JPH08292690A - Cleaning device for electrophotographic system - Google Patents

Abstract

PURPOSE: To provide a cleaning device for an electrophotographic system printer capable of preventing various kinds of adverse effects caused by the press- contact of a cleaning blade with an image carrier when a device is not used. CONSTITUTION: The cleaning device for a electrophotographic system printer is capable of removing toner remaining on the image carrier by using the cleaning blade 8. This cleaning blade 8 is constituted in such a manner that a bimetal 6 deformed by the degree of heat generation amount of the device is wrapped in an elastic body 7. The press-contact force of the cleaning blade 8 can be released or reduced in response to reduction in the heat generation amount of the device when it is not used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic printing apparatus, and more particularly to a cleaning apparatus having a function of adjusting a pressure contact force with an image carrier.

[0002]

2. Description of the Related Art In a well-known electrophotographic printing apparatus that repeats a process of transferring a toner image formed on an image carrier to a transfer material, it is necessary to sufficiently remove residual toner remaining on the image carrier. As a cleaning means for this purpose, a cleaning blade made of an elastic resin material such as polyurethane rubber is pressed against the surface of the image carrier to scrape off the residual toner, which has been widely put into practical use. In this case, since the cleaning blade is made of resin, elasticity changes depending on the temperature, and the desired action cannot be obtained.Therefore, the initial pressure contact force setting should be slightly adjusted so that the desired action can be obtained even if the elasticity becomes weak. It is common to keep it strong.

However, in the above-mentioned conventional apparatus, since the initial pressure contact force is increased, pressure marks are generated on the image carrier by the cleaning blade and the toner pressed by the cleaning blade is fused on the surface of the image carrier. It has been confirmed that many of these obstacles occur when the apparatus in which the image carrier and the cleaning blade are in contact with each other for a long period of time is stopped.

Therefore, in order to solve this problem in the prior art, (1) the cleaning blade support portion is of a mechanical movable type and is operated by operating it as necessary, and (2) the movable type support member is a bimetal. Those that are made of metal or shape memory alloy and can be operated by an external heat source, and (3) those that have a temperature control unit in the cleaning device to keep the elasticity constant and that keep the temperature of the cleaning device constant, such as The support is movable according to need, and the heat source system for keeping the elasticity of the cleaning blade constant is provided outside to prevent the initial pressure setting from being set higher than necessary. JP-A-60-135982, JP-A-62-9382, JP-A-64-23272, JP-A-3-4597. No. reference).

However, the mechanically movable system of the cleaning blade supporting portion has a drawback that the apparatus becomes extremely complicated, and the metal bimetalization of the cleaning blade supporting portion causes the accuracy of the mounting portion due to expansion / contraction of the supporting portion. Deviations, further, when the metal comes into contact with the outside air, corrosion products are generated on the metal surface and malfunction occurs.In addition, when an external heat source is provided, the size of the device and the cost increase cannot be avoided. There were problems such as these, and none of them were in a situation that fits the reality.

[0006]

SUMMARY OF THE INVENTION The present invention avoids various harmful effects caused by the cleaning blade being pressed against the image carrier when the apparatus is not used, and automatically responds to the temperature inside the apparatus without an external mechanism. It is an object of the present invention to provide a cleaning device for an electrophotographic printing apparatus, which has a function of releasing or relaxing the pressure contact force of a cleaning blade.

[0007]

According to the first aspect of the present invention,
In a cleaning device of an electrophotographic printing apparatus that uses a cleaning blade to remove residual toner on the image bearing member, the pressure contact force of the cleaning blade with respect to the image bearing member reduces the heat generation amount of the device itself when the device is not used. It is characterized by having a pressure contact force adjusting function that releases or relaxes in response to.

According to a second aspect of the present invention, the cleaning blade has a structure in which a bimetal metal that deforms depending on the amount of heat generated by the apparatus itself is wrapped with an elastic body.

According to a third aspect of the present invention, the decrease in the amount of heat generated by the apparatus itself is made to depend on the decrease in the amount of heat generated by the fixing device provided in the apparatus.

[0010]

According to the cleaning device of the first aspect of the present invention, the pressure contact force of the cleaning blade for removing the residual toner on the image carrier against the image carrier is determined by the amount of heat generated by the device itself when the device is not used. Since a pressure contact force adjusting function for releasing or relieving in response to a decrease in temperature is provided, an extremely simple structure that does not require an external movable device or an external heat source can be obtained, and the device can be downsized and the cost can be reduced.

According to the second aspect of the present invention, since the cleaning blade has a structure in which a bimetal metal that deforms depending on the amount of heat generated by the device itself is wrapped with an elastic body, the bimetal metal is directly imaged. It is possible to avoid the occurrence of pressure contact marks on the image bearing member and the fusion of the toner on the surface of the image bearing member, since the toner does not come into contact with the bearing member, and it is possible to eliminate malfunctions and pressure accuracy errors.

According to the cleaning device of the third aspect of the present invention, the decrease in the amount of heat generated by the device itself is made dependent on the decrease in the amount of heat generated by the fixing device provided in the device. Due to the decrease in the amount of heat generated by the fixing device at this time, the pressure contact force of the cleaning blade with respect to the image carrier can be reliably released or alleviated.

