JPS6150178A - Cleaning device - Google Patents

Abstract

PURPOSE:To remove foreign matters other than a toner to form images in a high speed by using an elastic rubbing member in a cleaning device and using a heating body to heat this member and controlling the temperature in accordance with the environmental humidity. CONSTITUTION:A rubbing roll 8 is provided with a hollow shaft 8a and is supported axially in a proper position of the cleaning device, and a heater 11 is provided in the hollow shaft 8a. A control part 10 turns on or off the heater 11 by a temperature sensor to hold the roll at a prescribed temperature. The heater is not operated in case of <40% relative humidity, and the heater 11 is operated otherwise. Since the rubbing member whose size and heat capacity are smaller than those of an image carrier is heated, the response for temperature control is every quicker than that in the case where the image carrier itself is heated, and this device is suitable for high-speed image formation, and various foreign matters other than the toner are removed well.

Description

[Detailed Description of the Invention] (1) Object of the Invention (Field of Industrial Application) The present invention relates to an image forming apparatus that uses an electrostatic transfer process, such as an electrophotographic copying machine or a printer, and particularly to a cleaning device therefor. .

(Prior art and problems to be solved) After forming a transferable toner image on the surface of a moving image carrier,
In a well-known image forming apparatus that repeats the process of transferring toner onto a transfer material, it is essential to sufficiently remove residual toner remaining on the surface of the image carrier after each process.

In such an image forming apparatus, corona products generated due to the presence of a high-pressure member in the apparatus together with toner,
It is necessary to remove foreign substances such as precipitates of Merck, rosin, etc., which are precipitated from transfer materials mainly made of paper.

Such foreign matter is difficult to remove with toner particles, cleaning blades, etc., and at the same time, in high humidity environments, it absorbs moisture and lowers the resistance of the image carrier surface, causing so-called image blurring. In order to remove the above-mentioned foreign substances that inevitably cause deterioration of image quality, in addition to toner removal means such as a cleaning blade and a fur brush, a rubbing member made of an elastic material such as silicone rubber is used. The applicant has already proposed a method in which foreign matter other than toner is mainly cleaned by rubbing the surface of the image carrier with a brush.

Such an elastic rubbing member applies C to the photoconductive layer on the surface of the image carrier.
When using materials with relatively low hardness such as ds and Sel organic semiconductors, the surface layer of the layer can be polished and removed together with foreign matter, so the foreign matter removal function is high. In the case of removal, satisfactory results were not always obtained.

Therefore, in such a case, the image carrier is heated to an appropriate temperature (40
It has been proposed to prevent deterioration of image quality such as image blurring by heating the image to a temperature of ~45°C) to maintain a state in which it is difficult for foreign substances to absorb moisture, but it has not yet been sufficiently effective, especially under high humidity conditions. Sometimes there isn't.

The present invention has been made to deal with such a situation, and uses a rubbing member equipped with a heater to appropriately combine the humidity of the environment and the temperature of the member to create an activated or inactive state. It is an object of the present invention to provide a reading/reading device that prevents image smearing from occurring on an image carrier.

(2) Structure of the invention (technical means for solving the problem 1) In order to achieve the above object, in the present invention, an elastic sliding member is used in the cleaning device of the image forming apparatus, and The heating element is also used to heat the member, and the temperature of the member is controlled depending on the environmental humidity.

With this configuration, it has become possible to effectively remove various foreign substances other than toner as described above.

(Description of Embodiments) FIG. 1 is a schematic explanatory diagram of the main parts showing the case where the present invention is applied to a copying machine. section 3, developing device 4, transfer material passage 5
, a transfer charger 6, a cleaning device 7, etc. are arranged in the same manner as in a known copying machine.

The surface of the photoreceptor is uniformly charged by the charger 2, and a light image is applied thereto by the exposure section 3 to form an electrostatic latent image. Then, as the photoreceptor rotates, the latent image is transformed into a transferable developed image by toner supplied by a developing device, and this is transferred to a transfer material supplied by a passage 5 by the action of a transfer charger 6. Ru.

