US 5,845,173 A · Conductive assembly for a drum in an image forming apparatus

Abstract

An improved grounding plate or contact assembly is provided for a photosensitive drum of an image forming apparatus such as a printer or photocopier. The arrangement ensures contact between the grounding plate/contact assembly and a contact area disposed on an interior surface of the drum regardless of the rotational orientation of the grounding plate/contact assembly with respect to the drum. In a preferred form of the invention, the grounding plate includes a plurality of circumferentially spaced contact members and is mounted upon a flange which is inserted into the end of the drum. Since the circumferential spacing of the contact members is less than a length of a laser scribed contact area on the interior surface of the drum, contact between the laser scribed area or patch and one of the contact members is ensured despite variations in the rotational or angular position of the flange with respect to the drum. Additional advantages are provided by the arrangement of the radially outwardly extending contact members with respect to a radially inwardly projecting contact member (which contacts a grounding shaft) so that satisfactory contact is not diminished by deflection of the contact members as the flange is assembled onto a drum and a grounding shaft is inserted through the flange.

Claims23

Dependent claims

A drum for an image forming apparatus comprising:

(a) a hollow tubular member having:
(i) a first end and a second end;
(ii) an interior surface and an exterior surface;
(iii) a first opening at said first end and a second opening at said second end;
(iv) a scribed portion on said interior surface at a location adjacent said first end, said scribed portion having a circumferential length extending along an inner circumference of said interior surface;
(b) a flange having:
(i) a first portion disposed in said first end of said hollow tubular member;
(ii) a grounding assembly connected to said first portion, said grounding assembly comprising:
(A) a plurality of circumferentially spaced contact members, each of which is in contact with said interior surface of said hollow tubular member, and wherein at least one of said plurality of contact members is in contact with said scribed portion;
and
(B) wherein each circumferential spacing between adjacent contact members of each of said plurality of spaced contact members is smaller than said circumferential length of said scribed portion to ensure that at least one of said plurality of circumferentially spaced contact members is in contact with said scribed portion regardless of rotational orientation of said flange with respect to said hollow tubular member.

8 more elements

An image forming apparatus which includes a drum comprising:

(a) a hollow tubular member having:
(i) a first end and a second end;
(ii) an interior surface and an exterior surface;
(iii) a first opening at said first end and a second opening at said second end;
(iv) a scribed portion on said interior surface at a location adjacent said first end, said scribed portion having a circumferential length extending along an inner circumference of said interior surface;
(b) a flange having:
(i) a first portion disposed in said first end of said hollow tubular member;
(ii) a grounding assembly connected to said first portion, said grounding assembly comprising:
(A) a plurality of circumferentially spaced contact members, each of which is in contact with said interior surface of said hollow tubular member, and wherein at least one of said plurality of contact members is in contact with said scribed portion;
and
(B) wherein each circumferential spacing between adjacent contact members of each of said plurality of spaced contact members is smaller than said circumferential length of said scribed portion to ensure that at least one of said plurality of circumferentially spaced contact members is in contact with said scribed portion regardless of rotational orientation of said flange with respect to said hollow tubular member.

8 more elements

A drum for an image forming apparatus comprising:

(a) a hollow tubular member having:
(i) a first end and a second end;
(ii) a contact area formed on the interior of said hollow tubular member for providing an area for electrically coupling said hollow tubular member, said contact area disposed in a region adjacent to said first end and having a higher electrical conductivity than other portions of said region, and wherein said contact area has a length extending in a circumferential direction;
(b) a flange having:
(i) a first portion disposed in said first end of said hollow tubular member;
and
(ii) an electrical coupling assembly comprising:
(A) a plurality of circumferentially spaced radially protruding contact members, wherein at least one of said circumferentially spaced radially protruding contact members is in contact with said contact area, and
(B) wherein a circumferential spacing between adjacent contact members of each of said plurality of contact members is less than said length of said contact area.

6 more elements

Dependencies are inferred from the claim text.

Conductive assembly for a drum in an image forming apparatus

Life of this patent

Conductive assembly for a drum in an image forming apparatus

Life of this patent

Abstract

Claims23