constantly applies a pressing force to the cleaning roller in a direction of contacting the surface of the fixing roller; and the cleaning roller against the action of the pressing unit. And an attachable / detachable space member for holding the sheet at the separated position. 2. An electrophotographic apparatus including a fixing device having a cleaning roller that comes into contact with the surface of a fixing roller and rotates, wherein the cleaning roller comes into contact with the surface of the fixing roller and is separated from the surface of the fixing roller. A pressing unit that is movably supported between the cleaning roller and a pressing unit that constantly applies a pressing force to the cleaning roller in a direction of contacting the surface of the fixing roller; and the cleaning roller against the action of the pressing unit. And a space member for holding the cleaning roller at the separated position by being rotationally driven by being driven and connected to a space member for holding the cleaning roller at the separated position. And a detaching means for detaching and disconnecting the drive connection with the drive transmitting means by its rotational drive. Electrophotographic apparatus, wherein the door.