JPH0446432B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an electrostatic recording device that transfers and fixes a toner image formed on an image forming member onto a recording paper fed into contact with the image forming member.

BACKGROUND ART Conventionally, in electrostatic recording devices such as electrophotographic copying machines as described above, foreign matter such as paper dust brought into the machine along with recording paper has caused the following troubles.

Contaminants adhere to the image forming body and degrade the image quality.If the cleaning device for the image forming body uses a scraper blade, the contaminants accumulate on the scraper blade and get between the blade and the image forming body. , causing poor cleaning.
In particular, when the scraper blade is separated from the surface of the image forming body while recording is not being performed, the above-mentioned cleaning failure is likely to occur frequently.
Contaminants adhering to the image forming body are scraped off in the developing section and enter the developing device, where they mix with the developer and cause development defects such as uneven development density, black lines or fog, or damage the surface of the image forming body. In particular, when the toner collected by the cleaning device is recycled, more foreign matter enters the developing device, and the occurrence of the above-mentioned developing defects becomes more noticeable. If the developer is a one-component magnetic toner and the developing device uses a dritter blade with a cutting length of 0.5 mm or less to form a magnetic brush, contaminants or agglomerates may occur. Charging devices, transfer devices, and ionization devices in which contaminants are installed around the image forming body, where the developer gets clogged in the cutting section, disrupting the developer conveyance and causing white streaks to appear on the recorded image. , adheres to the wire electrodes of corona generating devices such as static eliminators, reducing discharge performance and image quality.
Contaminants may adhere to optical instruments such as mirrors and lenses, obstructing the image forming body, or otherwise adhere to the inside of the machine, causing dirt inside the machine.

Therefore, as a method to prevent the occurrence of such troubles, a rotating brush that rubs the surface of the recording paper and a rotating brush that rubs the surface of the recording paper between the conveyance rollers provided at a distance in the conveyance means that feeds the recording paper to the image forming body. Japanese Patent Laid-Open No. 53-55128 discloses a method in which a suction suction is provided to remove impurities removed by a brush. A method of removing impurities by providing a filter is known from Japanese Unexamined Patent Publications No. 43745/1982 and No. 1280608/1983. Among these methods, the method using a rotating brush to rub the surface of the recording paper requires a suction in addition to the rotating brush, which not only increases the size of the device, but also makes it difficult to synchronize the recording paper with the rotation of the image forming body. It tends to have a negative effect on the conveyance,
In order to prevent this, the apparatus including the conveyance means becomes complicated and the cost increases. There is also the problem that when the recording paper is rubbed by the rotating brush, paper dust and the like are unreasonably generated. The problem with the method of installing a filter in the recycling system is that it is not very effective in dealing with problems other than those mentioned above.

Furthermore, Japanese Patent Application Laid-Open No. 56-122052 discloses a method in which a paper charging device and a paper powder suction roller are provided, but this method not only requires a charging device that charges the paper in advance, but also requires a charging device that charges the paper in advance. There is a problem in that it becomes difficult to remove paper dust.

The present invention addresses the fact that in electrostatic recording devices where the above-mentioned trouble occurs, a considerable amount of paper dust, etc. adheres to the surface of the rubber-coated nipping feed roller of the conveying means that feeds the recording paper to the image forming body. Focusing on
This was done based on the idea that it would be possible to prevent the above-mentioned troubles by removing paper dust etc. adhering to the nipping feed roller without having to rub the surface of the recording paper with a brush. It is something that

The present invention provides a roller whose surface in contact with at least the transfer surface side of the recording paper is coated with rubber among a pair of pressure rollers that feed the recording paper to the image forming body in synchronization with the formed toner image. A rubbing member made of a conductive brush or fiber surface that contacts the surface of the roller to remove deposits, and a sliding member that contacts the surface of the roller on the downstream side of the sliding member and A cleaning means including a rubbing member and a receiving member for collecting the deposits falling off from the surface of the roller is provided, and the outer surface of the recording paper feeding side of the roller is surrounded from the recording paper path to the rubbing member. An electrostatic recording device is characterized in that it is provided with an enclosing member that prevents the airflow accompanying the roller from flowing toward the image forming body, and due to this feature, it is possible to eliminate the need for a rotating brush that rubs the recording paper. This provides an excellent effect of preventing the above-mentioned troubles.

