JPH055581Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to an improved cleaning apparatus for removing residual particles from a photoconductive member in an electrophotographic apparatus.

BACKGROUND OF THE INVENTION In known copiers, a charge is applied to a photoconductive member as it passes through a charging station. The photoconductive member is then passed through an exposure station where it is exposed to light corresponding to the image of the document to be reproduced to form a latent image. This latent image is then developed by depositing opaque particles, such as toner particles, and the developed image is transferred to paper. The photoconductive member is then cleaned and prepared for the next copy.

In order to maintain image quality in such copiers, it is important to remove residual toner particles before the next copy. Published in August 1983
Research Disclosure No. 23215 describes the use of a rotating fiber brush positioned adjacent to and in contact with the path of travel of a photoconductive material to mechanically remove residual toner particles from its surface. ing. Vacuum means are provided along substantially the entire length of the brush for collecting toner particles removed from the photoconductive member.

Problems to be Solved by the Invention Problems arise when the above-described cleaning device is used in a copier that operates at relatively high speeds. When the copier is operated at high speeds, the cleaning capacity is significantly reduced and therefore the quality of the copies is degraded due to insufficient removal of residual particles. In high speed copying, the ability to maintain the fiber brush in the required clean condition is also reduced, and when the brush becomes dirty, there is a tendency for toner to build up on the surface of the photoconductive member.

OBJECTS OF THE INVENTION It is an object of the present invention to provide an improved apparatus for removing residual toner particles from the surface of a photoconductive member. It is further an object of the present invention to provide a cleaning device for an electrophotographic developing device that prevents the brush from getting dirty and causing toner particles to adhere to the surface of the photoconductive member even in a copying machine operated at high speed. The purpose is

Structure of the Invention A cleaning device according to the present invention includes a rotating fiber brush for removing toner particles from the surface of a photoconductive member, and a rotating fiber brush that surrounds the brush and passes air containing the removed toner particles between the brush and the rotating fiber brush. It has a housing that defines a space. It has a nozzle extending from the inner surface of the housing toward the circumferential surface of the brush and slightly spaced from the circumferential surface. The nozzle has an inner opening facing radially inwardly toward the circumferential surface of the brush and is in communication with a vacuum source. The inner opening is located within the housing at a distance of approximately 25 to 250 microns from the circumferential surface of the brush. Any air containing toner particles is passed through the brush adjacent the nozzle to fluff the brush and remove toner particles that adhere to the bristles, thereby cleaning the photoconductive member. increase the ability to The present invention also provides a nozzle member for attachment to known cleaning devices.

Embodiments Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.

FIG. 1 shows a web-type electrophotographic copier 10 that can utilize the present invention. As shown, a photoconductive member in the form of a web 16 is wrapped around rollers 4, 5, 6, 7, 8, 9 and moved in the direction indicated by arrow A. The roller 4 is driven by a drive device 18, such as a motor pulley device. Insulating layer 1 of web 16
6a is charged in a conventional corona charging station 20. Charging station 20 includes one or more corona generating wires, a shield, and a grid that regulates the flow of negative corona current from the wires to the photoconductive member. Information media such as documents 1
3 is illuminated by a flash lamp or the like at an exposure station. The illumination light is reflected from the medium 13 and projected onto the insulating layer 16a of the charged web 16 by the lens 15, discharging a predetermined portion and forming an electrostatic charge image of the information medium.

At development station 22, the electrostatic charge image contacts and adheres to the toner particles to form a visible image. This visible toner image is then transferred to a copy sheet 26 at a transfer station 25 and subsequently fused onto the copy sheet. The remaining toner particles are removed at a cleaning station 31.
Cleaning assist erase lamp 29
and corona charger 30 reduce the electrostatic force with which toner adheres to the photoconductive member.

At the developing station 22, the web 16
The electrostatic charge image on the insulating layer 16a of the housing 27
It is passed through two magnetic brushes or rollers 24a located inside. Housing 27 contains a developer containing toner particles and carrier particles. Brush 24
a and 24b may have any conventionally known structure.

Although a web-type copying machine has been shown above, it is also suitable for durham-type copying machines, copying machines of a type using a sheet film photoconductive member, and the like. In either case, a microcomputer can be used as the logic controller to control the copier.

A typical conventional cleaning device 31 is shown in FIGS. 3a and 3b. A conventional cleaning device is also shown in FIG. 2, which includes a brush housing 32 having a hollow hood portion 33 supporting a cleaning brush 35 therein. The brushes are supported by general purpose bearings (not shown) for rapid rotation by a drive device (not shown) including a motor, timing chain, etc. The hood portion has an opening adjacent the web of photoconductive member to allow brush bristles to contact the web and remove residual toner. As is well known, residual toner is toner that has not been transferred from photoconductive member 16 to copy paper at transfer station 25. The end walls 34a, 34b define between them a manifold portion 34 of the brush housing, in which air drawn into the housing is collected and an outlet 3 made in one end wall of the manifold portion 34.
7 into the flexible vacuum tube 36. A vacuum source 50 with a toner separator 52 is connected to tube 36 . A vacuum source, shown as blower 50, produces an air flow shown by arrow 54. A toner separation device 52 located between outlet 34 and vacuum source 50 separates toner from air stream 54 by well-known cyclone separation techniques. The air flows through the inner wall 33a of the hood portion 33 and the rotating brush 35.
and into the housing 32 through a passageway 38 (FIG. 3b) between the two.

