JP3451063B2 - Cleaning equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning device used in a copying machine, a printer and a facsimile machine using an electrophotographic copying system, and more particularly to removing residual toner on a photoconductor by a cleaning blade and a cleaning roller. Cleaning device.

[0002]

2. Description of the Related Art Conventionally, a cleaning device for removing untransferred toner remaining on a photosensitive drum has a cleaning blade mainly for removing residual toner, and a fur brush for cleaning and an auxiliary function. Cleaning rollers such as rollers and polishing rollers are often used together. In this system, a cleaning roller is arranged on the upstream side of the rotation of the photoconductor so that the residual toner on the surface of the photoconductor is rubbed and disturbed so as to be removed as it is or easily removed. After that, the cleaning blade on the downstream side completely detaches from the surface of the photoconductor, and the toner that has fallen to the cleaning roller side and adhered is removed by the scraping plate. Here, the detached toner easily scatters from both ends of the cleaning device due to the air flow generated by the rotation of the photosensitive drum, the air flow caused by various cooling fans and exhaust fans, or the centrifugal force caused by the rotation of the cleaning roller. Sealing members and sponges are provided at both ends of the cleaning device so as to contact both ends of the photosensitive drum.

[0003]

However, since the both ends of the cleaning roller and the seal member are in contact with each other in order to prevent the toner from scattering, or are only separated by a slight gap, the toner on the surface of the cleaning roller is constantly sealed. Easy to move to. If image formation is repeated in this state, the amount of toner adhering to the end surface of the seal continues to increase and migrates to the seal surface. Since the seal and the surface of the photoconductor are in contact with each other or there is a small gap therebetween, the toner stains transferred to the surface of the seal member are transferred to the surface of the photoconductor. As a result, toner stains on the collar are attached to the surface of the photosensitive drum, and since this toner stain continues to grow, when a certain amount of toner is accumulated, toner agglomerates, and the adherent detaches from this gap. It drops and contaminates the transfer device and the transfer paper conveyance path below. Contamination of the charger wire or the transfer roller of the transfer device causes transfer failure and stains on the transfer paper.

Therefore, the present invention prevents the cleaning toner from leaking out of the cleaning device,
(EN) Provided is a cleaning device capable of eliminating contamination of an optical system and a drive system, preventing troubles due to various toner contamination, and shortening maintenance time of a service person.

[0005]

In order to achieve the above object, the invention of claim 1 includes a cleaning blade, a cleaning roller located upstream of the cleaning blade in the rotation direction of the photosensitive drum, and a housing. In a cleaning device provided with a seal member provided at both ends in the longitudinal direction of an opening corresponding to a photoconductor drum, the cleaning device is configured so as to be coaxial with a roller rotation shaft between the cleaning roller and the seal member. It is not the same as the photosensitive drum that is conveyed toward the roller.
Provided is a cleaning device having a contact conveyance member. According to the invention of claim 1, the toner accumulated in the middle of the cleaning roller and the seal at both ends is always sent to the cleaning roller side by the toner conveying action of the conveying member that rotates in synchronization with the cleaning roller, so that the toner agglomerates at the seal members at both ends. It is possible to prevent problems caused by toner leakage to the outside of the cleaning device.

Further, the invention of claim 2 is characterized in that the axial length of the cleaning roller exceeds the maximum width of the transfer sheet and is less than the axial length of the cleaning blade. The cleaning device described in 1. is provided. With the configuration of the second aspect of the present invention, even if the conveying members are provided at both ends of the cleaning roller, the cleaning effect in the image area by the cleaning roller can be maintained.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a partial schematic explanatory view showing a main part of a copying machine in which a developing device according to an embodiment of the present invention is adopted. Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, KM4 manufactured by Kyocera Mita Co., Ltd.
230 modified machines were used. The image forming apparatus shown in FIG. 1 uses a reversal development method. Reference numeral 1 denotes a photosensitive drum as an electrostatic image bearing member, which is formed by forming a photosensitive layer made of an organic photosensitive material on the surface of a metal tube made of metal such as aluminum. The photosensitive drum is rotationally driven by a drive unit (not shown) so as to be in the forward direction with respect to the transfer paper P conveyance direction in the transfer area. A charging unit 3, an exposure unit 4, a developing unit 5, a transfer unit 6, a cleaning unit 7, and a charge eliminating unit 8 are arranged in this order on the peripheral surface of the photosensitive drum in accordance with the rotation direction thereof. A sectional view of the cleaning device of the present invention is shown in FIG. 2, and a schematic front view of the cleaning device of the present invention is shown in FIG.

