JPH01134389A - Cleaning device for image forming device - Google Patents

Abstract

PURPOSE:To prevent toner from leaking out of an opening part, to improve maintainability, and to obtain an image of good quality by arranging auxiliary blades which receive the toner leaking out of both ends of a cleaning blade nearby both ends. CONSTITUTION:A shaft 5 is allowed to slide axially while rotating and then the cleaning blade 3 is moved forth and back in the axial direction of the shaft 5. Auxiliary blades 9 arranged on both sides of the blade 3 are fixed to an elastic member 9a and pressed against the surface of an image carrier 1. Consequently, the toner which leaks out of both ends of the cleaning blade 3 is securely recovered by the cleaning roller 7. A fiber material is implanted in the gap between the cleaning blade 3 and the side wall of a casing where no auxiliary blade 9 is present, thereby preventing the toner from overflowing.

Description

Detailed Description of the Invention (1) Purpose of the Invention (Field of Industrial Application) The present invention relates to an image forming apparatus that uses an electrostatic recording process, such as an electrostatic copying machine or a printer, and particularly to a cleaning device for the same. be.

(Prior art and problem to be solved N) A well-known image that repeats the process of transferring a transferable toner image formed on the surface of an image carrier such as an electrophotographic photoreceptor drum or an insulating drum to a sheet-like transfer material such as paper. In a forming device, it is essential to thoroughly clean residual toner that does not transfer to the transfer material and remains on the image carrier each time during transfer, in order to obtain a high-quality image. Cleaning blades made of elastic materials such as rubber have been widely used in practice because they have a simple construction, low cost, and excellent toner removal function.

As is well known, the basic structure of a cleaning blade is such that one edge of a plate-shaped blade is held immovably and one edge of the other edge is pressed against the surface of the image carrier. Furthermore, if necessary, the blade edge may be configured so that the edge is brought into pressure contact with the image carrier with uniform pressure over the entire length by an equalization method, or the blade is configured to reciprocate in the longitudinal direction. A structure has already been proposed that prevents toner from adhering to the surface of the image carrier and exerts a uniform leaning action over the entire surface of the image carrier.

However, in such a cleaning device, the toner is forcibly scraped off from the surface of the image carrier on which the cleaning blade runs, but depending on the characteristics of the toner and its changes due to the environment, the scraped toner may fall off immediately. Instead, a phenomenon occurs in which the blade runs sideways along the length of the blade edge and falls only when it reaches the end. Since an appropriate gap must be formed between the toner and the toner, the toner may escape from this area, causing contamination inside the image forming apparatus.
Furthermore, there was a risk that the image quality would deteriorate.

In particular, in the case where the blade reciprocates as mentioned above, it is necessary to form a relatively large gap between both ends of the blade and the opposing side wall of the casing, so this part of the toner There was a great risk that it would accumulate in the water and escape to the outside.

In order to avoid such inconvenience caused by the sideways movement of toner, for example, as schematically shown in FIG. At both ends of the edge of the cleaning blade B (only one of which is shown in the figure) of the cleaning blade B provided on the cleaning device 22c, a notch X that slopes inward as shown in the figure is formed, and the cleaning blade B is cut in the direction of the arrow E. It has been proposed to cause the toner running horizontally to fall from the blade as far as possible inside the casing.

However, since this type of device does not close the gap between the image carrier and the periphery of the casing of the cleaning device facing it, it is not a wood-based solution and the process speed is high. When the amount of toner running sideways increases, the effectiveness inevitably decreases.

Therefore, in order to more effectively prevent toner from escaping, an equalization type cleaning device has been proposed in which the above-mentioned gap between the image carrier and the cleaning device casing is actively shielded.

FIGS. 7 and 8 schematically show an example of such a device.

A cleaning device 40 is disposed parallel to and close to the axis of a cylindrical image carrier 30 rotating in the direction of arrow A.

A cleaning blade 41 is disposed in the cleaning device, and its edge that presses against the image carrier causes
It is assumed that residual toner on the surface of the image carrier is removed.

