JPH02306282A - Image forming device - Google Patents

Abstract

PURPOSE:To prevent dewing on the surface of a drum and to make a surface potential uniform by incorporating a heater and setting an image carrier drum to any temperature. CONSTITUTION:The image carrier drum 1 forms an electrostatic latent image, transfers a toner image onto paper and is provided with a heater 18. By controlling the energization of the heater 18, the drum 1 is always set to any temperature. A large temperature difference between in and out of the drum 1 never occurs, and therefore dewing on the surface of the drum is prevented at a low temperature. When an image forming device starts operation at a low temperature, the surface potential of the image carrier drum can be made uniform.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus with an improved image bearing drum.

[Conventional technology]

Conventionally, this type of image forming apparatus forms an electrostatic latent image on an image bearing drum, develops the image with toner, and transfers the image onto paper. At this time, the inside of the apparatus becomes high temperature due to the fixing device, etc., and temperature differences also occur locally. The image carrier drum used at this time is not subjected to any special temperature control.

[Problem to be solved by the invention]

The temperature of the image bearing drum in the conventional image forming apparatus described above is not particularly controlled, so when the image forming apparatus operates and the temperature inside the apparatus increases rapidly, the surface temperature of the image bearing drum increases inside the apparatus. The inability to keep up with the temperature creates a large temperature difference both inside and outside the drum. This temperature difference has the disadvantage that dew condensation is likely to occur on the surface of the image carrier drum when the device is started at low temperatures, and the performance of the OPC drums currently used as image carriers can be either high or low depending on their temperature characteristics. Therefore, it has the disadvantage that a uniform surface potential cannot be obtained.

An object of the present invention is to provide an image forming apparatus that can prevent dew condensation on the drum surface and obtain a uniform surface potential.

[Means to solve the problem]

The image forming apparatus of the present invention is an image forming apparatus that develops an electrostatic latent image formed on an image bearing drum with toner and transfers the image to a sheet of paper, and has a heater inside the image bearing drum, and always has an optional It is configured so that the temperature can be set to

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view of an image forming apparatus showing an embodiment of the present invention.

As shown in FIG. 1, the image forming apparatus of this embodiment rotates an image carrier drum 1, which is an image carrier, in the direction of the arrow around the image carrier drum support shaft, and goes through the following steps.

■ Potential loss due to eraser lamp 8.

■ Charging by charger 6.

■ Electrostatic latent image formation by exposure means 2.

■ Toner development using developing device 3.

■ Transferring the toner image onto transfer paper (not shown) using the transfer charger 9.

■ The cleaning blade 4 scrapes off the toner remaining on the drum surface.

The above process is performed continuously to form an image on the transfer paper. Further, the toner image transferred to the transfer paper is fixed onto the paper by a fixing device 13, and sent to a stacker 15 by an ejection roller 14.

Here, when the apparatus is operated at a low temperature, the temperature of the gas inside the apparatus rises rapidly due to the high temperature generated by the fixing device 13. However, in order to prevent a difference between the surface temperature of the image carrier drum and the internal temperature of the drum, a heater is provided inside the image carrier drum 1 in this embodiment.

Note that 5 is a waste toner storage section, 10 is a paper feed roller, 11 and 12 are paper guides, and 16 is a rotation fulcrum.

2 is a perspective view of the image carrier drum shown in FIG. 1. FIG.

As shown in FIG. 2, the image carrier drum l in this embodiment is provided with a heater 18 inside to equalize the temperature of the gas inside and outside the image carrier drum l, and to adjust the surface temperature of the image carrier drum l and the device. This is to prevent differences in internal temperature. The heater 18 is controlled by a thermo-mechanism or the like so that it can always be set at an arbitrary temperature.

〔Effect of the invention〕

As explained above, the image forming apparatus of the present invention has a heater inside the image carrier drum, thereby preventing a large temperature difference from occurring between the inside and outside of the image carrier drum.
This has the effect of suppressing dew condensation on the surface of the image bearing drum, which occurs immediately after the apparatus is operated at low temperatures.

Furthermore, the present invention has the effect of improving the performance of OPC drums currently used as image carriers due to their temperature characteristics. That is, since the surface temperature of the OPC drum can be kept constant, the characteristics can be maintained at a constant level.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of an image forming apparatus showing an embodiment of the present invention, and FIG. 2 is a perspective view of the image bearing drum shown in FIG. 1. 1... Image carrier drum, 2... LED
Head, 3...Developer, 4...Cleaning blade, 5...Waste toner storage section, 6...
... Charger, 7 ... Image carrier drum support shaft, Eraser lamp, 9 ... Transfer charger, 10 ... Feed Laura, 11.12
...Paper guide, 13...Fuser, 1
4... Discharge roller, 15... Stacker, 16... Rotation fulcrum, 17... Image carrier drum support frame, 18... ·heater.

Claims (1)

[Claims] In an image forming apparatus that develops an electrostatic latent image formed on an image carrier drum with toner and transfers the image onto paper, a heater is provided inside the image carrier drum, and the temperature can be set to any desired temperature at any time. Features of the image forming device.