JPH04267281A - Fuser roller - Google Patents

Abstract

PURPOSE:To provide a fixing roller small in diameter, and capable of improvement in heat efficiency. CONSTITUTION:A hollow heater pipe 2 is provided which has a heating body 4 in the inner part, while it is brought into contact with a press roller 11 on the outer circumferential surface, both ends are closed tight and held free of rotation, and in addition, a connecting terminal 5 being connected to the heating body 4 while connected to a power terminal 8 free of rotation is clamped to both ends of the heater pipe 2, whereby a diameter of a fixing roller is reduced. Moreover, the heater pipe 2, where the press roller 11 is contacted, and the heating body 4 and the connecting terminal 5 are all rotated as one body, so that an interval between a double end inner circumference of the heater pipe 2 and the connecting terminal 5 can be closed tight. Accordingly, at time of rotation of the heater pipe 2, the outside air is prevented from coming into the inner part, thus heat efficiency is improved.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing roller for fixing an image transferred to a transfer sheet in an electrophotographic apparatus.

0002

[Prior Art] Conventionally, a cylindrical exterior member with openings at both ends, whose outer peripheral surface is in contact with a press roller, is rotatably provided, and an elongated filament case containing a built-in filament is inserted into the center of this exterior member. There is a fixing roller that fixedly supports both ends of a filament case and further has connecting terminals connected to the filament fixed to both ends of the filament case.

0003

[Problem to be solved by the invention] The conventional fixing roller is
Since the filament case is fixed and only the exterior member is rotated, the exterior member and the filament case cannot be integrally formed. This increases the outer diameter. In addition, in order to rotate only the exterior member, a space is required between the inner circumferential surface of the exterior member and the filament case, and in addition, in order to connect the filament case to the power source by protruding from both ends of the exterior member, the exterior member It is necessary to open both ends. Therefore, due to the rotational movement of the exterior member, air flows into the space between the inner circumferential surface of the exterior member and the filament case, and outside air is also drawn into this space. Therefore, there is a problem that it takes time for the outer circumferential surface of the exterior member to reach a certain temperature.

0004

[Means for Solving the Problems] A hollow heater pipe is provided which has a heating element inside and is rotatably held with its outer peripheral surface in contact with a press roller and sealed at both ends, and is connected to the heating element. Connection terminals that were rotatably in contact with the power supply terminals were fixed to both ends of the heater pipe.

[0005]

[Function] The heater pipe, heating element, and connection terminal can be rotated integrally, and the press roller can be brought into direct contact with the outer circumferential surface of the heater pipe, so the diameter of the fixing roller can be reduced. becomes possible. Furthermore, since the heater pipe, heating element, and connection terminal that are in contact with the press roller can be rotated together, it is possible to seal between the inner periphery of both ends of the heater pipe and the connection terminal. Outside air is prevented from being drawn into the interior of the pipe when it rotates, thereby making it possible to improve thermal efficiency.

[0006]

[Embodiment] A first embodiment of the present invention will be explained based on FIG. 1 is a frame, and a bearing 3 that rotatably holds a hollow heater pipe 2 is fixed to this frame 1. A heating element 4 is inserted into the heater pipe 2, and connection terminals 5 connected to the heating element 4 are fixed to both ends of the heater pipe 2. Further, both ends of the heater pipe 2 are narrowed and sealed by connection terminals 5. Furthermore, a motor (
A gear 6 driven by a motor (not shown) is fixedly fitted therein. One end of a power terminal 8 connected to a power source via a cord 7 is fixed to the frame 1, and the other end of the power terminal 8 has a pivot 10 in contact with a recess 9 at the center of the end surface of the connection terminal 5. It is provided. Further, a press roller 11 pressed against the outer peripheral surface of the heater pipe 2 is rotatably held by a bearing portion (not shown).