The cleaning blade 41 is supported by a support member 4 rotatably supported on a shaft 43 extending in a direction parallel to the paper surface.
Further, the shaft 43 is rotatably supported by a shaft 44 extending perpendicular to the plane of the paper, so that the edge of the blade 41 is attached to the image carrier by a spring or the like (not shown). Since the blade edge is pressed against the image bearing member and is also swingable as shown by the arrow in FIG.

In the illustrated apparatus, the opening side of the casing 45 provided with the cleaning blade, especially the inner surfaces of the side walls 46, 47 facing the blade, etc., are designated by reference numerals IL and 12 in FIG. The ms, which is slightly longer than these gaps and has high insulation properties, is implanted in the portions, and with this configuration, it is possible to actively prevent toner from escaping from these gaps.

Note that the toner and other particles collected in the cleaning device usually contain a mixture of positively and negatively charged particles, so there are two types of fibers with different charging characteristics. It is preferable to mix.

With the above configuration, the toner that is to be prevented from escaping is
In addition to being mechanically captured by the fibers, toner and the like are usually electrically charged, so that they are electrostatically attracted to the fibers, thereby effectively preventing the toner from escaping.

However, even with such a device, there is a limit to the amount of toner that can be held in the fiber portion, and when excess toner accumulates, it falls within the casing and is usually present in the lower part. There is a risk that the particles may fall near the transfer charger and contaminate the pair of electric wires, or may fall on the transfer material and damage the image.

The occurrence of such a situation is more likely to occur if a reciprocating means for reciprocating the blade as described above is added in addition to the above-mentioned equalization method, since it is necessary to provide an even larger gap corresponding to 11 above. become noticeable.

The present invention has been completed in view of the current situation as described above, and is capable of preventing toner from escaping from the opening of a cleaning device using a cleaning blade as much as possible. Another object of the present invention is to provide a leaning device that is easy to maintain, can obtain high-quality images, and is advantageous in terms of reducing running costs.

(2) Structure of the invention (technical means for solving the problem and its operation) In order to achieve the above object, the present invention provides a cleaning device equipped with a cleaning blade that comes into pressure contact with the surface of a moving image carrier. The cleaning blade is characterized by a structure in which auxiliary blades are detachably disposed near both ends of the cleaning blade on the upstream side of the cleaning blade to receive toner escaping from both ends of the cleaning blade.

With this configuration, the toner escaping from the end of the cleaning blade can be reliably collected and collected in the cleaning device over a long period of time.
The maintenance interval can be sufficiently extended while maintaining good image quality.

(Description of an Embodiment) FIG. 1 is a perspective view showing the external appearance of an embodiment of a cleaning device for an image forming apparatus to which the present invention is applied, in which the cleaning device faces an image carrier (not shown) in the lower right direction in the figure. A cleaning blade 3 is disposed in the opening so that its edge is exposed.

Reference numeral 5 in the figure will be described later. Drive shafts 7a and 8a for reciprocating the cleaning blade are shafts on which a cleaning roller and a conveyance screw are respectively pivotally mounted.

FIG. 2 is a cross-sectional view of the above-mentioned cleaning device, in which the cleaning device 2, which extends vertically on one page, is close to and parallel to the image carrier L, which is formed in a cylindrical shape and rotates in the direction of the arrow in the figure. As described above, the edge of the cleaning blade 3 exposed at the opening faces the image carrier.

One edge of the cleaning blade 3 is attached to a support member 4a, and the support member 4a is rotatably pivoted to the shaft 4.

Further, the shaft 4 is attached to a support member 5a which is pivotally connected to a shaft 5 extending in a direction perpendicular to the front of the paper.
is attached to the other end of a spring 6 whose one end is locked to a support member 6a fixed to the M-removable lid 21 of the cleaning device. Therefore, the cleaning blade 3 is always 1
The edge is given a rotational habit in the counterclockwise direction shown in the figure, and the edge is pressed against the surface of the image carrier with a predetermined force by the action of the spring 6, and is pressed against the surface of the image carrier with a uniform force over the entire length by the action of the shaft 4. It will touch the surface.

Furthermore, in the device described in L, one end of the shaft 5 and the shaft of the magnetic roller 7 protrude outward from their bearing portions, and in that portion, as shown in FIG.
A gear GD attached to the shaft 7 & of the magnetic roller 7 and a gear train G1 . G2. G3 and gear G
A transmission system is formed by a screw-shaped cam C disposed on the shaft 5 and a cam follower 5b disposed on the shaft 5 so as to sandwich the cam.

