JPH04162078A - Fixing device - Google Patents

Abstract

PURPOSE:To perform long-term stable load dispatching to a heating column body by providing a driving means for rotating this heating column body reversely to the conveying direction so as to be in a specified position before the approach of recording material and rotating it in the conveying direction so as to be in a specified position after the approach of the recording material, and coil like wire material connected to both end faces of the heating column body to perform load dispatching. CONSTITUTION:Before printing paper 5 approaching a fixing heater roller 2 and a lower roller 3, the roller 2 is placed in the state of being rotated in the A direction by electrical control so as to be stopped in the specified position. At the time of fixing an image, the roller 2 is rotated in the B direction by electrical control so as to perform paper discharge while heating an unfixed developer image 4 on the sheet 5. Load dispatching to the roller 2 is performed by a feed curl cord 1. Since the cord 1 is provided with such structure as to apply no stress at all to the connection to a heater and a heater driver circuit substrate regardless of the rotated direction of the roller 2, a fixing device highly reliable in durability can be obtained.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a fixing device that is incorporated into an image forming apparatus such as a copying machine, a laser beam printer, a facsimile machine, a microfilm printer, an image display device, and a recording machine. It is related to the device.

[Prior Art] Conventionally, a fixing device includes a fixing device cleaner 30, a fixing roller heater 3L, an upper roller 32, and a lower roller 35, as shown in FIG. In such a fixing device, an air layer is interposed between the fixing roller heater 3 and the upper roller 32.
1 maintains the temperature of the upper roller 3z at -''N, and adjusts the temperature from 150 degrees to 20 degrees according to the print sequence.
Adjustment is made between 0 degrees, and paper is discharged by rotating the upper roller 32 and lower roller 35. Further, in this apparatus, the fixing roller heater 31 was supplied with power in a fixed state, and good fixing was possible.

However, the above conventional example has the following problems.

(1) Since there is an air layer between the fixing roller heater and the upper roller, the heat capacity is large, and it takes time to reach a predetermined fixing temperature and also requires a large amount of electric power.

(2) In the upper roller, the heat distribution tends to be uneven in the axial direction, and heat dissipates rapidly at the end of the roller, causing an increase in the wait time after turning on the main switch.

(3) In order to reduce the above-mentioned wait time, many electrical control means and means for increasing the pressure of the fixing roller heater have been provided, resulting in increased cost and complexity of the apparatus.

Therefore, a fixing device has been proposed in which the above-mentioned problem is solved by forming the upper roller 32 itself from a heater material and eliminating the air layer between the upper roller and the heater. In this fixing device, since the heater itself rotates, a sliding contact or a flexible wire was used as a power supply means for the heater.

[Problems to be Solved by the Invention] However, the above conventional example has the following problems.

(1) When power is supplied using a sliding contact, there are problems with the wear resistance of the contact, and there are cases where the contact does not heat up or heats up.

(2) When power is supplied using a flexible wire, there are problems with durability and reliability, and the wire sometimes breaks.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and provide a fixing device with high durability and reliability without providing an air layer between a heater and a roller.

[Means for Solving the Problems] According to the present invention, the above object is achieved by: a heating cylindrical body formed of a heater material and rotatably disposed; and a heating cylinder disposed in pressure contact with the heating cylindrical body. In the fixing device 2, which fixes the unfixed developer image on the recording material by conveying the recording material under pressure with a pressure cylinder, the heating cylinder is arranged in the recording material conveyance direction before entering the recording material. a driving means for rotating the heating cylinder to a predetermined position in the opposite direction and rotating it to a predetermined position in the recording material transport direction after the recording material enters; and a winding connected to both end faces of the heating cylinder for supplying power to the heating cylinder. and a heater power supply means formed of a linear electric wire material.

This is achieved by

[Operation] According to the present invention, the heating cylindrical body is rotated to a predetermined position in the opposite direction to the recording material conveyance direction before the recording material enters.

When the recording material enters, the heating cylindrical body is rotated to a predetermined position in the recording material conveyance direction. I wanted to,
The unfixed developer image on the recording material that has passed through the pressure contact portion of the heating cylinder and the pressure cylinder is fixed, and the recording material is discharged. On the other hand, a heater power supply means formed of a wound electric wire is connected to the heating cylinder, and the heater power supply means itself rotates following the rotation of the heating cylinder. However, the rotation range is limited as mentioned above, and the heater power supply means has a high degree of freedom, so there is no stress.
To provide stable power supply over a long period of time.

