JPS62279381A - Image forming device - Google Patents

Abstract

PURPOSE:To preclude deterioration is picture quality by providing a fall preventing member which abuts on the surface of a conveyor roller on the upstream side in its rotating direction and allows paper powder which moves by sticking on the roller to pass, but inhibit paper powder removed by a scraper from passing. CONSTITUTION:A scraper support member 33 is fixed on a conveyance guide 25 and a film support member 34 which supports a fall preventing film 32 is fixed there with a screw 35. The fall preventing film 32 is provided having its intermediate surface in elastic contact with the conveyor roller 14b to allow the paper powder S' which moves by sticking on the peripheral surface of the conveyor roller 14b rotating as shown by an arrow to pass, but inhibits a lump S of paper power which is formed by being scraped by the scraper 31 to pass backward. Consequently, no paper powder lump S which is accumulated falls in a main body and an image defect due to paper powder is eliminated.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an image forming apparatus such as a copying machine or a printer, and particularly relates to image forming apparatuses such as copying machines and printers. The present invention relates to an image forming apparatus having a mechanism for removing powder.

[Prior Art] Sheet paper used in image forming apparatuses such as copying machines and printers is covered with paper dust generated during cutting and dust received during subsequent handling. For example, in the case of the copying machine shown in FIG. 4, if these paper dusts move from the sheet paper onto the photosensitive drum 2 and from there reach the developing device 5 and cleaner 7 and accumulate, they cause so-called image deletion, image omission, and image bearing member. Filming or the like occurs, and the quality of the image formed on the sheet paper is significantly degraded.

In order to deal with such inconveniences, a paper dust removal mechanism is provided in which paper dust is attached to the surface of a conveyance roller 14b provided on the conveyance path from the paper feeding section to the image forming section, and the paper dust attached to the surface of the sheet paper is removed. 30 have been devised. Figure S6 is a partially enlarged view of this paper dust removal mechanism 30. Paper dust S' attached to the circumferential surface of the conveyance roller 14b is
It is scraped off by a scraper 31 attached to the upper guide plate 25.

[Problems to be Solved by the Invention] In the above configuration, the paper powder S' scraped off by the scraper 31 becomes a fluff-like lump of paper powder due to the fibers intertwining with each other, as shown in FIG. It becomes S. Therefore, as long as the main body of the apparatus was left still, there was no need to worry much about the paper powder lumps S scattering around.

However, in the case of devices that have a structure in which a part of the main body of the device can be separated, such as the so-called Wanilo-type copying machine that has become widely used in recent years, a lump of paper powder S falls along the path indicated by arrow A, as shown in Figure 5. , which adheres to the conveyance path, the transfer charger 6, and the surface of the image carrier drum 2, and adversely affects image formation.

Additionally, in recent years, copying machines have become more compact, and models with handles that make them portable have been proposed. At this time, if the main body of the apparatus is stood up for transportation, the paper powder lumps S will fall, causing the above-mentioned problem.

[Configuration for Solving the Problems The present invention has been made to solve the above problems, and has the following configuration. That is, there is an image forming means that forms an image on a sheet of paper, a conveying roller that is located upstream of the image forming means and conveys the sheet paper, and an end that abuts the circumferential surface of the conveying roller to remove paper dust attached to the conveying roller. The scraper to be removed is in contact with the circumferential surface of the conveying roller at a position on the upstream side in the rotational direction of the conveying roller relative to the scraper, and the scraper An image forming apparatus is characterized in that it has a fall prevention member that prohibits passage of paper dust removed by the image forming apparatus.

[Embodiment] FIG. 2 is a sectional view showing an embodiment of an electrophotographic copying machine using the present invention. This has basically the same configuration as the copying machine shown in FIG.
The housing 21 can be rotated around @20 to open the inside. The image carrier drum 2, which is rotatably supported by the second housing 21 and rotates in the direction of the arrow, is surrounded by a corona discharger 3, a short focus optical element array 4, a developer 5, a transfer corona discharger, and a transfer corona discharger along the rotation direction. An electric appliance 6 and a 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 with a fluorescent lamp 11, and the reflected light is transmitted to a short focus optical element array. 4, the image is formed on the surface of the image carrier drum 2.

