JPS6180185A - Moisture condensation removing device for photosensitive drum - Google Patents

Abstract

PURPOSE:To make possible the sure and quick removal of the moisture condensation on the surface of a photosensitive drum without trouble such as the roughened film of a photoconductive layer by disposing a water adsorber to the prescribed position in the peripheral part of the photosensitive drum so as to contact with the drum surface. CONSTITUTION:The dews formed on the surface of the photosensitive drum are absorbed away by the water absorber 18 by the rotation of the drum 3 in the stage of warming up after throwing an electric power source when the condensation arises on the drum 3 surface owing to a decrease in atmospheric temp. while the drum is not in use in the nighttime or the like. As a result, the condensation is thoroughly removed in the stage of starting transfer and the uniform electrostatic charge of the drum 3 surface to prescribed electric charge by a main electrostatic charger 11 is made possible. The condensation owing to a change in ambient temp. during the use of the copying machine is surely and quickly eliminated by the absorber 18, by which the sure image formation is made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a dew condensation removal device for removing dew condensation from a photoreceptor drum in an image Q forming apparatus such as an electrostatic copying machine.

(Prior Art) In electrostatic copying and the like, dew condensation may occur on the surface of the photosensitive drum due to changes in temperature and humidity. If a copying machine is used in this state, a predetermined charge cannot be applied to the surface of the photoreceptor drum, which may interfere with the transfer operation. Condensation is vaporized by installing a heater or the like nearby to heat the drum.However, if the surface of the photosensitive drum is rapidly heated, film roughness may occur on the photoconductor layer such as the selenium layer. This has the disadvantage that it takes time to completely vaporize the condensation, making it difficult to remove the condensation reliably and quickly.

(Purpose of the Invention) The present invention has been made to eliminate the above-mentioned drawbacks, and is capable of reliably and quickly removing dew condensation on the surface of a photoreceptor drum without causing any adverse effects such as roughening of the photoconductor layer. The present invention provides a dew condensation removal device for a photoreceptor drum that can remove condensation from a photoreceptor drum.

(Structure of the Invention) The dew condensation removing device of the present invention has a water absorbing body made of a material that exhibits water absorption properties placed at a predetermined position on the periphery of the photosensitive drum so as to come into contact with the surface of the photosensitive drum. It is made by arranging it.

(Example) Fig. 1 shows the internal structure of an electrostatic copy chamber as an example of a stock forming apparatus. The optical scanning section 2 includes an exposure lamp 4 and a mirror 5.6;
, a lens 8, a mirror 9, etc., and an exposure lamp 4, etc. is driven by a tanabata (not shown), and irradiates light onto the document 10 on the contact glass 1 while moving along the lower surface of the contact glass 1. It is configured as follows. Then, the reflected light from the original gi10 is transmitted to mirrors 5, 6.7, lens 8, mirror ~
By irradiating the photoreceptor drum 3 through the photoreceptor drum 9, the document image is slit-exposed on the surface of the photoreceptor drum 3.

The photosensitive drum 3 is configured to be rotationally driven by a drive mechanism (not shown). A main charging device 11, a developing device 12, a transfer paper supply mechanism 13, a transfer charging device 14, a separation charging device 15, a conveyor 16, a cleaning device 17, and a water absorber 18 are arranged around the photosensitive drum 3. There is. As the photoreceptor drum 3 rotates, the surface of the photoreceptor drum 3 is uniformly charged and charged via the main charging device 11.
After being electrified, the slit exposure is performed to form an electrostatic latent image. This static latent image is developed into a toner image by coming into contact with a magnetic brush on a developing roller 19 provided in the developing device 12. This toner image is transferred to a transfer paper fed from a transfer paper supply RIi+"r 13 via a transfer charging device 1j.

Further, the transfer paper has a separate charge H'i'j 1 after the transfer.
After being separated from the photoreceptor drum 3 via the photoreceptor drum 5, it is configured to be sent to a fixing section (not shown) by an m-feed conveyor 16.

