JPH0330870B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for cleaning the surface of an image carrier such as an electrophotographic recording apparatus, and more particularly to an improvement in a cleaning method in which the surface of the image carrier is cleaned by bringing a blade into contact with the surface.

Conventionally, known methods for cleaning the surface of an image carrier include a cleaning method using a blade, a cleaning method using a magnetic brush, and a cleaning method using a fur brush. Among these methods, the method using a blade is often adopted because the device is simple, easy to operate, and has an excellent cleaning effect. In general, the surface of the image carrier is easily damaged by external forces and its performance deteriorates, so in order to reduce such damage, for example, when the movement of the image carrier is stopped, the contact of the blade is released. However, a method is known in which the blade is brought into contact with the image bearing member again when the movement of the image bearing member is resumed, thereby cleaning the image bearing member.

However, in general, when interrupting or stopping the copying process, the image carrier is not overrun and the residual toner on the upstream side of the blade is not cleaned from the viewpoint of copying efficiency, but the image is left with the residual toner remaining. The movement of the support is stopped. When the image supporter is moving, the contact portion of the blade is pulled downstream and bent, but as soon as the image supporter stops, the blade returns to its original position. At this time, when the toner is caught and floats, or the toner is scraped up, when the copying process is restarted, cleaning is restarted in an unstable state, resulting in a problem that efficient cleaning cannot be performed.

The present invention eliminates such disadvantages, and an object of the present invention is to provide a cleaning method using a blade that stops the image bearing member without overrunning it and does not cause problems such as poor cleaning. be.

The present invention provides a cleaning method for cleaning by bringing a blade into contact with the surface of a moving image carrier, in which the blade is brought into contact downstream from a normal position, and then the surface of the image carrier is directed upstream. The cleaning method is characterized in that the cleaning method is characterized by moving the cleaning device to a proper position while sliding it and cleaning at that position, and by this feature, the above-mentioned object has been achieved.

Hereinafter, the present invention will be explained based on illustrated examples.

1 and 2 are schematic side views each showing an example of an apparatus for carrying out the method of the present invention.

In the apparatus shown in FIG. 1, an electromagnet Mg1 brings the scraper blade 1 into or out of pressure contact with the surface of the image carrier 2, and an electromagnet Mg2 moves the center of rotation 1a of the scraper blade 1 onto the surface of the image carrier 2.
move up and down approximately parallel to the surface of the That is, in this apparatus, when the rotation of the image carrier 2 in the direction of the arrow is to be stopped for a long time from the state in which the illustrated cleaning is being performed, when the image carrier 2 is stopped, the switch S1 of the electromagnet Mg1 is normally first turned on. Turn off the electromagnet
By releasing the adsorption of Mg1, the scraper blade 1 is rotated counterclockwise by the weight of the movable core to release the pressure contact, and then the switch S2 of the electromagnet Mg2 is turned off to release the adsorption of the electromagnet Mg2. As a result, the spring 3 pulls up the movable core along the guide groove 4 and moves the rotation center 1 of the scraper blade 1.
Displace a upward. Next, when restarting the rotation of the image carrier 2, first turn on the switch S1 of the electromagnet Mg1 to press the scraper blade 1 against the surface of the image carrier 2, and then turn on the switch S2 of the electromagnet Mg2. Then, the rotation center 1a of the scraper blade 1 is brought to the illustrated position, and the image carrier 2 is rotated there in the direction of the arrow. As a result, when the rotation of the image carrier 2 is resumed, the scraper blade 1 is brought into pressure contact with the surface of the image carrier 2 that has already been cleaned, and then brought to the normal cleaning position. Even if the carrier 2 is not stopped after overrun, the scraper blade 1 will not pick up toner or the like, and complete cleaning will be performed from the beginning. In this example, when stopping the rotation of the image carrier 2, the same effect can be obtained by first turning off the switch S2 of the electromagnet Mg2 and then turning off the switch S1 of the electromagnet Mg1. Although not shown, a stopper is of course provided for restricting the rotation of the scraper blade 1, which rotates to press and release due to the weight of the movable core of the electromagnet Mg1.

FIG. 2 shows an example in which pressing and releasing the scraper blade 1 and moving the pressing position are performed by driving one driving member 5. That is, the state indicated by the solid line in the figure indicates a state in which regular cleaning is performed, and when the rotation of the image carrier 2 in the direction of the arrow is stopped and the drive member 5 is rotated to the position shown by the two-dot chain line, Blade holder 6
The driven pin 6a of the blade holder 6 moves along the guide groove 7 from the 6a' position to the 6a'' position, and the interlocking pin 6b of the blade holder 6 also moves along the guide groove 8 from the 6b' position to the 6b'' position. Therefore, the contact end of the scraper blade 1 held by the blade holder 6 to the image carrier 2 is brought from position A to position A', which is the side that has already been cleaned, and to position A'', where the pressure contact is released. When the rotation of the image carrier 2 is restarted, the driving member 5 is first rotated from the two-dot chain line position to the solid line position,
Thereafter, the rotation of the image carrier 2 is restarted. As a result, even in the example shown in FIG. 2, when the rotation of the image carrier 2 is restarted, the scraper blade 1 may pick up the toner, etc. that was present near the tip of the blade when the image carrier 2 stopped. Therefore, the image carrier 2 can be completely cleaned from the beginning. Note that the spring 9, which biases the blade holder 6 to rotate clockwise around the driven pin 6a and stabilizes the changing posture of the blade holder 6, is activated when the drive member 5 is rotated to the two-dot chain line position. Then, it is also in the state shown by the two-dot chain line.

As described above, according to the present invention, when the image carrier stops for a long time, the pressure contact of the scraper blade is released, so there is no risk of deforming the surface of the image carrier, and moreover, the image carrier does not overrun. Even if the machine is stopped without starting, complete cleaning can be performed from the beginning, and there is no possibility of cleaning failures, which is an excellent effect.

It goes without saying that the present invention is not limited to the illustrated example, and the release of the pressure contact of the scraper blade is not limited to the case where the scraper blade is completely separated from the image carrier surface, but is also performed in a manner that does not cause deformation of the image carrier surface. It may be such that the pressure is reduced from the steady cleaning state.

[Brief explanation of drawings]

FIGS. 1 and 2 are schematic side views showing an example of an apparatus for carrying out the method of the present invention, respectively. 1... Scraper blade, 1a... Rotation center, 2... Image carrier, 3, 9... Spring, 4, 7,
8... Guide groove, 5... Drive member, 6... Blade holder, 6a... Driven pin, 6b... Interlocking pin, Mg1, Mg2... Electromagnet, S1, S2...
Switch.

Claims (1)

[Claims] 1. In a cleaning method in which a blade is brought into contact with the surface of a moving image carrier for cleaning,
A cleaning method characterized in that the blade is brought into contact with the blade downstream from the normal position, and then the surface of the image carrier is moved to the normal position while sliding toward the upstream side, and the cleaning is performed at the position. .