This electrostatic latent image is then developed as a toner image by a 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 the timing is adjusted by a pair of transport rollers 14a and +4b, which also function as registration rollers, and the paper is sent to the transfer section. It will be done. The transfer paper P, onto which the toner image has been transferred in this manner, has the toner image fixed thereon by a pair of fixing rollers 17 and is discharged from the main body 1 of the apparatus via a pair of discharge rollers 18 .

A scraper 31 attached to a scraper support member 33 is disposed on the conveyance roller 14b with its end abutting. As a result, paper dust S' adhering to the circumferential surface of the conveying roller 14b is scraped off. The scraper support member 33 is raised above the conveyance guide 25. Fall prevention film 32
In this embodiment, a polyester film is assumed, but a film made of a material such as metal or rubber may also be used as long as it is an elastic material that satisfies the conditions described later. The fall prevention film 32 is provided with its belly elastically in contact with the conveyance roller 14b, and the fall prevention film 32 is provided with its belly elastically in contact with the conveyance roller 14b, and the conveyance roller 1 rotates in the direction of the arrow.
The paper dust S' adhering to the circumferential surface of 4b and moving is allowed to pass through the contact area, but the paper dust lump S scraped off by the scraper 31 is not allowed to pass in the opposite direction. prohibit. At this time, if the contact pressure of the fall prevention film 32 is too strong, the paper dust S' will be blocked at the contact area, so it is necessary to set an appropriate contact pressure. As a result of experiments, when a polyester film was used, the optimal thickness of the fall prevention film was 70 to 200 m.

Although the space 36 in which the paper powder lumps S accumulates has a shape with both ends open in this embodiment, a more complete fall prevention effect can be obtained by providing side walls as necessary. Can be done. In addition, when disposing of the accumulated paper powder lump S, the paper powder lump may be pushed out from the end of the space 36 using an appropriate leaning member, or the interior can be cleaned by removing the screw 35 and removing the film support member. You may do so.

[Effects of the Invention] By using the configuration of the present invention, a state in which a part of the device main body 1 (second casing 21) is rotated open as shown in FIG.
Even when the main body 1 of the apparatus is held upright for transportation by holding the handle 27 as shown in FIG. 3, accumulated paper powder lumps S will not fall into the main body, thereby preventing image defects due to paper powder. Can be done.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part of a paper dust removal mechanism of an image forming apparatus to which the present invention is applied, FIG. 2 is a sectional view of an image forming apparatus to which the present invention is applied, and FIG. 3 is an image forming system to which the present invention is applied. 4 is a sectional view showing the conventional image forming apparatus; FIG. 5 is a sectional view showing the conventional image forming apparatus with the main body opened; FIG. 6 is the conventional image forming apparatus. FIG. 3 is a cross-sectional view of a main part of a paper dust removal mechanism of the image forming apparatus of FIG. 14a-14b---One conveyance roller 25, 26---One conveyance guide 27---One grip 30---One paper dust removal mechanism 31---Scraper 32---One fall prevention film 33--- -Scraper support member 34---Film support member

Claims (1)

[Scope of Claims] An image forming means for forming an image on a sheet of paper, a conveying roller located upstream of the image forming means and conveying the sheet of paper, and a conveying roller having an end in contact with the circumferential surface of the conveying roller. a scraper for removing paper dust adhering to the scraper; and a scraper that contacts the circumferential surface of the transport roller at a position upstream in the rotational direction of the transport roller with respect to the scraper, and moves while adhering to the transport roller at the contact position. An image forming apparatus comprising: a fall prevention member that allows paper dust to pass through and prohibits paper dust removed by the scraper from passing through.