The cleaning device 17 includes a cleaning blade 20 that collects residual toner, and a transport roller 21 that transports the collected toner to a storage tank (not shown) in direction 1). The water absorbing body 18 is made of a porous material with open pores made of polyvinyl alcohol as a raw material, or a material with water absorbing properties such as a foam skin, and is attached to the surface of the photoreceptor drum 3 by means of a support member 22. They are supported so that they are in contact with each other.

In the above configuration, if the temperature drops and condensation occurs on the surface of the photoreceptor drum 3 when it is not in use, such as at night, the photoreceptor drum 3 rotates during warming up when the power is turned on. , the water absorbing body 18 removes condensation on its surface.
It can be absorbed and removed. As a result, at the start of transfer, the dew condensation is completely removed, and the main charging device 11 can charge the surface of the photosensitive drum 3 to a predetermined charge El-. In addition, in the event that condensation occurs due to changes in the atmosphere during use of the copying machine, this can be removed reliably and quickly by the water absorbing body 18, and a reliable image can always be formed. I can do it.

The condensation absorbed by the water absorbent body 18 evaporates naturally as the temperature inside the body rises, and is released to the outside. In addition, as in the above embodiment, the water absorbing body 18
The position of the water absorber 18 after the photoreceptor drum 3 has passed through the cleaning device 17 and residual toner has been removed is shown in FIG. , the water absorbing body 18
There is no layer of toner on the surface. In order to prevent the n air brush of one developing rCA roller from absorbing moisture, the water absorbing body 18 is placed close to the entrance of the developing device 12, and placed just before the developing device 12. It is desirable to remove dew condensation on the photoreceptor drum 3 in this case. in this case,
In order to prevent the charge applied to the surface of the photoreceptor drum 3 by the main charging device 11 from passing through the water absorber 18, the water absorber 18 is separated from the photoreceptor drum 3 during the transfer operation. It is necessary to configure the water absorbing body 18 to be placed on the photosensitive drum 3 during non-transfer operations such as during close-up.

Further, in the above embodiment, the water absorbent body 18 was configured to abut at a substantially right angle to the surface of the photoreceptor drum 3, but the water absorbent body 18 was constructed as shown in FIGS. 2(A) and 2(B). In addition, the water absorbing body 18 may be formed into a lawn shape and rotatably held by a supporting member 22. You may return the 1#J 3u.Furthermore, the water absorber 18
The arrangement of the above cleaning device 17 and main charging) 2 necks 11
It is possible to place the photoreceptor drum 3 at any position on the peripheral edge of the photoreceptor drum 3 other than at any IX port and in front of the developing device 12.

Alternatively, a heater or a dryer may be provided to heat the photoreceptor drum 3 to an appropriate temperature. In this way, the synergistic effect of the evaporation of condensation and the water absorption of the water absorbing body 18 will more reliably prevent dew condensation on the photoreceptor drum 3. and can be removed quickly.

(Effects of the Invention) As explained above, in the present invention, dew condensation formed on the drum surface is mechanically removed by a water absorbing body provided around the photoreceptor drum. The dew condensation can be removed reliably and quickly without causing problems such as film roughening due to overheating of the surface.

Therefore, it is possible to prevent the main charging operation by the main charging device from being obstructed by condensation, and also to prevent moisture from adhering to the transfer paper, etc., which may interfere with the transfer operation. This has the advantage of being able to form accurate and clear images.

[Brief explanation of drawings]

Fig. 1 is a schematic explanatory diagram of a small 1J embodiment of the present invention;
FIG. 3 is a cutaway diagram of a main part showing an example. 3...Photosensitive drum, 18...Water absorber.

Claims (1)

[Claims] 1. A dew condensation removal device for a photoreceptor drum, characterized in that a water absorbent made of a water-absorbing material is disposed at a predetermined position on the periphery of the photoreceptor drum so as to be in contact with the surface of the photoreceptor drum.