In the present invention, since there is no need to charge the paper in advance, paper dust can be easily removed from the roller with a brush fiber cloth, metal net, etc., and paper dust removed with a brush etc. can be easily removed from the roller with a brush, etc. It can be easily dropped onto the receiving member, and troubles caused by paper dust can be easily prevented.

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

FIG. 1 is a schematic side view of an electrophotographic copying machine according to the present invention, FIGS. 2 and 3 are partial cross-sectional views showing an example of a cleaning means for a conveyance roller, and FIG. 4 is another example of a sliding member. FIG.

In the illustrated electrophotographic copying machine, a photosensitive drum 1 serving as an image forming body rotates in the direction of the arrow, its surface is cleaned by a cleaning device 2 having a scraper blade 2a, and the cleaned surface is transferred to a charging device 3. The charged surface is uniformly charged with light 5 of the original image projected by the image exposure device 4.
is irradiated to form an electrostatic latent image, and the electrostatic latent image is developed into a toner image by a dry developing device 6.
On the other hand, the paper feeding means 7, 8, or 9 feeds the recording paper into the feeding and conveying means 10, and the feeding and conveying means 10 transfers the recording paper to the surface of the photoreceptor drum 1 in time to reach the toner image transfer position. the photosensitive drum 1.
The upper toner image is transferred to a recording paper by a transfer device 11, and the transferred recording paper is separated from the surface of the photosensitive drum 1 by a separation device 12, and sent to a fixing device 14 by a feeding conveyance means 13. The toner image transferred by the fixing device 14 is fixed, and is discharged outside the machine by the discharge conveying means 15, thereby performing copying, that is, recording. In addition, 1
6, so that the toner image is easily transferred to the recording paper,
This is a pre-transfer exposure lamp that exposes the surface of the photosensitive drum 1.

As shown in FIG. 2 or 3, cleaning means 17 and 18 for cleaning the surfaces of the pressure conveyance rollers 10a and 10a' of the feed conveyance means 10 of this copying machine are coated with rubber. It is set in.

The cleaning means 17 for the upper conveyance roller 10a in FIG. 2 includes a sliding member 17a that uses a brush to rub the roller surface, and the deposits on the roller surface removed by the sliding member 17a fall off from the sliding member 17a. A receiving member 17 made of a thin resin plate, a thin metal plate, or a combination thereof, which receives and stores the
b, the lower conveyance roller 10
The cleaning means 18 a' has a structure that includes only a rubbing member 18a that rubs the roller surface with a brush, since there is almost no problem even if the deposits removed from the roller surface fall downward. . Note that a hanging wall portion 17c of an enclosure member provided at the front portion of the sliding member 17a and surrounding the outside of the delivery side surface of the conveyance roller 10a prevents the accompanying airflow of the upper conveyance roller 10a from leaking to the photosensitive drum 1 side. prevent,
This is to ensure that paper dust and the like carried by the airflow are also captured by the cleaning means 17.
By providing such cleaning means 17 and 18 on the nipping conveyance rollers 10a and 10a', most of the foreign matter such as paper dust that is brought into the photosensitive drum 1 side with the recording paper is removed. The sliding member 17 adheres to the surface of the pressure conveyance rollers 10a and 10a'.
a, 18a, and the receiving member 17
(b) or fall downwards without causing any trouble, the possibility of foreign matter such as paper dust being brought into the photosensitive drum 1 side is significantly reduced, leading to the occurrence of the above-mentioned troubles. is prevented.

In FIG. 3, the receiving member 17b has a felt or sponge sheet that comes into contact with the surface of the upper conveying roller 10a to receive deposits, and the cleaning means 1 for the lower conveying roller 10a'
8 is also provided with a similar receiving member 18b.
7 and 18, the same effect as in the example of FIG. 2 described above can be obtained. Note that in these examples,
The underside of the upper guide plate 10b of the recording paper sent out by the pinch conveyance rollers 10a, 10a' is flocked with hairs, and the flocking dams up paper powder, etc. that is still going to be sent to the photosensitive drum 1 side together with the recording paper. That's what I do.

