JPH06100880B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming apparatus such as a copying machine or a printer, and in particular, has a mechanism for removing paper dust adhering to a conveying roller that conveys sheet paper. The present invention relates to an image forming apparatus.

[Prior Art] A sheet of paper used in an image forming apparatus such as a copying machine or a printer has paper dust generated during cutting and dust received during subsequent handling. For example, in the case of the copying machine shown in FIG. 4, when these paper dusts are transferred from the sheet paper onto the photosensitive drum 2 and then accumulated there to the developing device 5 and the cleaner 7, a so-called image flow is caused and an image is lost, and image carrying is carried. Filming on the body occurs and the image quality of the image formed on the sheet paper is significantly deteriorated.

In order to deal with such an inconvenience, a paper dust removing mechanism for removing the paper dust on the surface of the sheet paper by attaching the paper dust to the surface of the transport roller 14b provided on the transport path from the paper feeding unit to the image forming unit 30 have been devised. FIG. 6 is a partially enlarged view of the paper dust removing mechanism 30.
The paper dust S'attached to the peripheral surface of the transport roller 14b is scraped off by the scraper 31 attached to the upper guide plate 25.

[Problems to be Solved by the Invention] In the above configuration, the paper dust S ′ scraped off by the scraper 31 has a cotton dust-like lump of paper dust in which the fibers are intertwined with each other as shown in FIG. It becomes S. Therefore, as long as the apparatus body is left stationary, it is not necessary to worry so much that the paper powder lump S is scattered around.

However, in the case of a so-called alligator type copying machine, which has been widely used in recent years, having a structure capable of dividing a part of the apparatus body, as shown in FIG. However, it adheres to the transport path, the transfer charger 6, and the surface of the image carrier drum 2 to adversely affect image formation.

Further, in recent years, downsizing of copying machines has progressed, and it has been proposed that the copying machine can be carried with a handle. At this time, when the main body of the apparatus is stood up for transportation, the paper powder lump S falls and the above-mentioned problem still occurs.

[Configuration for Solving Problems] The present invention has been made to solve the above problems and has the following configurations. That is, an image forming means for forming an image on a sheet of paper, a conveying roller which is upstream of the image forming means and conveys the sheet of paper, and a paper powder adhered to the conveying roller with its end abutting on the peripheral surface of the conveying roller. A scraper for removing, and abutting against the peripheral surface of the transport roller at a position on the upstream side in the rotation direction of the transport roller with respect to the scraper, allowing the passage of paper dust that adheres to the transport roller and moves at the contact position, An image forming apparatus, comprising: a fall prevention member that prohibits passage of paper dust removed by a scraper.

[Embodiment] FIG. 2 is a sectional view showing an embodiment of an electrophotographic copying machine according to the present invention. This has basically the same configuration as the copying machine shown in FIG.
The housing 21 can be rotated around the shaft 20 to open the inside. Around the image carrier drum 2 which is pivotally supported by the second housing 21 and rotates in the direction of the arrow, along the rotation direction thereof, a corona discharger 3, a short focus optical element array 4, a developing device 5, and a transfer corona discharger are provided. The electric appliance 6 and the cleaner 7 are arranged in this order. After the surface of the image carrier drum 2 is uniformly charged by the corona discharger 3, the document set on the reciprocating document table 10 is illuminated by a fluorescent lamp 11, and the reflected light thereof is a short focus optical element array. Four
An image is formed on the surface of the image carrier drum 2 via. Then, this electrostatic latent image is developed as a toner image by the developing device 5.

On the other hand, the transfer paper P set on the paper feed tray 12 is separated and fed one by one by the paper feed roller 13, and is sent to the transfer unit by adjusting the timing by a pair of transport rollers 14a and 14b also having a function as registration rollers. To be The transfer paper P on which the toner image is transferred in this manner is fixed on the toner image by the fixing roller pair 17, and is ejected from the apparatus main body 1 via the paper ejection roller pair 18.

The scraper 31 attached to the scraper support member 33 is disposed on the transport roller 14b with its end portion abutted. As a result, the paper dust S'attached to the peripheral surface of the transport roller 14b is scraped off. The scraper support member 33 is fixedly installed on the conveyance guide 25, and there is a fall prevention film there.
A film support member 34 that supports 32 is fastened with screws 35. The fall prevention film 32 is assumed to be a polyester film in this embodiment, but a film made of another material such as metal or rubber may be used as long as it is an elastic body that satisfies the conditions described later. The fall prevention film 32 is provided by elastically contacting the antinode of the transport roller 14b, and the paper dust S'moving attached to the peripheral surface of the transport roller 14b rotating in the direction of the arrow contacts the transport roller 14b. However, the paper powder lump S scraped off by the scraper 31 is prohibited from passing in the opposite direction. At this time, if the contact pressure of the fall prevention film 32 is too strong, the paper dust S'will be dammed at the contact portion, so it is necessary to set an appropriate contact pressure. As a result of the experiment, when the polyester film was used, the optimum thickness of the fall prevention film was 70 to 200 m.

In the present embodiment, the space 36 in which the paper powder lumps S are accumulated has a shape in which both end portions are open, but by providing side walls as necessary, a more complete fall prevention effect can be obtained. You can When treating the accumulated paper dust lumps S, the paper dust lumps may be pushed out from the end of the space 36 by using an appropriate cleaning member, or the screw 35 may be removed to remove the film support member to clean the inside. You may do it.

[Effects of the Invention] By using the configuration of the present invention, a state in which a part of the apparatus main body 1 (second housing 21) is rotated and opened as shown in FIG. 5 or the handle 27 is provided as shown in FIG. Device body 1 for carrying and carrying
Even in the state of standing up, the accumulated paper dust mass S does not fall inside the main body, and it is possible to prevent image defects due to paper dust.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a paper dust removing mechanism of an image forming apparatus to which the invention is applied, FIG. 2 is a sectional view of an image forming apparatus to which the invention is applied, and FIG. 3 is an image forming to which the invention is applied. FIG. 4 is a sectional view showing a conventional image forming apparatus, FIG. 5 is a sectional view showing the conventional image forming apparatus with the apparatus main body opened, and FIG. FIG. 3 is a cross-sectional view of main parts of a paper dust removing mechanism of the image forming apparatus. 14a ・ 14b …… Conveying rollers 25 ・ 26 …… Conveying guide 27 …… Handle 30 …… Paper dust removing mechanism 31 …… Scraper 32 …… Fall prevention film 33 …… Scraper support member 34 …… Film support member

Claims (1)

[Claims] 1. An image forming means for forming an image on a sheet of paper, a conveying roller which is upstream of the image forming means and conveys the sheet of paper, and an end portion of the conveying roller is in contact with a peripheral surface of the conveying roller to form a conveying roller. A scraper that removes adhered paper dust, and a paper sheet that comes into contact with the peripheral surface of the conveyor roller at a position upstream of the conveyor roller in the rotational direction with respect to the scraper and adheres to the conveyor roller at the contact position. An image forming apparatus, comprising: a fall prevention member that allows the passage of powder and prohibits the passage of paper dust removed by the scraper.