JPS6014282Y2 - Fixing device in electrophotographic equipment - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a heat fixing device in an electrophotographic apparatus.

2. Description of the Related Art Heat-fixing devices that heat toner using a thermoplastic resin and fuse it onto transfer paper are widely used in electrophotographic devices such as copying machines, printers, and plotters.

Since this type of fixing device generally uses a large heat source, consideration should be given to locating this device away from other components or interposing a heat insulating material between it and other components to minimize thermal effects. Countermeasures have been taken to prevent this from spreading to other parts as much as possible.

However, even if these measures can reduce the thermal effects on other devices to some extent, if the device is operated for a long time, the internal temperature of the electrophotographic device itself may rise, causing deterioration of the photoreceptor. Also, in plotters, etc., it has a large effect on the temperature characteristics of the laser used in the writing unit.

In view of these problems, the present invention aims to provide a new fixing device in which the thermal influence of the heat fixing device does not affect other devices, and another purpose is to improve thermal efficiency. The objective is to provide a new and good fixing device.

Hereinafter, the details of the present invention will be explained based on the drawings.

FIG. 1 is a schematic diagram of a plotter incorporating a device constituting an embodiment of the present invention, in which reference numeral 1 indicates a photosensitive drum;
Surrounding this are a charger 2, an image information writing unit 3 equipped with a laser tube, a dry developing unit 4, and a transfer charger 5.
, a cleaning unit 6 and other image forming process members are disposed, and a transfer paper supply member 7 is provided in the transfer paper conveyance path.
, a registration roller 8, a transfer paper conveyance belt 9, a heat roller set fixing device 10, and the like are arranged, and is equipped with a well-known mechanism for visualizing image information on the transfer paper in response to human input signals.

Therefore, the feature of the present invention is related to the parts surrounding the above-mentioned fixing device, which will be explained below.
1 is a shielding body that covers the fixing device 1o, and in order to suppress the amount of heat dissipated as much as possible, the entire device except for the transfer paper loading section and the discharging section is completely covered with a heat insulating material.

Reference numeral 12 denotes a partition plate stretched so as to form an air flow path 13 on the outside of the shield 11. This partition plate 12 substantially separates the photosensitive drum 1 and writing unit 3, which are subject to thermal effects, from the fixing device 1o. It is melting away.

14 is a fan for taking in outside air provided inside the partition plate 12, and 15 is a suction fan for sucking the transfer paper onto the conveyor belt 9. In this embodiment, the partition plate 12
The transfer paper conveying belt 9 is taken inside the suction fan 1.
5 also has an air conveyance function.

16 is an air exhaust port bored in the side wall of the main body, and the air flow path 13
It is open at the end.

In the embodiment described above, the heat generated in the fixing device 10 is substantially contained by the shield 11 made of a heat insulating material.

A small amount of heat generated from the transfer paper loading section, the discharging section, or the surface of the shielding plate 11 is carried away by the fans 14 and 15 to the outside air flowing around the outer periphery of the shielding body 11.

Therefore, since only a small amount of radiant heat reaches the partition plate 12, heat transfer to the photosensitive drum 1 or the writing section 3 is completely prevented.

Furthermore, since the inside and outside of the shielding body 11 are only slightly communicated via the transfer paper input section and the transfer paper ejection section, the fixing section is always maintained at a high temperature and good fixing processing is performed.

Note that if there is transfer paper on the transfer paper conveyor belt 9, the air flow will be slightly obstructed, but this problem can be easily solved by providing a gap between the conveyor belt 9 and the side wall of the main body. can be solved.

FIG. 2 shows an application to an electrophotographic apparatus using a wet developing device 4' in the developing section and a hot plate fixing device 10' in the fixing section. An exhaust fan 17 is provided to create an air flow around the outer periphery of the shield 11 in cooperation with a fan 14 for taking in outside air.

As described above, according to the present invention, since the heat fixing device is covered with a shield made of a heat insulating material, a high temperature state can always be maintained inside, and a fixing process with high thermal efficiency can be achieved.

In addition, the outer periphery of this shield is further surrounded by a partition plate to allow air to flow between the two, so even if heat from the fixing section leaks from the shield, that heat will be carried away by the air. The heat does not reach the partition plate, making it possible to effectively prevent heat conduction to devices that are easily affected by heat, such as photoreceptors or lasers.

Moreover, according to the present invention, the shielding body and other members can be brought close to each other while leaving a gap large enough to form an air curtain between them, which facilitates the layout of the electrophotographic device and reduces the overall size of the electrophotographic device. It becomes possible to do so.

[Brief explanation of the drawing]

1 and 2 are schematic diagrams showing an embodiment of the present invention incorporated into a well-known electrophotographic apparatus. 1...Photosensitive drum, 10,10'...
- Fixing device, 11... Shielding body, 12...
・Partition plate, 13... Air flow path, 14, 15, 1
7...Fan, 16...Drain hole.

Claims (1)

[Scope of utility model registration request] In an electrophotographic apparatus using a fixing device of a type that fuses unfixed toner onto transfer paper by heat, the fixing device is covered with a shielding member made of a heat insulating material, and the outer periphery of the shielding member is surrounded by a partition plate, A fixing device for an electrophotographic apparatus, characterized in that a passage for gas conveyed by a gas conveying member is formed between the shielding body and the partition plate.