JPH0229223B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a fur brush cleaning device for cleaning toner remaining on an image bearing member of an electrophotographic copying machine.

Conventional technology A fur brush roll is rotatably provided in a housing, and the fur brush roll is rubbed on an image carrier to clean the remaining toner and trap it in the housing, and the toner is vacuumed together with the air in the housing. A fur brush cleaning device is known that uses suction and discharge by a source.

Such a fur brush cleaning device has a large suction air volume of about 3 m ³ /min for sucking air inside the housing, and has disadvantages such as large power consumption, large cost, large space, and large noise.

Therefore, as disclosed in Japanese Patent Application No. 57-068734, an electric field curtain sheet is provided on the inner wall of the housing to reduce the suction air volume to 0.3 to 0.6 m ³ /min. The device is known.

Problems to be Solved by the Invention The electric field curtain sheet is unreliable and deteriorates quickly, and when it deteriorates, the suction air volume is small and the clearance between the fur brush and the housing is large, so toner adheres to the inner wall of the housing. The toner accumulates and re-adheres to the fur brush, causing problems such as adversely affecting copying and staining the inside of the copying machine.

Further, toner blocks between the frit cover bars, causing a problem of clogging.

Means and action for solving the problem The clearance between the image carrier and the orifice plate is set to 1 to 2 mm, the clearance between the fur brush roll and the housing is set to zero, the width of the suction port is set to 1 to 3 mm, and the throat of the fritscar bar is set to 1 to 2 mm. the length
20 mm or more, even if the suction air volume is about 0.6 m ³ /min, toner particles inside the housing may leak out of the device, toner blocking or clogging of the suction port,
Furthermore, it is designed to prevent toner from adhering or accumulating inside the housing.

Embodiment FIG. 1 is a cross-sectional view of a fur brush cleaning device. Reference numeral 1 in FIG. , 2' and the backup rolls 3, 3'. 4,
Reference numeral 4' designates a pair of fur brush rolls that are in contact with the image carrier 1 and whose rotating shafts are perpendicular to the moving direction of the image carrier 1. It is made up of approximately 2000 acrylic fibers/cm ² flocked on the surface, and the
It is designed to rotate at 1200 rpm. 5 and 5' are first and second housings that cover the fur brush rolls 4 and 4'; 6 and 6' are the fur brush rolls 4 and 4;
The first and second fricker bars have the role of knocking off toner particles adhering to the brush fibers of brush fibers 6 and 6'.
are integrally formed at opposite ends of the first and second housings 5, 5', are made of a conductive material such as aluminum, and are grounded. , second housing 5,
A suction port 7 opening into the inside 5' is formed.

This suction port 7 is connected to a duct 9 via a flow path 8, and this duct 9 is connected via a hose (none of which is shown) to a dust collector having a vacuum source.

10, 10' form a slit with a high air flow rate between the image carrier 1 and the ends of the first and second housings 5, 5'.
These are first and second orifice baffles to prevent toner particles inside from leaking out of the cleaning device. 12 is corotron wire 1 for cleaner
This is a pre-cleaning corotron consisting of a corotron shield 14 and a corotron shield 14, and the pre-cleaning corotron 12 generates a current of 400Hz and 0.09 to 0.23 μA.
AC corona irradiation at sec/cm ² and plus DC corona irradiation at 0.046 μA·sec/cm ² are carried out, thereby processing the residual toner image on the image carrier 1 so that it can be easily cleaned.

Note that the polarity of the applied current is opposite to that described above when the image carrier 1 is made of a P-type semiconductor.

In the fur brush cleaning device described above, the untransferred toner image remaining on the image carrier 1 is treated with corona irradiation from the pre-cleaning corotron 12 to make it easier to clean, and then enters the fur brush cleaning device. I'll come. In the fur brush cleaning device, the untransferred toner image is removed by the wiping action of the rotating pair of fur brush rolls 4, 4' and the electrostatic attraction force, that is, the pre-cleaning corotron 1.
To clean the positively charged toner in step 2,
Cleaning is performed by a pair of negatively charged fur brush rolls 4, 4'.