With this structure, by making the shaft 5 rotatable and slidable in its axial direction, the cleaning blade can be reciprocated in the direction in front of the plane of the paper as viewed in FIG.

In the figure, reference numeral 7 is a magnetic roller for removing foreign matter adhering to the surface of the image carrier, and reference numeral 8 is a transport screw for transporting and discharging the collected toner to the outside.

Needless to say, a negative charger, an image information imparting means, a developing device, a transfer charger, and other members necessary for forming a mountain image are disposed around the image carrier 1, but these are not covered by the present invention. Since they are not directly related, they are all omitted.

In the cleaning device having such a configuration, the present invention provides auxiliary blades near both ends of the cleaning blade.

As can be seen from FIG. 1, the auxiliary blades 9 are disposed on both sides of the main cleaning blade 3, and are made of an elastic material such as urethane rubber. This blade 9 is a cleaning device fa2.
An elastic member 9a is attached to a support member 22a attached to a boss portion 22 formed on the casing of the image carrier, and is attached to an elastic member 9a which is removably attached to the support member 22a with a screw or the like. They are in pressure contact.

The auxiliary blade 9 is arranged at a location corresponding to the gap between the end of the cleaning blade 3 and the side wall of the cleaning device casing, as can be seen from FIG. In addition, the blade is tilted at an appropriate angle so that toner, etc. that has fallen onto the blade flows toward the image carrier or the center of the cleaning blade. It is possible to reliably collect it on the cleaning roller 7.

In addition, in the gap between the cleaning blade and the side wall of the casing, where the auxiliary blade 9 is not present, a fiber material is planted as shown in FIGS. Ikeda 1F can be carried out even more effectively.

With this configuration, the four bodies 2 can be adjusted as needed.
By removing 1, the auxiliary blade can be easily attached and detached.

FIG. 5 shows another embodiment of the present invention, in which parts corresponding to those shown in FIG.

In this device, the auxiliary blade 11 is in pressure contact with the surface of the image carrier in the running direction of the image carrier, that is, in the so-called forward direction.

As mentioned above, the toner to be collected by this auxiliary blade is mostly the toner that has been scraped off from the tl carrier by the main blade 3 and has traveled sideways, and the adsorption force to the image carrier is weak, so this method is not recommended. However, a sufficient effect can be obtained, and it is advantageous in solving the problems of blade curling and damage to the image bearing member caused by the blade.

(3) Effects of the Invention - As explained above, according to the present invention, in a cleaning device that uses a cleaning blade as a cleaning means, it is possible to reliably clean the toner that flows from the end of the cleaning blade by running sideways or the like. In addition to being able to collect the toner inside the device, its durability can be increased even when a spacer such as a fiber material is provided in the gap at the end of the blade to prevent the toner from escaping. Therefore, it is effective in obtaining high-quality images and is also effective in reducing running costs.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of a cleaning device to which the present invention is applied; FIG. 2 is a sectional view of the same; FIG. 3 is an end view showing an example of means for reciprocating the cleaning blade; FIG. FIG. 3 is an end view showing how the auxiliary blade is attached. FIG. 5 is a sectional view showing another embodiment, and FIGS. 6, 7, and 8 are a perspective view, a side view, and a plan view of essential parts, respectively, for explaining the operation of a known cleaning device. be. 1.Fist image carrier, 2.Φ.Cleaning device, 3.
-Cleaning blade, 4.5-...shaft, 4a, 5a
...Supporting member, 6.Φ.spring, 7.Elastic cleaning roller, 9.11.Auxiliary blade. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (2)

[Claims] (1) In a cleaning device equipped with a cleaning blade that comes into pressure contact with the surface of a moving image bearing member, on the upstream side of the cleaning blade, an auxiliary device is provided near both ends of the cleaning blade to receive toner escaping from both ends of the cleaning blade. A cleaning device equipped with a blade. (2) The auxiliary blade is arranged at an angle so as to intersect the generatrix of the image carrier so that the escaping toner is received and dropped toward the center of the image carrier and the cleaning blade. Cleaning device as described in section.