After the transfer, the transfer material is conveyed away from the photoreceptor, and residual toner and foreign matter as described above that do not contribute to the transfer and remain on the photoreceptor reach the cleaning device 7.

The cleaning device is equipped with a cleaning blade 7a, and residual toner is mainly scraped off by this blade and accumulated in the cleaning device. At the same time, foreign substances such as corona discharge products as described above are rubbed off by the elastic rubbing roller 8, collected together with the toner in the cleaning device, and further discharged to the outside by the screw conveyor 7b as necessary. shall be.

In such a device, the rubbing roller 8 is provided with a hollow shaft 8a and is supported in a suitable position in the cleaning device, as can be seen particularly from FIG. There is no interior decoration.

In FIG. 1, reference numeral 10 denotes a temperature control section which turns on and off the heater 1) using a temperature sensor (not shown) of the rubbing roller 8 to maintain the roller at a predetermined temperature. Reference numeral 9 denotes a humidity sensor or a temperature sensor, which is used to detect the humidity of the environment and the surface temperature of the photoreceptor, respectively, and control the temperature of the rubbing roller.

FIG. 3 is a graph showing a case where the heater is always turned on so that the rubbing roller is kept at a constant temperature.

FIG. 4 is a graph showing the case where the temperature of the rubbing roller is controlled by turning on and off the heater of the rubbing roller in response to changes in the humidity of the environment, and when the relative humidity is less than 40%, the heater is turned on. First, the heater is operated only in cases where the amount of heat is higher than that.

In this case, when the humidity is 40% or higher, the temperature of the rubbing roller may be maintained constant thereafter (solid line I in the figure), or the roller temperature may rise as the humidity increases (solid line ■ in the figure). .

In addition, when using an amorphous silicon photoreceptor, the surface temperature of the rubbing roller should be set at 40-45% when the humidity is 60%.
℃ is suitable.

Figure 5 shows how the surface temperature of the rubbing roller is controlled by the surface temperature of the photoreceptor. Control is performed so that the temperature of the roller increases as the solid line II [)6 in the figure or the temperature decreases (solid line ■ in the figure).

The above example shows the case where the surface temperature of the rubbing roller is controlled only by the relative humidity of the environment or the surface temperature of the photoconductor, but it is also possible to control both using a temperature/humidity sensor, that is, when the humidity is low, the surface temperature of the photoconductor is low. It is easy to understand that it is possible to perform combination control such that the heater is not turned on even when the surface temperature of the photoreceptor is high, or that the heater is not turned on even when the humidity is high when the photoreceptor surface temperature is high.

(3) Effects of the invention Since the present invention has the configuration and operation described above,
Various foreign substances adhering to the image carrier can be effectively removed, and thus stable image processing can be performed over a long period of time.

Also, because the sliding member is smaller and has a smaller heat capacity than the image carrier, the response during temperature control is far greater than when heating the image carrier itself. It is suitable for use in high-speed image forming apparatuses.

[Brief explanation of the drawing]

Fig. 1 is a schematic side view of the main parts showing the case where the present invention is applied to a copying machine, Fig. 2 is a partial perspective view showing the configuration of the rubbing roller, and Figs. 3 to 5 show the control mode. This is a graph showing. 1... Photoreceptor, 7... Cleaning device, 8...
Elastic sliding roller, 9... Temperature/humidity sensor, 10... Control unit, 1)... Heater

Claims (4)

[Claims] (1) A cleaning device equipped with an elastic sliding member that presses against and slides against the surface of a moving image carrier, in which a heater for heating the member is disposed within the sliding member. (2) The cleaning device according to claim 1, wherein the temperature of the sliding member is kept constant regardless of the humidity of the environment and the surface temperature of the photoreceptor. (3) The cleaning device according to claim 1, wherein the surface temperature of the sliding member is controlled by the humidity in the environment. (4) A cleaning device according to any one of claims 1, 2, and 3, wherein the surface temperature of the sliding member is controlled by the surface temperature of the image carrier.