[Embodiments] A first embodiment and a second embodiment of the present invention will be described based on the accompanying drawings.

<First Embodiment> First, a first embodiment of the present invention will be described using FIG. 1.

In FIG. 1, reference numeral 3 l denotes a curl coat for power supply, which is a heater power supply means, and is connected to both end surfaces of the fixing heater roller 2, which is a cylindrical heating body. A lower roller 3 is disposed in pressure contact with the fixing heater roller 2, and is configured to convey printing paper 5, which is a recording material, carrying an unfixed developer image 4 under pressure.

In the apparatus of this embodiment, before the print paper 5 enters the fixing heater roller 2 and the lower roller 3, the fixing heater roller 2 is rotated in the backward direction to a predetermined position under twelve-way control and then stopped. - On the other hand, when image fixing is executed, the fixing heater roller 2 is electrically controlled to rotate in the direction B, heating the unfixed developer image 4 on the print paper 5, and then ejecting the paper in the direction C. The power supply to 2 is
This is always performed by the power supply curl coat 1 regardless of whether the fixing heater roller 2 is in a rotating state or a stopped state.

The power supply curl coat 1 has a sufficient length to allow the fixing heater roller 2 to rotate to a predetermined position, and is connected to the heater and heater driver circuit board regardless of the direction in which the fixing heater roller 2 rotates. It has a complete structure that does not add stress.

As described above, since the rotation range of the fixing heater roller 2 is limited to a predetermined range and the curl coat with a large degree of freedom is used as the power supply means, the heavy-duty loading device has high durability and reliability even when the roller is made of heater material. It is possible to provide.

<Second Embodiment> Next, a second embodiment of the present invention will be described based on FIG. 2. Note that the same reference numerals are given to the same parts as in the first embodiment, and the explanation thereof will be omitted.

This embodiment differs from the first embodiment in that the power feeding means has spring properties.

In FIG. 2, reference numeral 6 denotes a metal wiring material for power supply that has spring properties. The apparatus of this embodiment rotates the fixing heater roller 2 in the direction A to a predetermined position before image fixing is performed.

Next, when performing image fixing, the fixing heater roller 2 is electrically controlled to rotate in the B direction ζ to heat and fix the unfixed developer image 4 onto the printing paper 5, and then discharge the paper in the C direction. After the paper ejection operation is completed, the fixing heater roller 2 is not electrically controlled and left in a free state. Then, the one-legged heater roller 2 is rotated in the direction due to the springiness of the metal wiring member 6, and returns to the predetermined position N of the fixing heater roller 2 before the above-described image fixing is performed. As described above, in this embodiment, the electrical control can be simplified by rotating the fixing heater roller by using not only electrical control but also mechanical means.

[Effects of the Invention] As explained above, according to the present invention, by limiting the rotation range of the heating cylindrical body and using a wound electric wire material as the power feeding means, the opening to the heater material can be used. This can improve reliability and durability when formed. Therefore, it is possible to provide a fixing device that can shorten wait time, reduce power consumption, and reduce costs by simplifying the device.

[Brief explanation of the drawing]

FIG. 1 is a side view showing a schematic configuration of a first embodiment of the present invention;
FIG. 2 is a perspective view showing a schematic configuration of an apparatus according to a second embodiment of the present invention, and FIG. 3 is a sectional view showing a schematic configuration of a conventional apparatus. 1... Heater power supply means (curl coat) 2...
... Heating cylindrical body (fixing heater roller) 3 ...
・Pressure cylinder (lower roller) 4...Unfixed developer image

Claims (1)

[Scope of Claims] A recording material is conveyed under pressure by a heating cylinder made of a heater material and rotatably disposed, and a pressurizing cylinder disposed in pressure contact with the heating cylinder. In the fixing device that fixes the unfixed developer image on the recording material, the heating cylinder is rotated to a predetermined position in the opposite direction to the recording material conveyance direction before the recording material enters, and after the recording material enters the fixing device. It has a drive means for rotating the recording material to a predetermined position in the recording material conveying direction, and a heater power supply means formed of a wound electric wire connected to both end faces of the heating cylinder and supplying power to the heating cylinder. , A fixing device characterized by: