JPS62198883A - Drum unit - Google Patents

Abstract

PURPOSE:To make provision of an exposure light source in the vicinity of the peripheral surface of an image carrying body unnecessary and to make a drum unit small in size, by guiding a light beam from the exposure light source of a destaticizing unit, through a light guide. CONSTITUTION:In a drum unit A, a destaticizing unit B is attached to a casing 1 so that an exposure light source 8 is attached to a fitting seat 5, and a tip part 14 of a light guide 13 is installed in a position being adjacent to the peripheral surface of a drum 2. Accordingly, an exposure destaticization can be executed by irradiating appropriately a light beam from an LED 10 to the peripheral surface of the drum 2 through the light guide 13. The light guide 13 is small in its thickness, and also, it is unnecessary to install it toward the center axis direction of the drum 2, therefore, a large installation space is not required. In such a way, a drum of a small diameter can be adopted, the drum unit A can be made small in size, and a copying machine can be made small in size.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a drum unit 7) having a static elimination exposure unit for eliminating static electricity from an image carrier 1j in a copying machine.

(Background of the Invention) In order to eliminate static electricity from the peripheral surface of an image carrier other than the image area, it is conventionally known that the peripheral surface of the image bearing member is charged and before image exposure. There are other problems, such as the structure for attaching the discharging static eliminating unit (referred to as a discharging static eliminator unit) is complicated, and the size of the image carrier that can be adopted is limited, making it difficult to downsize the drum unit and copying machine.

For example, a copying machine having a drum unit with a panel structure will be explained.

In the above-mentioned copying machine, the drum unit is a drum-shaped photoreceptor (hereinafter referred to as a drum) which is an image carrier, and is formed by integrally assembling a charger, a slit member for image exposure, a cleaning member, etc. into two parallel panels. The static elimination unit is a strip-shaped substrate with a plurality of LEDs, etc., which are exposure light sources, arranged in a straight line, and is integrated into the drum unit so as to be located at an intermediate position between the charger and the image exposure slit member. It is assembled.

By the way, in order to accurately eliminate static electricity from the drum's peripheral surface other than the image area, it is necessary to expose the drum's peripheral surface to light so that the light from the exposure light source is not dispersed. The drum is provided at a position close to the circumferential surface of the drum so that exposure can be performed from a position as close as possible to the grooves.

In other words, the static eliminator is installed in such a way that the light from the exposure light source is directed toward the central axis of the drum, and at an intermediate position between the charger and the image exposure slit member. It is set in. Therefore, many parts are required to attach the static elimination unit to the panel, making the attachment structure complicated and the attachment work complicated.

In addition, in the copying machine, the charge eliminating unit is provided between the charger and the image exposure slit member, and is also provided in a position close to the image carrier, so that the distance between the charger and the image exposure slit member is narrow. Therefore, it is not possible to use a drum with a diameter as small as that used in a copying machine that does not have a static elimination unit. Therefore, the copying machine cannot be made smaller like a copying machine without a static elimination unit.

As described above, in the drum unit of a copying machine having the above-mentioned static elimination unit, the installation position and installation direction of the static elimination unit are restricted, so the installation structure of the static elimination unit is complicated, and the drum unit and the copying machine are small. The problem is that it is difficult to

(Object of the Invention) An object of the present invention is to solve the above-mentioned conventional problems, and is an exposure unit for static elimination that does not require a large space around the image carrier and can be easily installed. The objective is to provide a drum unit that applies the following.

(Structure of the Invention) As a result of the inventor's studies to achieve the above object, the following matters became clear.

By guiding the light from the exposure light source of the static elimination unit through the light guide, the peripheral surface of the image carrier can be irradiated without dispersing the light. That is, in order to eliminate static electricity on the circumferential surface of the image carrier, instead of placing the exposure light source close to the circumferential surface of the image carrier as in the conventional method, the tip of the light guide is placed on the circumferential surface. By arranging them close to each other, the light from the exposure light source can be appropriately irradiated onto the peripheral surface without being dispersed.

In addition, by setting the shape, length, and shape of the tip of the light guide in accordance with the arrangement in the applicable drum unit, it is possible to arrange the light guide close to the circumferential surface of the image carrier without requiring a large installation space. It has become clear that mag. 0 can do this.

The present invention has been completed based on the above-mentioned knowledge, and has a structure in which, in a drum unit in a copying machine, which has an image bearing member and an exposure unit for removing static electricity from the image bearing member, the peripheral surface of the image bearing member is An exposure unit for static elimination includes an exposure light source provided at a position separated from the image carrier, and a light guide whose tip portion is provided at a position close to the circumferential surface of an image carrier and guides light from the exposure light source. A drum unit characterized by having:

(Example) The present invention will be explained based on embodiments shown in the drawings.

FIG. 1 is a cross-sectional view of a main part of a drum unit according to an embodiment of the present invention, FIG. 2 is an overall perspective view of a static elimination unit applied to the drum unit shown in FIG. 1, and FIG.
It is a sectional view taken along the line -■.

The drum unit shown in FIG. 1 is a cassette-type drum unit in a copying machine configured to eliminate static electricity after being charged and before image exposure. In FIG. 1, A is a drum unit, B is a static elimination unit having a light guide 13 that guides light from the exposure light source 8, 1 is a casing molded with resin with the direction of arrows X and Y being the die cutting direction, and 2 is an image A drum is a carrier, 3 is a bearing of drum 2, 4 is a belt it
Reference numeral 5 designates a mounting seat for a device (not shown); 5 is a mounting seat for a static eliminator (uniform battery) B; 6 is an image exposure seat; 7 is a mounting seat and casing for a cleaning member (not shown).