In the copying machine having the above-described structure, the surface photosensitive layer of the drum 1 is charged to + 700V by corona discharge by the charging means 3. The charged drum surface is irradiated with light according to the original image read by the optical means (not shown) provided in the machine by the exposure means 4 having a laser source, and the photoreceptor drum surface is not exposed. An electrostatic line image composed of +700 V in the exposed area and +120 V in the exposed area is formed. By the developing means, charged toner is attached to the electrostatic latent image to form a toner image. The developing means 5 contains 95 parts by weight of a magnetic carrier having an average particle diameter of 90 μm and 5 parts of a positively chargeable toner having an average particle diameter of 9 μm. Since the developing bias is applied, the positively chargeable toner is developed on the exposed portion to form a toner image on the surface of the photoconductor. On the surface of the positively chargeable toner, titanium oxide for improving fluidity and chargeability,
0.2 parts by weight of silica (to 100 parts by weight of toner) are dispersed and adhered.

When the toner image formed on the surface of the photosensitive drum is rotationally moved to a position facing the transfer means 6, the surface of the transfer sheet P conveyed by the registration roller pair 9 in synchronization with the toner image. The toner image on the surface of the photosensitive drum is transferred onto the surface. In FIG. 2, the untransferred residual toner on the surface of the photoconductor is disturbed by the cleaning auxiliary brush fur brush 7a in which the chemical fibers for mechanically stirring the residual toner image are disturbed in the cleaning means 7, and then it is made of plate-shaped polyurethane rubber. It is removed by the cleaning blade 7b and falls again on the fur brush 7a. The toner attached to the fur brush 7a collides with the scraping portion 7c protruding from the bottom of the housing 21 when the fur brush 7a rotates. Then, due to the impact at the time of collision, the toner separates from the fur brush 7a, falls on the lower portion 21a of the housing 21, and accumulates in the toner conveying auger 7d. Then, by the rotation of the toner conveying auger 7d, the toner is conveyed to a toner collecting and conveying system (not shown) and is collected in a waste toner container. The photoconductor 1 that has been cleaned by wiping off the toner with the cleaning blade 7b is then subjected to the charge removal light L2 in the charge removal unit 8 to be discharged, and when the drum 1 has just rotated once since the previous charging, Prepared for image formation. On the other hand, the paper P on which the toner image has been transferred is sent to a pair of fixing rollers and heated while passing between the fixing rollers 10.
The toner image is fixed on the paper P under pressure.

Next, the construction of the cleaning device for a copying machine according to the present invention will be described with reference to FIGS. The cleaning device 7 includes a cleaning blade 7b, a fur brush 7a that is a cleaning roll, and a front spiral 25a and a rear spiral 25 that are coaxial with the fur brush 7a.
It is provided inside a housing 21 that includes b and the like and has an opening 22 formed by opening a portion facing the photoconductor 1. The cleaning blade 7b is a plate-shaped member formed of an elastic material such as polyurethane rubber, is attached to the upper portion of the opening 22 of the housing 21, and the tip of the blade 7b is attached to the photosensitive member 10.
Hangs so that it can contact the surface of the.

The fur brush 7a is arranged parallel to the housing opening 22 with both ends of the brush shaft 23 being supported by both side walls of the housing 21. The fur brush main body 7a is configured by winding a pile shaft 7f having a back surface coated with an adhesive around a brush shaft 23 having a diameter of 5 mm. The pile belt 7f has a large number of 15 denier polypropylene fibers planted on the base cloth 7g.