Rotating brush 35 contacts photoconductive member 16 to mechanically remove residual toner. Airflow within passageway 38 (indicated by arrow 54) carries most of the removed toner from brush 35 to manfold section 3.
Carry it to 4.

4a, 4b and 5 show a cleaning device according to the present invention. In this device, a vacuum nozzle 60 is provided in the narrow space between the hood section and the manifold section, ie, the throat section 39. The nozzle extends into the hood passageway 38 from the throat. At operating speeds of the brush, the nozzles extend approximately to the circumference of the brush and are spaced from the circumference by a small distance, such as about 25 to 250 microns, such that no mechanical contact occurs therewith. The nozzle extends parallel to the axis of the brush over its entire length. The brush can be any general purpose brush made of acrylic, nylon, bristles, or other fibrous materials used for this type of cleaning. The brush is rotated in a direction opposite to the movement of the photoconductive member, as shown by arrow B, and an air flow containing toner particles is created in the space between the circumferential surface of the brush 35 and the inner wall 33a of the hood portion. Passage 38 is approximately 0.6
cm deep (using a brush with a nominal outer diameter of approximately 8.8 cm),
It extends over the axial length of the brush (approximately 43 cm). The surfaces 61, 62 of the nozzle block define the air flow path.
towards manifold section 34. The majority of the airflow is directed into the brush at the portion opposite the nozzle opening 64. Since it is desirable to keep the brush as free from toner particles as possible, it appears undesirable to direct all the toner contained in the air stream into the brush. However, it has been found that the cleaning effect can be increased by adjusting the airflow as described above, and the introduction of high-velocity airflow (approximately 550 to 670 meters/min) into the brush can fluff the brush more effectively. The bulging condition provides more cleaning surface on the brush, which allows the brush to more effectively clean the photoconductive member.

The nozzle air passage 65 can be tilted up to about 45 degrees in its direction of rotation relative to the radius of the brush to facilitate air flow into the nozzle opening 64.
The end faces 67, 68 of the nozzle positioned adjacent the nozzle opening can be flat or radiused to the shape of the circumferential surface of the brush. As shown in Figure 5,
The nozzle has specially shaped surfaces 69, 70 as shown.
The nozzle can be installed within the throat of an existing brush housing. The nozzle is molded in two parts from urethane, polycarbonate, or polyvinyl chloride. Three or more thin rib members 71 are appropriately spaced along the nozzle opening between the two sections to connect the sections and maintain the opening. The rib members can be integrally molded with one member and interference fit into complementary recesses in the other member. The axial end of the nozzle opening may be sealed with a suitable tape, or may be left open and sealed with toner as it is used.

An example of a modification of this device is to reduce the gap "d" between the circumferential surface of the brush and the inner wall surface of the hood section on the downstream side of the nip section of the brush, so that air can be removed from the toner particles as the brush rotates. It can also be prevented from returning onto the photoconductive member.

Effects of the Invention In the present invention, since the bristles of the brush can be made to look fluffy, the bristles themselves can be cleaned more effectively, and the amount of toner deposited on the photoconductive member can therefore be reduced. The cleaning of the brush bristles is therefore more thorough and may also remove toner particles contained within the relatively static air space at the root of the bristles. Other effects of the present invention are as follows:
By incorporating the nozzle member 60 into an existing cleaning device as shown in FIGS. 4b and 5 and described above, improved cleaning efficiency can be easily obtained without the need to increase the capacity of the blower motor.

In new applications, the blower motor capacity may be designed to provide a nozzle air velocity that is related to the photoconductive member velocity. If the photoconductive member is at high speed, then the nozzle air velocity may be high.

Other unexpected effects of this invention are:
A uniform air velocity is obtained along the axial length of the nozzle. This adds a more uniform vacuum action to the rollers without additional buffling structure in the manifold section.

[Brief explanation of the drawing]

1 is a schematic side view of a conventional copying machine to which the present invention can be applied; FIG. 2 is a perspective view of a copying machine equipped with a cleaning device to which a nozzle member according to the present invention is attached; FIG. 3a is a schematic side view of a conventional copying machine to which the present invention can be applied. A side view of the cleaning device; FIG. 3b is a sectional view taken along the line 3b-3b of FIG. 3a; FIG. 4a is a sectional view of the cleaning device according to the present invention; FIG. FIG. 5 is a perspective view of the nozzle member. 35...Brush, 32...Brush housing,
38... passage, 60... nozzle, 64... nozzle opening, 65... air slot.

Claims (1)

[Claims for Utility Model Registration] 1. A rotating brush for removing toner particles from the surface of a photoconductive member; surrounding the brush and defining a path for the removed toner particles away from and between the brush and the brush; a nozzle communicating with the passageway and facing radially inwardly toward the circumferential surface of the brush, with an inner opening spaced within the housing at a distance of about 25 to 250 microns from the circumferential surface of the brush; A cleaning device for an electrophotographic developing device, comprising: a nozzle having a narrow slot located therein. 2. The cleaning device according to claim 1, wherein the narrow slot extends parallel to the axis of the brush. 3. The cleaning device according to claim 2, wherein the slot is designed such that the air passing through the brush is approximately 550 to 670 meters/min.