The static elimination unit B is configured as shown in FIGS. 2 and 3. 2 and 3, 8 is an exposure light source, 9 is a strip-shaped substrate, 10 is a plurality of LEDs arranged linearly on the substrate 9, 11 is a case of the exposure light source 8, 1
2 is the attachment part of the static elimination unit B, 13 is the ci milight 1 guide, 14 is the tip of the light guide 13, and 15 is the L
This is light deflection means such as a prism that changes the direction of light from EDIO.

In addition, the case 11 and the light guide 13 are LEl) 10
The inner surface is a reflective surface to prevent light from leaking outside. L
The EDIO may be arranged in a direction other than that shown in FIG. 3, and the light emitting means of the exposure light source 8 may be other than an LED.

The shape, length, shape of the tip portion 14, etc. of the light guide 13 are set as appropriate depending on the arrangement in the applied drum unit. Alternatively, it may be made of a fibrous material such as glass or plastic that has good light transmittance. As shown in FIG. 4, it may be integrally constructed of acrylic resin, glass, etc., and by constructing it in the shape shown in the figure, the luminous intensity directing means 15' can be integrally provided. There is no need to provide a separate light deflection means as shown in FIG.

The static eliminator unit 7)B shown in FIGS. 2 and 3 is configured as described above, and the light from the LEDIO is transmitted to the light guide 1.
3 and is irradiated to the outside from its tip 14.

In the drum unit A shown in FIG. 1, the static elimination unit B shown in FIGS. 2 and 3 has an exposure light source 8 attached to the mounting seat 5 of the static elimination unit B, and a light guide 13.
is attached to the drum unit 1 so that the tip 14 of the drum 2 is located close to the circumferential surface of the drum 2 without facing in the direction of the central axis of the drum 2. Therefore, LEr)
The light from 10 can be appropriately irradiated onto the circumferential surface of the drum 2 through the light guide 13, and the static electricity can be removed by exposure.

The light guide 13 has a small thickness and does not need to be installed toward the center axis of the drum 2, so it does not require a large installation space. Therefore, when installing static eliminator unit B, it is often necessary to use a small-diameter drum, and the
It is possible to downsize the image unit, that is, to downsize the copying machine.

Moreover, since the mounting seat 5 of the static elimination unit B is provided on the outer surface of the casing l, the mounting structure of the static elimination unit IH is simple and can be easily installed. In addition, the mounting seat 5 of the static elimination unit B is
Since it is provided on the outer surface facing the die-cutting direction X during molding of the casing 1, it can be molded simultaneously with the molding of the casing 1, and the casing 1 can be obtained at low cost.

Although the present invention has been described with respect to a cassette-type drum unit shown in FIG. 1, it goes without saying that a panel-structured drum unit to which the static elimination unit shown in FIGS. 2 and 3 is applied may also be used. Further, the above-mentioned charge eliminating unit may be applied, and the charge may be removed after development and before transfer after separation and before cleaning.

(Effects of the Invention) The drum unit of the present invention employs a static elimination unit configured to transmit light from an exposure light source using a light guide, so unlike conventional drum units, the exposure light source is not connected to the image carrier. There is no need to provide it close to the peripheral surface, and there is no need to secure a large space to install the static elimination unit around the image carrier. Therefore, a small image carrier can be used, and by extension The drum unit can be downsized.

Further, since it is not necessary to provide the exposure light source of the static elimination unit close to the circumferential surface of the image carrier, it can be easily mounted with a simple mounting structure.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a main part of a drum unit that is an embodiment of the present invention, FIG. FIG. 4 is a sectional view taken along the line m-m, and FIG. 4 is a cross-sectional view of an exposure unit for static elimination of another embodiment. 1... Casing of drum unit, 2... Drum, 5... Exposure for static elimination. Unit mounting seat, 8...Exposure light source, 11...Exposure light source case, 12.
... Mounting part of exposure unit for static elimination, 13... Light guide, 15.15'... Light deflection means, A...
・Drum unit, B... Exposure unit for static elimination, X
, Y...Direction of cutting the casing. Patent Applicant Konishiroku Photo Industry Co., Ltd. Figure 1 Order: Figure 2 Figure 3 Procedural Amendment Letter Date of July L1, 1985 Director General of the Patent Office Michibe Uga 1, Indication of Case Patent Application No. 39062 of 1988 No. 2, Name of the invention Drum unit 3, Relationship with the person making the amendment Case Patent applicant

Claims (2)

[Claims] (1) In a drum unit in a copying machine, which has an image carrier and an exposure unit for eliminating static electricity that neutralizes the image carrier, an exposure light source provided at a position away from the circumferential surface of the image carrier and a tip end of the image carrier What is claimed is: 1. A drum unit comprising a static elimination exposure unit that is provided in a position close to the circumferential surface of a body and includes a light guide that guides light from the exposure light source. (2) The drum unit has a resin-molded casing, and an attachment portion for the exposure light source of the static elimination exposure unit is provided on the outer surface of the casing facing the die-cutting direction. Drum unit listed.