JPS58100874A - Toner image fixing device - Google Patents

Abstract

PURPOSE:To exactly prevent a careless coupling of a cleaning roll and a fixing roll due to coagulation of a toner, by providing the cleaning roll so as to be freely attachable and detachable to and from the fixing roll, and separating it from the fixing roll when the latter is not driven. CONSTITUTION:To the tip of a moving arm supported by a shaft 8 so as to be freely turnable, a cleaning roll 11 is fitted, and it is made to press-contact with a fixing roll 1. The arm 9 is energized counterclockwise by a pinch spring 14, and a cam roll 18 is made to press-contact with a cam 20. When the fixing roll 1 stops, the cam 20 turns by 180 deg., the arm 9 moves counterclockwise by the spring 14, and the roll 11 is separated from the roll 1. Therefore, a remaining toner on the roll 1 is cooled and coagulated, a careless coupling of the rolls 1, 11 is prevented, and at the time of start, large torque is not required. Also, damage of the roll surface due to a shock at the time of start is also prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to a toner image fixing device used in electrophotographic copying machines and the like.

Technical Background of the Invention In electrophotographic machines and the like, toner II? At the same time as transferring, the copy paper is passed through a fixing device to fix the toner particles.

As this type of O fixing device, four types of heat and roller types are widely known. This system consists of a fixing roller with a heat source and a pressure roller that comes into pressure contact with the fixing roller. Copy paper is inserted through the O-contact between both rollers, and the toner*1 is heated and pressurized. by compounding it
It is designed to be fixed on paper. At this time, not all of the toner in the toner image is necessarily fixed on the copy paper, and some of it often adheres to the surface of the fixing roller. Generally, the toner adhering to the surface of the fixing plate O is removed by causing the fixing roller to follow the fixing roller by the frictional force between the toner and the fixing roller.

Problems with the Background Art Conventionally, the cleaner roller that is in rolling contact with the fixing roller is in pressure contact with the fixing roller even when the fixing roller is not driven #bjI#. When the fuser roller is not energized, the heat source built into the fuser roller is also deenergized, and the temperature of the surface of the fuser roller decreases, resulting in a reduction in the temperature of the fuser roller and the cleaning roller. The solidified toner solidifies, and both the fixing roller and the cleaning roller are firmly bonded to each other, and a large torque is required to start driving the fixing roller next time. At that time, a large amount of dust was generated, and there was a risk that the surrounding surface of the cleaning roller in the fixing roller would be damaged or damaged by the ζO dust. The object of the present invention is to provide a toner image fixing device which can actually prevent inadvertent coupling between a fixing roller and a cleaning roller due to toner coagulation.

Summary of the Invention The present invention provides a fixing roller 91 that is movable toward and away from the fixed fixing roller, and is separated from the fixing roller when the fixing roller is not driven. A toner fixing device characterized in that it prevents O-coupling of both rolls.

Embodiment of the Invention Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawing, 1 is a fixing roller, and 2 is a pressure roller. The fixing roller 1 includes a heater J as a heat source inside, and a cylindrical body 4 made of good metal.The outer peripheral surface of the cylindrical body 4 is coated with, for example, a silicon film layer 5t, which is relatively thin and uniform, and has excellent toner releasability and heat resistance. It becomes. The pressure opening roller 2 is formed by applying a relatively thick and uniform silicone coating layer similar to that described above on the outer peripheral surface of a metal cylindrical body 6. This pressure roller 2Fi is freely provided with respect to the fixing roller 1, and when the fixing roller 1 is driven and rotated, the fixing roller 1
It is designed to be pressed against the outer circumferential surface of the cylinder with a constant pressure.