The configuration of the present invention will be described in detail with reference to FIG. As shown in the figure, the axial length of the cleaning blade 7b is longer than that of the fur brush 7a, and the front and rear ends thereof have a front seal 24a and a rear seal 24 to prevent toner from scattering.
It is provided in b with a slight gap of 1 mm or less. An edge surface of the cleaning blade 7b at the upstream end in the photoconductor rotation direction is in contact with the photoconductor by a support mechanism (not shown). The fur brush 7a has a length in the axial direction that exceeds the maximum width of the transfer sheet in order to maintain the cleaning effect of the image area, and a front spiral 25a and a rear spiral 25b are provided between the fur brush 7a and the seal member on both sides thereof. The length is less than the axial length of the cleaning blade 7b in order to be provided. Both ends of the exposed surface of the brush shaft 23 protruding to the outside of the fur brush 7a have front wall 21a and rear wall 2 of the housing 21.
It is pivotally supported with respect to 1b. Brush shaft 2
3 of the exposed surfaces before and after the brush shaft 2 are not covered by the front seal 24a and the rear seal 24b.
A spiral structure made of resin is formed around 3 to form a front spiral 25a and a rear spiral 25b. The front spiral 25a and the rear spiral 25b are symmetrical in pitch shape and have a gap of about 1 mm from the surface of the photoconductor and are not in contact with each other. Further, when the front spiral 25a and the rear spiral 25b are extended below the front seal 24a and the rear seal 24b, they are not in contact with the back surface of the seal. The front and rear spirals 25a and 25b convey the toner dropped from the upper cleaning blade by the rotation of the brush shaft 23 to the central fur brush 7a, so that the toner protruding to the outside of the fur brush is aggregated between the front and rear seals. Disappears. The scraping portion 7c is the fur brush 7
Since the axial length extends from a to the front and rear spirals 25a and 25b, of the toner conveyed from the front and rear spirals, the toner that cannot be transferred to the surface of the fur brush 7a is promptly swept by the scraping portion 7c. Can be dropped to the side.

Here, in the present embodiment, the fur brush 7a is rotated by the frictional force generated by the rotation of the photosensitive member, but in some cases, it may be rotated at a speed different from the peripheral speed of the photosensitive member by a driving means (not shown). It may be rotated in the opposite direction to the photoconductor. Further, as the material of the fur brush, synthetic fibers such as acrylic and nylon other than the polyester fibers of this embodiment can be used, and natural fibers such as wool can also be used.

Although the fur brush is used as the cleaning roller in this embodiment, it is also possible to use a sponge roller made of urethane foam resin, silicone foam resin, or various elastic rubber materials such as urethane rubber and silicon rubber. Further, the roller material may be impregnated with carbon black, silica, alumina, magnetite or the like in order to adjust the polishing property of the roller surface, the friction coefficient and the electric resistance of the roller.

In this embodiment, no bias voltage was applied to the fur brush, but it is also possible to apply a bias voltage in order to enhance the effect of removing the residual toner on the surface of the photosensitive member.

In this embodiment, the spiral is made of resin, but various resins can be used. Further, the screw threads of the front and rear spirals 25a and 25b are symmetrical in shape, but the present invention is not limited to this, and any one that can convey toner to the cleaning roller can be used. Further, although the spiral structure is used as the toner conveying member, any shape can be used as long as it has a toner conveying ability. It is also possible to extend the main body of the cleaning roller and form threads only in the transport area.

In the present embodiment, the acrylic pile is used as the seal member, but it is also possible to use other various fiber piles, felts and the like.

As described above, according to the present invention, the toner conveying spiral is arranged between the cleaning roller of the fur brush or the like and the front and rear seals in the axial direction of the photosensitive member, and both spirals are rotated according to the rotation of the fur brush. Since the cleaning toner is sent from the printer to the fur brush, the cleaning toner is prevented from staying and aggregating in the vicinity of the seal portion, and it is possible to prevent problems such as copy stains caused by the cleaning toner.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an image forming apparatus according to the present invention.

FIG. 2 is a cross-sectional configuration explanatory diagram of the cleaning device of the present invention.

FIG. 3 is a schematic diagram showing the configuration of the present invention.

FIG. 4 is a schematic diagram showing a configuration of a conventional technique.

[Explanation of symbols]

1 photoconductor drum 3 charging means 4 Exposure means 5 Developing means 6 Transfer means 7 Cleaning means 7a fur brush 7b cleaning blade 7c scraping part 7d toner transport auger 7f pile belt 7g base cloth 8 Static elimination means 9 Registration roller pair 10 fixing roller 11 Transfer roller B Paper transport path P paper 21 housing 22 opening 23 brush shaft 24a front seal 24b Rear seal 25a front spiral 25b rear spiral

Claims (2)

(57) [Claims] 1. A cleaning blade, a cleaning roller located upstream of the cleaning blade in the direction of rotation of the photosensitive drum, and seal members provided at both longitudinal ends of an opening of the housing corresponding to the photosensitive drum. And a photosensitive drum which is configured to be coaxial with the roller rotation shaft between the cleaning roller and the seal member and which conveys the cleaning toner toward the cleaning roller.
A cleaning device having a non-contact transport member. 2. The cleaning device according to claim 1, wherein the axial length of the cleaning roller exceeds the maximum width of the transfer sheet and is less than the axial length of the cleaning blade. .