JPH0675486A - Fixing device for electrophotographic printer - Google Patents

Abstract

PURPOSE:To make an entire device small in size and to reduce the number of component parts by fixing toner with heat and pressure between a fixing part and a pressure roller while the endless tape is allowed to go round. CONSTITUTION:The endless tape 14 is wound round a driving roller 17, a driven roller 11 and the fixing part 13, and is driven by the roller 17 so as to go round in a direction shown by an arrow A. A heater 12 is incorporated in the fixing part 13, and the pressure roller 18 formed of silicone rubber is provided to be opposed to the heater 12 in a state where the tape 14 is interposed between them. The pressure roller 18 is pressed to the fixing part 13 by a spring. Printing paper 15 on which a toner image 16 is transferred from a photosensitive body is carried in a direction shown by an arrow C and inserted in a gap (nip part) between the fixing part 13 and the pressure roller 18. The toner 16 on the paper 15 is fixed with the heat and the pressure by coming in contact with the tape 14 heated by energizing the heater 12 when it comes to the position of the fixing part 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device for an electrophotographic printer, and more particularly to an electrophotographic fixing device which applies heat and pressure to a printing paper on which a toner image formed on a photoconductor is transferred. The present invention relates to a fixing device for a type printer.

[0002]

2. Description of the Related Art FIG. 2 is an exploded perspective view showing an example of a conventional fixing device for an electrophotographic printer.

A conventional fixing device of an electrophotographic printer, which performs fixing by applying heat and pressure to a printing paper on which a toner image formed on a photoconductor is transferred, has a structure as shown in FIG. ing.

That is, the heat roll 1 containing the lamp 9 for heating is supported at both ends by bearings 6 and fixed to the frame 5 by screws 8.
The pressure roll 2 provided so as to face the heat roll 1 has both ends thereof supported by bearings 3 and is held by a lever 4, and the lever 4 has a hole 4a provided at one end thereof. Shaft 10 provided on the frame 5
The lever 7 is inserted in the lever 4 and is rotatably held, and a spring 7 is provided at the other end of the lever 4.

Therefore, the pressure roll 2 is pressed against the heat roll 1 by the spring 8 at a constant pressure.

At both ends of the heat roll 1, the surface of the aluminum tube is coated with Teflon, while the pressure roll 2 is made of silicone rubber.

The printing paper on which the toner image is transferred from the photoconductor is inserted into the contact portion (nip portion) between the heat roll 1 and the pressure roll 2 of the fixing device thus formed, and heat is applied by energizing the lamp 9. The toner is fixed by the pressure and the pressure.

[0008]

In the conventional fixing device for an electrophotographic printer as described above, fixing is performed by heating the heat roll. However, the heat capacity of the heat roll is large, resulting in large power consumption. have. Further, since it has two rolls, a heat roll and a pressure roll, as constituent parts, it has a drawback that the degree of freedom in design is limited, and it is difficult to reduce the number of parts and simplify the mechanism.

[0009]

A fixing device for an electrophotographic printer according to the present invention heats a photosensitive member on which a toner image is formed and a printing sheet on which the toner image is transferred from the photosensitive member to heat it. A fixing unit having a heater, an endless tape circulating between the fixing unit, a drive roller, and a driven roller, and a pressure member provided facing the fixing unit and pressed against the fixing unit with a predetermined pressure. A roller, and as an endless tape, a seamed belt formed into a ring shape by connecting both ends of a film having a predetermined length, or a seamless belt formed of a film having a predetermined length that is previously formed in a seamless ring shape,
Alternatively, those obtained by subjecting them to Teflon processing are used.

[0010]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of the present invention.

In the embodiment shown in FIG. 1, the endless tape 14 is wound around the drive roller 17, the driven roller 11 and the fixing portion 13, and is driven by the drive roller 17 to make a circular motion in the direction of arrow A. .
The driven roller 11 guides the running of the endless tape 14 while controlling the meandering of the endless tape 14.

A heater 12 is built in the fixing unit 13, and the heater 12 is sandwiched by an endless tape 14.
Pressure roller 18 formed of silicone rubber facing the
Is provided. The pressure roller 18 is pressed against the fixing portion 13 by a spring (not shown) (arrow B).

A printing paper (paper) 15 to which a toner image (toner) 16 is transferred from a photoconductor (not shown) is indicated by an arrow C.
And is inserted between the fixing unit 13 and the pressure roller 18 (nip portion). The toner 16 on the paper 15 is
When it reaches the position of the fixing unit 13, it contacts with the endless tape 14 which is heated by energizing the heater 14, and is fixed by heat and pressure.

The endless tape is formed by connecting both ends of a film having a predetermined length into a ring shape (seamed belt), or an endless tape formed of a film having a predetermined length which is previously formed in a seamless ring shape. Use tape (seamless belt). Moreover, you may use what gave Teflon processing to them.

By configuring as described above, it is possible to reduce the size of the entire apparatus and the number of constituent parts.

[0017]

As described above, the fixing device of the electrophotographic printer of the present invention uses an endless tape, and the endless tape is circulated and heated by the heater of the fixing unit to contact the fixing unit and it. By inserting the printing paper on which the toner image formed on the photoconductor is transferred between the pressure roller and the pressure roller and fixing the printing paper by heat and pressure, the size of the entire apparatus can be reduced, and There is an effect that it is possible to reduce the number, so that there is an effect that the mechanism can be simplified and the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing an example of a conventional fixing device for an electrophotographic printer.

[Explanation of symbols]

 1 Heat Roll 2 Pressure Roll 3 Bearing 4 Lever 4a Hole 5 Frame 6 Bearing 7 Spring 8 Screw 9 Lamp 10 Shaft 11 Driven Roller 12 Heater 13 Fixing Part 14 Endless Tape 15 Paper 16 Toner Image (toner) 17 Drive Roller 18 Pressure Roller

Claims (5)

[Claims] 1. A photosensitive member for forming a toner image, a fixing unit having a heater for heating to fix the printing paper on which the toner image is transferred from the photosensitive member, the fixing unit, a drive roller and a driven roller. And an endless tape circulating between the fixing unit and a pressure roller that is provided to face the fixing unit and is pressed against the fixing unit with a predetermined pressure. . 2. The fixing device for an electrophotographic printer according to claim 1, wherein the endless tape is a seamed belt formed by connecting both ends of a film having a predetermined length into a ring shape. 3. An electrophotographic printer according to claim 2, wherein as the endless tape, an endless belt obtained by connecting both ends of a film having a predetermined length into a ring shape and applying Teflon processing thereto is used. Fixing device. 4. The fixing device for an electrophotographic printer according to claim 1, wherein a seamless belt formed of a film having a predetermined length which is previously formed in a seamless ring shape is used as the endless tape. 5. The electronic device according to claim 4, wherein as the endless tape, an endless belt which is formed of a film having a predetermined length which is previously formed in a seamless ring shape and which is Teflon-processed is used. Photographic printer fixing device.