In such a configuration, when the gear 6 is driven by a motor, the fixing roller rotates. That is, the heater pipe 2, heating element 4, and connection terminal 5 rotate integrally, and the press roller 11 also rotates accordingly due to contact friction with the heater pipe 2. As a result, although not shown, the transfer paper onto which the developed image formed on the photoreceptor has been transferred is conveyed while being held between the heater pipe 2 and the press roller 11.
During this conveyance process, the transferred image is fixed by receiving heat from the heating element 4 and pressure from the press roller 11.

As described above, the heating element 4, the connecting terminal 5, and the heater pipe 2 can be rotated integrally.
1 can be brought into direct contact with the fixing roller, making it possible to reduce the diameter of the fixing roller. Furthermore, since the heater pipe 2, the heating element 4, and the connecting terminal 5 that are in contact with the press roller 11 can be rotated integrally, the space between the inner periphery of both ends of the heater pipe 2 and the connecting terminal 5 can be sealed. Can be done. Therefore, outside air is not drawn into the interior of the heater pipe 2 when it rotates, thereby making it possible to improve thermal efficiency.

Next, a second embodiment of the present invention will be explained based on FIG. The same parts as in the previous embodiment are designated by the same reference numerals, and the description thereof will be omitted. This embodiment consists of a cylindrical case 12 in which a heating element 4 is built and a reinforcing pipe 1 that covers this case 12.
3 to form a heater pipe 14. This reinforcing pipe 13 is made of a material with high thermal conductivity, and its end portion is filled with a highly thermally conductive elastic member 15 in contact with the outer periphery of the end portion of the case 12 and the outer periphery of the connecting terminal 5. The case 12, the reinforcing pipe 13, and the connecting terminal 5 are integrally connected by the elastic member 15. Further, a sealed air layer 16 is formed with a slight gap between the outer peripheral surface of the intermediate portion of the case 12 and the inner peripheral surface of the intermediate portion of the reinforcing pipe 13. Further, both ends of the reinforcing pipe 13 are rotatably supported by bearings 3, and a gear 6 is fixedly fitted to one end.

In such a configuration, the heater pipe 14 has a double structure having the case 12 and the reinforcing pipe 13, but the case 12 and the reinforcing pipe can be integrally connected by the elastic member 15 and rotated. Therefore, the gap between the case 12 and the reinforcing pipe 13 can be made extremely small, or the two can be brought into close contact with each other, thereby making it possible to reduce the diameter of the heater pipe 14 that the press roller 11 comes into contact with. It is. Furthermore, since both ends of the heater pipe 14 can be sealed, it is possible to prevent outside air from being drawn into the interior of the heater pipe 14 when it rotates.

Although FIGS. 1 and 2 show the structure of one side of the fixing roller and its supporting structure, the structure of the other side is also similar.

0012

Effects of the Invention The present invention provides a hollow heater pipe which has a heating element inside and is rotatably held with its outer peripheral surface in contact with a press roller and is sealed at both ends, and which is connected to the heating element. Since the connecting terminals, which are in rotatable contact with the power terminals, are fixed to both ends of the heater pipe, the heater pipe, the heating element, and the connecting terminals can be rotated as one. Since the press roller can be brought into direct contact with the fixing roller, the diameter of the fixing roller can be reduced, and the heater pipe, heating element, and connection terminal that the press roller comes into contact with can be rotated integrally. It is possible to seal between the inner periphery of both ends of the heater pipe and the connection terminal,
Therefore, when the heater pipe rotates, outside air is not drawn into the interior of the heater pipe, which has the effect of improving thermal efficiency.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view showing a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional front view showing a second embodiment of the present invention.

[Explanation of symbols]

2 Heater pipe 4 Heating element 5 Connection terminal 8 Power terminal 11 Press roller 14 Heater pipe

Claims (1)

[Claims] 1. A hollow heater pipe is provided which has a heating element inside and is rotatably held with its outer peripheral surface in contact with a press roller and sealed at both ends, and is connected to the heating element and rotated to a power terminal. A fixing roller characterized in that connection terminals that can be contacted freely are fixed to both ends of the heater pipe.