[0013]

EXAMPLES Examples of the present invention will be described in detail below.
FIG. 1 shows a schematic configuration of an electrophotographic printing apparatus including a cleaning device 2 according to the present embodiment. The electrophotographic printing apparatus is an image bearing apparatus that carries an electrostatic latent image by an electrophotographic method on its outer periphery. The photoconductor drum 1 as a body, a cleaning device 2 arranged so as to be in proper contact with the photoconductor drum 1 to remove toner remaining on the outer periphery of the photoconductor drum 1, and the vicinity (downward) of the cleaning device 2. And a fixing device 3 that contacts the photoconductor drum 1 to allow a sheet on which an image is transferred to pass through and fix the image formed on the sheet.

In the cleaning device 2, the first metal 4 having a high coefficient of thermal expansion and the second metal 5 having a low coefficient of thermal expansion are welded and thinned to form a bimetal metal 6 which bends at a low temperature, and an elastic body 7 is provided. The cleaning blade 8 is formed by wrapping with.

This cleaning device 2 is used when the temperature inside the device rises due to the heat generated by the fixing device 3,
As shown in FIG. 4, the bimetal metal 6 expands due to the expansion of the first metal 4 having a high coefficient of thermal expansion, the tip of the cleaning blade 8 comes into pressure contact with the photosensitive drum 1, and the fixing device 3 is stopped so that the apparatus is stopped. As shown in FIG. 5, the bimetal metal 6 is curved due to the contraction of the first metal 4 so that the tip of the cleaning blade 8 is separated from the photosensitive drum 1 when the device in which the internal temperature decreases is not used. I am configuring.

That is, the cleaning device 2 according to the present embodiment utilizes the fact that the bimetal metal 6 expands or curves depending on the presence or absence of heat generated by the fixing device 3 arranged in the device, and when the device is not used. The pressure contact of the cleaning blade 8 with the photosensitive drum 1 is released or alleviated. That is, according to the present embodiment, the decrease in the amount of heat generated by the device itself is made to depend on the decrease in the amount of heat generated by the fixing device 3 provided in this device, so the amount of heat generated by the fixing device 3 when the device is not used. As a result, the pressure contact force of the cleaning blade 8 with respect to the photosensitive drum 1 can be reliably released or alleviated.

The cleaning device 2 of this embodiment as described above
According to this, an extremely simple structure that does not require an external movable device or an external heat source as in the conventional example can be achieved, and the device can be downsized and the cost can be reduced.

Further, according to this embodiment, since the bimetal metal 6 is wrapped with the elastic body 7, the bimetal metal 6 does not come into direct contact with the outer periphery of the photosensitive drum 1, and the It is possible to avoid generation of pressure contact marks and fusion of toner to the photosensitive drum 1, and it is possible to eliminate errors in operation and pressure bonding accuracy.

Further, since the bimetal metal 6 of the cleaning blade 8 is not exposed to the outside, the bimetal metal 6
It is also possible to prevent corrosion and eliminate malfunction due to this.

Therefore, according to the present embodiment, not only is it possible to reduce the size of the entire apparatus, but it is also possible to improve operating performance through simplification and further improve productivity and maintainability. The cleaning device can be provided.

[0021]

According to the first aspect of the present invention, the pressure contact force of the cleaning blade with respect to the image bearing member is released by the function of adjusting the pressure contact force in response to a decrease in heat generation amount of the device itself when the device is not used. Or can be relaxed,
It is possible to provide a cleaning device that can have an extremely simple structure that does not require an external movable device or an external heat source, and that can reduce the size and cost of the device.

According to the second aspect of the present invention, the bimetal metal does not come into direct contact with the image carrier, and it is possible to avoid generation of pressure contact marks on the image carrier and fusion of toner to the surface of the image carrier. It is possible to provide a cleaning device capable of eliminating malfunctions and pressure bonding error.

According to the third aspect of the present invention, by utilizing the decrease in the heat generation amount of the fixing device, the pressure contact force of the cleaning blade with respect to the image carrier can be reliably released or alleviated when the device is not used. A device can be provided.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram illustrating an electrophotographic printing apparatus including a cleaning device according to an exemplary embodiment.

FIG. 2 is a perspective view showing a cleaning blade of the cleaning device of this embodiment.

FIG. 3 is a sectional view taken along line AA of FIG. 1;

FIG. 4 is a state explanatory view when the cleaning device of the present embodiment is in use.

FIG. 5 is an explanatory view of a state when the cleaning device according to the present invention is not used.

[Explanation of symbols]

 1 Photosensitive Drum 2 Cleaning Device 3 Fixing Device 4 First Metal 5 Second Metal 6 Bimetal Metal 7 Elastic Body 8 Cleaning Blade

Claims (3)

[Claims] 1. A cleaning device for an electrophotographic printing apparatus, which uses a cleaning blade to remove residual toner on an image bearing member, wherein the device itself applies a pressure contact force of the cleaning blade to the image bearing member when not in use. A cleaning device for an electrophotographic printing apparatus, which has a pressure contact force adjusting function that releases or relaxes it in response to a decrease in the amount of heat generated by the printer. 2. The cleaning device for an electrophotographic printing apparatus according to claim 1, wherein the cleaning blade has a configuration in which a bimetal metal that deforms depending on the amount of heat generated by the device itself is wrapped in an elastic body. 3. The cleaning device for an electrophotographic printing apparatus according to claim 1, wherein the decrease in the heat generation amount of the device itself depends on the decrease in the heat generation amount of the fixing device provided in the device. .