That is, a pair of fur brush rolls 4, 4' made of acrylic resin are integrated with first and second housings 5, 5' made of metal such as aluminum, and first and second frit cover bars 6, Since it is negatively charged by frictional electrification by contacting the fur brush roll 6', approximately 90% of the fur brush roll 4 is efficiently cleaned by the first fur brush roll 4 due to the electrostatic cleaning action and mechanical contact action. Since the remaining 10% of toner is a small amount, it is easily cleaned by the second fur brush roll 4'.

Then, this removed toner is transferred to the first and second toners.
It is knocked out from between the fibers of the pair of fur brush rolls 4, 4' by the fritz coverrs 6, 6' and scattered into the air, and is sent to the dust collection device by a vacuum source via the suction port 7, flow path 8, duct 9, and hose. (not shown), where the toner and air are separated.

In the fur brush cleaning device as described above, the fur brush rolls 4, 4' and the first and second
The first and second housings 5, 5' are made by varying the clearance with the housings 5, 5' and the suction air volume.
An experiment was carried out to determine whether toner adhesion or accumulation occurred on the inner wall of 5', and even if the suction air volume was as small as 0.6 m ³ /min, toner adhesion or accumulation did not occur if the clearance was set to zero.

In addition, the width A of the suction port 7 was varied to measure the wind speed in the flow path 8, with the depth direction length of the first and second frit cover bars 6, 6' being 466 mm, and the suction air volume being 0.6 m ³ /min. When inspecting whether or not toner blocking or clogging occurred at the port 7, the results were as shown in FIG.

From this result, if the width A was made smaller than about 4.5, toner blocking or clogging did not occur even if the suction air volume was 0.6 m ³ /min. It is preferable that the width A is 1 to 3 mm.

At the same time, when the width A of the suction port 7 is 3 mm, the wind speed in the flow path 8 is 0.2 m/sec, and according to another experiment, if the wind speed in the flow path 8 is 4 m/sec or more, the toner It has been confirmed that no blocking or blockage occurs, and this also shows that the width A of the suction port 7 is
It is preferable to set it to 3 mm.

In addition, the suction air volume was set to 0.6 m ³ /min, and the throat lengths B of the first and second frit cover bars 6, 6' were varied to draw air from the back side of the flow path 8. When we measured the variation in wind speed from side to side, if the throat length was 20 mm or more, the variation was within about 25%, and we were able to maintain a minimum wind speed of 4 m/sec without causing the aforementioned toner blocking or clogging.

As a result, the first and second frit cover bars 6,
The throat length B of 6' should be 20 mm or more.

Further, experiments were conducted to find out that toner particles in the first and second housings 5 and 5 leaked out of the apparatus by varying the gap between the image carrier 1 and the first and second orifice plates 10 and 10'. By setting the gap to 1 to 2 mm, toner particles did not leak out of the device.

Effects of the invention Even if the suction air volume is as small as 0.6 m ³ /min,
There is no toner adhesion or accumulation on the inner surface of the housing, no toner blockage or blockage occurs between the suction port 7, that is, the throats of the first and second flicker bars 6, 6', and toner particles inside the housing are not removed from the device. Since there is no leakage and extremely good cleaning performance can be maintained, it is possible to downsize the dust collector, thereby achieving reductions in cost, space, power consumption, noise, etc.
Further, in the present invention, since the clearance between the fur brush roll and the housing can be made zero, there is an effect that the space can be reduced synergistically.

[Brief explanation of drawings]

FIG. 1 is an overall sectional view showing an embodiment of the present invention, and FIG. 2 is a table showing the relationship between the width of the suction port and the wind speed of the flow path. 1 is an image carrier; 4 and 4' are a pair of fur brush rolls; 5 and 5' are first and second housings;
6' is the first and second fritz cover, 7 is the suction port,
8 is a flow path, and 10 and 10' are first and second orifice plates.

Claims (1)

[Claims] 1. A fur brush roll in contact with the image carrier 1 is provided in the housing, a suction port 7 is formed between the first and second flicker bars 6 and 6' in contact with the fur brush roll, and the suction port 7 is connected to the flow path 8. In the fur brush cleaning device, the housing is connected to a vacuum source through the housing, and orifice plates are provided at both ends of the housing.The gap between the orifice plate and the image carrier 1 is set to 1 to 2 mm, and the inner surface of the housing and the outer peripheral surface of the fur brush roll are connected to each other. A fan of an electrophotographic copying machine, characterized in that the clearance from Brush cleaning device.