The present invention is not limited to the example described above, and the cleaning means may also be provided on the conveyance rollers of the paper feed means 7 to 9, or may be provided only on the upper conveyance roller, and the explanation about the lower conveyance roller is omitted. You may. Further, the rubbing member of the cleaning means is not limited to a brush, but may be made of felt or sponge, and a brush may be used as the receiving member in the same way as the sliding member.

Rubbing member 17 of cleaning means 17, 18
In addition to the brushes and fibers already mentioned, a thin metal mesh as shown in FIG. 4 can also be used as a, 18a. Such a net can be made by weaving wire or by etching. The roller is preferably pressed against the roller so that the sides of the stitches are oblique to the rotating direction of the roller.

In addition, by making the sliding member of the cleaning means and the receiving member that rubs the conveyance roller like the sliding member conductive, the effect of collecting deposits will be improved and unnecessary electric charge will be removed from the transfer paper. This is preferable because it prevents the transferred image from being disturbed during transfer.

Embodiment Cleaning means 17, 18 as shown in FIG. 2 are added to the clamping conveyance rollers 10a, 10a' of the feeding conveyance means 10 of the electrophotographic copying machine shown in FIG.
When copying was carried out with a cleaning device installed, it was found that a large amount of foreign matter such as paper dust adhered to the scraper blade 2a of the cleaning device 2 after about 6,000 copies, resulting in poor cleaning of the photosensitive drum 1. The problem occurred and the developer in the dry developing device 6 had to be replaced after about 10,000 copies.However, the cleaning failure did not occur until 70,000 copies were made, and the developer had to be replaced after 30,000 copies due to deterioration of the carrier in the developer. Good results were obtained in that replacement was not necessary until the effects began to appear.

The rubbing members 17a and 18a of the cleaning means 17 and 18 are made of acrylonitrile-vinyl chloride copolymer and have lengths of 2-5.
The receiving member 17b of the cleaning means 17 was made of a polyester film with a thickness of 100 μm. The brushes of the rubbing members 17a and 18a have a roller surface of 0.5
The receiving member 17b is used with the tip of the film lightly touching the roller surface, and corresponds to the brush of the rubbing members 17a and 18a and the receiving member 17b at the end of 70,000 copies. A large amount of paper dust etc. was captured.

Similar results were also obtained when the rubbing members 17a, 18b were made of tetrafluoroethylene resin and had brushes similar to those described above.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of an electrophotographic copying machine according to the present invention, FIGS. 2 and 3 are partial cross-sectional views showing an example of a cleaning means for a conveyance roller, and FIG. 4 is another example of a sliding member. FIG. DESCRIPTION OF SYMBOLS 1... Photosensitive drum, 2... Cleaning device, 2a... Scraper blade, 3... Charging device, 4... Image exposure device, 5... Projection light, 6... Dry developing device, 7-9... Paper feeding means, 10... Feeding conveyance means, 10a, 10a'... Nipping conveyance rollers, 10b... Upper guide plate, 11... Transfer device,
12... Separation device, 13... Sending conveyance means,
14...Fixing device, 15...Discharge conveyance means, 16
... Pre-transfer exposure lamp, 17, 18 ... Cleaning means, 17a, 18a ... Rubbing member, 17
b, 18b...receiving member, 17c...hanging wall portion.

Claims (1)

[Scope of Claims] 1. In an electrostatic recording device that transfers and fixes a toner image formed on an image forming body onto a recording paper that is fed into contact with the image forming body, the recording paper is transferred and fixed at the same timing as the toner image. At least one of the pair of pressure rollers sent to the image forming body, the surface of which is in contact with the transfer surface of the recording paper is coated with rubber, is contacted with the surface of the roller to remove the deposits. a rubbing member made of a conductive brush or fiber surface, and a receiver that contacts the surface of the roller downstream of the rubbing member and receives the deposits that fall off from the rubbing member or the roller surface. an enclosing member that surrounds the outer surface of the recording paper feeding side of the roller from the recording paper path to the rubbing member to prevent the airflow accompanying the roller from flowing toward the image forming body; An electrostatic recording device characterized by being provided with. 2. The electrostatic recording device according to claim 1, wherein the receiving member of the cleaning means is made of a thin metal plate. 3. The electrostatic recording device according to claim 1, wherein the receiving member of the cleaning means is made of a porous member. 4. The electrostatic recording device according to claim 1, wherein the receiving member of the cleaning means is made of felt.