A shaft 1 supported by seven frames (not shown) is provided on the side of the pressure roller 1, and one end of a movable arm is rotatably supported on this shaft 1. And this movable arm 9
A cleaning roller 11 is rotatably attached to the other end via a shaft 1f, and this cleaning roller 11 faces the circumferential surface of the fixing roller 1. Cleaning reeler 1
1 is formed by uniformly applying a heat-resistant silicone film layer 11 on the outer peripheral surface of a metal cylindrical body 12 and having a greater affinity for toner than the silicone film layer JK of the fixing roller 1. [The supported shaft 8 is provided with an iron spring 14, and one end of this iron spring 140 is attached to the arm 15 and the other end is attached to the 7-ray 5 mentioned above. The earth is lifted up to each pin 1#, and the iron spring 1
Due to the elastic force of 4, the movable arm p is elastically urged in the clockwise direction in the figure with the axis at-crossing point, and in the direction in which the cleaning roller 1 is separated from the fixing roller 1.Movable arm 9 A shaft 11 is provided in the middle of the shaft 11, and a cylindrical cam roller 1# is rotatably mounted on the outer periphery of the shaft 11. A camshaft 19 is provided parallel to the shaft 110 on the side of the shaft 110. This camshaft 1# is supported by the frame, and a cam 20 is rotatably mounted on ζ and the outer periphery of the camshaft 19. ing. The cam sou rotates in conjunction with the movement of the pressure roller 2 toward and away from the fixing roller 1, and when the cam sou contacts the fixing roller 1 and when the -B fixing roller 1 is driven to rotate,
The movable arm 9 is pressed clockwise in the figure against the iron spring 14 by rotating the cam #m, and the cleaning roller 11 is brought into pressure contact with the fixing roller 1 jl18Wi. . Incidentally, reference numeral 21 denotes a guide plate that guides the copy paper a onto which the toner image has been transferred between the fixing roller 1 and the pressure roller 1.Next, the operation will be explained. When the pitting to start fixing is carried out, the fuser J is energized and the fixer 1 is heated. and fixing roller 1
When the fixing roller 1 starts to rotate, the pressure roller 2 comes into pressure contact with the periphery of the fixing roller 1 at step 4. In addition, the cam 2o rotates in conjunction with this pressing operation, and its protrusion 2o1 contacts the cam roller 18, and the movable arm 9 rotates clockwise in the figure against the iron spring 14. The shift cleaning roller 11 comes into pressure contact with the surface of the fixing roller 1, and the pressure roller 2 and the cleaning roller 11 each rotate following the fixing roller JK.

Under this condition, the copy paper a is introduced into the rolling contact between the fixing roller 1 and the pressure roller 2 via the guide plate 21t, and while the copy paper a is inserted through the rolling contact, the Copy paper a
K-transferred toner Ilb is heated and pressurized to fix it. During this fixing process, toner b' that adheres to the circumferential surface of the fixing roller 10 comes into contact with the wire surface KW of the cleaning roller 11 as the fixing roller 1 rotates. And that cleaner roller 11
In this way, the toner image is sequentially fixed on the copy paper a, and after the fixing is completed, the fixing roller 10 rotations are stopped and the power to the heater 1 is cut off. The pressure roller 1 separates from the foot care roller 1, and the cam 20 rotates 180 degrees in conjunction with this separation movement.
The protrusion 20m separates from the cam roller 1#.

With this separation, the movable arm 9 is rotated counterclockwise in the figure by the elastic force of the iron spring 14K), thereby separating the shift cleaning roller 11 from the fixing roller 1.

In this way, when the fixing roller 1 is not driven, the cleaning roller 11 is kept in a state separated from the fixing roller 1, instead of being left in pressure contact with the fixing roller IK as in the conventional case. The fixing roller 1 and the cleaning roller 11 are never connected to each other due to the toner stuck on the circumferential surface of the fixing roller 1 being solidified, and therefore a particularly large torque is required when starting to drive the fixing roller 1 next time. There is no damage to the peripheral surface of the fixing roller 1 or the cleaning roller 110 during damage.

Note that the configuration for bringing the cleaning roller into contact with and separating from the fixing roller can be modified in various ways, and
The m operation does not necessarily have to be carried out in conjunction with the movement of the pressure roller toward and away from the fixing roller.Furthermore, the fixing roller is not limited to one equipped with a heat source and uses a specific heat fixing method, but may also be one of a pressure fixing method.

Effects of the Invention As explained above, according to the present invention, it is possible to reliably prevent the cleaning roller and the fixing roller from being inadvertently connected due to toner coagulation, and therefore, especially when the fixing roller is re-driven. There is no need for large torque, and there is an effect that the peripheral surfaces of the cleaning roller and fixing roller are not damaged or damaged.

[Brief explanation of the drawing]

Face map! 1 is a sectional view showing an embodiment of the present invention. 1... Fixing roller, 2... Pressure roller, 1... Heater (heat #
A), Jl...cleaning roller, Hatake...copy paper, b...toner image.

Claims (1)

[Claims] A pressure roller and a printer roller are in rolling contact with the circumference f of the fixing roller, respectively, and copy paper having a toner image is inserted between the rolling contact between the fixing roller and the pressure roller. In a device that fixes a toner image by applying heat and pressure, the cleaner roller is provided so as to be able to approach and separate from the fixing roller, and is maintained in a state where it is separated from the fixing roller when the fixing roller is not driven W#. If# moldy toner image fixing device