JPH0680475B2 - Copier cleaning device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning device for a copying machine such as an electrophotographic device or an electrostatic recording device, and more particularly to a cleaning device for a copying machine of the type using a powder developer as a developer.

To reuse a latent image carrier, for example, an electrostatic latent image formed on the surface of a photoconductor, by developing it with a colored fine powder called toner, transferring the developed image to a transfer material such as paper, and then using the photoconductor. Then, the toner remaining on the surface is removed by the cleaning device. The cleaning device usually includes a cleaning member such as a fur brush or a rubber blade that comes into contact with the surface of the photoconductor to remove residual toner. When the contact between the cleaning member and the surface of the rotating photoconductor is continuously continued for a long time, the larger the relative speed difference between them is, the more the temperature of the cleaning member increases due to the frictional heat. The cleaning member is
Generally, it is a poor conductor of heat, and its thermal conductivity is significantly different from that of the photoconductor, so that the temperature difference from the photoconductor tends to be large.
When the temperature of the cleaning member rises, toner adheres to the surface of the photoconductor, forming a film of toner,
In the case of a copying machine that uses an amorphous photosensitive material such as a selenium photosensitive material, the photosensitive material is crystallized, and the crystallized part is less likely to be charged than other parts, and the image density of that part is significantly reduced. Or the heat softens the cleaning member, causing undesirable problems such as deformation and faster wear. However, in the past,
As disclosed in Japanese Unexamined Patent Publication No. 56-47079, the friction coefficient of the surface of the photoconductor is detected, and lubricating oil is applied to prevent the friction coefficient from exceeding a predetermined friction coefficient. To prevent toner sticking to the body surface,
As disclosed in Japanese Patent Publication No. 55-84653, an air jet is blown on the surface of the photoconductor to reverse the triboelectrification of the cleaning brush around the nozzle and the toner, and the toner is electrostatically charged while vibrating the brush slightly. Although some consideration has been given to the temperature control of the photoconductor such as the method of adsorbing and removing the same, no consideration is given to preventing the temperature rise of the cleaning member.

Therefore, an object of the present invention is to provide a cleaning device that prevents toner sticking to the surface of a latent image carrier such as a photoconductor, that is, toner filming.

Another object of the present invention is to provide the above-mentioned cleaning device in which crystallization of an amorphous photoreceptor such as a selenium photoreceptor is prevented.

A further object of the present invention is to provide the above-mentioned cleaning device that prevents earlier deterioration of the cleaning member.

The above and other related objects of the present invention are achieved by providing a cleaning device with means for cooling the cleaning member, thereby suppressing an increase in the temperature of the cleaning member.

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

FIG. 1 shows an example in which the present invention is applied to a far brush type cleaning device. A casing 3 surrounds the outer surface of the cleaning brush 2 that rotates in contact with the surface of the rotating photosensitive drum 1 from the opposite direction. An air suction device (not shown) is connected to the casing 3,
The toner removed by the cleaning brush 2 is sucked and collected in the direction of arrow A. The cleaning member cooling means in this embodiment is in contact with the brush tip portion of the cleaning brush 2, and the cooling plate 4 also serving as a flicker plate for knocking off the toner adhering to the brush.
And a temperature control element 5 provided on the cooling plate 4,
It includes a heat exchanger or a radiator plate 6 provided on the element 5. As the cooling plate 4, a material having high thermal conductivity such as aluminum is used, and as the temperature control element,
For example, a cooling element commercially available under the name "Thermomodule" from Melco, Inc. can be used. This element is a semiconductor that can be heated and cooled freely by a DC power source, but in addition to this, a normal Peltier element that generates heat or absorbs heat by changing the direction of current flow can also be used. When these elements are used, in addition to the heat exchanger or the radiator plate 6 as shown, a temperature sensor, a temperature controller and the like are required.

When the temperature of the cleaning brush 2 rises due to friction with the surface of the photosensitive drum 1, this is detected by a temperature sensor (not shown) (which is attached to the casing 3 in contact with the brush tip portion of the cleaning brush 2), and the signal is output. It is input to the temperature controller and a controlled current is passed through the temperature control element 5. As a result, the temperature control element 5 takes heat from the cleaning brush 2 through the cooling plate 4 and dissipates the taken heat through the heat exchanger or the heat radiating plate 6, so that the temperature rise of the cleaning brush 2 is suppressed.

FIG. 2 shows an example in which the present invention is applied to a blade type cleaning device, in which a cleaning blade 8 housed in a casing 7 is held by a holder 9 and pressed against the surface of the photosensitive drum 1. An auger or screw 10 is provided at the bottom of the casing 7 to convey the removed toner to the outside of the apparatus. The cleaning member cooling means in this embodiment is constituted by a cooling air blower including an air ejection pipe 11 and an exhaust pipe 12 for cooling the tip portion of the cleaning blade 8.

Friction heat generated by sliding between the cleaning member and the photoconductor is local heat called a hot spot, and its temperature may reach several hundreds of degrees or more in a microscopic view. In particular, in the case of blade cleaning, since the sliding portion between the cleaning blade and the surface of the photoconductor does not change, the temperature rises quickly due to frictional heat and the harmful effect of hot spots is great. However, as in this embodiment, the tip portion of the blade 8 is efficiently cooled by the cooling air, so that the temperature rise can be efficiently suppressed. Such a technique for suppressing the temperature rise of the cleaning member by the cooling air can be applied to the far brush type cleaning device as shown in FIG. 1, and conversely, the cooling technique by the temperature control element can be used as the blade as shown in FIG. It can also be applied to a mold cleaning device.

As described above, according to the present invention, the sliding portion of the cleaning member that causes friction with the photoconductor is efficiently cooled.
It is possible to effectively prevent filming of the toner, crystallization of the amorphous photoreceptor, and early deterioration of the cleaning member.

The cleaning member cooling technique in the present invention can be similarly applied to the seal member 13 provided in contact with the surface of the photosensitive drum 1 at the lower part of the casing 7 in FIG. 2, for example. Such a sealing member 13 is for preventing the removed toner from scattering outside the casing 7, and a developing device is also usually provided with a similar toner scattering preventing sealing member.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of the present invention, and FIG. 2 is a schematic view showing another embodiment of the present invention. 1 ... photosensitive drum, 2 ... far brush, 3 ... casing, 4 ... flicker and cooling plate, 5 ... temperature control element, 6 ... heat exchanger, 8 ... rubber blade, 11 ... air injection Pipe, 12 ... Exhaust pipe

Claims (3)

[Claims] 1. A toner image is obtained by adhering toner to an electrostatic latent image formed on a latent image carrier, transferring the toner image to a transfer material, and then removing the toner remaining on the latent image carrier. A cleaning device for a copying machine, which is provided with means for cooling a cleaning member. 2. The cleaning device according to claim 1, wherein the cleaning member cooling means is a temperature control element provided on a member that contacts the cleaning member. 3. The cleaning device according to claim 1, wherein the cleaning member cooling means is means for blowing cooling air to the cleaning member.